IMPROVEMENTS IN THE MANUFACTURE OF SALT AND IN THE APPARATUS EMPLOYED THEREIN.
Year: 1870

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF SALT AND
IN THE APPARATUS EMPLOYED THEREIN. ."—A communication from abroad
by J. R. Buchanan, of the City of New York, in the United States
of America.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition,
on the 21st October 1870.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Civil Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF SALT AND IN THE APPARATUS EMPLOYED THEREIN," to be as follows:-
This Invention relates to certain novel methods or processes for
manufacturing salt, and also to novel constructions or arrangements of
apparatus to be used in such manufacture, and has for its object :-
1st. The purification of the brine from its calcareous ingredients.

page_text: 2nd. Effecting the largest possible amount of evaporation with the
smallest possible amount of caloric.
3rd. The use or application of all the caloric evolved from the fuel.
And, 4th. The complete removal of salt from the evaporating apparatus,
and its delivery by mechanical means.
The process of the production of salt from the brine is effected by
pouring the latter through a vessel in which the brine is submitted to
a high temperature, say 300° under pressure in concentrator boilers to
effect the precipitation of the sulphate and carbonate of lime after
which the brine is passed at low pressure through filters. In the
evaporation of the brine in bigh pressure boilers at temperatures
between 300° and 600° Fahrenheit, the transmission of the same caloric
is effected to carry on successive evaporations in a series of boilers, these
high temperatures being gradually reduced down to temperatures below
150° Fahrenheit.
The boilers employed are constructed with a vertical system of tubing
so as to produce rapid and unobstructed evaporation of the brine.
In the purifier and its associate parts the removal of sulphate and
carbonate of lime is effected by using a temperature of about 3000 with
but a small expenditure of caloric.
Concentric cylinders are arranged in combination so as to make
concentric steam spaces.
Brine pumps are adapted to and used in combination with high and
low pressure brine boilers so as to inject by the expulsive force of the
water of condensation a corresponding quantity of brine heated as it is
injected by heat from the water of condensation.
In combination with the precipitating salt boilers a detachable salt
chamber (moving on wheels) is employed to receive and discharge the
salt.
"
Another feature of novelty consists in the use of high-pressure steam,
condensing tubes for evaporating the brine, and the combination of
a series of these condensing tubes to produce successive evaporations of
brine by the transfer of the same caloric at temperatures above the
ordinary boiling point. The reduction of superheated steam to saturated
steam (when used for brine evaporation) is effected by forcing it through
the water of condensation, or by compelling it to traverse rapidly a
long range of steam condensing tubes.

page_text: In the brine boilers there are ascending and descending channels for
the purpose of accelerating the circulation of the brine. A pump and
a salt reservoir are also adapted to the brine boiler in order to compel a
rapid circulation over the evaporating surfaces, and the salt is removed
from the interior of the boiler by scrapers which deliver it into the salt
reservoir. Compound vacuum evaporators are combined with a series of
boilers for evaporating the brine and precipitating salt under less than
atmospheric pressure, and in the combination with the vacuum evaporators
above mentioned there is a rotary scraper or rake for the removal of
the salt as it is deposited in the evaporators. In a close salt boiler
revolving spiral scrapers may be used to effect the removal of the salt,
and in combination with the revolving scraper in a close horizontal salt
boiler propelling floats and steam cups are employed to produce rotation
by ebulition. In the vertical brine boiler vertical rotary scrapers or
brushes are employed, and also oblique paddles for its propulsion by
ebulition currents.
Another feature of the Invention consists in the combination with a
monothermal series of boilers of double steam pipe connections so as to
make their serial action reversible. The boilers and furnace are sur-
rounded with some non-conducting substance to prevent the waste of
caloric by radiation, and thereby effect an economy of fuel. The brine
boiler is detachable and is provided with a mushroom-shaped heater
and serial connections or with a flask heater for evaporation, and the
boiler is capable of being tilted. The boilers of a monothermal series
are arranged concentrically within one large boiler, the heating tubes
and heating steam spaces are also arranged in the boilers in a similar
manner. Narrow descending smoke channels and ascending hot air
channels are employed to effect the recovery of the sensible and latent.
heat in the products of combustion. Flattened air channels are arranged
so as to slide in a rack contained in a box, the sides of which open
as doors for convenient access and removal. The taking up and
by the medium of
transferring the heat of the furnace is effected
pyrostatic liquids circulated in suitable channels. These liquids are the
saturated solutions of caustic soda, or potassa, or purified petroleum tar,
and its combinations with alkalies or oil of terpentine converted by
prolonged heating and chemical agents into meta-terebenthene and its
analagous associates. The wires of a galvanic battery are adapted to
the steam heaters and condensers in order to maintain a constant electric
current through the condensing structure.

