IMPROVEMENTS IN AND APPER- TAINING TO THE MANUFACTURE OF SALT FOR DOMESTIC, MANUFACTURING, AND OTHER PURPOSES, AND IN APPARATUS OR MACHINERY THEREFOR." PROAL SP
Year: 1880

page_text: LETTERS PATENT to John Howard Worthington Biggs, of Liverpool, in the
County of Lancaster, for an Invention of "IMPROVEMENTS IN AND APPER-
TAINING TO THE MANUFACTURE OF SALT FOR DOMESTIC, MANUFACTURING,
AND OTHER PURPOSES, AND IN APPARATUS OR MACHINERY THEREFOR."
PROVISIONAL SPECIFICATION left by the said John Howard Worthington
Biggs at the Office of the Commissioners of Patents on the 22nd December
1880.
JOHN HOWARD WORTHINGTON BIGGS, of Liverpool, in the County of Lancaster.
"IMPROVEMENTS IN AND APPERTAINING TO THE MANUFACTURE OF SALT FOR
DOMESTIC, MANUFACTURING, AND OTHER PURPOSES, AND IN APPARATUS OR
MACHINERY THEREFOR."
This Invention consists in improvements on a part of the Invention secured
to me by Letters Patent No. 4324, of 1876, and on the further improvements
on and additions thereto secured to me by Letters Patent, No. 1788, of 1877,
No. 2106, of 1877, and No. 1336, of 1878, and is, like the three previous ones, rather
more what would be called on the continent a patent of improvement (" brevet
de perfectionment"), a perfecting of the foregoing rather than an original
Invention.
A few days ago I filed an application for Provisional Protection for improve-
ments on that part of the aforesaid Patents referring to evaporation; this application
is for improvements on the remaining portion of the process.
The first portion of my Invention relates to the purification of brine by pans or
apparatus in which I first boil the brine, to precipitate the carbonate of lime and
certain other impurities, and afterwards treat it with a solution of carbonate of
soda, mineral alkalies, or other chemicals, to remove the sulphate of lime and
deliquescent properties by filtration or precipitation.
The apparatus I prefer to construct for this purpose consists of a submerged
cylinder with scrapers and means for removing impurities, or of one or other forms
of brine heaters described in my previous Patent. This I place in connection

page_text: with (preferably alternate) solution tanks and mixing-tub (in which I place stirrers
and alternate filters, arranged to discharge their impurities downwards into
wagons, and provided with means for removing their filter cloths from above. I
arrange pumps for passing the brine through the heater, mixing-tub, and filters
into a tank, also for passing a regular quantity of solution into the mixing-tub.
They are worked in time with one another or governed by floats preferably working
in tubes in which there is oil. I sometimes heat the brine in a pan after the
style of a preparatory pan in my last Patent, fitted with cleaning and flushing
arrangements or use progressive pans for the purpose. When using downwards
filtration I preferably divide the filter into two equal parts with a low division
projecting above the filtering material. I employ a floating cover over the side at
work to hinder evaporation, and by admitting additional brine float it over to the
other half of the filter when the first wants cleaning. In place of filtering the
brine when mixed with the solution, I sometimes run it into tanks or pans arranged
for cleaning to allow the impurities to settle, but prefer passing the brine hot into
the pans as it comes from the filters. I use this purified brine more especially
for brine heaters, pans arranged for the circulation of brine, and for making pine
salt for fishery or other purposes, in pans heated by steam below or air above. Of
this latter type I arrange deep covered pans supplied with heated air, preferably
from the air-case of an adjoining fire surface pan, sometimes also arranging for the
air to be heated by flues, cases, or pipes, connected with the furnaces, or heat air in
pipes or cases containing pumice stone to give additional heating surface.
The deep pans have doors at their ends, or sides, or covers, that can be raised
and moved to one side, and are preferably supplied with hot brine from a pan
heated by the steam from the fire surface pan. I arrange to suspend strings pre-
ferably made with lateral projections, wires, nets, or other substances on which the
crystals may form when immersed in the brine. These I either let down through
the cover or attach to its under side by hooks. or otherwise, sometimes attaching
them to poles, ropes, angle-irons, or tubes, and preferably supporting these on ledges,
pendants, or projections placed above the brine. I provide a carriage on rails to assist
in removing the poles, et cetera, when the pan is emptied; I also arrange to with-
draw the strings, nets, et cetera, from the pan, and replace them by others by machinery
without emptying the pan or removing the cover. For this purpose I use moving
chains or ropes resting on wheels or ledges at the sides of the pan, on which I rest
or fix the poles, rods, et cetera, or attach ropes carrying the strings or nets. I arrange
for winding out the salt or for removing the poles, nets, et cetera, as they come
out of the pan, sometimes employing belts or wagons to receive the same and pass
them on for washing, drying, crushing, or storage.
When salt is made in this way from ordinary brine it is very desirable to drain
or wash it, so as to produce as clean and pure a quality as possible under the
circumstances, and have it thoroughly dried. Salt for curing purposes is much
enhanced in value by being made from purified brine, or by being well washed to
free it from such of its deliquescent properties as are removable from the surface of
the crystals. Crystals taken from an evaporating pan filled with ordinary brine
are liable to be coated with impurities contained in the mother liquor, or if
produced by passing the products of combustion over the surface of the brine, are
liable to be more or less mixed with soot, while salt coming from a store room or
mine is more or less mixed with dirt. With a view of freeing salt from these and
other impurities, I arrange apparatus for thoroughly subjecting them to washing
and draining, either in a dry, moist, or wet state preparatory to drying, or for other
purposes. I prefer to wash the salt with purified brine, and after use repurify it
for further washing, or for making salt in an adjoining pan. In some cases however
ordinary brine or even water may be used. To lessen or avoid evaporation I prefer
to use the brine for this purpose at a low heat or cold. In some cases I arrange
for the same apparatus to both wash and dry the salt, but preferably separate the
washing and drying.
The class of apparatus I prefer to construct for the purpose is arranged for the

page_text: salt to be spread upon gauze or permeable surfaces, and subjected to currents of
brine or air passed from above or below, preferably in large quantities, by powerful
exhaust or forcing machinery, or otherwise. In some cases I shower brine on salt
placed over exhausted surfaces, or use steam or water for washing and other
purposes. Other substances have been treated somewhat after this fashion, but
the injurious effects produced by placing damp salt upon copper gauze or metal
plates, together with its disposition to cake and block up small airholes, render
special alteration and improvements necessary, which I arrange as follows:-In
the first place I protect the gauze, perforated plates, et cetera, through which I
blow or exhaust air, or pass brine water or steam, from the corrosive or chemical
action of damp salt, or from discoloration by rust, by employing iron instead of
copper, and coat the same with magnetic or black oxide. In cases where I employ
canvas I similarly protect it as far as possible by preparing it with tan or cutch,
washing it, and subsequently boiling it in a solution of glue, to render the pro-
tection more durable. I preferably treat all belts for washing, drying, or carrying
salt in the same manner. When using drying or draining surfaces of perforated
or other forms of pottery or other non-corrosive materials, as also sometimes
for the permeable materials mentioned above, I arrange for their thorough
washing and cleaning. In some cases I use wood arranged with holes, slits,
or spaces at the joints, through which air can be blown, exhausted, or passed.
For drying loose salt and for forming light cakes or nuts of salt, I prefer to
mount prepared gauze or other suitable material over one or more air cases forming
part of a rotating annular table or part of tables which have a reciprocating
motion. I sometimes employ the permeable material in the form of moving
endless belts or series of frames, preferably connected, supported on rollers, cross-
bars, slides, or otherwise placed in the upper part of one or more air-cases. When
using belts or connected frames in this way for washing salt I prefer for the return
belts to pass through water to wash off the impurities and keep the air holes open.
With a belt or series of frames of sufficient length, by means of suitable hoppers
and perforated pipes, the salt may first be washed and then dried or caked on the
same belt with air exhausted or blown preferably from the case below. In some
cases I exhaust first and blow afterwards, or vice versa. The belt is preferably
covered in to protect it from dust, to retain the heat, and for other purposes.
When using material for belts, both here and elsewhere, which is likely to stretch,
I employ lever weights or other arrangements to keep them tight. In place of
both washing and drying on the same belt I prefer to separate the operation, and
use two belts, one for washing and the other for drying; or in place of the first
belt use a revolving gauze or permeable drum, arranged with hollow axles, or of
ring form on wheels, into which or through the side of which I exhaust or blow
air, et cetera, arranging for it to dip in water or be washed from inside.
To avoid choking the gauze with fine particles of salt I prefer to previously
remove them by centrifugal action, winnowing, or otherwise. In cases where it is
inconvenient to wash the exhaust or blowing surfaces I arrange with suitable
hoppers, measuring wheels, screws, etcetera, to lessen or prevent incrustations forming
thereon by placing a thin layer of dry salt on them, over which I place the damp
salt in such wise that the dry salt absorbs most or all of the moisture from the
damp salt above, when both may be easily dried. I apply this system also to the
belt stove and arrangements shown in Figs. 3, 5, 19, et cetera, of my Patent
No. 1336, of 1878.
I also arrange partial divisions over the moving salt in such stoves to cause the
heated air admitted from below to pass through their surfaces, which are then all
made permeable, or to zigzag repeatedly from end to end or from side to side of the
stoves before escaping or being drawn off at the top. I provide all the various
apparatus with the necessary elevators, hoppers, measuring rollers, spouts, washing
arrangements, and means for feeding, manipulating, and removing the salt. I
sometimes also add self cleaning knives or rakes, wires, rollers, et cetera, for stirring
up the salt, forming it into shapes or exposing it to pressure. I much prefer to

page_text: employ the above with moving permeable surfaces, but I sometimes arrange for
the latter to be stationary in the form of annular or lineal tables or otherwise,
when I cause some of the former to move for the proper manipulation and
treatment of the salt. When caking the salt I frequently add fine salt at the top
of the coarser particles, and provide means for passing steam, brine, or water,
preferably boiling, through the salt, sometimes treating successive layers of salt in
this way.
I generally employ rollers (or millstones preferably with long shafts)
placed a little apart, or other crushing, stamping, or grinding machinery to reduce
lumps or large grained salt to a proper size for caking or other purposes. I prefer
to grind damp salt in brine or with the addition of brine. When moving annular
tables of large diameter are used for drying, washing, or caking salt, I sometimes
arrange an aircase round a central stove or space that may be usefully occupied,
resting the table upon suitable wheels, or arranging it with wheels running on
rails, and form water joints round the aircase over which the permeable surface
moves, and through which air or gases are forced, exhausted, or passed. I prefer
to supply small tables with air or exhaust from, at, or round their centres with
which I connect their aircases under the permeable surfaces by broad channels,
pipes, or otherwise. When cleaning salt on exhaust surfaces arranged for self
washing and for other purposes I sometimes arrange an exhaust or counter-acting
exhaust cover or channel over them in one or more places so arranged as to
withdraw the fine particles left on the gauze after the bulk of the salt has been
removed, at times also using brushes. The tables are preferably mounted on wheels
and covered in.
When displacing light particles of salt by forcing air upwards I add one or more
chambers into which they are blown and settle for further treatment. For preparing
the salt for certain chemical purposes I sometimes blow or pass products of
combustion or other gases through the permeable surfaces on which the salt rests
and cause it to absorb a portion of the same whilst drying or otherwise. In place
of washing the salt from above I sometimes force brine through the permeable
surfaces from below, preferably using fixed surfaces with scrapers, or moving
annular tables arranged with side ledges for the purpose, or belts moving between
side ledges, means being provided for withdrawing the surplus brine and
manipulating the salt. By this system of washing the minute particles of salt
amongst the crystals may be floated off into a pan for further growth, or into a
settling tank or otherwise, leaving the rest of the salt after washing far less likely
to choke exhaust or centrifugal surfaces in subsequent drying operations. It also
lessens the amount of very fine salt sieved out after drying, which is a desideratum.
I sometimes pass brine, and salt through a mixing vessel, discharging the same
down a plane or trough, where the crystals sort themselves by the current or get
trapped by suitable divisions. For washing lumps of rock salt or fine salt from
fire surface pans to prepare it for putting back into another pan for further growth
or for other purposes I often employ wagons arranged for draining and emptying,
and pass them under a shower of brine or water, or employ tall fixed cases showered
on from above. I sometimes employ rotating ledged cylinders placed horizontally
or at an angle through which I pass the salt and currents of brine, or use dipping
cages worked by hand or machinery. Rock salt when washed, ground, and freed
from moisture or stoved, is particularly suited for curing purposes from its
comparative freedom from chloride of magnesium. When washing salt in my
centrifugal apparatus shown at N, Fig. 3, of my Patent No. 1336, of 1878, I prefer
to wash the dust and dirt from the salt in the first division with common brine,
and use purified brine in the second. I arrange special means for flushing and
washing the gauze drum N at intervals. For this object I attach or cast inside the
screw drum N* preferably two pipes or channels with openings to discharge an
abundance of water against the gauze drum without. These channels I preferably
supply with water from chambers formed round the centre funnel n³ and on the
upper part of the drums. To carry off the water thus flushed in quantities through
the gauze I arrange one or more conduits, preferably outside and below the casing,

page_text: "
opened by suitable valves. I sometimes arrange below the gauze drum a slowly
revolving wheel, ring, or receiver to collect the salt from above and pass it, with
the aid of a scraper or otherwise, to the elevator or shoot. To assist the drying
operation I arrange to admit air, preferably heated, into the lower part of the
drum, but prefer adding one or more centrifugal machines for the purpose where
the salt may be kept longer under operation. They are preferably also arranged
for flushing and with perforations in drum N* which is generally provided with
heated air from a pipe or channel below with a fan or vane inside the drum or
other means for supplying air. To clean the blade n* of the screw drum N* I
sometimes arrange a scraper which moves in a groove inside the gauze drum N.
This groove when the apparatus is at work is filled in or covered with a piece of
metal or wood which can be withdrawn or turned to permit the scrapers being
inserted. I sometimes also employ endless scrapers with their wheels fixed preferably
at the top and bottom of the gauze drum. I occasionally arrange to stop and start
the salt and flushing by automatic regulating machinery. For the drying or
production of heavy blocks on the exhaust or blowing system revolving or moving
tables may be used, but I prefer to arrange special permeable fixed surfaces,
preferably made of wood, metal, or pottery, which I term "air beds," which may
be more strongly supported from below, and be connected by one or more chambers
or air cases or otherwise with more powerful exhaust or blowing machinery. I
provide for washing or saturating the salt on these air beds as occasion may require
with brine, water, or steam, either from below or above. I place these "air beds
in rooms or stoves, and preferably connect them with other stoves or apparatus, and
frequently make use of the heated air coming from the same or otherwise. To
prevent or lessen blocks of salt placed upon the air beds for drying from sticking
to their surfaces I prefer to spread over them coarse salt, or use loose pieces of
wood on which the blocks are placed or kept from touching the air beds. I some-
times use perforated or permeable pads over the table which can be moistened or
well up water or brine to damp the bottoms of the blocks and facilitate their
removal. I prefer to arrange the greater part of the air bed to be permeable, but
sometimes arrange the air holes in lines or squares to dry the sides of the blocks only,
or dry the sides first and the centres after by suitable communications. In cases
where the air beds are only used for drying blocks I place them over one or more
chambers into which salt falling through their surfaces collects for subsequent
removal. When forming or making blocks on the air beds I provide hoppers or
means for supplying salt preferably from above, and either employ balanced mould
case made to move up and down in guides, divisions which may be removed by hand,
or employ travelling carriages suitably driven passing over the air bed fitted with
knives or saws (which I prefer to have coated with black or magnetic oxide) which
cut the salt whilst drying or when dry, preferably lengthways, crossways, and
underneath to form blocks or cakes. When using circular saws and band saws upon
the carriages I prefer to drive them by compressed air or wire ropes. I arrange
sides and ends to this style of air bed, forming it into a sort of tank for the
salt, providing spaces in them to let the saws pass, or arrange for them to be
turned down or be removed. Means are provided for levelling the salt or caking
it in progressive layers, and also for subjecting it to pressure when desired. I
sometimes provide troughs round the air beds for catching waste brine or for
washing or saturating the salt contained in the mould case or tank. When
drying loose salt in bulk on these air beds I provide means for stirring it up, and,
preferably, blow heated air through it from below. In connection with the first
and second style of air beds for blocks preferably employ a large stove room or
shed for further drying the blocks by a continual current of warm air rising up
through perforations or spaces in the floor on which they are placed or stacked
I preferably heat stoves of this description by flues placed under their permeable
floors, and blow air with perforated pipes between and over the top and sides of
the flues to become heated and rise through the blocks above. I provide a long
steady self moving carriage on rails to transfer the blocks from the air bed to the

page_text: stove. For the first class of air bed I also preferably employ a somewhat similar
carriage, on which I place rows of moulds which are passed under a salt hopper,
showering arrangements, or perforated tubes for washing the salt filled into the
moulds, or drenching them with brine water or steam, preferably at boiling point,
to cause the crystals to cohere. A space is provided between the carriage and
the air bed where the blocks may be turned out. The brine run through the
blocks is preferably collected and used over again. For improving the circulation
of air in stoves of the ordinary type for stoving salt, which may also be used
in connection with the foregoing air bed apparatus, I arrange permeable cases or
stands of suitable material for the blocks, placed a few inches above the flues.
I preferably place a saddle over the flue under the stand in such wise that air
is drawn in at the sides of the flue and discharged warmed under the stand.
I occasionally heat the air for the stand or stove in a case forming the top of the
flue, or provide pipes in the flue for the purpose. In some cases I blow heated
air on the top of the flue under the stand by a long perforated tube, or otherwise.
Provision is made for the vitiated air from the stove to escape or be drawn off for
passing over pans or drying wetter salt on an exhausted air bed, or otherwise. To
save trouble in heating large volumes of fresh air for the drying apparatus,
stoves, and pans, I sometimes dry the air coming from the same after use and
use it over again, or employ dry air in the first instance. The form of apparatus
which I prefer to construct for this purpose consists of one or more tall chambers
with sloping bottoms, in which I place chloride of calcium, and through the lower
portions of which I pass the fresh or damp air. The dry air is preferably drawn
or passed through a fine strainer placed at the top of this or an adjoining chamber.
Dry chloride of calcium is supplied to the chambers by a shoot, or preferably by a
distributing disc near the top, and is withdrawn when charged with moisture from
the bottom and passed through a drying cylinder or other form of heating apparatus
to be again returned to the top of the chamber by an elevator, or otherwise, for
further use. In place of this arrangement I sometimes use rotating tables or
endless belts, on which I spread the chloride of calcium and pass the air over
or through it. I arrange various combinations amongst the foregoing apparatus,
stoves, pans, et cetera. Also special works for the treatment of salt received by
boat, rail, or otherwise, for its conversion into "handed squares," bag salt, "shoot
salt," and other qualities. The salt as received is taken by an elevator or otherwise
to the top of a chamber, preferably passed through a coarse sieve, and spread over
the stove by a disc wheel, or otherwise. The bottom of the stove is preferably
arranged with deep grooves or hoppers with screws or endless scrapers beneath.
These pass the salt forward to the various apparatus for preparing and manipulating
it. I provide stoves and sieves for the dried salt, and employ numerous elevators,
belts, et cetera, to economise labour. In places where wood is subjected to a high
heat I prefer to treat it with tungstate of soda. The iron work is preferably all
protected from rust by being coated with black or magnetic oxide.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, and of
an Order of the Lord Chancellor, filed by the said John Howard Worthington
Biggs in the Great Seal Patent Office on the 21st July 1881.
JOHN HOWARD WORTHINGTON BIGGS, of Liverpool, in the County of Lancaster.
"IMPROVEMENTS IN AND APPERTAINING TO THE MANUFACTURE OF SALT FOR
DOMESTIC, MANUFACTURING, AND OTHER PURPOSES, AND IN APPARATUS OR
MACHINERY THEREFOR."
This Invention consists in improvements on a part of the Invention secured to
me by Letters Patent No. 4324 of 1876, and on the further improvements on and
additions thereto secured to me by Letters Patent No. 1788 of 1877, No. 2106 of
1877, No. 1336 of 1878, and No. 5350 of 1880, and is, like the four previous ones,
rather more what would be called on the continent a patent of improvement
"brevet de perfectionment," a perfecting of the foregoing rather than an original
Invention.
The first portion of my Invention illustrates special apparatus for the purification
of brine for bottom heated pans, brine heaters connected with pans, table pans,
washing purposes, the manufacture of pure fishery or bay salt, and other
purposes.
The apparatus is complete in itself, but is preferably connected with a preparatory
pan arranged for exposing a large area of heated brine to the atmosphere, where
the excess of carbonic acid is to a certain extent given off. The brine is passed
through the apparatus, where it is boiled and filtered in its course, being mixed
with the purifying solution of predetermined strength before or after boiling. In
some cases I add the purifying materials in powder instead of solution to the
boiling brine in alternate vessels provided for the purpose, but prefer employing
solutions on account of being able to regulate their strength with much greater
nicety. Fig. 178 to 186 illustrate different methods of heating and filtering the
brine for purifying it with filters specially arranged for upwards and downwards
filtration.
Fig. 178, 179, 180, and 181 are the side plan, detail end, and detail views of an
apparatus arranged with duplicate chemical vessels and filters, so as to keep
continuously at work and supply a steady flow of purified brine to pans or
elsewhere. A and Ax are large vessels of equal capacity fitted with stirrers a
and ax driven by bevel wheels from the cross shaft X and driving pulley X 1 to
mix the solution and keep it well stirred up. These alternate vessels are provided
for containing the purifying solution. Both are connected with the apparatus, and
one supplies it with solution while the other is filled or cleaned, so as to keep it
constantly at work. There is a graduated scale in each vessel, so that they can be
alternately filled up to a predetermined height with water or brine before adding
the chemicals, which should be carefully weighed or measured for each vessel. The
class of chemicals I prefer to use for purifying the brine are carbonate of soda,
barilla, or mineral alkalis, but others may be used. By paying careful attention to
the height of the brine or water in the vessels, and the exact quantity of chemicals
added, a strength of solution is provided exactly suited for the requirements of the
brine under treatment. This is a matter of importance, as irregularity in this
respect would either result in leaving impurities in the brine and impure salt being
subsequently made, or in an unpleasant flavour being imparted to the salt which
might detract from its value.
B are a set of pumps, preferably three or more, arranged to work in time with
one another, and of suitable size for the purposes required. Their speed is governed
by floats regulated by the rate of filtration. C is a mixing tub, in which brine and