page_text: With the boiling tubes of a steam generator is combined a pump and
a system of interior tubes to maintain a steady supply of water at the
bottom of the tubes.
SPECIFICATION in pursuance of the conditions of, the Letters Patent,
filed by the said William Edward Newton in the Great Seal Patent
Office on the 21st April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the.
County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of October, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Edward Newton, Her special
licence that I, the said William Edward Newton, my executors, adminis-
trators, and assigns, or such others as I, the said William Edward
Newton, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the time therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
“ IMPROVEMENTS IN THE MANUFACTURE OF SALT," being a communication to
me from abroad by J. R. Buchanan, of the City of New York, United
States of America, upon the condition (amongst others) that I, the
said William Edward Newton, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
'
NOW KNOW YE, that I, the said William Edward Newton, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Drawings

page_text: This Invention of improvements in the manufacture of salt and in
the apparatus employed therein has for its objects :-
First. To effect the purification of brine from its impurities.
Second. To obtain the largest possible amount of evaporation with the
smallest possible amount of fuel.
Third. To effect the most perfect utilization of all the caloric evolved
by the fuel.
Fourth. To obtain removal of all the salt from the evaporating
structures by mechanical means and appliances.
First. The purification of the brine from sulphate of lime is effected
by passing the brine through a vessel in which it is raised to a tem-
perature of three hundred and ten degrees Fahrenheit, and then filtering
it to remove the precipitate thereby produced. The chlorides of calcium
and magnesium are removed by precipitation with carbonate of soda,
or if they are superabundant they may be concentrated and discharged.
Second. The largest possible evaporation is attained by using high
pressure steam generators for the first evaporation, and using the latent
heat of this high pressure steam (as it is given off in condensation) to
heat another boiler and produce an equal quantity of steam of lower
temperature and tension, from which again a third evaporation is effected
in like manner, and thus the process is repeated (as often as it may be
profitable so to do) between the highest and lowest boiling points of the
brine, between which extreme points as many as twenty or thirty
repetitions of effect may be produced by proper apparatus. This extreme
repetition of effect is produced by raising the temperature of the first
evaporation as high as it can be carried without danger to the apparatus
(about five hundred degrees Fahrenheit), and continuing the repetition.
or transfer of the same caloric from one boiler to another at small
intervals until the temperature is below the atmospheric boiling point.
A partial vacuum is used to assist the last evaporations. The range of
three hundred and fifty degrees thus obtained renders twenty or thirty
repetitions of effect (in pure water) (from the same caloric) entirely
practicable in laboratory experiments, and ten or fifteen repetitions may
be used in manufacturing operations upon-brine. The great cheapness of
production, however, with six or eight repetitions renders it unimportant

page_text: to go further where fuel is not very dear. This repetition of the effect
of the same caloric in a series of boilers constitutes a monothermal series
which the Invention renders practicable and profitable by combining in
one series of apparatus high-pressure steam tubing for high temperatures
and vacuum pans for low temperatures, and also removing the hindrances
which have heretofore prevented the application of the monothermal
principle in salt making.
Third. The complete utilization of the caloric (which is an important
additional economy) is gained by arranging an economical furnace in
which (the walls of the furnace being made efficient by means of non-
conductors) the heat which is usually lost by passing off with the
products of combustion is thoroughly recovered and returned to the
furnace witn the air that supports combustion, which air robs the smoke
of its sensible and latent heat, and is thrown into the furnace at the
ordinary temperature of the chimney or much higher. This furnace
being deprived of the usual escape for its heat by the chimney becomes
self-accumulative of its caloric, and if deprived of the consumption of
heat by the generator would soon become white hot and destroy every-
thing metallic about it. Hence it compels all the heat evolved in the
combustion to go into the boiler, and by preventing waste of calóric
renders all kinds of boilers about equally efficient with the same fuel.
As the conversion of temperatures above five hundred degrees by means
of saturated steam developes too high a pressure for ordinary structures
liquids which are capable of conveying high temperatures without much
pressure are employed, and may by circulating in tubes in the furnace
take up and convey the heat to the point where it is required. These
liquids are, first, saturated solutions of caustic soda or potash; second,
purified petroleum tar; third, certain preparations of oil of turpentine.
When actively circulated such liquids may convey as much heat as a
mass of red-hot iron. In salt making this method enables us to make
our first evaporations at very high heats and with very great rapidity.
Fourth. Thorough removal and proper mechanical handling of the
salt. On evaporation of brine in close vessels the salt necessarily collects
or forms crusts on the evaporating surfaces, and the prompt removal of
this, which is indispensable, may be effected under different circumstances
by different methods, which as they should all be understood by the
manufacturer will be specified :-
First. Currents produced by ebullition in long vertical channels.

page_text: Third. Mechanical force, as by friction, brushing, or scraping.
+
Fourth. Preventive measures, as by using electric currents to prevent
deposition, or by rendering the evaporative surfaces smoother and less
adhesive.
Fifth. Re-solution by introduction of fresh brine. The ebullition
currents and pump currents should be prolonged through the boilers so
as to carry the salt to an exterior depository or salt receiver. The
mechanical removal by scraping leaves the salt to fall through a
> funnel arrangement into a salt receiver, from which (after the brine
has been expelled) it is discharged through a valve and taken by
élevators to a drying cylinder, from which it is removed to be deposited
in barrels.
In the accompanying Drawings Fig. 1, Sheet I., represents the
purifier Pu; SP 1, the supply steam pipe; wp, the pipe for drawing
off the water of condensation; hc, hc, the heating coil of the steam
pipe cg, the current guide; cf, a cloth filter; F, a filter; BP, the
brine pipe; dc, its discharging chamber; S P 2, steam pipe from
purifier; co, its cock; ep, eduction pipe for purified brine; ip, in-
duction pipe for brine; P, pump; No. 1, valve leading to pump; No. 2,
valve leading from pump; GV, gate valve.
Fig. 2, Sheet I., represents the monothermal series apparatus above
mentioned; CB 1, 2, 3, and 4 are concentratory boilers; 8p, their
steam pipe connections; T1, tank of purified brine; T2, tank of
concentrated brine; CP, compound pump (shewn detached and in
section at Fig. 24, Sheet I.); wp, its water pipe; wpd, its water pipe
discharge; bpd, its brine pipe discharge; bsp, bsp, brine supply
pipes; PB 1, 2, 3, 4, are the precipitatory boilers; s³, p¹, their steam
pipe connections; VE, vacuum evaporator (see Fig. 20); GV, GV,
gate valves.
Figures 3 and 3*, Sheet II., represents a high-pressure generator,
Fig. 3 an exterior view, and Fig. 3 the section of a main pipe with its
connections; MP, main pipe; SP1, steam pipe; IP, induction pipe;
EP, eduction pipe; ct, ct, circulation tubes; bt, bt, boiling tubes;
cc, cross connection of main pipes for equilibrim; MP, end view of
main pipes; GB, grate bars.