page_text: the chemical solution are well mixed together; D is a boiling chamber, or a scaling
pan may be used in its place; d is a revolving steam cylinder for boiling the brine
in the chamber arranged with the usual hollow bearings, stuffing boxes, steam and
water pipes, etcetera; dx is a scraper placed across it for cleaning the sides of the
cylinder; d1 is a screw for removing the scrapings from the bottom of the chamber
to an elevator d2; d3 is a cover to collect the steam and pass it off by pipe d 4;
d5 is the pipe supplying steam to the cylinder.
The top of the chamber is curved over so as to cause carbonate of lime and
certain other impurities precipitated by the boiling to fall near the end of the
screw near the elevator. I generally float a board cover on the surface of the brine
in the chamber to lessen evaporation. E and Ex are alternate filters with the brine
forced upwards; they have removable covers e, which when down enclose the
filtering medium between perforated plates e 1. There are large bottom valves e 2
to discharge the impurities strained out of the brine. Steam and water pipes are
also provided for cleaning the filters. The tops of the filters are provided with
spouts which pour the purified brine into a central tank F; f is a floating board
cover to lessen evaporation in the tank. It is also arranged to actuate the lever f1,
which governs the speed of the pumps by lever f2 and rod f3 with suitable
connections. In some cases I regulate the speed of the pumps by floats placed
outside the tank in a suitable side vessel connected with it at the bottom. On the
brine in this vessel I employ a layer of oil, on which the float rests and which
prevents or lessens it and the sides of the vessel being incrusted with salt, insuring
greater regularity of action. I frequently employ similar arrangements both inside
and outside pans or vessels for regulating other pumps, engines, valves, or apparatus.
The pumps are arranged for passing the brine and solution into the various portions
of the apparatus as required. I preferably connect them as follows:-ba supplies
brine either to the chamber D or to the mixing tub C, which communicates with D
by a suitable valve. The pump be draws chemical solution from either of the
solution vessels and passes it into the mixing tub C. A pump is also provided to
pass hot brine from D to C when required. The pump bf communicates with
either chamber D or mixing tub C, and forces the liquid from either upwards
through one of the circular filters E or Ex alternately. In this way the brine can
be mixed with the purifying solution after it has been boiled in D, or it can be
mixed with the incoming brine in C before it is boiled in D, and in either case
passed to the filters in a hot mixed state. By using properly proportioned pumps
all driven in time with one another the same quantities of solution and brine are
always mixed together, so that by regulating the strength of the chemical solution
in A or Ax the proper proportion is certain. A wagon way is provided under the
filter with a wagon G for removing the impurities from either filters when they
are emptied. They are arranged with draining bottoms and pass over grated
conduits, one of which is shewn at H, which convey away the brine and washings
when the filters are first opened.
The machinery is preferably driven as follows:-A belt from a pulley on shaft X
drives the cylinder by turning the drum 2 and a worm shaft x 3.
A belt from x2 drives the screw d1 by its shaft projecting through a stuffing
box, on which there is a wheel x 4. The elevator x may be driven by lengthening
the shaft X with suitable wheels and belt, or it may be driven elsewhere.
arrange to balance the filter covers, and frequently lift and lower them by
power.
An enlarged view of one of the filter tops is shewn in Fig. 181, illustrating how
the filtering medium ex is confined between the perforated plates e 1 and e1x, and
kept in position by screws e 3 screwed fast by removable handle e 4. There are
holes e 5 in cross bar e 6, to facilitate the top being lifted. A pipe e 7 carries off
any leakage.
The brine is forced upwards through ex, and overflows by an opening and
spout e 8 to the tank through e 9. A floating board cover e 9x is provided to hinder
evaporation. I generally also provide steam and water pipes and valves for

page_text: cleansing the filters. The filters and tank are supported by framing I and pillars J,
and a gallery K is arranged for their inspection and for removing the cover to the
filters. The apparatus is preferably worked as follows:-One of the alternate
solution vessels A or Ax is filled with brine or water to a given height. The correct
quantity of carbonate of soda, mineral alkalies, or other chemicals, are measured or
weighed out and put into the cistern and stirred up. Steam is turned on to the
cylinder d, and the pumps are started. Brine from pump b, a, and purifying liquid
from b, c, are forced into tub C, and kept thoroughly mixed. These discharge into
the chamber D, where they are boiled, and precipitate the carbonate of lime and
some other impurities, which are removed to scraper dx, screw d 1, and elevator d 2.
The hot liquid from D is then forced upwards through one or both of the alternate
filters E, Ex. The purified brine rising through them runs into tank F, which is
connected with and supplies brine heaters, pans, or other apparatus with brine in a
hot, pure, filtered state. When boiling the brine in this apparatus so as to precipitate
the carbonate of lime previous to mixing the chemical solution with it, I pass the
boiling brine from the chamber D into the mixing tub C, and then pump both
through the filters.
By the use of the alternate chemical vessels and filters, the apparatus can be kept
continuously at work, permitting one of the vessels A or Ax at a time to be
carefully charged with the correct solution for purifying the brine, and one of the
filters E or Ex to discharge its filtrate, or to have its filtering medium partially
cleaned with steam or water or both, or to be removed by raising the cover, so that
a new one may be substituted without stopping the general process, or the supply
of purified brine to the pans or apparatus with which it is connected.
Figs. 182, 183, and 184, show two side views and end view of a simple style of
filter which may in some cases be used instead of the filters E and Ex.
A is a tank with a low division B forming two separate vessels on occasion C
and D. These have perforated bottoms c and d and are placed over chambers Cx
and Dx.
The filtering medium f is placed over c and d; G is a frame of floating boards
to prevent or lessen evaporation. Duplicate pipes e and ex with valves are provided
so as to fill either of the vessels Cor D with brine or water, others f and fx to
exhaust air from Cx or Dx, and g and gx to withdraw the filtered liquid, and to
wash out the lower chambers with water or steam when required. Man holes h
and hx are also provided for each chamber.
The object of using the division B and floating boards G together with the
duplicate arrangement of pipes, etcetera, is that one half or part of the filter may
be cleaned while the other is working, which arrangement I employ in other forms
of filters and elsewhere; Fig. 182 shews compartment C working and compartment'
D ready for cleansing; Fig. 183 shows C and D filled with brine and the board G
being floated over to cover D, so that C may be subsequently drained and
cleaned.
I sometimes use this filter in connection with a scaling pan after the style of that
shown in Fig. 18 in my last Patent (No. 5350, of 1880). Both systems of filters
are sometimes arranged to have their brine heated by pans or other forms of
brine heater, but the arrangement shewn, Fig. 178, is preferably used in various
forms, as it is compact and suited for continuously supplying large brine heaters
or numerous pans.
Figs. 185 and 186 are the side and plan views of a filter, in which brine is
boiled and filtered in the same apparatus. The filter is preferably made circular
and arranged with sloping layers of filter cloth.
A is the filter cloth stretched over a perforated plate and kept tight in position
by a central collar at a 1 and ring ax at the side fitting in a groove b. The collar
is screwed down from above and the ring preferably from below at bx.
The surfaces of the collar ring and permeable surface are arranged as nearly as
possible level with one another, so that curved scrapers c, and cx suspended or held
from the revolving arms d keep the surface of the filter well scraped, and pass

page_text: the scrapings through a hole e into a deposit box E at the side of the filter. The
arms d are supported from a central boss D, which can be moved up and down
or lifted off a central shaft F driven from below, by which they are made to
revolve by suitable projection on a collar f on which the boss rests. When the
filter cloths have to be removed, the scrapers are lifted off the shaft by a ring di
and chain d 2 passing over a pulley above the filter.
The shaft F is carried in suitable bearings at the bottom and upper end, and is
made to revolve by the worm wheel G and screw shaft H, or otherwise. The brine
in the filter is preferably boiled by steam or products of combustion mixed with
them in a jacket I arranged with sloping sides; or I sometimes use a coil of pipes
in its place, preferably arranged with parallel rings after the style of Fig. 7,
Sheet 3, in my Patent No. 1788, of 1877, which enables the scrapers to keep them
better cleaned. High pressure steam or other heat is supplied to the jacket or
pipe in place of it, and the condensed water is drained by pipe i arranged with a
cock ix.
Below the permeable bottom of the filter there is a receiving chamber J drained
by pipe j. The shaft passes through a long tube jx arranged in its centre, and
extending above the brine in the filter above.
To lessen evaporation I place a floating board K on the surface of the brine, and
case the side of the steam jacket in with wood. I prefer to keep the chamber J
filled with brine, regulating the flow of brine through the filter by a cock in the
pipe j. I sometimes connect a steam pipe to the chamber J to assist in cleaning
the filter cloths. In some cases I boil the brine in a little brine heater at the side
of the filter, or connect the filter with a boiling pan, and dispense with the steam
jacket I. The brine from the filter is preferably run into a cistern or pan to
cool when wanted for washing purposes, as shewn, Fig. 256, where I employ an
apparatus of this description driven from above with the scraper boss sliding up
the central shaft.
In place of filtering the brine when mixed with a purifying solution I sometimes
run it into tanks or pans arranged for cleaning to allow the impurities to settle,
but prefer passing the brine hot into the pans as it comes from the filters. I use this
purified brine more especially for brine heaters, pans arranged for the circulation
of brine, and for making pure salt for fishery or other purposes, and in pans heated
by steam below or air above.
Of this latter type I arrange deep covered pans supplied with heated air
preferably from the air case of an adjoining fire surface pan. I sometimes also
arrange for the air for passing over these and other pans or stoves to be heated
by flues, cases, or pipes connected with the furnaces, or heat the air in pipes or
cases containing pumice stone to give additional heating surface.
Figs. 187 and 188 are the plan and side views of an arrangement of works for
producing large crystals and certain other varieties of salt preferably from purified
brine, together with stoves and waste heat pans to facilitate or economize the cost
of the manufacture.
A are long deep pans in which I sometimes arrange a slow circulation, or
partially heat with brine heaters. They have doors at their end a through which
wagons can be passed preferably on rails ax; B is a cover to the pans (shown
partially removed), and serves with suitable arrangements to conduct heated air
over the surface of the brine from passage C to chimneys D, which are preferably
fitted with broad bases d at the bottom near the cover so as to keep the current of
air drawn from over the pan well spread out. The chimneys are better fitted with
revolving vane tops dx or other means for improving the draught and keeping out
the rain.
E is the air cover to the surface pan Ex after the style of those described in my
last Patent (No. 5350 of 1880).
It serves to supply heated air to passage C for the pans. It is made in two
halves, so that when either pan is being emptied the air is only allowed to pass
over one half or part. There are separate hot air channels e 1 and e 2 for this

page_text: purpose. The air is preferably also heated by passing through a hot air stove F
at the side and back of the boiler Fx. It may be constructed on any approved
pattern, but is preferably arranged as to supply itself with a continuous volume
of air without the use of blowing or pumping machinery.
With this object I prefer to place the boiler and air stove at some depth below
Divisions are
pan cover E so as to create a draught from the stove to the cover.
arranged to direct the air into either half of the air case E. The stove is partially
heated by the boiler fires, and the waste products of combustion passing from the
boiler and its own fires are carried over the surface of pan Ex and again passed
with steam from the brine under a bottom heated pan G to chimney H by the
deep chamber Gx. The pan is fitted with water joints at its side, and is supported
by pillar gx or otherwise after the style of similar pans described in my last
Patent (No. 5350 of 1880).
The deep pans Ex have doors at their ends ex and rails el running down them
to facilitate their being periodically emptied.
Pan G may be worked by hand, but is here shewn with a travelling carriage I
and sloping end board J, after the style of Fig. 82, and has also preferably perforated
air tubes at its sides, or cover over its top.
The purifying apparatus K and its filters L supply the pan G with purified brine
from which there is a pipe or conduit m to a trough or pipe M. passing over the
ends of the pans A. This trough is provided with valves and floats m 1, and keeps
the level of the brine in pans A at an even height, or stops any brine entering a pan
in case it requires emptying. A steam pump M is provided with suitable pipes
and valves for transferring the brine between any two pans, especially from one
pan which has to be emptied to one that requires filling. It is also arranged to
pump the brine from one of the pans A into G if required.
For facilitating the formations of large crystals I generally arrange to suspend
strings, preferably made with short cross bristles or other lateral projections, wires,
nets, or other substances on which the crystals may form when immersed in the
brine. These I either let down through the cover or attach to its under side by
hooks or otherwise, sometimes attaching them to poles, ropes, angle irons, or tubes,
and preferably supporting these on ledges, pendants, or projections placed above
the brine, see Fig. 190. I generally affix small weights to the strings or thin rods
to the bottom of the nets to keep them steady in the pan.
.
When the strings or poles in any one pan are ready for removal I pump the
brine out of it into G or elsewhere, and open the door a at the end of the pan.
Operatives now proceed to lift down the poles (which I preferably use) and transfer
them with their salt to a suitable carriage running on the rails ax which conducts
them to a store house. Fresh poles with nets or strings are substituted for the
ones withdrawn; the door a is closed, and the pan filled by the aid of the pump N,
pan G, or otherwise, as quickly as possible consistent with not entangling the
strings or nets by too great a rush of brine on first opening the valves. During
the emptying and refilling of the pan the air for C is cut off from it to save the
waste of heat by suitable valves or canvas attached to the cover B.
As making large crystal salt requires a considerable length of time, I prefer to
arrange several of these narrow deep pans in the same works, so that the same set
of workmen may be kept steadily at work emptying and refilling the pans in
succession.
The nets and strings covered with salt are sometimes passed between rollers
placed a short distance apart, and used over again.
When using ordinary brine for this style of pan, the crystals should be steamed
and thoroughly washed and drained to free their surfaces from deliquescents and
other impurities, for which I provide special arrangements described later on.
In some cases I arrange to remove the strings or nets from the pans without
having to pump or drain the brine from them each time.
This I effect in various ways. A simple method is illustrated in Fig. 189, where
the covers to the pans are made to lift off the pans, and be transferred with their

page_text: load to the side. I arrange for the strings or nets to be hooked or attached to the
under side of the covers, and to be lifted in and out of the pan with them.
A are the surface air heated pans in which the strings a are seen dependent from
the covers.
B, the covers to which they are hooked or fastened.
C, the divisions between the pans.
D, overhead rails placed across the pans at suitable distances, and supported by
pillars d and walls E, or otherwise.
F, travelling carriage (after the style of travelling cranes) arranged to raise and
lower the covers from the pans and to transfer them to the sides, where they are
lodged on ledges or bars G.
In this way with sufficiently powerful apparatus the nets or strings from the
whole of a short pan or sections of a long one may be transferred to one side for
draining and subsequent removal, as shewn at H, while a spare cover with new
nets or strings filled at leisure may be taken from the other side I and put back
on the pan with its strings or nets hanging down into it for fresh crystals to form
and the process be continued. I transfer the covers alternately from one side to the
other. The brine draining from either side is run back into one of the pans or
otherwise disposed of. Work people unhook or detach the strings or nets of salt
from the covers just raised, and remove them to a storeroom or elsewhere. They
then attach fresh strings to the cover for the next pan. I sometimes arrange for the
carriage to transport the covers into a room where the crystals may be steamed or
washed when still hanging from the cover, in which case I prefer to separate such
room from the pans by a canvas screen on one or more long rollers, or use sliding doors.
With a view of rendering unnecessary the lifting of the covers, I sometimes
employ a pair of long chains, ropes, or wires (marked a in Figs. 190 and 191, end
and side views) on each side of the pan, on which rest the ends of poles, rods, bars,
angle irons, tubes, etcetera, marked c, to which the nets or strings are attached.
These chains are supported by slides or pulleys b at the two sides of the pan, and
bx under the pan.
The chains are preferably passed round a pair of large winding wheels D and E
at the two ends of the pan.
The pair D are driven by a small wheel e on the shaft of a worm wheel E,
turned by an engine F or otherwise. The wheels are arranged to be driven either
way, so as to drag the poles to or from the opening G in the pan cover Gx. From
this point the poles may be raised out of the pan by hand or otherwise. I prefer
to employ lifting machinery especially adapted to the purpose.
The form of apparatus I generally use for the purpose is a double carriage
lifting crane, preferably made self moving after the style of those used in timber
and stone yards.
There is an upper carriage H moving to and fro on rails i on the top of a lower
carriage I, which itself moves on rails J placed over and at the side of the ends of
several pans constructed on the same system.
The rails are supported by numerous pillars Jx placed between the pan and the
wall or otherwise. The upper carriage has a central winding shaft turned by
powerful machinery.
To it are keyed two chain wheels h, from which there are chains h1 and h 2
passing over pulleys h 3 and attached to the ends of bars or stirrup K, one bar or
stirrup being arranged for each side of the pan. When down these stirrups are
passed under the projecting ends of the poles lying on the chains.
The machinery is set in motion and they are wound up, lifting the strings or
nets out of the pan, as shewn in Figure 191. Carriage H then traverses with its
load to Hx, and lowers the poles on to the top of a carriage L arranged for trans-
porting them to a store room or elsewhere; L runs on rails extending as far as
rails J. After depositing its load it returns for a second batch of poles, and so on
until the pan is emptied.
M is a footway by the side of the rails J. When one pan is emptied the carriage

page_text: is moved along J to another pan, and so on. The pan may either be recharged by
running the machinery backwards, that is, bringing up poles with new strings on
the carriage L, and transferring and putting them through G on to the chains a,
which are then wound backwards, or they may be put on the chains at Mx, where
one or more trap doors m, the width of the pan, are provided. In this case the
poles have their nets or strings wound round them for easy transfer, and are
brought up to the side of M by carriage N running on rails n extending across the
ends of all the set of pans. I sometimes dispense with the carriages H and
the rails J, and wind the poles and strings out of the pan direct, either preferably
sloping the end of the pan next to D, or by placing D above the level of the brine
and over the end of the pan, and raise the poles to such a level that they can be
transferred by hand or machinery or have their nets or strings detached and passed
into a waggon or on to a belt for removal to the store room. By using two of
such pairs of wheels D at one end of the pan, one placed above the others, I some-
times wind the strings out of the pan and carry them direct to the store room.
I generally pass the strings or nets between rollers to free them from salt and
return them again to the pan. In some cases in a less advantageous arrangement
when suitable provision can be made for heating the brine in the pans by con-
necting them with brine beaters or otherwise, I sometimes dispense with the covers
to the pans and arrange for the ends of the poles or rods holding the strings or
nets to rest on the two sides of the pan and be removed or replaced by hand or
machinery. In this case I either arrange for the pans to be entered as previously
described or provide footways at the sides of the pan, or preferably provide
travelling over head carriages to lift the poles as they move along the pan from
end to end or side to side of the pans.
When salt is made from ordinary brine, I preferably arrange to drain or wash it,
so as to produce a clean and pure quality and afterwards preferably stove it. For
curing purposes salt is much enhanced in value by being made from purified brine
or by being well washed to free it from such of its deliquescent properties as are
removeable from the surface of the crystals. Crystals taken from an evaporating
pan filled with ordinary brine are liable to be coated with impurities contained in
the mother liquor, or if produced by passing the products of combustion over the
surface of the brine are liable to be more or less mixed with soot, while salt
coming from a store room or mine is more or less mixed with dirt. With a view
of freeing salt from these and other impurities I arrange various apparatus for
thoroughly subjecting the crystals to washing and draining either in a dry, moist,
or wet state, preparatory to drying, or for other purposes I prefer to wash the salt
with purified brine, and after use re-purify the brine for further washing or for
making salt in an adjoining pan; in some cases however ordinary brine or even
water may be used. To lessen or avoid evaporation I prefer to use the brine for
this purpose at a low heat, or cold. In some cases I arrange for the same apparatus
to both wash and dry the salt, but preferably separate the washing and drying.
For washing lumps of rock salt or fine salt from fire surface pans to prepare it for
putting back into another pan for further growth or other purposes, I often employ
wagons arranged for draining and emptying and pass them under a shower of brine
or water, or employ tall fixed cases showered on from above.
Figs. 192 and 193 shew the end and side view of an arrangement for washing
salt in carriages direct from a mine, pan, store, or elsewhere.
A is a brine or water tank supported by pillars a or otherwise kept filled to a
given level by a self regulating pump, or in connection with a reservoir or pan at a
higher level.
B is a floating board used when heated brine or water is employed for washing
to lessen evaporation.
C, case valves for admitting fluid into the lower chambers D which are arranged
with perforated bottoms for showering brine or water on salt in carriages E.
Chamber D is provided with suitable valves and pipes for admitting air or washing
out the chambers with water or steam.

page_text: The carriages E are here shown with sloping sides and perforated bottoms e to
drain off the brine or water.
They are arranged for discharging their contents from below, but any style of
wagon may be used for this system of washing, providing proper provision is made
for the water or brine to drain through the salt, and preferably into channel F over
which I sometimes place a grating. G are the rails for carriages E supported over
the trough by little girders or beams e; H is a wire rope for moving the carriages
about; h, one of the rope wheels. With the object of more thoroughly draining
and cleansing the salt under treatment I preferably employ an intermittent shower,
and alternately shower and drain it for several minutes. For this purpose the
valves C are arranged to be alternately opened and closed by rods c and levers c 1.
These levers are carried in bearings at jx and have a wheel at j moved up and down
by cams K. The cams are turned by wheel L, screw M, and driving pulleys N.
I arrange the cams to slide on a feathered or slotted shaft k moved by handles kx,
or otherwise provide for stopping the showering in one or more cases when the full
complement of wagons is not under the tank. I sometimes arrange this class of
washer for single wagons when they may be moved by hand, and for any suitable
number, preferably washing a train of them at a time and moving them about by
power.
Fig. 194 represents an arrangement for washing and draining salt in a series of
tubes or cases preferably made of wood or lined with wood, to which damp salt
appears to adhere less easily than to metal cases. A is the supply wagon supported
on platform B; it discharges its salt into the cylinder or case C which is of any
desired length; D is a perforated pipe under the partial cover round the top of the
case or cylinder for showering the brine; it is preferably governed by intermittent
regulating machinery as in the previous Figure. E is the discharge valve; F, the
receiving wagon; G, the conduit for drainings, etcetera. Holes care provided at
the bottom of C to allow the brine to escape. I sometimes arrange arrange a stirrer
inside C to quicken the discharge of the salt after washing. I prefer to employ
several of these cylinders or cases in a line, and preferably arrange for cach case to
contain one wagon full of salt. In place of using top wagons I sometimes fill the
cases by means of a screw or belt fed by an elevator or otherwise.
Fig. 195, side view; 196, front view; 197, side view of an apparatus more
especially designed for the treatment of rock salt, but which may be used for other
purposes. There are two balanced dipping cages A and B with perforated bottoms
held in frame a, b, moving in side guides C, D, E, F, which in this instance are
arranged at the side of their respective pillars which support the upper framing.
The cages are moved up and down by chains g passing over a grooved wheel G;
this wheel is sometimes moved by steam, air, or water cylinders, or by any suitable
apparatus or machinery. It is here shown moved by a worm wheel Gx keyed on
the same shaft and turned backwards and forwards by the belt drums I by inter-
mediate bevel wheels and worm H. One or more pins g 1 on G cause a tipple
weight J to swing to and fro alternately, which actuates the fork rod j and reverses
the motion. A handle is provided at jx to work the fork rod; K is a tank filled
with water or brine which is kept constantly changing; Kx is the top cover or
part of the floor of a salt house supported by suitable girders or bearers; is the
front of the tank with a moveable balanced shoot board L actuated by a rod and
short lever M by the movement of the cage frames a and b by hand or otherwise.
Fig. 197 shows the two cages on a level being filled with salt by wagon O with the
shoot board L in a vertical position; Fig. 195 and 196 show B in the tank and
A discharging its salt into wagon P after having been several times dipped in
tank K. When using this apparatus for cleaning lumps of rock salt from dirt
previous to grinding I frequently use water in tank K and place a hopper or a pair
of crushing jaws and sometimes rollers at P using elevators to forward the crushed
product for subsequent washing, drying, stoving, or other treatment. Rock salt
when properly washed, ground, and stoved is particularly suited for curing purposes
from its comparative freedom from chloride of magnesium.
In another arrange-

page_text: ment for washing salt, more especially rock salt, I sometimes employ rotating ledged
cylinders placed horizontally or at an angle through which I pass the salt and
currents of brine to remove the dirt or impurities.
Figs. 198, 199. For wasting, drying, stoving, caking, or otherwise treating salt
that requires more care and attention than can be paid to it in the foregoing
arrangements, I preferably construct a class of apparatus where the salt is spread
out over gauze or other permeable surfaces and subjected to currents of brine or
air passed through it from above or below, preferably in large quantities, by
powerful exhaust or forcing machinery, or otherwise. In some cases I arrange to
shower brine on the salt placed over exhausted surfaces and use steam or water for
washing it and for other purposes. Other substances have been treated somewhat
after this fashion, but the injurious effects produced by placing damp salt upon
copper, gauze, or metal plates together with its disposition to cake and block up
small air holes render special alteration and improvements necessary, which I
arrange as follows:-
When
In the first place I protect the gauze, perforated plates, etcetera, through which I
blow or exhaust air, or pass brine, water, or steam from the corrosive or chemical
action of damp salt, or the latter from discoloration by rust, by employing iron
instead of copper, gauze, or permeable surfaces, and coat the same with magnetic or
black oxide. In cases where I employ canvas for the purpose I similarly protect
it as far as possible by preparing it with tan or cutch, washing it and subsequently
boiling it in a solution of glue to render the protection more durable. I preferably
treat all belts for washing, drying, or carrying salt in the same manner.
using, drying, or draining surfaces of perforated or other forms of pottery, or other
non-corrosive materials, as also sometimes for the permeable materials mentioned
above, I preferably arrange for their thorough washing and cleaning. Figs. 198
to 232 illustrate varieties of this class of arrangements. Figs. 198 and 199 are the
side and plan views of an apparatus for freeing salt from fine particles and
subjecting it to a current of brine for assisting to remove impurities. A is the
trough with a bottom B finely perforated between 6 and bx composed of plates,
gauze, canvas, or other material supported and kept even by bars or other suitable
supports on the under side to which it is fastened; C is a pressure tank beneath B,
and fed with water or brine from the brine head, purified brine cistern, or
otherwise. It is here supplied with brine under pressure by a centrifugal pump
and engine D, and causes innumerable fine streams of brine to pass through B into
the trough above; E is an overflow cross trough at the end communicating by a
pipe e with a filter tank pan or other receptacle to collect and utilize the small
particles washed over the overflow. In some cases I employ an open trough in
place of the pipe e or pass the overflow brine into a deep cistern where the
particles may settle, withdrawing the brine from the further end of the cistern
through a strainer and pass it back again through the apparatus; F is the platform
for filling the hopper G with salt which should previously be passed between
rollers set a little apart to break up lumps; H and I are two pairs of chain wheels
round which endless scraper chains J, ropes, or wires are stretched and by which
they are moved. The chains preferably rest on side ledges and carry numerous
bars, or rakes, or scrapers j, moving along or near the gauze to stir up and transfer
the salt from the hopper G to a cross trough K, in which there is a screw kor
other means for removing the salt to the elevator L. With long troughs I some-
times employ rollers. to support the chains. The apparatus is here driven by a
belt from the engine D and drum d, turning the belt, drum M, pinion m, gearing
into Ix keyed into the shaft of the chain wheels I. The elevator L and screw k
are turned by belts or chains from the drum mx or by gearing, but they may be
driven in any suitable manner. As the salt moves over the innumerable fine
streams rising through the gauze, many of the impurities and lighter particles are
floated off and escape at the overflow, the salt remaining in the apparatus and
finally discharged by the elevator L, being the coarser or heavier crystals which

page_text: the current has failed to remove. The minimum size of these remaining crystals
may be to a certain extent regulated by the pressure of brine in C.
Figs. 200, 201, and 202 are the side, plan, and detail views of a somewhat
similar apparatus designed for the same purpose. In this case the brine or water
instead of overflowing the end of the trough is withdrawn by a partially or wholly
submerged cross pipe E of which a section is shewn, Fig. 202, which is arranged
to carry off a large volume of brine or water from the surface only. Small
rollers jx are placed over the side chains at the back of the cross pipe E to deflect
the chains, which as they move up a somewhat sharper slope, empty the salt into
a wagon N placed at the end of the apparatus.
The guaze or permeable surface of the apparatus only extends as far as b× to
avoid disturbing the salt as it moves forward in shallow brine to be discharged
into the wagon. To facilitate moving the salt from one end of the trough to the
other, I sometimes employ a permeable endless belt moving on rollers along its
bottom or over a case, through which brine is forced for washing or floating off the
fine particles.
In a simpler arrangement I sometimes pass brine and salt through a mixing
vessel, discharging the same down a widening plane or trough where the crystals
sort themselves by the current or get trapped by suitable divisions. By the
above methods of washing the minute particles of salt amongst the crystals may be
floated off into a pan for further growth or into a settling tank, or otherwise,
leaving the rest of the salt after washing far less likely to choke exhaust surfaces
or the gauze of centrifugal machines in subsequent drying operations. It also
lessens the amount of very fine salt sieved out after drying, which is a desideratum.
For some kinds of salt it is desirable to avoid scraping the crystals along the gauze
more than necessary when removing the fine particles. To this end I arrange a
permeable surface on an annular rotating table A. Fig. 203, side; 204, plan;
205, 206, details. The table is sometimes. mounted after the ordinary style of
rotating tables, but is here shown fitted with rollers a resting on a circular rail
road b connected with a hollow centre pivot B round which the table rotates. The
table is preferably divided into three compartments A, D, and C. A is the permeable
annular surface suitably supported through which the brine or water from tank L
rises and overflows into a deep trough D. The brine is here supplied through the
hollow centre and flows into the tank at Bx, but is sometimes supplied from above
or direct to the annular surface by connections with a suitable central joint below
or above the table, in which case the tank C may be dispensed with. I prefer
bowever to use the tank, as it secures a more even pressure of brine under the gauze
ring A, and permits any dirt collecting under it to be readily removed when the
tank is emptied. The trough D is supported at intervals by uprights dx from
below. I sometimes place this trough on the outside of the annular table A
to equalise the current of moving brine. It is emptied by one or more syphons
or exhaust pipes E (see Fig. 296). There is a regulating valve at e and a
pipe ex with stop cock to fill the syphon, a valve being provided further down
the large tube to raise the brine to el, and make the pipe draw when first
starting the apparatus. F is a belt bringing salt to be treated; G, the hopper into
which it is filled. The hopper slopes inwards near the bottom, and discharges its
salt on to the table, by which it is removed in a thin layer, sometimes passing
under a roller to equalise it. H, H, H, H, H, are pillars or frames outside the
table, supporting bars h over the annular permeable surface. These bars carry
rakes or numerous little vertical plates set at an angle to keep the salt stirred up
and evenly distributed over the permeable surface. I is an incline up which the
salt is pressed by the rotation of the table; J is an endless chain of scrapers,
delivering the salt into hopper K on to a belt L for removing it for drying or
other treatment. I prefer to have the permeable surface of the table horizontal,
but sometimes arrange it sloping to equalize the current of brine or to keep the
salt more evenly distributed. The table is caused to rotate by a circular rack ax

page_text: on its underside, gearing with a small wheel on the shaft of M turned by n on the
shaft of the belt drum N. This shaft also turns the drum of the belt L by wheels
and chains. The scraper wheel Jx and the top belt F are turned by straps or
chains from drum O on shaft o and bevel wheels ox. P is a short girder supported
at its two ends on H, H, and assists to carry the hopper G and syphon pipe E.
Valves are provided for regulating the supply of brine to the tanks and for emptying
it. Oil pipes are also arranged to lubricate the central pivot and other working
parts of the apparatus in the usual manner. In place of floating off fine particles
of salt I sometimes employ currents of air or steam under suitable seives or rollers
to transfer the lighter particles into a settling chamber or elsewhere. Occasionally
I use centrifugal action for the same purpose in connection with suitable grinding
rollers or other machinery. In cases where it is inconvenient to wash the exhaust
or blowing surfaces I arrange with suitable hopper measuring rollers, screws,
etcetera, to lessen or prevent incrustations forming thereon, by placing a thin layer
of dry salt on them, over which I place the damp salt in such wise that the dry
salt absorbs most or all of the moisture from the damp salt above, when both may
be easily dried.
Figs. 207, 208, 209, and 210, are the side, plan, partial end, and detail view of
an annular permeable rotating exhaust or blowing table, arranged for drying damp
salt and other purposes, where the system of protecting the gauze with a layer of
dry salt is illustrated. The table is specially arranged with the object of affording
a large area of permeable surface for treating the salt or similar substances, while
combining steadiness of movement with wide connections or conduits of large
diameter or area to facilitate the passage of large volumes of air or gas between
the permeable surface on the table and powerful exhausting or blowing machinery
or chimnies. There are two circular frames; A, the basement, and B, the rotating
table. Each is preferably cast or made in one piece, but where this is not
practicable they are made in sections, and firmly bolted together. A is bedded at
its circumference on masonry a, a, and concrete, and is bolted at the centre to a
vertical column c, which latter forms part of a case C, also firmly bedded on
masonry and concrete Cx. At the circumference of A there is a circular rail ax,
which should be turned up true and smooth. From it are radial arms b connecting
it with a central boss bx bolted to c. In the centre of bx there is a hardened steel
pin d (which can be slightly moved up and down by a wedge dx), moved under it
by a screw shaft d 1 and hand wheel d 2. There is a ring a 1 extending between
the top and bottom of the radial arms. Its upper surface supports a stuffing box e
made in two parts, and arranged with slot holes so that it may be properly adjusted
on ax and fitted thereto. The lower part of ring ax is bolted to the outer portion
of case C. From the side of case C there is a broad pipe E the width of the case,
but forming a circle at ex, to which is bolted a spacious exhaust or blowing pipe Ex,
connected with powerful machinery, a high chimney, or otherwise. The upper
frame B has deep radial arms b which support the annular trough Bx, on the sides
of which are ledges for supporting frames of permeable material, on which the salt
is placed for drying or caking. In some cases I cover the whole surface of the
table with permeable material so as to provide a greater area for the salt to rest on
and be exposed to blowing or exhaustion. The ring is supported at intervals
by short stays bx from below, and I sometimes also support the ring frames at
intervals of their width. On the upper and lower sides of b there is a thin metal
casing 61 and 6 2, forming an air tight communication between the annular trough
and the centre. The upper case b1 is preferably made removable by bolting it
to ledges 63. The lower one I prefer to cast or rivet on to the radial arms b
to give them strength and steadiness. The lower casing slopes so that any
accumulated moisture, brine, or water passing through the permeable ring finds
its way down to the centre, where there are wide openings between the arms b
communicating with C by a circular ring b4 dipping below the stuffing box e.
There is a boss b 5 from which the arms b radiate. It rests on the hardened steel
centre d, and causes the table to turn true, for which object the pin is employed.

page_text: This enables me to employ a stuffing box at e, or in place of it a circular trough
and dripping ring, filled with mercury or water to keep the pipes air tight at the
joint. There are numerous wheels 6 6 carried in bearings at the end of the radial
arms which run on the rail a. I sometimes place the wheels on the lower frame A
and let the table revolve over them. There is also a rack 67 at the edge of the
table by which it is made to rotate as in the previous apparatus. It intergears
with a small wheel on the shaft of fx turned by fx and the belt drum F. This
arrangement of table is serviceable for various purposes, viz.:-Washing, steaming,
draining, drying, caking, or fuming salt or other substances according to the
various arrangements of apparatus placed over it for manipulating the substance
placed upon the permeable surface for exhausting or blowing treatment. Small
ring tables have been used supported only near the centre, where however a large
surface is advisable, as in drying salt it is very desirable to support the outer edge
of the table as well as the centre, enabling much larger tables to be employed. I
sometimes withdraw or supply the air, gas, etcetera, from the upper instead of the
underside of the table. In this case I form a central hole in b1, the upper cover,
and provide a projecting ring, which is made air tight, with a pipe above,
preferably by a similar stuffing box to e fastened to the pipe or table. When
employing this arrangement I allow a frame in the centre of the pipe to rest on the
boss, preferably with bearings, or a steel pin like d to keep the pipe true, and
sometimes place girders over the table to carry the principal weight of the pipe or
conduit. For drying damp salt on this table, as shewn in the Drawing, I arrange
preferably to use a subdivided hopper H, Fig. 210, in which I sometimes arrange
stirrers. It is fed in any convenient manner with dry salt in h, and damp salt
in hx. In the Drawing I have shown two belts, g and gx, for bringing up the dry
and damp salt. Fig. 210 shows an enlarged view of the means preferred for
spreading the salt upon the table, which I frequently adopt elsewhere. Below
each hopper there is a pair of adjustable rollers i, and ix, in this instance cone
shaped to suit the radiation of the table, but made parallel for belts, as shewn,
Fig. 220.
One roller of each pair is sometimes made to turn a little faster than the other
so as to break up small lumps; as they turn inwards they deliver salt on to the
permeable surface Bx below. I occasionally also employ reciprocating sieves below
these rollers. The dry salt reaches the table first, and is levelled by a projection h 1.
On the top of this a layer of damp salt is deposited by rollers i. The object of
this arrangement is to protect the permeable surface from the injurious action of
damp salt coming next its surface. I employ various methods to the same end, but
prefer the one shewn, as the amount of dry salt used can be easily regulated, while
gently dropping the damp salt on to the dry layer of salt from above, tends less to
displace it than when delivering the damp salt direct from an open end of a damp
salt hopper. The salt spread upon the table is subject to exhaustion or blowing
from below until it comes round again in a dried state by the movement of the
table and is forced up an inclined plate j, on the upper side of which is a quickly
turning screw jx, which transfers it by a hopper K and belt Kx for removal to a
store or elsewhere. Each pair of the hopper rollers are intergeared at i. One of
each pair being driven from the cross shaft by bevel wheels fx. The screw jx is
also driven from the cross shaft f. The cross shaft f is turned by a vertical
shaft f2 from the drum shaft f1. The upper belts are driven from a wheel at the
end of cross shaft f, and the lower belt is driven by a chain or gearing from the
drum axle or otherwise. The hoppers are supported by a girder Lx at one end, and
by projections from the frame carrying the machinery at the other. The girder is
bolted to pillars L. There are rakes m also supported by pillars at L, and a
perforated hot air supply pipe N encircles most of the table supported by the
pillars, and blows hot air over the salt to supply the exhaust and assist in drying
the salt. I sometimes use wires stretched across the ring to stir up the salt as well
as the rakes and occasionally cover the table in with an air case to keep out the
dust and facilitate the drying by supplying it with hot air. In place of exhausting

page_text: air from below the table I sometimes force air or gas upward through the salt from
below; this keeps the salt more open but is liable to displace the finer particles of
salt subjected to the treatment. When arranging the table on the blowing system
instead of the exhaust, I generally place a cover over the table and connect it with
one or more deposit boxes or chambers into which the fine particles carried by the
current of air settle and collect for subsequent removal and use elsewhere. For
preparing the salt for certain chemical purposes, I sometimes blow, exhaust, or
pass products of combustion or other gases through the permeable surfaces on
which the salt rests and causes it to absorb a portion of the same while under
treatment.
As
After
I arrange a somewhat similar form of annular table for washing, drying, or
caking salt, illustrated in the next Figure. Figs. 211, 212, 213, side, plan, and
detail views of an apparatus for subjecting salt or other substances to repeated
washings and drainings for facilitating the removal of deliqueseints and other
impurities; B is a rotating table with an annular permeable surface Bx, which is
preferably arranged after the style of table B, in the preceding Fig., and
connected with powerful exhausting machinery; A is an endless belt bringing up
salt to be washed, which it empties into hopper C, from which it is carried to the
table hopper E by elevator D and fed upon the table. This hopper is supported
by a cross girder and frame Ex, bolted at each end to pillars e¹ and e². The salt
falling on the table passes under a roller F, and is subjected to repeated showers of,
preferably, fully saturated brine from numerous perforated pipes g, which are
supplied by the curved pipe G. The brine for this pipe enters at Gx, where there
is a regulating valve and handle; G is supported by pillars H. These have radial
bars which are bolted to the girder Ex at the centre, and also support a ring gx,
by which the other end of the perforated pipes y are supported or fastened.
the table slowly turns, the salt is repeatedly showered on and then allowed to drain,
which is facilitated by the exhaust from below. I sometimes employ rakes or wires
to stir the salt up on the table, especially when using heated or boiling brine or
steam for washing, as a powerful exhaust is liable to make the salt cake.
the salt has been repeatedly washed and drained, it is subjected to a long course of
exhaustion between e 2 and the inclined plate I. With tables of considerable
diameter I sometimes admit or blow hot air over this portion of the table, preferably
screening it off from the rest of the table by a cover attached to Ex. The salt is
forced up the incline plate I and is removed by the endless chain scrapers J into
the hopper K which feeds the belt L, as in Figs. 203-4, by which the salt is carried
forward for further treatment. As washing salt in this way is liable to choke up
the air passages in the permeable surface Bx, I provide special means for keeping
it in working order. I preferably arrange at the back of the scraper bottom and
inclined plate I a case M supported on each side of B×; Figs. 213, end and
side view containing a revolving brush m and screw mx, acting in such wise
as to brush any loose salt lying on the table up an inclined scraper m 1 into the
screw trough m 2, so that the screw may forward it down the pipe m 3. In some
cases I employ an endless belt or a stream of flowing brine or water in the
trough m 2 to carry off the scrapings or brushings. With the object of causing the
loose salt to leave the table easily, in spite of the exhaust from below, I preferably
arrange a counter exhaust in chamber M, usually of greater power than the exhaust
from below the table. To do this I arrange to check air entering on the left, and
place a flap m 4 on the side of the chamber, and let its ends rest on slight
ledges m 5 on the two sides of the table. The pipe m 3 is then either connected
with the main exhaust pipe of the table or to other exhausting machinery.
I prefer to place a fan or stean jet between m 3 and the main exhaust pipe,
also a deep chamber into which the light salt transported or carried by the
draft can settle and collect for subsequent removal. frequently employ this
arrangement in various forms and positions, whenever loose salt remains on
he exhausted surfaces of tables, belts, or elsewhere, which requires removal
before the surfaces are washed. The permeable surface thus freed from loose salt

page_text: is next subjected to a thorough washing by water raining on it from the tank N
which is provided with a perforated bottom and supplied with water by pipe Nx
valve n, and regulating float and valve nx. The tank is supported by ring gx on
one side, and a ring g, n, bolted to the pillar el and the machinery frame P.
The exhaust
Under the tank there are scrapers n1 and sometimes brushes.
draws the water through the permeable surface, dissolving fine particles of salt
A short open
which may still remain, and prepares the table for further use.
space O is left so that the permeable surface may be partially or thoroughly dried
before receiving a fresh supply of salt. The length of the tank and this space
should be carefully adjusted, according to the power of the exhaust below the
table. In place of the tank I sometimes use perforated pipes for washing the
permeable surface, or blow steam upon it for the same object. The machinery is
driven by an engine or belt wheel Q, which turns the table as described in the
preceding Figures 207, 203, and drives the belts by an endless chain q and strap qx.
The scrapers are turned by a cross shaft q2, belt q 3, and scraper shaft q 4. The
elevator is turned by bevelled wheel 5, pulley 96, belt 77, and pulley 98.
Although the apparatus is here shewn with an endless belt elevator and endless
scrapers for removing and feeding the salt, I frequently employ other methods for
the same end. I sometimes arrange a table with an inner and an outer ring, one
for washing and the other for drying the salt. In this case I prefer to remove the
salt from the washing ring to the drying ring by endless scrapers, and from the
drying ring to the o-take belt by a screw. The object in using endless scrapers
and screws for removing and transferring the salt about and from the table is to
economise the space on the table that would otherwise be covered if curved shoots
were used for large tables, as in small annular tables used for other purposes. For
caking salt on exhaust tables I employ showers of boiling brine, or numerous jets of
steam, to saturate the salt and draw hot air through it, sometimes breaking
successive layers of salt in this way. I preferably arrange vertical knives to cut
the salt into rings or strips, so that the sides of the cakes may harden by the
currents of air passing by them. After they have somewhat set, I cross cut the
rings or strips with a dipping vertical knife which has quick action, and also
undercut the salt with wires, knives, or saws, so as to produce small compact
blocks or cakes of salt which can be easily removed from the table. For this
purpose I prefer to let them slide on a plate placed across the permeable ring,
which I arrange to move up and down, and have a tipping motion by the action of
suitable cams and levers driven from the main shaft of the apparatus. As a row
of small cakes or blocks slides on the plate, it rises and tips them off on to an
endless belt or other arrangement by which they are removed to a store or else-
where. It then sinks with a short forward movement, receives another row of
cakes, and removes them in the same way and soon. In order to cake salt properly,
it is better to employ small crystals or add fine salt. To prepare the salt for
caking or block making, I generally employ rollers or millstones (preferably with
long shafts), and placed a little apart, or other crushing, stamping, or grinding
machinery to reduce lumps or large grained salt to a proper size. I prefer to grind
damp salt in brine, or with the addition of brine.
When using annular tables of considerable diameter so as to dry blocks on them,
or for other purposes, I sometimes dispense with the central bearing and mount
the ring, as shown in the next Figure.
Fig. 214 is a side sectional view of a large permeable ring table A placed round
a central stove or space B which may be usefully occupied. It is arranged for
exposing salt or other substances for a long time to currents of hot air, gas, or
vaponr, and for enabling them to be placed on and taken off the table at convenient
fixed spots at its side. A is the ring table made in parts strongly bolted together
so as to have an even surface for salt to be spread over, and is arranged with
suitable frames to support the permeable surface. Below each side of the permeable
ring there are projections with bearings for suitably proportioned and ledged
wheel c, c, to run on the circular rails d, d. There are vertical dipping rings or

page_text: I
plates e, e, also on the inner and outer side of the ring, rivetted or bolted to it to
stop air escaping from the sides of the table. These plates dip into two deep
circular water troughs F and Fx fitted with supply pipes, and are of any suitable
depth. Below the permeable ring and confined between F and Fx, there is an air
channel G in connection with one or more conduits Gx connected with blowing or
exhausting machinery, or with furnaces, chimnies, or otherwise. This apparatus
is useful for various purposes, and when fed with loose salt, or cakes of salt, is
generally fitted with the arrangements previously explained, for protecting or
washing the permeable surface, and for placing and removing the salt. The table
has a rack h round it, into which wheels on two vertical shafts i gear; these are
driven by worm wheels j by a cross shaft K in a tube or channel and engine L,
or in any suitable manner to make the ring slowly turn. I frequently use an
annular table of this description for drying blocks of salt which are easily placed in
and removed from it at one or more places, as the table slowly turns. When
passing products of combustion or other gases through the permeable surface, so as
to coat or impregnate the crystals on the table for certain chemical purposes,
generally place a cover over the table to remove the waste gases or vapours, or in
some cases for admitting them when exhausting them through the table by
connecting Gx with a chimney or exhaust fan, or otherwise. In some some cases
I arrange the circular permeable surfaces to be stationary instead of moving, which
affords certain facilities for connecting them with exhaust or blowing apparatus or
chimneys. I then generally provide travelling carriages driven from the centre or
arms from the centre which move over the salt on the permeable surface. They
are usually mounted on wheels at the side of the circle, and arranged with a
bearing at its centre, and provided with hoppers, spreaders, rakes, rollers, or other
machinery for feeding, manipulating, and removing the salt under treatment as
they travel round. In place of mounting the permeable surface upon rings or
circular tables, I sometimes employ reciprocating frames or cases for carrying it.
These I arrange to move to and fro, preferably on wheels, slides, or otherwise, and
I provide them with telescope tubes, jointed elbow pipes, or other arrangements for
connecting them with blowing or exhausting machinery. When using lineal
surfaces of permeable materials for subjecting salt to exhausting or blowing, I
preferably employ it in the form of endless belts or frames, as illustrated later on.
Figs. 215 to 219. In place of using annular, circular, or reciprocating tables for
washing and drying salt, I sometimes employ centrifugal machines, after the style
of N, Fig. 3, of my previous Patent, No. 1336 of 1878. These I preferably arrange
in duplicate or in sets for washing and drying, and construct with special arrange-
ments for cleaning their permeable surfaces by flushing, and add other improvements,
as explained in the next Figures.
Fig. 215, side, 216 plan, 217 detail of cup; 218, detail of top feed, 219 detail
of hot air feed of a centrifugal machine, after the style of N, Fig. 3, of my previous
Patent, No. 1336 of 1878, with certain alterations and improvements. A is the
frame, preferably supporting a pair of centrifugal machines arranged to work
together or alternately, for flushing or other purposes; B is the outer case, the top
of which is bolted on at bx, so that it may be readily lifted off when required to
take out the inner drum; C is a gauze drum with a long sloping ring at its
bottom c;
D is the inner or screw drum, which works the salt down from top to
bottom by its differential movement, as previously explained. The two drums are
driven by bevel friction wheels Cx and Dx by wheels on the cross shaft E by a
belt, engine, or otherwise. F is the brine case in D, with holes at its sides for
washing the salt as it passes downwards. It is supplied with brine by pipe ƒ and
the funnel c 1. This latter is supported on the frame, and dips into a cone on the
top off. Within this drum I place one or more perforated pipes G, preferably two
pairs, placed at equal distances round the drum. They are arranged to commu-
nicate with a copious supply of water or brine, which issues from holes in the
pipes opposite the gauze to flush and clean it. I illustrate two methods of
supplying the pipes with liquid. In Fig. 215, there are three circular funnels or

page_text: cases H, h, and hx. The upper one, H, is fastened to the cross arm b of the outer
case B, which carries the upper bearings of the drums. It is supplied with brine
or water by a pipe, not shewn. The liquid flows through its bottom through spaces
between the cross arms, and passes through similar openings, but preferably
inclined ones, in the arms c of the outer drum C. It is here spread out by a
centrifugal force, and strikes against the case h, and falls through openings between
the arms d of the drum D, and is conducted into the pipes G by the case hx.
The edges of the cases are arranged to overlap to lessen the escape of the liquid when
passing from one to another. The second arrangement is shewn, Fig. 217; the
cross arms b form part of the outer case B, and carry the beaarings for the drums at
61. On this is bolted a large cup or vessel I, into which the brine or water is
conducted by the pipe J. Above this are the curved supports j, carrying the
funnel c 1, supplied by the pipe Jx, for the case F. The lower part of the cup I
has a cone i attached to it, which pours liquid down the vertical pipe g connected
with and supplying the pipes G connected at g 1 and g 2. There is a cone head g 3
at the top of the pipe, into which i dips, and conducts the liquid down the pipe.
Within this pipe there is a smaller tube, conveying brine from funnel c 1 to
case F. It is steadied at fl by projections from the outer pipe g, and passes
through a short pipe in I. On its top there is a disc f 2 and a funnel head f3,
into which the end of the funnel c 1 dips. I employ the disc to prevent brine
entering the cup in case the funnel c 1 is filled too full and overflows. The pipe g
is the central shaft attached to the inner drum D. Round it the arms c of the
outer drum C turn, as in the previous machines. The gauze of the outer drum
terminates at cx, where there is a ring covering the sloping ledge B 1 on the outer
case. The brine or water used for flushing the gauze drum chiefly passes into the
outer casing B, where it is collected by the ledges and drained off by pipe K. The
liquid passing beneath the drum is withdrawn, as shortly explained. With the
above or other arrangements for frequently flushing the gauze drum, I prefer to
avoid a large accumulation of dry salt below the drums, as in the former machine,
where it might become wetted with the flushing. To remove the salt received
from the drum quickly; and to provide for water falling from the bottom of the
drums, I arrange a chamber L below them, in which there rotates an angular
ring M, on which the salt thrown off the bottom of the drum at c collects. This
ring has preferably a rail m, and a rack mx, on its bottom, the former resting on
small wheels, whose axles are supported by bearings on the outer casing
and the inner partial ring Lx. The ring M is caused to turn by a small rack
wheel n, intergearing with the rack mx. This is turned by wheel Ñ by a wheel o
on the shaft of the driving drums O or otherwise. In some cases I employ friction
wheels instead of gearing for moving the ring. The salt collected on the
ring is swept off into a pocket Pat its side by the curved scraper Q, which
is attached to one end of the pocket at p, and scrapes both the bottom and the
side of the ring M. The pocket P communicates with a central elevator S by the
shoot r, and with the drain pipe T by the channel t; rx is a similar shoot for
the second machine. There is a moveable V shaped valve U, which when placed
in the position shewn in the Drawing directs the falling salt down to the bottom
of the elevator, where it is removed by its buckets. When the valve is turned
up it forms a clear way for water or brine to run into the drain pipe T. The valve
is moved by a short shaft u and handle Ux rising through an opening in the stand,
or is sometimes moved by mechanism. There is a gutter 1 round the bottom of
the case L, communicating by channels t 1 and 2 with the drain T below. When
the druin is flushed the valve U is turned up. The liquid falling on the ring M,
which is slightly sloped, or on the bottom of the case L, runs off by the pocket
channel t and the side channels t 1 and t 2. When using this class of apparatus for
washing salt for stoving purposes, as illustrated in Fig. 253, I preferably employ a
pair of machines, as shewn in Fig. 216, driving them by drums o and ox with belts
from the shaft of a common engine, or arrange separate engines for each machine,
so that either or both of them may be started or stopped as desired. The salt is

page_text: alternately passed into one of the machines, and a small quantity of ordinary brine,
but fully saturated, is preferably poured on the top of the drum D to wash out
any dust or dirt that may be in the salt. It is afterwards preferably washed with
purified brine admitted by the small central funnel c 1. The salt passes down the
gauze drum, and is thrown off on to the ring M until it is scraped off down the
pocket P, and finds its way to the elevator S. The brine used for washing it is
preferably cold or cool here as elsewhere, to lessen the amount of incrustation
taking place on the fine meshes of the guaze from the brine draining through it.
When the guaze requires a thorough washing the supply of salt is turned into the
second machine, and the first one is allowed to work out the salt that remains in it.
The valve U is then turned up, and a copious supply of water or brine is poured
into the flushing cup I or funnel H, as the case may be, when the gauze is thoroughly
washed and again prepared for further work. The valve U is then placed in its
former position, and the supply of salt is again turned into the apparatus, when
the second machine may be similarly treated. I preferably arrange for the shoots
directing the salt into the alternate machines at top, and those feeding the elevators
at bottom, together with the valves for regulating the supply of brine and water
to the machines, to be actuated by levers and turning cams placed between the
sides of the two machines and suitably driven. I arrange the cams to be started
and stopped by a time cam, as in former arrangements in my previous Patents, or by
a lever moved by the attendant, so that when either machine requires flushing the
salt is passed into the other, and the process of washing and drying the salt
is continued without intermission. To provide for a more even distribution of
salt over the gauze surface of the outer drum, I sometimes employ an arrangement
shewn in Fig. 218, which is a portion of the apparatus shewn in section from Y
to Z. On the upper side of the arms c which support the guaze drum, I arrange
an upper and lower ring c2 and c 3 connected at intervals by narrow vertical cross
pieces c 4, in such wise as to give a firm support to the gauze drum fastened to it
at c 5, while providing a series of channels or passages between the two rings for
the salt to pass to the inside of the gauze drum C. The lower ring is curved on
its inner side at c 6, so that brine or water may be poured into it to wash the top
of the gauze drum, or for other purposes. The salt is fed on to it by the hopper V,
which is sometimes provided with a guide to charge or level the salt passing in
between the two rings. The outside of the channels terminates a short distance
from the gauze drum, and is preferably arranged so that the salt passing through
the channels jams up against it, and hinders further salt passing through the
channels until it has been removed. In some cases I curve the end of the channel
downwards, so as to feed the salt to the drum in that direction. With the former
arrangement I provide one or more sloping projections or scoops d 1 attached to
the inner drum D, which work round the space between the gauze and the end of
the channel, and transfer the salt to a lower level. I preferably employ four
scoops set at equal distances round the drum or other suitable frame. Below
each scoop I place a row of inclined short plates d 2, which pass the salt down the
guaze from one set to the next progressively at the back of each of these inclined
plates, which serve in place of a screw for passing salt down the drum. I place
the flushing tubes G and arrange suitable openings in them under each plate, so
that when the machine is flushed the scrapers are well washed at the same time.
Bx is the extension of the case covering revolving ring c2 to which the hopper V is
bolted. In order to clean the blades of the screw, as shewn in Fig. 215, I sometimes
employ a sliding scraper, which from time to time is inserted into a vertical groove
arranged on the inside of the gauze drum C, it is moved down to a suitable opening
from which it is taken out by turning the drum slowly round. This groove, while
the apparatus is at work, is filled in or covered with a piece of metal or wood,
which can be withdrawn or turned for a scraper to be inserted. I sometimes also
employ endless scrapers with their wheels carried in bearings on the top and bottom
of the guaze drum C, which continually scrape their surfaces as they are worked
round by the differential movement of the two drums C and D. When using

page_text: machines of the above type for drying or stoving salt, I arrange preferably at their
bottom a case W, see Fig. 210, end view, to which air can be admitted in large
quantities by one or more channels Wx connected with a stove or otherwise. I pre-
ferably place the channel in the space X between the bearings of the driving shaft and
the pipe t, see Fig. 215. At the top of the case W there is a vane w or series of
radial inclined plates through which the air is drawn by a second vane c 2 attached
to the lower arms of the outer drum C with its sloping plates inclined in the
opposite direction. In place of the vanes I sometimes employ a horizontal fan
fastened to the bottom of the drum. As the drum revolves air is passed by these
vanes or fan into the inner drum D, which for the purpose of drying or stoving
salt I arrange with numerous side slits, holes, or air passages through which the air
can freely pass over the salt spread on the surface of the gauze drum. The air
passing through the salt is collected in the outer casing B, and is conducted away
by suitable air passages. I preferably provide this apparatus also with flushing
tubes G and rotating ring M. as in previous machines. I sometimes arrange to
stove the salt in the same machine as that in which it is washed, but in order to
lessen the incrustation on the gauze drum, and also to allow more time for passing hot
air through the salt on its surface, I prefer to use one machine to wash the salt,
preferably, with cool or cold brine, occasionally blowing cold air through the bottom
of the drum, and pass the salt on to one or more stoving machines by elevators or
otherwise. In these latter machines I arrange for the admission of hot air over
the entire surface of the gauze drum, and provide for the passage of large volumes
of hot air through the salt under treatment. I frequently place vanes or a fan like w
and c2 at the top as well as at the bottom of the drums (or in place of the bottom
vane), and connect them with a hot air stove or otherwise. Occasionally I place a
horizontal division in the inner drum, and admit cool air at the top and hot air
below. The bearings of the drums are made long to lessen friction, and are preferably
cooled by jackets through which cold water is constantly running.
When using belts or connected frames of permeable material for washing salt I
prefer to arrange for the return belts to pass through a water trough to dissolve
and wash off impurities or incrustations and keep the air holes open. With a belt
or series of jointed frames of sufficient length by means of suitable hoppers,
perforated pipes, et cetera, I sometimes first wash the salt, and then dry or cake
it on the same belt with air exhausted, or blown preferably from the case below.
In some instances I. exhaust first and blow afterwards, or vice versa. The salt is
preferably covered in to protect it from dust, to retain the heat, and for other
purposes. When using material for belts, both here and elsewhere, which is likely
to stretch I employ lever weights or other arrangements to keep them tight. In
place of both washing and drying on the same belt I prefer to separate the operation
and use two belts, one for washing and the other for drying, or in place of the first
belt use a revolving gauze or permeable drum, dipping in a water vessel or
otherwise washed, and arranged with hollow axles or of ring form on wheels, into
which or through the side of which I exhaust or blow air, etcetera, arranging for it
to dip in water or be washed from inside.
Fig. 220 is a side view of an arrangement of endless belts or jointed frames of
permeable material for washing and drying salt. a is the washing belt, passing
round drums A and B and rollers C, and turned by a small wheel D suitably
driven. It is mounted over a case E arranged with a sloping bottom and exhaust
pipe F. At the top of the case there are numerous rollers e on which the belt rests,
or in place of or addition to there are wheels or slides at the sides and elsewhere
on the case to support the jointed frames or bars when they are used to form or
support the permeable belt. When using jointed frames instead of belts I arrange
the drums A, B, and C to suit them. The roller C causes the belt to pass through
water in a tank G where it gets washed to keep the fine air-holes in the belt in
better working order. The water is preferably kept at one level, and constantly
running through the tank to keep it fresh. In place of this arrangement I some-
times place perforated pipes or troughs across or under the belt, and blow or

page_text: shower steam or water on the belt for the same object. There is preferably an
inverted exhaust trough H after the style of Fig. 213 fitted with a brush h and
screw hx to collect and remove salt from the belt before it is washed. I generally
place rollers on each side of inverted exhaust troughs to facilitate belts passing
over them. I is the hopper, into which the salt for washing is filled by belts,
elevators, or otherwise. It allows the salt to be removed from its bottom by the
travelling belt a and suitable spreading arrangements. The salt passes under
numerous perforated pipes J placed over the belt, which shower fully saturated and
sometimes purified brine (preferably cool or cold) over the salt as it passes under
them. The belt moves slowly, and the pipes are placed some distance apart so as
to give the salt time to drain well with the assistance of the exhaust from below.
After being thoroughly washed the salt travels for some distance, having cool or
cold air drawn through it to remove surplus moisture, and is passed over the
drum B into a pocket or hopper K, being assisted in its course by a scraper K,
preferably in bearings at the sides, and pressing forward against the belt. I make
this belt of various lengths, and use more or less perforated pipes, according to the
number of washings as is desired to give the class of salt under treatment. At the
back of the hopper K there is a screw trough Kx, and at the bottom of both there
are rollers placed a little apart, and slowly turning which feed salt into the stoving
belt M after the style of Fig. 210. Kx is supplied with dry salt which it spreads
on the belt M, on the top of which the wet salt coming from the belt a rests.
The object of this arrangement is to protect the permeable surface of the belt M
from the injurious action of the damp salt. The belt M is of any suitable lengths,
but preferably long enough to thoroughly dry and stove the salt. It is stretched
between the drums N and O, which latter is turned by a small wheel P. It passes
over and under an air case Q fed with hot air by one or more channels Qx. At
its top are rollers 9 or slides, as previously explained for case E. Above the belt
there is a cover R to collect steam and hot air rising from the salt, and pass
one or more chimnies S, where it may be conducted for other purposes. In some
instances I exhaust instead of blow hot air through the belt, admitting it into the
cover and connecting the channels Q with exhausting machinery or otherwise, and
occasionally blow hot air under one part of the belt, and exhaust the hot air through
damper salt on the other. The salt as it travels along the belt is stirred up by
knives, scrapers, or wires to keep it loose, or with suitable arrangements may be
formed into cakes. The salt on the belt at last passes from under the cover and
falls over the drum O down a second scraper and shoot T on to a travelling belt U
or into a waggon or otherwise, being washed and stoved and ready for sieving,
grinding, or other purposes. The apparatus is strongly supported by suitable
frames and preferably driven by a small engine, turning both belts in time with
one or other by suitable straps or shafts. In some cases I wash the second belt
as well as the first, when I often omit the supply of dry salt at Kx. Although the
washing and sloping belts are here worked together I sometimes work them inde-
up
pendently and in combination with other apparatus. To lessen the escape of air
at the sides of the belt I generally arrange long slides at the sides of the cases on
which it rests. In place of using the first belt I sometimes use a revolving gauze
or permeable drum fitted with hopper and showering pipes, and arranged with
hollow axles or made in ring form, supported by wheels, after the style of previous
apparatus described in my former Patent. From the interior of these drums I
arrange to exhaust the air, brine, and water, preferably through the hollow axles
(or by using close fitting cases when rings are used) suitably connected with
exhausting machinery.
With the view of improving the circulation of heated air in belt stoves of the
type shewn, Fig. 3, in my Patent, No. 1336, of 1878, I arrange cross divisions in
them to cause heated air passed through them to zig-zag to and fro over the salt
on the belts. I also add other improvements for stretching the belts, etcetera.
Figs. 221, 222, 223, and 224 illustrate a side portion of one of these belt stoves

page_text: with explanatory details. The salt to be dried is introduced at the top of the stove
and is passed backwards and forwards on belts or permeable surfaces, and falls from
one belt to the next until it is removed by a screw at the bottom. A is the stove
case and framing of any suitable size, and preferably made in two compartments so
that narrow belts may be used. It is strongly stayed and firmly mounted. bare
the endless belts stretched on rollers c and d. E, E, are partial divisions placed
across the stove and fastened to the alternate ends to cause heated air to repeatedly
zig zag backwards and forwards over the salt on the belts before escaping by a
broad based chimney E at the top. I arrange these divisions preferably so as to
cause the current of hot air admitted by suitable opening at the bottom of the case
to pass to and fro from end to end of the case, as shewn by the arrows in Fig. 221.
In some cases I arrange so that the heated air has a side way passage (see end view,
Fig. 223) and zig-zigs to and fro across the belt in each half of the case. At the
alternate sides the divisions arranged for this purpose are turned up so as to form a
channel ex for the air to pass to the upper side of the next belt. The rollers on
which the belts are mounted are also set a little to the right and left to make room
for the air channels at their sides, and suitable shoots are provided at their ends to
pass the salt properly forward from one belt to the next. I prefer to place these belt
stoves over hot chambers with flues in them (as shown, Fig. 253) and arrange
for the chamber to be copiously supplied with heated air. When so doing I
preferably construct the upper belts of canvas prepared with tan or cutch and
boiled afterwards in glue, as previously described. The lower ones I preferably
make of gauze or of permeable plates (see Fig. 224, end view) coated with black
oxide and jointed together so that the hot air can rise freely through them, an
arrangement which I sometimes employ for all the belts in the stove. At the sides
of the case I place inclined plates or boards g to keep the hot air better under the
upper belt of each pair on which the salt is spread out, and through which it rises.
I sometimes extend the divisions much further under the belts so as to oblige such
air as may escape round the sides of the belts to travel more under and over the
salt on them in its passage. The canvas belts and sometimes the lower ones are
preferably kept tight with suitable levers and weights H outside the stove, which
are keyed to cross shafts h mounted on the framing, from which are short levers hx
carrying the bearings for the rollers d. Safety chains or stops are attached to the
weights to prevent them from swinging round too far in case the belts come undone
and for other purposes. The belts are driven preferably by an endless chain c×
passing round their wheels G on the ends of rollers c, as in the previous apparatus.
They are similarly fed with salt by an elevator I, screw, and distributing roller,
whose wheels are marked i, j, and k respectively. To keep the salt on the belts
better exposed to the currents of warm air in the stove I preferably place knives,
rakes, or scrapers over the belts on which it is spread. These I generally mount on
small cross shafts passing through one side of the stove, and turn very slowly by
vertical shafts and bevel wheels or otherwise. Over each of the cross shafts there
is a plate with nicks or spaces in it, through which the knives or projections pass,
and which is employed for the purpose of removing any damp salt from them which
might otherwise clog their sides and render them less efficient. The knives used
are preferably circular, and set so that the salt formed in ridges by one set is split
and again stirred up by the next. I sometimes also employ slowly moving endless
wires across the belts under the salt from side to side of the stove for the same
purpose. These I generally mount on wheels at the two sides and cause to pass
through suitable holes in plates so as to keep them clean and in working order. I
apply this same system of keeping knives, rakes, scrapers, and wires clean when
using them for stirring up or shaping salt in other forms of apparatus. When using
belt stoves or other drying arrangements where large quantities of heated air are
employed, I sometimes connect the air shaft F or other channels with a chimney,
but preferably arrange to pass the escaping air over heated brine in adjoining pans
to assist in evaporation, or over air bed where air is being exhausted from under

page_text: damp salt placed upon them. This not only economises heat, but prevents fine
particles of salt carried by the current being wasted by passing up a chimney
or into the outer air.
When drying very damp salt in stoves of this class I sometimes arrange to feed
dry salt on one or more of the upper belts before placing the damp salt in them,
after the style of the system shown Fig. 210. The stove is then preferably made
longer so as to give the salt on the belts more time to dry before being passed to the
next belt.
The foregoing travelling belts, annular tables, centrifugal machines, and other
forms of moving permeable surfaces arranged for passing air through salt are more
especially designed for the treatment of thin layers of salt or similar substances.
When applying the same blowing or exhausting system to heavy layers or masses
of salt, or to salt in the form of blocks, "handed squares," etcetera, I provide special
permeable surfaces strongly supported by suitable framing, and especially con-
structed for withstanding their additional weight. These surfaces with their frames
I term "air beds," and arrange over cases or one or more chainbers connected with
powerful exhaust or blowing machinery, chimnies, or otherwise. I generally form
the permeable surface of these air beds with layers of gauze, protected from rust by
black oxide placed over perforated metal plates resting on or fastened to the
framing of the air beds. In some cases I dispense with the gauze and use
perforated plates of metal or pottery or sometimes use a perforated wooden covering
or employ wooden boards laid with narrow spaces between them to allow the
heated air to pass upwards or downwards through salt or blocks placed upon the
air beds. I generally construct the framing of the air beds of numerous narrow
beams or girders supporting intermediate cross frames to give the permeable
surface the necessary support and present an even surface. I preferably mount
these air beds on masonry and concrete at their sides, and arrange chambers or
passages under them for various purposes. I usually arrange the surface of the
air beds level with the ground or floor of the chambers in which they are situated.
I provide such chambers with suitable connections with stoves or heating
apparatus or the covers of surface pans, so as to provide a copious supply of heated
air to be drawn through the salt on the air beds by the exhaustion below. In some
cases I cause air to rise up through the air beds with salt placed upon them by
connecting the cases or chambers beneath them with a similar supply of hot air.
I frequently arrange a separate exhaust or blowing apparatus or fan preferably
driven by its own engine for each air bed, or connect several of them by long pipes
or channels of considerable diameter to more powerful exhausting machinery or a
high chimney, so that all or any may be worked by opening or closing suitable
valves or dampers. Fig. 225 to 240 illustrate the way in which I prefer to mount
and work these air beds.
Fig. 225, plan, 226, 227, two sectional end views of an arrangement for facilitating
the process of drying and stoving heavy cakes or blocks of salt; also special
arrangements for producing and handling the blocks before and after treatment.
A and Ax are "air beds" or permeable surfaces supported by cross framing and
frames at the side bedded on masonry. They are covered with perforated plates,
pottery, wood, or gauze, canvas, or other suitable permeable material, through
which air can be exhausted or blown, and on which heavy cakes or blocks of salt
or other material can be placed, and subjected to currents of air, preferably heated,
and passed amongst them. I arrange these "air beds" in various forms and ways
to suit different methods of treating salt. The ones illustrated, see Figs. 225
and 226, plan and cross section, are placed over a chamber B, into which salt
falling through its surface collects for subsequent removal. They are supported
at their sides on walls b, and elsewhere if required. bx is a door by which the
chamber is entered for the removal of salt as other purposes; c is an exhaust pipe,
preferably arranged with holes along its sides, and is connected with an exhaust
pan C fitted with its own engine cx or other arrangement for exhausting the air
from B; C blows the exhaust air into the chimney D, or preferably over hot brine

page_text: in pans when situated near the apparatus to trap any small crystals carried by the
current, and assist evaporation. The surface of the air bed for simply drying
blocks is preferably arranged with numerous cross lines of small air holes or gauze,
so as to draw air down the sides and corners of the blocks placed in the spaces
between them. In some cases I also arrange air holes in the spaces as well, with
the same or separate exhaust connections, to draw air through the blocks or round
under their bottoms. To prevent damp blocks sticking to air beds I sometimes
place thin loose pieces of wood, cardboard, or other material under the blocks; or
preferably employ a thin covering of coarse dry salt spread over the air bed before
placing them on it. In the latter case the whole surface of the air bed is covered
with small air holes, the air finding its way down the sides and under the bottoms
of the blocks between the crystals of coarse loose salt in which they stand. This
form of air bed may be used for drying blocks for a number of pans or stoves of
the ordinary type, or otherwise supplied, the blocks being placed or stacked on its
surface. It is however preferably supplied with blocks to dry in the following
manner:- -E is a hopper fed with salt by a belt, elevator, or otherwise. Under it
moves a long carriage F, on which moulds, preferably of the ordinary wooden type,
are placed for filling. It is arranged to move very slowly with the least vibration
possible. The moulds are placed in rows upon the carriage, preferably arranged
with spaces on its surface, separated from one another by shallow channels or ridges
on its surface, so as to keep them well in line, both crossways and lengthways.
The carriage is caused to move slowly under the hopper, and salt is run into the
moulds by means of suitable spouts and valves. They are afterwards subjected to
one or more thorough saturations with scalding brine or water by pipes e placed on
each side of the hopper, and used alternately. The salt is preferably pressed down
in the moulds during the process of saturation by flat bottomed tools moved by
hand or machinery. When all the rows of moulds have been filled, and the
carriage has moved to either end of its short traverse, it is arranged to stop itself,
and the salt in the moulds is left to set. In some cases I arrange to again saturate
the salt in the moulds by showering scalding brine on them when the carriage
reaches the end of its traverse. When the blocks are ready to be turned out of
the moulds the operator takes them off the carriage, and preferably turns them out
on to the draining space G at the side of the carriage, where they are left for a
short time to further harden, the moulds being returned to the carriage. The blocks
are afterwards removed to the air bed through the sliding doors g in partition g 1
to be subjected to currents of warm air for further drying. There is a passage
between the air beds at a, and at their sides at a 1, to facilitate placing and moving
the blocks. When the moulds have been all emptied and returned to the carriage
it is reversed, and started moving in the opposite direction. I preferably wash the
rows of moulds as they come up to be filled by letting them pass under perforated
water pipes. They are again filled with salt by the hopper E, and thoroughly
saturated with scalding brine, as before, and similarly treated. The blocks from
this traverse are turned out at the other end of the space G, and afterwards
transferred to the air bed. I sometimes turn the moulds out on the air bed instead
of on G, but when this is done there should be a thick layer of dry coarse salt on
the air bed to absorb the brine draining from the blocks, and protect the fine
openings of the permeable surface below. The carriage F is arranged with gutters
to transfer the drainings from the moulds or washings from the carriage into a
trough which conveys them for re-use or elsewhere. There is also a draining
board gx under G. To insure the moulds receiving a definite charge of salt
each time they are filled I preferably arrange that the salt coming from hopper E
shall be measured out ready for them as they come up to be charged. For
this purpose I arrange a row of small hoppers at the bottom of E after
the style of the pair shewn, Fig. 43ª, 45, and 46, in my Patent 1336, of
1878, and similarly fitted with upper and lower valves with a space between
them, and means for regulating the charge of salt. The valves are preferably
actuated by levers with rollers at their ends, arranged to trace lineal çamıs

page_text: fastened to the carriage F, which as it moves causes the correct charge of salt
to fall into each row of moulds, and also regulates valves governing the water for
washing the moulds, and the flow of scalding brine for saturating the salt in the
moulds. The blocks are left on the air bed as long as desired, and then removed
in rows to a second long travelling carriage H to make room for the admission of
fresh blocks to the air bed. The carriage H conveys its blocks into the store
room Ix, which I also employ with other forms of air beds, see Fig. 227, cross
section, preferably arranged under the floor of a long room J for bagging salt, as
described in my previous Patent, No. 1336, of 1878, supported by pillars j, and
provided with a sunken carriage way jx. The floor of Ix is arranged to allow currents
of warm air to pass through it from below and rise through blocks placed or stacked
on its surface. It is suitably supported after the usual manner with beams or girders
resting on walls at the sides and centre. Below the floor are the hot flues K
supplied with heated air by the cross flue K 1. There are regulating dampers to
admit the heat evenly amongst the flues or otherwise. They discharge their spent
heat by the cross flue K2 which communicates with the chimney by flue K. 3
under the draining board G in the blocking room. Over the flues is preferably
a thin casing of sheet iron, wood, or other material L, following the shape of the
flue tops, and kept from them by narrow strips of metal or otherwise, so that there
is a narrow passage for air between the tops of the flues and holes or openings
at their crowns. Air is admitted between the flues by perforated channels or
pipes to provide for its more even distribution, or by numerous openings m com-
municating with the cross channels Mx and main are passage M, which is connected
with the outer air or with other stoves or air heating arrangements when
practicable. The air channels are preferably governed by valves or dampers
regulated from above. The air entering M passes along the numerous passages Mx
rises between the sides of the flues, and passes close to the hot top of the flues
under L, when it escapes at their tops under the boards or plates lx, which
spread out the current under the floor I, and protect the openings from salt
falling through from above. With the object of providing for the better diffusion
of heated air over the whole drying surface of I, I preferably arrange that the
total area of the opening for the air to escape through I is less than the total
area of the openings over the flue tops under lx, and theirs are again less than
the area of the supply channels and passages Mx and M. In another arrangement
I place long perforated air tubes between the flues, arranged to blow air between
them and over their tops as evenly as possible, and so diffuse the warm air under
the whole bottom of I. The blocks from carriage H or elsewhere are placed or
stacked on the permeable floor I, where a constant current of heated air rises
amongst them. The air is preferably withdrawn from the top of the chamber I×
by a series of air channels n, each of different length, or so arranged as to with-
draw air from the stove in progressive lengths, forming a long line of holes or
openings extending the length of the stove. These channels convey the heated
air over the air bed, and diffuse it by similar channels and holes to supply the
exhaust caused by the fan C, or otherwise. In this way the blocks in the stove
are constantly subjected to warm or heated currents of fresh air rising from
below, while the newly made blocks on the air bed utilize the remaining heat as
the air is drawn down amongst them on its way to the fan and chimney D. To
lessen the disturbance of the ordinary course of the air currents when moving
from room to room, or transferring the salt, I arrange various short passages,
with two sets of doors. There are provided at g1 and 92, an entrance from the
stove to the blocking room at 1 and 2 leading to the delivery stage where the
salt is delivered from stage i3, on which are rails 4 and a carriage i 5.
At jl
and 2 the staircase to the upper room and to the lift o, top and bottom at o 1
and o 2 for transferring the blocks to the upper floor when required.
There are
single doors placed low down at j3 to let the carriage H pass through, which it
is arranged to open and shut as it passes in the ordinary manner.
The carriages
are moved by wire ropes p and px passing round horizontal or vertical wheels P

page_text: and Px. When placed as shewn there are rollers and clips on the carriage H
through which the two ropes pass. When the carriage is required to travel a
small handle h or weighted lever over and between both the ropes tightens the
clip over the rope, moving the way required, and so moves the carriage. Both
carriages are arranged to stop themselves at both ends of their traverse. The rope
wheels are driven with suitable gearing and intermediate shafts by the cross
shaft g, which is driven by the drum Q, or otherwise. The building is well
lighted, and I prefer to use double windows to retain the heat in this and other
stoves. It is preferably annexed to other works, and utilizes the waste gases from
their boilers or pan furnaces, or is sometimes arranged with separate furnaces.
When using these I heat air for the passages to increase the efficiency of the stove,
and often supply dry hot air direct over the air bed as well. When it is desired
to stove large quantities of blocks, one or more buildings or sheds are placed at
the end or sides of the one drawn, and are entered by passages and double sets of
doors for the wagons to pass through. When there is no upper floor to cover the
room over I sometimes allow the air from the stove to escape and supply the
air-bed with hot air from a separate source. In some cases I arrange a permeable
floor like I over the thin metal covering of surface pans, and pass air under the
floor, preferably by perforated air pipes placed along the metal cover, so as to be
treated by the hot plates, and afterwards arrange for it to rise through stacks of
blocks placed on the floor above.
The next form of apparatus illustrates an air bed arranged for producing as well
as drying blocks. It is placed in a chamber copiously supplied with hot air as
previously explained, and the apparatus is connected by pipes or otherwise with
an ample supply of water boiling brine, steam, etcetera, preferably both over and
below the air bed.
Figs. 228, 229, and 230 are the side, end, and plan views, shewing upper hoppers,
and mould case,
and lower floor of an apparatus for moulding blocks or cakes of
salt or other material, also for drying damp crystals when not otherwise required.
A is the air bed or permeable surface on which the salt is placed. It is provided
with sides a and gutters ax; B is the case under the air bed communicating with
the main exhaust or blowing pipe D by pipe C; E is the upper frame supported
by pillars e; F, the hopper case; G, the moveable mould case; H, the mould
filler; I and J, endless belts; K, chamber under B; L, valve handles; M and N,
brine and water pipes; Mx and Nx, brine and water drain pipes; O, brine cistern;
P, upper floor; Q, waggon; R, waggon way; S, driving drum. The case B is
made in one or more parts firmly bolted together and made air tight. Its upper
framing supports the permeable surface of the air bed by numerous frames, girders,
or divisions b, and other cross frames between these to render the top level and
the whole strong and steady. The under side of the case slopes to the centre, and
is arranged with a central gutter bx so as to drain liquid passing through the
permeable surface quickly into the central pipe C. The case is bolted to a frame
or forms part of one, to which the pillars e are bolted. The whole is firmly
supported by walls Bx, girders b1, and pillars 62, or otherwise. The surface of
the table should be laid as level as possible. The pipes C and D are of wide
diameter to facilitate the passage of large volumes of air, gas, steam, etcetera; D is
preferably placed on rollers d, with an expansion joint at Dx, which I preferably
use with all long pipes of this description, and arrangements are provided by
syphons or otherwise to keep the pipe thoroughly and quickly drained. The
pipe C has a valve c to disconnect B with D; the valve is preferably moved by
hydraulics, but it is here shewn moved by a handle and shaft and wheels 1, 2, 3.
Above it there is a chamber or well feeding pipes Mx or Nx, which have valves
mx and nx moved by handles 14 and 15. Mx drains brine into cistern O, which
is arranged to avoid delay in emptying case B when charged with brine at a
certain stage of the process. The brine is pumped out of the cistern by a small
regular acting or self governed pump, and returned to a pan or brine heater or
used for other purposes. These and the strap drum S are preferably placed outside

page_text: the room in which the apparatus is placed to protect the dry air in the room from
steam from the engine and the belt from injury. Pipe Nx communicates with the
drain or otherwise. The case is provided with a pressure of brine, preferably
boiling, by pipe M, regulated by handle 16, and of water by pipe N regulated by
handle 17. These two pipes also communicate with the gutter ax regulated by
handles 18 and 19, so that brine or water may be passed upwards or downwards
through the permeable surface of the air bed. I sometimes also provide a steam
supply to case B as well as brine and water, but prefer to arrange a perforated
pipe ex round the edge of a to blow steam or spray water or brine over the air bed
for washing and other purposes. The mould case G is strongly put together and
is composed of numerous taper moulds g, preferably made of or lined with wood.
I frequently arrange to make different sized blocks with the same apparatus, and
arrange rows of moulds of various capacity or shape to suit the requirements of
different markets. The case has preferably a raised ledge gx round its sides for
facilitating washing the salt, and is kept true by a metal frame g 1 placed round
its sides, with corner wheels or guides g 2 moving in grooves or guides on the
pillars e. The case is balanced by weights g3 attached to chains which pass over
wheels g 4, and are attached to projections from the case. The case may be moved
up and down by hand or otherwise. It is here moved by turning the wheels g 4,
on whose shaft there is a worm wheel g 5 turned by a worm g6 on shaft t turned
by wheel 1. This wheel is geared with two loose wheels on shaft s, on which
there is also a clutch or friction box sliding on the shaft and causing one or other
of the wheels to turn according to the position of handle g, s. When the handle
is vertical both wheels are out of gear. The clutch bar is also moved by pro-
jections on the case and chains, which are arranged to stop the case when it gets
to the top or bottom of its course to avoid over winding. The hopper case F
preferably contains as many little hoppers as there are moulds below in the mould
case G. These are made to correspond as nearly as possible in position and
capacity with those below, so as to measure out the correct charge of salt for each
mould. I sometimes however arrange only a shallow bottomed open case with few
or no divisions in it, but with numerous holes on the bottom through which the
salt can run and fill the moulds. The bottom of each little hopper or hole is opened
or closed by thin plates or bars of metal fx, in which there are corresponding holes.
These plates or bars are attached to one or more sliding frames, moved to and fro
by eccentrics f1 on shaft f2, driven by wheel f3 and 4 and a worm 8x on shaft 8.
Handle f, 8, stops or starts the eccentrics moving by a clutch on the shaft of ƒ 4.
I sometimes employ hydraulics, steam, or compressed air to open and shut the
valves in place of eccentrics. The hoppers are preferably filled with salt by the
travelling screw carriage H and belt I, which style of carriage I also use for other
purposes, and sometimes arrange with an endless belt or scrapers in place of the
screw. H is preferably arranged for filling the little hoppers of several
apparatus set in a line one after the other. It moves over the hoppers, and is
mounted on wheels h running on rails 1. There is preferably a rack at the side
of the rails into which wheels on the carriage intergear to insure the carriage
keeping square with the hoppers. The carriage carries a long trough H×, with
sloping sides open at the bottom over the moulds, or is sometimes made with a
series of openings in its bottom for each mould in the width of the case. In this
trough there is a revolving screw hx, which, were the bottom complete, would
carry salt from one end of the trough to the other. The screw is turned by a
wire rope wheel h 2, or a turning shaft, or otherwise. At the receiving end of
the trough there are two belt rollers, an upper one i and a lower one ix, carried by
the carriage H in suitable bearings. The belt moves in the direction of the arrow
and passes over i and under ix in such wise that when charged with salt by an
elevator or otherwise, it shoots the salt into a space or hopper hi which feeds
the screw hx, and then dips round ix and continues its way for recharging to
bring up fresh salt for the apparatus. At the other end of the trough I arrange a
wheel 3 with two loose wheels and clutch box on a shaft h4 for driving the

page_text: carriage to and fro by wheels h 5, shaft h6, and small wheels h7 gearing with
rack wheels or wheels turning the same. The movement of the carriage is regulated
by handle hs. To charge the hoppers the apparatus is moved and stopped so that
the open bottom or row of holes in the trough H× is over the first row of hoppers.
The belt I is started and the screw kept turning. As the salt is carried up the
trough it falls into the first hopper and continues to do so until rising to a level,
which forms a bottom to the trough, when the stream of salt flows into the next
hopper, and so on until the row is completely filled. The surplus salt is then
screwed along a shelf hf into a portion of the trough with a bottom and passes on
to a belt J by which it is returned to the main store. The operator on observing
a row of moulds filled, moves the carriage to the next row and fills it and others
in the same way until the whole case is charged. When a series of cases have
to be filled in succession the space Fx between two cases is raised to the level
When the case F
of fx and forms a bottom to the trough during its traverse.
is charged with salt if all is ready below, handle gs is moved and the mould
case G lowered on to the permeable surface A, as shewn, Fig. 229 (where
the moulds are represented filled with salt), handle fs is moved. The valves at
the bottom of the hoppers are opened and salt showers down into the moulds
below until they are filled or nearly so. The valves are then closed; handle lb
is now turned to cause scalding brine to rise through the salt in the mould until
it reaches its surface, or it may be admitted into the trough ax with handle 18
and poured over the top of the moulds. The salt is preferably pressed down
in the moulds by a double handled rod held on each side of the machine and
moved from one row to the next progressively. It is arranged with numerous
projecting stops on it corresponding with the spaces in the row of moulds, and is
useful for equalizing the height of the blocks and for shaping or marking their tops.
A handle 4 is turned, and the brine drained through the salt and passed into the
cistern. When the salt has been once saturated, I prefer to wash it again once or
more by passing scalding brine through from above. The salt in the mould is
allowed a short time to drain and set, when the exhaust is put partly on, and
preferably steam blown over the moulds by pipe ex, or otherwise, and drawn
through the salt. After this, hot air is copiously admitted above the air bed, and
drawn through the salt for some time. I raise the mould case a little when the salt
is sufficiently set, so as to cause sharp currents of air down the sides of the moulds
and blocks to help to harden them. It is afterwards wound up, leaving the blocks
on the air bed, as seen in Figure 228. I continue to exhaust the hot air through
and amongst the blocks preferably until they are well dried and ready for
removal, to facilitate which I place or riddle coarse salt on the surface A before the
fine salt is filled into the moulds, or employ pads or pieces of perforated felt, thick
canvas, paper, cardboard, wood, metal, or other material, at the bottom of the
moulds, or over A before the moulds are filled with fine salt. I sometimes saw the
blocks off A or loosen them by filling the case B underneath with water, and
letting a little of it rise through A (which should be quite level for this purpose)
so as to moisten the pads or bottom of the blocks and facilitate their removal.
The blocks are loaded into waggon Q, which I sometimes arrange to move close to
the machine, or move with a wire rope. The blocks are then removed to have
their ends dried or sawn off, and the air bed A is washed down (a drain from α x,
being provided for the purpose) and prepared for the next charge when the process
is repeated. I sometimes employ this description of air bed for drying damp salt
in bulk or in the moulds. For so doing I put a layer of dry salt over A, and
preferably blow hot air from the case upwards. In place of using the numerous
self charging hoppers f, bere described, I sometimes use one or more large
hoppers over the apparatus and fill them from waggons, or otherwise, or less
advantageously fill the moulds from one or both sides or ends of the apparatus.
I prefer to employ several of these machines in a line when they are tied together
by intermediate girders e, e, which also serve to support the rails for carriage H, so
as to fill up the time of the operatives and utilize the full time and power of the

page_text: exhausting or blowing machinery. I sometimes supply separate exhaust or blowing
machines for each apparatus, and dispense with the main pipe. In this case
the hot air, passing through nearly dry blocks in one apparatus, is frequently
passed through damper ones in another, to economise the cost of heating the air.
I sometimes utilize the hot air coming through the salt for heating air in tubes or
chambers arranged for the purpose, which air I employ for further salt drying or
for assisting evaporation or other purposes.
The next form of apparatus, Fig. 231 to 240, illustrates a method for caking a
large mass of salt on an air bed specially arranged for the purpose, and after it
has been so prepared cutting it up into cakes or blocks by circular and other
saws.
The object of this arrangement is to cause heated air to pass more equally
through the entire mass of salt under treatment than can be arranged when the
salt is formed into separate blocks on an air bed when there are large air passages
necessarily left between them. In this apparatus, as in the preceding ones where
salt is caked, the salt is specially prepared by grinding or otherwise, or a quality
of salt selected suitable for the purpose. Fine salt is preferably placed on the top
of the salt under treatment, and the brine used for caking purposes is as nearly at
boiling heat as possible.
Figs. 231 and 232, end and side view; 233 to 240, details of an apparatus for
caking salt in bulk on a specially arranged air bed with travelling carriages for
cutting it up into blocks, et cetera. A, endless belt bringing up salt; B, hopper
carriage; C, hoppers; D, upper floor; E, girders; Ex, pillars supporting hoppers,
floor, and carriage; F, hopper rails; G, salt case over air bed; H, case under ditto;
I, walls on which case is bedded; J, pipe to K, the main pipe to exhaust or
blowing machinery; M, drain, brine, or water supply pipe; N, pipe chamber;
O, side gutter and space for saw drums; P, rails to support the machinery to
manipulate the salt on air beds, et cetera ; Q, wire rope to drive machinery; R, lower
or ground floor; S, brine and water trough; T, carriage to level, roll, and saturate
salt, see Figs. 233, 234, 235, side, plan, and end view; U, carriage to cut salt
lengthwise; V, carriage to cut salt cross ways, see Figs. 236, 237, 238, and 238a,
side, plan, and two sectional end views; W, carriage to undercut salt, see
Figs. 239, 240, side and plan view; X, railway; X 1, waggons for removing
blocks or salt from the air bed. The endless belt A is fed with salt from an
elevator or otherwise. It traverses the length of the hoppers supplying the air
bed, and when not raised by the rollers on the carriage runs on rollers a and ax,
placed at intervals along the hoppers to support its weight. The belt passes over
roller b and under roller bx, both carried in bearings on carriage B, and projects
its salt down a double shoot b 1, also carried on the carriage. In another arrange-
ment I employ scrapers to direct the salt from the belt into the side hoppers, after
the fashion of r 3, Fig. 172 in my Patent, No. 5350 of 1880. The hopper on the
carriage B is supported by wheels 62 and rails F, and is made to move by cog-
wheels working in racks by the side of F, or otherwise. The cogwheels are driven
by wheels 63 on shaft 64, turned by rope wheel 65. The endless wire ropes 6 6,
when not raised by the carriage, rests in grooved wheels 67. In some cases I
employ a revolving shaft in place of this arrangement for moving the carriage.
The carriage traverses the length of the hoppers and is sometimes arranged with
high sides as well as centre to carry two or more belts for filling the hoppers
more quickly. The hoppers C are provided with sliding grid valves c in short
lengths along their bottoms, which are opened and shut by levers on numerous
shafts cl moved by handles c2, or otherwise. The hoppers are arranged
of sufficient capacity to charge the air bed with its proper depth of salt
each time they are emptied, with the object of saving time in charging the
latter. I sometimes fill them by tip waggons running on rails placed on
the upper floor at Dx on each side of the hoppers, or by a central line placed
between the hoppers. In some cases I place the hoppers across the apparatus
and feed them by hand or machinery. The weight of the hoppers filled

page_text: with salt is supported by girders E, pillars Ex, and wall E1, or by two
sets of pillars or walls, or in any suitable manner. Under the hoppers is a
perforated pipe F for steam, water, air, or brine. The salt is discharged
on to the air bed G, which' is of permeable material laid as level as possible,
and strongly supported from below by divisions and subdivisions forming
part of the air case H. The surface is preferably protected from the risk
of injury from the saws by having thin bars placed at intervals of its width
along the length of the bed. These bars are made flat on the lower side, and
slightly rounded on the upper, and help to hold down the permeable surface by
being rivetted or screwed down to the framing below. The case Gx is preferably
placed on the level of the ground, except for small apparatus, when I generally
raise them a few feet above the ground to facilitate their management. The air
bed G is made in parts firmly bolted to framing at the sides, or arranged so that
its long bottom is as level and true from end to end and side to side as possible.
There are sides g to the case Gy which fold down or withdraw. When up, as shewn
in Figs. 231 and 233, they form a sort of long tank. They are supported by rods
at their backs or otherwise. When down, as in Fig. 236 and 239, they leave room
for the saws to operate upon the salt. This air bed like the one previously
described, Figs. 228 to 230, is provided with the necessary means of support,
supply, and draining. I prefer to subdivide the air bed in short lengths, each
being provided with a pipe j which puts it in communication with the main
exhaust or blowing pipe K. Valves j are placed in each of these pipes J regulated
by side handles Jx with shafts and bevel wheels or otherwise, so that each section
of the air bed may be regulated separately, and receive the entire force of the
exhaust or blowing as occasion requires. I sometimes drain the brine or water
from the air bed into K, arranging for its discharging such liquid by syphons or
otherwise, but prefer to arrange a separate drain M with pipe m and valve mx,
also regulated by side handles by suitable shafts and wheels. This pipe also serves
for passing brine, water, or steam upwards through the air bed from below. The
pipes and valves are placed in a passage or chamber N, where they can be inspected
and kept in working order. Gutters o are arranged on each side of the air bed,
and space in O at their sides is left for the passage and movement of the saw drums.
Walls and rails with side racks P are arranged on each side of the air bed, and
extend beyond it at each end, so that the machinery may be moved clear of the air
bed, and preferably be screened from it by canvas curtains, which are made to roll
up, or by doors when not at work over it. The walls are lined inside with wood,
and their tops are above the level of the sides g of the air bed, so that for certain
purposes the whole may be flooded with water or brine. The machinery is here
driven by one or more wire ropes Q, for which rollers q and q' are provided. I
sometimes drive them by compressed air, or steam, or gas, after the fashion of the
pan carriages in my Patent, No. 5350, of 1880. When only one rope is used for
driving all the different carriages, I arrange for their rope wheels to be put out
of gear with the machinery on the carriages not being used. I frequently arrange
for them to turn loose on their shafts, or arrange them on separate shafts when
they have no work to do, and use a strong pin q 2, or clutch box, or other con-
necting means to enable them to turn their main shafts when required.
The salt in the case Gx may be saturated with brine or water, either by
welling it up from below by pipe M by showering down from above by
pipe F, or by flooding the spaces O at the side of the air bed according to
the treatment certain styles of salt require. I preferably wash and saturate
the salt by means of a travelling syphon and perforated pipe or pipes on
a carriage passing over the air bed. For this purpose I use a high level
trough S, which is copiously supplied with brine or water from a higher
level, the supply preferably being regulated by floats and valves. For this
purpose, and for levelling and rolling the salt sometimes in successive layers
I employ a travelling carriage T, Figs. 233, 234, 235, side, plan, and end view,
which is made self-moving, after the style of my pan carriages previously referred

page_text: to. It is mounted on wheels t, and is made to pass over the air bed by worm
wheel 1 on shaft t 2, turning cog wheel tx gearing in the racks P. The worm
wheel is driven either way round by a worm on shaft t3 and two bevel wheels t4
turning loose on shaft t5, which is turned by the rope wheel t6 or otherwise. A
clutch box moving over a slot or feather or shaft t 5 is moved in contact with one
of the wheels t4 by handle t7 and causes it to turn, and the carriage to travel
back wards or forwards. This carriage carries on it two spreaders or ploughs t8,
which split the ridges of salt deposited by the hoppers C from above, partially
level it, and are followed by a large roller t9, which completes the levelling process.
The roller is carried in bearings on strong levers t 10 keyed to shaft t 11 in order
that it may always be kept parallel with the air bed below. Its height is adjusted
by turning handle t 12, which screws round wheel t 13 keyed to shaft #14, on
which there are winding drums t 15 with chains to the end of the levers t 10. A
scraper carried on these levers is provided to keep the roller as free from
incrustations as possible. At the back of the roller there are two perforated pipes
t16, 17, the perforations extending the width of the air-bed. They are supplied
with brine or water from the trough S by the syphon t 18, which is attached and
stayed to the carriage, and while travelling with it dips its end into the trough
and causes a pressure of brine or water in the perforated pipes t 16, 17, regulated
by valves t 19, 20. One of these pipes sprays the salt, as seen, Fig. 235, for
washing it during the first levelling, the other sprays the under side of the roller t 9
to wash off any salt sticking to its surface on its return passage when the salt is
damp and liable to be adhesive. When both these pipes are in operation a copious
supply of scalding brine can be poured on the salt to drain through it, and cause
its crystals and particles to adhere and cake. I sometimes arrange to turn the
roller 9 by machinery on the carriage in connection with the shaft t2, so that
when only lightly pressing the salt it still turns in the same way that it would do
if entirely resting on it, which system I frequently apply to other rollers for
pressing salt with the object of not disturbing the salt more than necessary. I also
sometimes employ two rollers instead of one, and pour the brine in between them,
so as to more fully saturate the salt by banking up the brine between the rollers
and plates which I place at their ends, thus forming a sort of tank with salt for a
bottom. After the salt has been levelled and pressed and fully saturated with
scalding brine it is allowed to drain, and the exhaust is gently turned on. I
sometimes add additional brine on the surface of the salt by causing carriage T to
pass up and down the air bed as many times as required, or turn on steam from
pipe F, or use both methods for cleaning and assisting in caking the mass.
provide a copious supply of hot air to the chamber in which the air bed is situated
to supply the exhaust and dry the mass of salt under treatment. For this purpose
I sometimes arrange a surface pan fitted with an air heating case like Figs. 287,288,
on one side or end of the building containing the air bed, and discharge the air
direct into the chamber. When the mass of salt is nearly set I preferably remove
the ends and sometimes the sides g, or arrange slits in the ends and portions of the
sides through which the carriage saws can pass without touching. When using
slits I preferably provide strips of metal or wood to keep them covered or filled
in when the salt is first placed and wetted on the air bed 1 and until it
has partially hardened. After the exhaust has been left on for some time
carriage U is slowly passed over the air bed, see Fig. 231, 232. It has numerous
circular saws u on shaft ux, driven by the rope wheel Ux. Suitable bearings are
provided for this shaft, and the carriage has a fast and slow travelling motion, so
that it may move slowly whilst sawing and quickly when otherwise travelling.
The quick motion is arranged after the style of that for the last carriage. The
Blow motion, preferably by a worm, on shaft ux, turning wheel ul on shaft u 2,
which also has a screw turning worm-wheel u 3 keyed on to a shaft in gear with
the rack wheels on the ends of the carriage. The pace at which the carriage
travels should be carefully adjusted to the cutting power of the saws. In order,
however, to prevent their being over-taxed both here and elsewhere I preferably
I

page_text: ย
V
employ a friction clutch weighted by a lever and weight u 5 on shaft u 4 in such
wise that if the saws are over-taxed the clutch slips and the carriage moves at a
reduced speed or stops until the saws have worked themselves free. The attendant
should take care that the saws are not driven forward too quickly. This carriage
cuts the caked salt lengthways, and allows the sides g of the case to be laid down
as seen in Fig. 236. To cut the salt cross ways I sometimes use similar saws
mounted on a double carriage after the style of H, L, J, Fig. 190, and driven by
suitable engines or machinery. I prefer, however, to use a carriage V, shewn
Fig. 236, 7, 8, and 8a, which is provided with drums v for carrying horizontal band
saws placed in a frame vx, which is moved up and down in guides v1 by cranks v 2
on shaft v3, turned by worm wheel v 4, and screw shaft and pulley v 5. In this
instance, and in cases where more than one saw is used, the space between the
drums is arranged to be equal to the diameter of the drums, see Figs. 238a, so that
the carriage after sawing the salt into large sections may be moved the width of
one block at a time for one or more times to subdivide the section, and then be
moved over a fresh reach of salt beyond the mass last sawn and treated in a
similar manner. The saw drums v are mounted on shaft v6 in bearings on the
dipping frames vx; on the top of these shafts are level wheels gearing with
wheels on shaft v7, also carried by bearings on the top of ux. This shaft is
turned by a wheel at the end of v8, a feathered or slotted shaft on which slides
a wheel in gear with wheel v9 on the main driving shaft 10 turned by the rope
wheel v11. The sliding wheel and the end of shaft 10 are carried in bracketed
bearings v12 outside the dipping frame vx. The frame vx is balanced by
weights v13 connected by chains with the frame, and passing over pulleys v 14.
The wheel 5 actuating the cranks is turned by a belt or chain from wheel v 15
driven by shaft v16 turned by a wheel on the shaft v10. There is a stop on the
worm wheel v4 which actuates a balance weight and stopping gear (not shewn)
which causes the crank to take one turn down and up, and then remain up
till again started. The carriage is moved by three wheels and a clutch box,
as previously described, in groups U and T by shaft v17, worm wheel v 18,
sbaft 19 driving the rack wheels 20. The dipping frame and carriage frame
are strengthened with rods to keep the working parts true, and the guides v 1
are well supported from the carriage. In some cases I arrange to disconnect
the two ends of the dipping frame vx, arranging that the strain of the saws
is withstood by the guides v1, which are then arranged for the purpose. The
usual arrangements are made for replacing and stretching the band saws. In
another arrangement I employ a frame of reciprocal saws driven by a hori-
zontal shaft and cranks, or excentrics near the bottom of frame vx, and
raise and dip them by cranks or other machinery suitable for the purpose..
The operation of undercutting the blocks is performed by carriage W, which, like
the previous carriage, traverses over the length of the air bed, see Fig. 239
and 240. It has two drums w, w, carrying the endless band saw wx.
These are
mounted on shafts w1, and the first is driven by wheels w 2 and w3, with teeth
set at an angle by the shaft w4 and rope wheel w 5 or otherwise. Close behind
the lower saw there is a thin metal wedge held in position by the projections w6
from the frame 27 and kept up to its work by rods from the opposite side frame
of the carriage. The object of this arrangement is to lighten the work of the saw.
This carriage, like the other, is fitted with self moving gear actuated by handle w 8.
I generally blow air through the bottom of the air bed during the time that the
saws are at work to keep the saw gauges or slits free from dust or use other
arrangements on the carriage for the same purpose. The salt having been thus cut
lengthways, crossways, and freed from the bed, is ready for removal, to facilitate
which rails X extend by the side of the apparatus, on which waggons X 1, preferably
drawn by a wire rope, move to and fro. When driving the machinery by compressed
air with engines on the carriages I prefer to pass part of the saws through one or
more tubes or cases, through which the cool air escaping from the engine passes,
and I also make use of the escaping air for blowing the dust out of the saw

page_text: gauges. The air in question, from its expansion being exceedingly cold, helps to
keep the saws cool and in working order. I sometimes mount the saws of frames U
and W on the same carriage, either using a pair of pilot saws to go on first to cut
the sides g of a case loose, or let the sides down by hand, while they can be
detached from the salt without much of it slipping down. The undercutting may
in some cases be partially dispensed with by using coarse salt on the air bed before
the salt from the hoppers is let down, or the previous methods for loosening the
salt from the air bed, as described in Fig. 228, may also be employed for this
apparatus. I sometimes cut the salt into shapes before it has quite consolidated
and use knives and wires instead of saws for the purpose. Here and elsewhere, as
far as practicable, I coat the knives, saws, scrapers, wires, et cetera, with black
oxide to avoid tainting the salt with rust, or else provide special means for keeping
them clean. I occasionally also employ divisions across the air bed, which I arrange
to remove by hand or machinery to save time in cross cutting. When not using
the air bed for caking the salt I sometimes use it for stoving loose salt in bulk by
first spreading dry salt on the air bed and then filling case Ğx with the salt to be
stoved. I preferably blow hot air through it from below while it is kept stirred
up by a carriage with deep knives, rakes, or ploughs on it, which I arrange to move
quickly from end to end of the air bed during the process to prevent the salt caking.
When arranging long air beds specially for this purpose I sometimes employ a deep
waggon way or endless belt on one or both sides of them, along which the salt
when dried is removed by laying down the sides of the case and passing along the
air bed a travelling carriage arranged with a horizontal revolving screw or endless
scrapers to feed the waggon or belts after the style of Fig. 101 in my last Patent,
No. 5350 of 1880.
In order to adopt the foregoing system of drying and stoving blocks by causing
copious currents of heated air to pass between and amongst them to stoves of the
ordinary type commonly used in the salt district, I arrange a special form of case,
cover, or saddle, provided with a permeable top, which I place over the stove flues,
or in some cases arrange to form part of them. I term these coverings "permeable
flue cases or block stands," and arrange them in different forms. They are
preferably made of narrow bars placed side by side or of perforated plates of metal
.or pottery, or sometimes of wood (which is generally rendered fire proof with
phosphate of ammonia or other suitable material), and which I cover with coarse
salt. In order to increase the draught of heated air through them I generally
arrange side pieces reaching part of the way down the sides of the flues arranged
in such wise that air from the spaces at their sides, termed " ditches," is drawn in
close contact with the sides and top of the flue and escapes through the permeable
cover amongst the blocks or salt placed on it for drying: I generally also employ
means for ventilating and heating the stoves at the same time. The various
methods by which I preferably carry out this system is illustrated in Fig. 241
to 249.
Figs. 241, 242, are the side and plan views of a portion of an ordinary stove for
drying blocks, shewing two flues fitted with my improved arrangements for
securing a better circulation of heated air amongst the blocks or salt under
treatment, also arrangements for heating fresh air for the stove, and withdrawing
the cooler vitiated air, preferably for blowing over an adjoining pan to assist
evaporation.
"
Figs. 243 to 249 are enlarged end and side views of flues fitted with permeable
air cases and other appliances applicable under this system. A is a stove room;
B, B, the flues running through it; C, the usual entrance from a stove pan which
is here fitted with a sliding or other door c, so as to keep steam from the pan from
entering the stove and other purposes. c1 is the slope leading to D, the " ditch
or space between the flues, where the blocks are usually left to drain, as shewn at d;
E are salt blocks placed upon the flue top in ordinary cases, but in accordance with
my system are placed upon the permeable block stands F raised a few inches above
the flue top, and extending the length of each flue. The object of these permeable

page_text: flue coverings is two-fold, first, to cause a continuous circulation of warm or hot
air amongst the blocks or salt treated; and secondly, to prevent or lessen the
drippings from the blocks falling upon the flue tops, where it usually forms a crust
of salt. This crust lessens the amount of heat given off by the flues, resulting in
the heating gases escaping to the chimney at an unnecessarily high temperature,
without their having done their proper work in the stove. Figs. 243 to 249 shew
enlarged end and side view of different varieties of the flue cover F seen in
Figs. 241 and 242, arranged to carry out the above object. Fig. 243 shows the
flue cover projecting over the sides of a flue, supported by narrow cross bars or
divisions arranged to support the permeable surface a few inches above the flue
top, and to carry the weight of the blocks placed on it for drying. Side cases fl
in connection with the block stand are preferably placed on each side of the flue a
short distance from it, and are supported by framing ƒ2. They serve to collect
heated air rising from the flue sides, and pass it through the block stand above
(see Fig. 241). Their action is somewhat similar to that of short chimneys, causing
a beneficial circulation of air over and amongst the blocks in the "ditch," and also
sending a greater volume of air through the blocks above. To increase the draught
of the sides, I sometimes carry the casing nearly to the bottom, as shewn, Fig. 245,
and occasionally place perforated pipes at f3, through which I admit or blow air to
assist the current. To facilitate heating the air, and also to protect the top of the
flue more effectually from the drippings from the salt blocks above, I place one or
more horizontal plates or divisions f4 over the flue at a short distance from it, as
seen in Figs. 244 and 245. A central division is arranged to add support to the
block stand, and to direct the air more evenly under its whole width. Fig. 246
shows a case with permeable top fed with hot air by a perforated pipe f 5. This
air is preferably heated in a case f6 beneath it, which forms a covering to the flue.
The air is forced through the lower case, or sometimes only drawn through by the
withdrawal of the vitiated air from the stove. The sides f7 of the case preferably
extend part of the way down the sides of the flue to assist in retaining the heat,
and for lessening the escape of smoke. Fig. 247 shews a similar method of heating
the air. The case f7a is however provided with side passages f8, which extend
along its sides for the whole length or variable distances. The air is admitted into
f7, and is heated on its way to the other end of the flue, and is then distributed
by the channels f8 to different lengths or compartments under the block stand by
means of the different channels and suitable openings in the horizontal divisions ƒ 9.
In connection with this system of heating the air, I frequently employ pipes f10
placed in the flues, see Fig. 245, for supplying the flue cases or the stoves with
fresh warm air, and sometimes employ an arrangement shown in Figs. 248, 249,
end and plan view, for the same purpose. The air in this latter instance is admitted
or forced by one or more pipes fil to a case f12, to which are attached air pipes
or channels 13 placed in the flue, preferably vertically, and heated by its waste
gases. These discharge their air into f14, which is placed over the flue, like f7 in
Fig. 247, and provided with one or more side air channels f15. I sometimes
discharge the air from these flue top air heaters direct under one end of the space
under the block stand F, but prefer to distribute it more evenly in separate com-
partments at intervals of its length. For heating the fresh air for the stove, I
preferably employ pipes in the flues, like f10, marked g, g, in Figs. 241-2. The
air is introduced or drawn in at gx, where it rises into a case g1 communicating
with the pipe g in the flue or flues. The pipes g extend the length of the flues,
and curve round at their ends, and return to case g1, from which there ascends an
escape pipe g 2, which enables the air to rise and cause a draught through the
pipe g. H is an exhaust pipe to draw off the vitiated air, placed by preference
with its suction pipes / near the ground, where the air is at its lowest temperature.
I sometimes connect this or other suitable pipe with the chamber, in which an
exhaust table or air bed is situated. When pans are situated next to the stove, I
preferably blow the air by a fan I over the brine, as explained in my last Patent,
to assist evaporation. The permeable surface is preferably made removable, so as

page_text: to clean out the space under when required. Occasionally I make the flues of
metal, or construct air passages in the brick-work of the flues, for either heating
air for the block stands or stove, or both. As far as practicable, I prefer to make
the flue covers and cases of pottery or wood, the latter being preferably prepared with
phosphate of ammonia or other suitable material, to render the wood inflamable;
the parts exposed to the direct heat in the flues should be of metal or fire clay.
To save heating large volumes of fresh air for the drying apparatus, stoves, and
pans, I sometimes dry the air coming from the same after use, and use it over
again, or employ dry air in the first instance. The form of apparatus which I
prefer to construct for this purpose consists of one or more tall chambers with
sloping bottoms, in which I place chloride of calcium or other suitable material,
and through the lower portions of which I pass the fresh or damp air. The dry
air is preferably drawn or passed through fine strainers placed at the top of this
or an adjoining chamber. Dry chloride of calcium is supplied to the chamber by a
shoot valve, or sometimes by a distributing disc near the top, and is withdrawn
when charged with moisture from the bottom, and passed through a drying stove
or other form of heating apparatus to be again returned to the top of the chamber
by an elevator or otherwise for further use. I sometimes use rotating tables or
endless belts, on which I spread the chloride of calcium and pass the air over or
through it for freeing it from excessive moisture.
Figs. 250, 251, and 252 are the side, plan, and end views of an arrangement for
the purpose. A is the inlet for fresh air or warm damp air from adjoining drying
rooms or elsewhere; B is a blowing fan, driven preferably by its own engine Bx,
which also drives the machinery about the apparatus; C is the pipe with suitable
connections and valves to the circular air cases or jackets d placed near the bottom
of the sloping bottoms of each of the alternate chambers D and Dx, and arranged
to blow air through numerous holes in the sides of the chambers from the bottom
of the rings. These cases are suitably supported and preferably enamelled within.
E is a heap of chloride of calcium or other suitable substance, through which the
air blown by the fan passes, and by which it is freed from moisture. The air then
rises in the chamber and passes through steaming material d x, suitably supported,
into an upper chamber d 1, and passes by a pipe and valve d 2 moved by handle d3
into a depositing chamber E behind a long partial division e to spread the air out.
At the top of E there are again strainers suitably supported, preferably three,
e 1, e 2, e 3, extending over the whole area of the chamber. These are provided to
strain out any fine particles of chloride or calcium that might be floating in the
dry air. The chamber is made air tight, and is sometimes constructed of wood.
There is a door e 4 to enter it by from time to time to remove any chloride of
calcium that may have collected on the bottom of the chamber. Over the strainers
there is a low chamber Ex, which is arranged to receive the dry air from the large
area over the strainers. Room is left for a workman to enter by a suitable
opening, and pass over the strainers to replace or repair them. The air from this
chamber is conducted by a wide channel F under the end of an air case G placed
over the metal covering h of the surface pan H. The apparatus is sunk somewhat in
the ground so as to keep the top of the chamber Ex nearly on a level with G. The
air passing along G gets heated, and is returned to the stoving room or elsewhere
dry and hot, and ready for further drying and evaporation. It is of importance
that the metal covering to the pan should be made and kept steam tight, otherwise
I prefer to exhaust the air from Ex and pass it through pipes or cases in a hot air
stove, and so on to the stoving rooms, et cetera. In order to keep up the supply of
dry chloride of calcium to dry the air, I provide on the upper part of each of the
chambers D and Dx a compartment or chamber D1 with sloping top and bottom,
or connect them with suitable chambers elsewhere. They are fitted with valves d 4
and d 5 at the top and bottom, and made air tight. At their bottom I sometimes
employ revolving discs to distribute the chloride of calcium, as in the stove S,
Fig. 10, in my former Patent, No. 1336 of 1878. They are alternately filled
through their upper openings by a right and left screw in an air tight case or

page_text: pipe I fed by the elevator J, and a suitable shoot is provided in the spout of the
elevator to direct the chloride of calcium into either chamber as required. When
additional chloride is provided it is emptiéd into a pocket at the side of J. The
saturated chloride of calcium at the bottom of D and Dx passes down pipes k from
each of them, governed by valves and handle kx, into an air tight screw channel K, by
which it is removed to the elevator L, also made air tight. In some cases I employ
endless scrapers or other means for passing the saturated substance forward to L. This
elevator takes the damp chloride up to the top of a stove M arranged for drying it,
and distributes it by a screw Mx turning in a case with a line of holes at its bottom
or otherwise across the top table m. This stove is arranged of any suitable length,
and with numerous flue tables m suitably supported above one another, and so
arranged with alternate side channels m x, as to cause the heating gases admitted
by a long flue N (sometimes placed in the other side) to zig zag sideways through
them until they discharge the spent heat over the surface pan H. The flue tables
are arranged so that the chloride may be passed progressively downwards from one
table to the next by the assistance of moving endless scrapers m 1, which move in
the opposite directions by wheels and shafts m 2, as seen in Fig. 250. The chloride
at last finds its way down to a right and left screw m 3 at the bottom, which
supplies the elevator J. The steam from between each pair of tables is preferably
conducted into one or more central vertical side channels to a chamber for collecting
any fine particles of chloride carried by the steam, and from thence under a pan to
heat brine. Before any fresh chloride is run into either of the chambers D or Dx,
the top valves d 4 should be closed. The valve d 5 is then opened by a suitable
handle at the side, and the chloride passes downwards. Wheels q 1 and q 2 and
chains are provided to open and close the top valves d 4. The various valves are
provided so that the steam from the stove M, air from chamber E, or from without,
may be carefully excluded, and further to prevent as far as possible the escape of
dry air. A belt p from a wheel on the engine turns a small shaft P, which drives
a cross shaft Px with bevel wheels. This drives the screws Mx and m 3, the scraper
wheels m 2, the lower screw k, and the end elevator L, by belts, gearing chains, or
otherwise. There are belts p 1 and p2 for the wheels of the upper screw and
elevator to wheels on Px. I sometimes employ circular flue tables with rotating
arms for driving the chloride, or use revolving cylinders or other means, preferably
employing the steam rising from them for heating brine or other purposes, keeping
the outer air from their surfaces as much as possible. I frequently employ coupled
fans in connection with this and similar apparatus, one for blowing damp air
through the apparatus, and the other for exhausting it through the drainers, after-
wards blowing it through heating apparatus. The two fans should be of the same
capacity, or nicely apportioned, so as to pass the air freely through the apparatus
and lessen pressure within, which tends to lessen the escape of dry air into the
stove or elsewhere. Drying the air in this manner is useful when waste heat can
be used for the purpose, as it enables stoves, air beds, and other drying arrange-
ments to do far more work, especially on foggy days. By its use the same air can
be largely used over and over again, and be maintained at a much higher tempera-
ture in the stoves and elsewhere. The air in this way is used as a carrying medium
to convey the moisture to a convenient locality, where the air can easily be redried
and reheated, and the moisture driven off be used for heating brine in neighbouring
pans for increasing the production of salt or for other purposes.
I arrange various combinations of the foregoing apparatus and machinery for
treating salt in various ways, frequently arranging works simply for washing and
drying salt received by boat, or rail, or elsewhere; others for washing, drying, and
stoving salt, arranged with special appliances for making cakes or "handed
squares," while others are especially laid out for the manufacture of " factory filled
salt," or salt for curing purposes put up in bags or other receptacles. For
producing the class of salt termed "shute salt," the works are preferably laid out for
stoving the salt in bulk on large air beds, whilst for washing and preparing rock
salt for curing purposes the dipping cages, Fig. 195, grinding machinery, annular

page_text: tables, or belt stoves are more appropriate. For preparing salt for chemical pur-
poses I generally lay works out with large annular tables, like Fig. 214. I frequently
employ carriages, Fig, 192, or cases, Fig, 194, for removing the sulphur from salt
produced in surface pans, and afterwards return it to pans to increase in size, and
be used for subsequent stoving or other purposes. When laying works out for
washing, drying, or stoving salt, apart from mines or evaporating pans required for
supplying them with salt, I generally provide two sets of store chambers connected
with the apparatus, one for receiving at intervals the salt to be treated and holding
enough of it to keep the machinery, stoves, et cetera, regularly and constantly
supplied, the other to receive the steady flow of prepared salt coming from the
stoves and other apparatus, and store it up so as to suit the working hours of
operatives employed for filling it into bags, or otherwise handling it at irregular
intervals of time. A small complete plant for receiving salt by boat, rail, or else-
where, and preparing it for shipping purposes in the form of factory filled salt put
up in sacks, Figs. 253 to 257, serves to illustrate the class of works and arrange-
ments I generally adopt for one of the above objects, so as to economise time and
labour. The works are arranged for receiving salt from neighbouring pans, other
works, or elsewhere, for washing, stoving, and otherwise treating and preparing it
for curing or other purposes, arranged with facilities for turning out a large
quantity of salt in sacks with store rooms and other conveniences. Fig. 253 is a
side view; Fig. 254, a plan view of upper floor; Fig. 255, a plan view of ground
floor; Fig. 256, end view of washing and storing apparatus; Fig. 257, end view of
receiving store. A is the main building; a, brick wall supporting it, which I
sometimes carry up to the roof, but which are preferably partially replaced by
wooden walls a x, suitably strengthened. The object of using wooden walls is to
cheapen and lighten the structure; B is an annex; Bx, a shed; B1, a covering
over rails with glass at 61; bx, wall; C, a shed or store room for sacks with a
slightly raised floor Cx; c, lower walls of masonry lined with wood against which
the bags are placed; cx, wooden walls; D, ground floor; Dx, stoke hole floor
for boiler and hot air furnaces; E, upper floor connected by gallery Ex, and
approached by stairs ex, from E1, a raised platform, also approached by stairs
el and e2; F, a hopper for receiving salt for treatment from waggon, boat, or
otherwise; Fx, a sieve or riddle case with distributing disc below; G, a store for
containing salt received from F at intervals, so as to supply the machinery con-
tinuously provided with hopper bottoms and endless belts beneath; G 1, cool room
under store, communicating with outer air and partitioned off from rest of works,
arranged to lessen the chance of salt caking in the stove above if received in a damp
state; H, elevators supplying the hopper Hx arranged with grinding rollers beneath.
I, elevator from rollers to alternate centrifugal machine J and Jx; K, cistern to
receive brine used for flushing, etcetera; L, a tank supplying brine and water to
centrifugal machines; M, hot filter for preparing purified brine connected with N,
a cooling pan; O, elevator from the centrifugal machines to the belt stove P.
Px, outlet shaft for vitiated air from stove; Q, hot air chamber over flues under P ;
R, inlet air shaft; Rx, hot air stove communicating with Q; S; elevator, conveying
salt from stove P to the sieve T; U, subdivided stove with hopper bottoms pro-
vided with endless belts beneath for receiving stoved salt continuously, and for
supplying bagging machinery intermittently; V, elevator to bagging machine W;
Wx, rails for sack waggons; X, engine driving shafts and belting; Y, boiler;
Yx, hoppers for self-stoking machinery; Z, chimney; +, tramway for bringing up
fuel, salt, et cetera, to works, and for removing the sacks when filled. In some cases
I erect the works on a river or canal bank, when I sometimes dispense with this
line; F is the hopper into which salt from the works is placed; f is an elevator
removing the salt from hopper, and delivering it on to a reciprocating sieve or
riddle f1 over case Fx, moved by cranks on the shaft f 2, on which there is a fly-
wheel 3, turned by bevel wheels f4 by a shaft and pullies f 5. This sieve or riddle
is used to prevent large lumps of salt, or stones, or other bulky material likely to

page_text: damage the machinery passing into the store below; it is sloped so that lumps,
et cetera, may fall off and be collected in a suitable receptacle at its end for
subsequent inspection and grinding or rejection. The riddle moves in slides or on
swinging arms over a case Fx, which has a sloping hopper fx within which
conducts the salt falling from above to a tube f6, supplying a revolving disc f7
which scatters the salt over the store G beneath. The disc f7 is driven by a
vertical shaft f8, by bevel wheels 9 and f10, by a pulley at f11 with a belt from
a pulley on shaft f2. The store is sometimes made with brick sides. It is lined
with wood, and has its bottom hoppers Gx suitably supported by metal or wooden
framing g, double stands g 1, and the central pillar gx (both bedded on masonry).
The store is also supported at the sides by the walls a, a, and by a cross girder a 1
or otherwise. At the bottom of the hoppers there are valves g1 moved by hand
wheels at their sides. They permit salt to pass from the hoppers on to the endless
belts g 2 stretched between the drums g 3 and g 4, and supported on rollers under
the valves. The belt drum g 4 is carried in bearings on the swinging arms keyed
to the shaft g 5, to which there are also attached levers and weights g 6 moving in
a recess in the wall. The drum g 4 is mounted in this way so as to keep the belt
always tight, and I generally apply the system to all similar endless belts. The
belt drums g 3 are suitably mounted and turned by a shaft g 7, on which is keyed
a bevel wheel g 8 turned by a wheel on shaft g 9 by the pulley gh. The belts
deliver their salt into the hoppers of the two short elevators H, which pass it
forward to the hopper Hx, supplying the three pair of rollers h 1, h 2, and h 3,
beneath. In place of the above hoppers and belts I sometimes arrange deep grooves
from side to side of the store room provided with sloping ends. At the bottom of
these deep grooves I arrange long turning screws in suitable bearings, or provide
endless chains of drag scrapers (as described in my Patent, No. 5350, of 1880), but
with their return chain passing under the store. These convey the salt to a cross
trough in which a right and left screw revolves, or in place of it I sometimes
employ two sets of endless drag scrapers. The salt is in this way brought up from
the store to one or more elevators for supplying the roller hopper Hx or other
purposes. On account of the power required for driving the screws or endless
scrapers, I prefer to use the hoppers and belts, as shewn in the Drawing, unless it
is necessary under certain circumstances to empty the store with greater dispatch.
One of the elevators H is driven by the wheel h, which drives the other by the
cross shaft hx with bevil wheels, or the elevators may be otherwise driven. The
rollers of each pair h1, h2, and h 3, are arranged so that they are a little apart,
and easily adjusted by set screws or otherwise, and able to be taken out for
refacing or other purposes. The object of placing the rollers a little apart is to
enable them to pass crystals of the right size for bagging purposes, and to break
larger ones up in case coarse salt is filled into the store. The rollers are mounted
on bearings on suitable framing so as to be easily replaced with others when
requiring refacing, and are driven by wheels g, h, and suitable shafts and gearing.
They deliver their salt into a long sloping shoot Ix communicating with the
elevator I. I sometimes arrange to blow, exhaust, or winnow out the dust or fine
particles of salt resulting from grinding, both here and elsewhere. When so doing
I cause the necessary draught of air or steam to pass below the rollers and over the
shoot, providing a deep chamber near at the side of the rollers, into which they
may settle and accumulate for subsequent removal by hand or otherwise.
elevator I is arranged to feed either or both of the centrifugal washing
machines J and Jx. It has a shoot i in which there is a moving division,
which has a shaft at its bottom moved by a wheel Il and chain 2, or
otherwise. When placed vertically the salt from the elevator I passes down
both the lower shoots i3 and 4. When turned to either side it causes the
salt to pass into one of the centrifugal machines, so that either may be used or
flushed, as desired. The centrifugal machines are preferably constructed after the
style shown, Figs. 215 to 218, and are mounted on masonry J1, or otherwise,
preferably with a passage ja below. They are turned by engines attached to
The

page_text: them or by the wheels j 1, and suitable belts from the shaft of an engine, not
shown, but preferably placed near the belt stove P. They are supplied with
brine, purified brine, and water by pipes from the tanks L, Lx, and L1 in the
annex B. The brine passing through them is preferably collected in a cistern K
placed at their side into which the drain pipe j1 empties. Pipe j2 is connected
with j1 and communicates with a drain to carry off waste water. Valves are
provided in the pipes to regulate the flow of liquid either way. The handles or
cam machinery for flushing the centrifugal drums are placed on the platform E 1,
which is approached by the stairs e 1 and e 2. The salt from both of the machines
falls into the pocket j 3 and is removed by the elevator O to the belt stove P. The
tanks L, Lx, and L1 for supplying brine and water to the centrifugal machines are
placed above their level and receive their liquid by pumps Kx, or otherwise. One
of the pumps transfers the liquid from the flushing cistern K to tank Lx, a second
from the cooling cistern or pan N containing the purified brine to tank L, and a
third water from a well or elsewhere to tank L1, or otherwise. The tanks are
provided with overflow pipes or floats and arrangements for stopping their separate
pumps or supply of liquid. To produce the purified brine for the washing process
I employ two alternate cisterns, shown in dots L 2 and L 3, fitted with stirrers and
fed with brine from the tank Lx or from the brine head. I either employ them in
the same way that A. and Ax, Fig. 178, are employed, running or pumping a fixed
proportion of purifying solution into M the hot filter, at the same time admitting
the correct quantity of brine to the filter also, or else, since the quantity of pure
brine for washing is very small, fill each tank separately with brine and add the
correct proportion of barilla, carbonate of soda, or other chemicals, so that it is in
a mixed state ready for filtration as required. The filter M is arranged as
previously described, Fig. 185, and runs its brine into the long cooling pan Ň from
which it is pumped into tank L. The belt stove P receives the salt from the
elevator O, is preferably arranged after the style of P, Sheet 1 of my Patent,
No. 1336, of 1878, but with the addition of tightening weights, like Fig. 221, to
keep the belts tight, and current divisions p, described Fig. 221, to cause hot air
admitted into q 1 so as to traverse zig-zag, backwards, and forwards over the salt
on the belts (which are preferably chiefly of prepared canvas) until it escapes or
is withdrawn by the broad-band air channel Px, by which it escapes up the outlet
pipe px. When blocking works or evaporating pans are placed in connection
with works of this class, I preferably use the hot air coming from the stove
for blowing over pans or supplying rooms in which exhausted air beds are
situated. A vane is arranged at p1 to increase the draught of air in the stove
driven by the vertical shaft p 2, and a cross shaft with multiplying wheels p 3,
or otherwise. A revolving screw-head p is also added to the pipe for the
same purpose. Occasionally I connect the air pipe pa with the chimney of
the works. In placing of using the vane to withdraw the air from the stove,
I sometimes employ a fan or blow air through the stove by a fan or
compressor placed near the boiler. The stove P is preferably erected over a
hot air chamber Q arranged over the flues y coming from the boiler Y and
hot air stove Rx and leading to the chimney Z. The chamber is provided with
a supply of air by the cross channel q, which passes air from a long opening
at its bottom over qx, the metal covering to the flues. The air is supplied to q
by an air channel rx, see Fig. 256, placed over the boiler flue q. Fresh air is
admitted to rx by an inlet air shaft R provided with a revolving head r 1, which
is arranged to force the air downwards as it is turned by the wind. In some cases
I employ a blowing fan or compressor for supplying rx, preferably drawing the
fresh air from the top of the building. The air from R is passed through heating
pipes or cases in the hot air stove Rx before it enters rx, and afterwards escapes
in the chamber Q and through the stove P. The air pipes or cases in Rx are
preferably heated by the waste gases from the boiler furnaces Y, again ignited or
assisted by a second fire in the air stove. The waste heat from all the furnaces

page_text: passes along flues y and yx, under the chamber Q, and onto the chimney Z, giving
off much heat to the air above for the stove. The salt from the bottom belts in P
is transferred by a right and left screw p 4 to one or more pairs of quickly turning
rollers & which are placed a little apart, and used for breaking up any small lumps
formed in drying. The rollers are driven by a shaft sx and a wheel 8 1, or from
a belt from the shaft above or elsewhere. S is an elevator to convey the salt to a
It is driven like
long reciprocating sieve T placed over the stoved salt store U.
the other sieve f1 by belt wheel t 2, and is fitted with a fly wheel t3. It separates
the crystals into various degrees of fineness, which are passed by shoots t, tx,
and t1, into the compartments of the store U, Ux, U1. The compartments have
hopper bottoms like those of the previous store, and are similarly supported. They
are fitted with valves at u to deliver salt on to the endless belt ux, which have
The belts convey the
drums Ux arranged like g 3 and g 4 previously described.
salt to the end of a revolving right and left screw v, which passes it through an
opening in the screw trough at its centre through one or more pairs of adjustable
rollers v x.
The drums of the belt ux are driven by side wheels u1 and 2 turned
Suitable provisions are
by smaller wheels on the shaft u 3 driven by wheel u 4.
made for driving either belt without the other, or driving both together, so that
the salt from any one hopper may be withdrawn separately, or the salt from two
A driving belt from
or more may be blended on the belts and passed forward.
wheel u 5 turns the stove rollers 8 by wheel s1 when not driven otherwise. A
sloping cross shaft V 1 drives the screw and the rollers vx by suitable gearing
shafts, et cetera. The salt coming from the rollers vx falls into the hopper v2, and
is transferred by elevator V to the hopper of the bagging machine W constructed
The wheel of
after the style of Figs. 43a to 47 in my Patent No. 1336 of 1878.
the elevator V is driven by a belt xv from a wheel at the end of the roller
shaft vx. The driving drum w of the bagging machine is driven by a belt u 5 from
a wheel u 6 on shaft u 3. I prefer to arrange that the bagging machine W should
fill different sized sacks on its two sides, and I sometimes arrange it to fill three
or more rows of different sized sacks at each traverse of the sliding frame, to which
the sacks are clipt. For this purpose I provide suitable measuring compartments
above, after the style of F, with valves F1 and F 2 of the Figure already referred
to, arranged with different sized holes and clipts in the sliding frame A. I
preferably move the measuring valves F 1 and F 2 by lineal cams at the top of the
reciprocal frame A. The carriage for removing the sacks is also arranged for
receiving two or three rows, as the case may be. Where room permits, the bagging
machine is worked at both ends with the system of rails as previously described or
otherwise. In the small works drawn it is considered more important to have
plenty of room in the store for storing sacks, and the single line of rails Wx enables
men to wheel them at once to the side of the store, where the tops are sewn up by
women in the usual manner. A weighing machine is provided at W 1 for the
bagging superintendent to check off and correct the weight of salt in the sacks
filled. A second weighing machine is provided at W 2, near the entrance door, to
keep a register of the weight of salt sent from the works, and for other purposes.
C1 is a store room for sacks, fitted with a sliding door c1; Ca is an office; c2 is
a passage; c, c, the entrance to the works; aa, ab, and a c are doors from one
part of the building to another. The chamber containing the tanks for chemicals
is entered by a door a b1 from the raised platform E. The building is preferably
constructed of masonry for a few feet above the ground, and of wood for the sides
and roof, properly tied and stayed by cross rods or otherwise, and well covered in
and lighted. A shed B1 is provided over the waggon way to keep the salt dry as
it comes to the works, and to protect the sacks when sent from the store room
The machinery is driven by an engine Xx supplied with steam from the boiler Y
On the
or otherwise. It drives a long shaft X suitably supported by a bell x.
shaft X there are belt drums x1 driving the riddle f1 and disc f7 by a belt x 2 to
wheel f5. The shaft X turns the endless belts g 2, elevators H, and rollers h 1, 2, 3

page_text: by belts x 3 and x 4. The belts ux, screw v, and bagging machinery W are
driven by belt from drum x 5, turning wheel u 4. A belt from 5 is sometimes
used for driving the rollers 8. The elevators are turned by wheels x 6, 7, 8,
and belt 1; the revolving vane pl is turned by bevel wheels x 9; the sieving
machine T and the belts in the stove P are driven by a cross shaft x, x, turned by
bevel wheels x 10. x 11 is a belt to p, p, the driving wheel of the belt stove, and
12 a belt to wheel t 2 of the sieving machine T. A small shaft xa is turned by
a belt 13, and drives the pumps Kx ; it also drives a little shaft xb by a
belt x 14 which turns the agitators in the cisterns L2 and L3 by wheels x 15
and x 16. A belt x 17 from xb turns a third little shaft xc which drives the
revolving scraper in the hot filter M, and drives the self-stoking machinery and
rocking bars of the furnaces by wheels x 18, cross shaft x 19, belt x 20, turning the
shaft 21. A grating D 1 is placed over the stoke hole so as to enable the hoppers
to be filled by wheeling fuel up to them. A belt is provided to drive a shaft d
in the tool shop D2. There are various doors, passages, staircases, ladders, lights,
as illustrated to facilitate conducting the process. Doorways are preferably built
into the outer wall of the store for similar apparatus to be added on the other side,
with the common store room between them. Such apparatus preferably feeds the
bagging machine W with salt, or blocking apparatus is sometimes added in place of
stoving apparatus, and some of the blocks are stored in the shed C or are ground
up and filled into the hoppers of the bagging machine, with suitable grinding
rollers and elevators provided for the purpose. I sometimes reduce the height of
the stove P by lowering the height of the chamber Q, or sink the flues yx,
somewhat so as to leave plenty of head room in the chamber.
When room
is of importance I sometimes arrange the bagging room over the stoving
apparatus and salt stores, supporting it with strong walls. I then place
the bagging machine with tramway lines to one side or the upper floor and
otherwise, and re-adjust the machinery shown for its supply and working.
Occasionally I cover the whole of the works in with one or more large sheds,
partitioning the different rooms off with suitable boarding or otherwise. Several
similar sets of stoves and apparatus may in this way be added side by side, and
their salt be moved about the works by elevators and belts or tramways, to
supply the same set or group of bagging machines in one common store room or
warehouse. The iron is preferably all protected from rust by being coated with
black or magnetic oxide. Where wood is employed under high heat, I prefer to
make it fire-proof by treating it with phosphate of ammonia, tungstate of soda, or
other similar material. When salt is placed on such surfaces, I generally treat the
wood with phosphate of ammonia. In this way woodwork may be employed in
stoves or other hot places where otherwise iron, brickwork, or pottery would have
to be used; and in the case of flue coverings, air-shafts, and hot air chimneys a
much lighter material can thus be used, which is also a matter of importance where
large tables or other apparatus working with hot air have to be covered in or
supplied with hot air from heating apparatus.
In the foregoing Figures and descriptions I have shown various apparatus, pans,
machinery, and combinations of the same (also combinations with previously
described apparatus), together with illustrated works, all or any of which I vary
somewhat or otherwise combine according to circumstances for the economical
production of pure or purified salt from pan or mine, in a washed or dried or stoved
form, or any or all combined, with facilities for its production. I have shown how
a large continued supply of purified brine can be provided for bottom heated pans,
pans worked by brine heaters, and other purposes, and how large crystal pure salt
can be readily made in large quantities and with economy of labour in handling.
I have shown how impure salt from mines, ordinary evaporating pans, store houses,
or elsewhere may be treated so as to produce a pure article, with arrangements
specially adapted for preparing it for market. I have shown how salt from surface
pans can be practically freed from sulphureous impurities, for returning to another

page_text: pan to acquire size, or for other purposes. I have also shown how crystals may be
coated or impregnated with products of combustion or other gases over a large area
of permeable surface, and so prepared for certain chemical processes. I have also
shown how stoves of the ordinary type may have inexpensive improvements
applied to them on my air-current system for increasing their efficiency, and a
method by which the temperature of certain stoves, air-beds, and drying apparatus
may be maintained at a high heat and fed with dry air. By purifying brine with
the apparatus described, I am able to provide a large continuous supply of hot pure
brine, purified with solutions of any degree of strength in a constant even flow,
which is a matter of considerable importance where an extensive area of pans are
worked with brine heaters on the circulating current system, and with bottom
heated pans where steam or a low heat is used, as described in my Patent,
No. 1336, of 1878. By the use of deep covered pans, described in Figs. 187
to 191, charged with their full complement of dependant springs, nets, et cetera, I am
able to expose a very large surface for inducing incrustation and the formation of
large crystals in pans, covering but a small area of ground, while the system
arranged for heating and working them, together with the use of purified brine,
not only produces large crystal salt with comparatively little hand labour, but a
quality in the first instance fully as pure as those classes of solar salt which have
been exposed for many months to the cleansing influences of the atmosphere. By
the arrangement of the apparatus for washing, grinding, and stoving rock salt I
am able to produce a quality of salt especially suited for curing purposes from its
small percentage of chloride of magnesium. By the use of permeable surfaces
protected from rust by black oxide, or surfaces of canvas prepared with cutch and
treated with a solution of glue, or of pottery, or of wood rendered fire-proof by the
use of phosphate of ammonia, or other suitable non-corrosive material, I am able
to employ a class of apparatus for washing, drying, and stoving salt, which it has
hitherto been almost impossible to employ on account of the injurious effect of salt
upon copper or iron gauze usually employed for such purposes. I have further specially
adapted this class of apparatus so as to present a large permeable area for treating
salt, with special appliances for manipulating it by machinery, drying it in bulk,
or forming it into cakes or blocks. By floating off fine crystals, or by removing
them by winnowing or other methods explained before exposing them on exhaust
or centrifugal permeable surfaces for washing, drying, stoving, or caking salt, I am
able largely to prevent the choking of the permeable surfaces, while the arrange-
ment for washing, flushing, cleaning, or in certain cases protecting them with a
thin layer of dry salt under the damp salt to be treated, enables them to be kept
in a far better state of efficiency than would otherwise be possible. There is also
less. fine salt sieved out when preparing it for bagging purposes, which is a
desideratum. By the use of alternate machines the apparatus can be kept
continually at work. By the use of the exhaust or blowing system for the
production of dry or stoved salt, or of cakes, blocks, or other forms of salt, their
moisture can be removed at a lower temperature and with greater despatch than
heretofore, while the facilities arranged for the production of "factory filled salt," or
of cakes and blocks of salt from store salt (instead of in pans and stoves as at
present), enable a small plant of this description to turn out a very large quantity
of salt in market form. By the application of the hot air current system to belt
stoves, and stoves of the ordinary type, not only is the air in them made to carry
away the moisture at a reduced temperature, but in the latter case the flues are
made to give out more heat, whilst the risk of bursting blocks is almost entirely
removed. By the system of drying air supplied to stoves or pans, and in some
cases re-drying it, I am able to make drying apparatus or pans produce a large
quantity of blocks or salt, and maintain the heat in stoves at a higher temperature.
I am also able to conduct the moisture to apparatus, where it is driven off in steam
and used for heating other pans. By the use of double stores, one for supplying
the machinery, and one for feeding bagging or other machinery, I am enabled to

page_text: receive salt for treatment by boat, rail, or elsewhere at irregular intervals, and suit the
working hours of the operatives while keeping the machinery almost constantly at
work. By the employment of endless belts, elevators, and other arrangements as
described, I am able to use several sets of drying or stoving apparatus in different
portions of the works, and bring thin salt to one common group of bagging, caking,
or block making apparatus in one common shed or warehouse. By the use of iron
protected from rust by black oxide, and woodwork rendered fire-proof by phosphate
of ammonia, tungstate of soda, or other suitable material, the structure and apparatus
can in many cases be made much lighter and more durable, even when exposed to
constant moisture of high heat, while by preparing endless canvas belts in the
way described, they may be rendered far more durable, and used in many places
where otherwise they would be unsuitable.
Having now described my Invention, which, as mentioned in my Provisional
Specification, is, as it were, an addendum or supplement to my previous Patents,
Nos. 4324 of 1876, 1788 and 2106 of 1877, and 1336 of 1878, I wish it to be
understood, that though in some of my Drawings and descriptions I may have for
convenience introduced small portions of my previously patented Inventions in
order to more fully explain my present Invention, I make no claim under this
present Patent for such items; but that what I believe to be new and claim as my
Invention to be protected under Letters Patent is,―
First. The system of economizing ground space herein described, namely,
employing deep pans and exposing therein pendent strings, wires, nets, or their
mechanical equivalent, substantially as described, for affording a large area of
surface for inducing incrustation and the formation of large crystal salt.
Second. The manufacture of salt suitable for curing purposes from rock salt
by washing, crushing, grinding and drying or stoving it, substantially as set
forth.
Third. In the manufacture of salt for domestic, manufacturing, or other purposes,
treating it upon permeable surfaces (protected with black oxide of iron or other
insoluble and not easy corrodable material) with exhaustion or blowing of large
volumes of air or gas through it and the said permeable surface so as to
facilitate the washing, drying, stoving, caking, or other treatment, substantially as
described.
Fourth. In the manufacture of salt for domestic, manufacturing, or other purposes,
eliminating and collecting the fine particles from the salt before exposing the
remainder to centrifugal action or exhaustion on permeable surfaces, substantially
as and for the purposes described.
Fifth. The herein described system and arrangements for maintaining permeable
and other surfaces in better working order by laying a dry layer of salt on
such surfaces before exposing the damp salt to treatment, for the purposes
described.
Sixth. The system, substantially as shewn and described in Figs. 213, 213a,
and 220, for removing loose salt from the exhaust or permeable surface after the
bulk of the salt has been removed by the shoot or scraper.
Seventh. The arrangements herein described for washing salt in such wise that
it is alternately washed and drained repeatedly for facilitating the removal of
deliquescents and other impurities with which the crystals may be coated,
preferably by the use of cold or cool brine or water, substantially as and for the
purposes described.
Eighth. The system of providing large areas of permeable surface in fixed or
mounted tables, as and for the purposes described and explained in Figures 207
to 209 and 214.
Ninth. In the manufacture of salt for domestic, manufacturing, or other purposes,
the application and construction of "air beds,” substantially as and for the purposes
described.
Tenth. The system of applying permeable covers and other arrangements to flues

page_text: (as described in Figs. 241 to 249, and Figs. 225 to 227) in stoves for facilitating
the drying of salt and blocks.
Eleventh. The general arrangement, construction, and manufacture of machines,
plant, or apparatus for the manufacture of salt from brine, substantially as herein
described or shown in the accompanying Drawings, no claim being made for those
parts already described in my former Specifications above mentioned, nor for any
one part taken separately or used for a different purpose to that set forth in my
Specification, but only when combined with the other parts or their equivalents so
as to make a complete single mechanism, substantially as described or represented
in any one or more of the numerous Figures annexed hereto and for the purposes
herein set forth.
In witness whereof, I, the said John Howard Worthington Biggs, have
hereunto set my hand and seal this Ninteenth day of July, in the year of
our Lord One thousand eight hundred and eighty one.
JOHN HOWARD WORTHINGTON BIGGS. (L.S.)