page_text: Fig. 4, Sheet II., is a sectional view of a horizontal tubular concen-
tratory boiler; SP1, supply pipe for steam; pa, pa, partitions in steam
space; ss, steam spaces; tt, steam tubes; WP, water pipe; D, steam
drum.
Fig. 5 represents the steam connections of a series of horizontal con- t
centratory boilers. B 1, B2, B3, B4, are the horizontal concentratory
boilers; D, D, D, D, steam drums; SP1, steam pipe from the generator;
SP 2, steam pipe leading to the precipitatory boilers.
Figures 6 and 7, Sheet I., are vertical and horizontal sections of
concentratory and precipitatory boilers. B 1, B 2,. concentratory boilers; 1
B 3, precipitatory boiler; S P 1, steam supply pipe; t, t, t, steam con-
densing tubes; pa, partition in steam space; ss, steam space; wp,
water pipe; flv, float valve; par, partition in precipitatory boiler
between ascending and descending currents; ht, horizontal tubes;
g, w, p, gwn, galvanic wires; sj, steam jacket space; S P 3, steam 1
pipe leading to salt receiver; co, cock; ac, air cock; G V 1, G V 2,
gate valves; SR, salt receiver; DP, discharging pipe; V, valve in
discharging pipe; fi, filter.
Fig. 7 is a horizontal section of B 3. sj, steam jacket space; par
partition; tt, rows of steam tubes.
Figures 8 and 8ª, Sheet III., represent the reciprocating scrapers.
st, steam tube; scr, section of scraper; RR, rods. Fig. 8ª, scr,
scraper rings in two halves held together by springs; spr, springs to
hold the halves together:
Fig. 9, Sheet II., represents the accelerator channels.
sc, salt 2
collector; B, boiler; 1, 2, 3, steam heating tubes; AC, DC, ascending
and descending channels; GV, gate valve.
Fig. 10, Sheet II., is a vertical section of the compound apparatus
arranged as a cylindric condenser and boiler with device for propelling
or forcing in the brine; cc, are steam heating condensers; par, is 3
the cylindrical partition; RP, the rotary pump; SC, the salt collector ;
SP 1, the steam supply pipe; wp, the water discharge pipe; and g wp,
gwn, are galvanic wires.
Fig. 11 is a sectional view of a steam jacket boiler shewing the spiral
scraper. sj, is the steam jacket space; sh, is the shaft of the screw 3
scraper sp, by the rotation of which the salt is removed from the
interior sides of the cylinder.

page_text: Figures 12 and 12ª, Sheet I., are sectional views of the water tube,
boiler, and longitudinal scraper. S P1, is a supply steam pipe; S P2, a
discharging steam pipe; wpa, water pipe; rt, rt, returning tubes;
88, steam spaces; bc, the bearing for small cranks; fr, the frame to
hold cranks; 12ª, returning tube and scraper; rt, returning tube;
8 cr, scraper; and cr, the crank.
Fig. 12b is a vertical section of a reciprocating scraper. RR, are
propelling rods; 888, spring scrapers; and W S, water spaces.
Figures 13 and 13ª, Sheet II., represent twin boilers. S P 1, a steam
supply pipe; S P 2 is the steam discharge pipe; CB, is the con-
centrating boiler; PB, the precipitation boiler; GV, a gate valve;
bsp, is the brine supply pipe. Fig. 13ª is a horizontal section of the
twin boilers; bsp, is the brine supply pipe; and tc, is a two-way
cock to supply brine to either inner or outer boiler.
Fig. 14, Sheet I., represents a reversible series of boilers. B1, B2,
B3, B4, B 5, are boilers connected together in a reversible series;
bsp, bsp, are brine supply pipes; a, b, c, d, are cocks, by opening
which the transfer of caloric is directed from a towards d or from B 1
to B5; efgh, are cocks, on opening which the steam and caloric are
transferred from B-5 towards B 1 or from right to left; af, af, are
automatic feeders for each boiler connected with its steam space above
and the water space below; fp, fp, are the feed pipes governed by the
automatic feeders; a', b', c¹, d', are cocks on the feed pipes to control the
transfer from left to right, corresponding to a, b, c, d, on the steam
pipes; e, f, g¹, h³, are cocks on the feed pipes to control the transfer
from right to left, and correspond to ef gh, on the steam pipes.
Fig. 14 represents the automatic feeder. fl, is a float; 1, a lever;
and wp, the water pipe.
Fig. 15, Sheet II., is a vertical section of a concentric boiler con-
structed on the monothermal series principle; B1, B2, B3, B4, are
concentric boilers; ttt, are steam tubes; pa, a partition in the steam
spaces ss; and wp, are the water pipes.
Fig. 16 represents a compound tubular boiler. ttt, are steam tubes
connected with the steam supply pipe S P1; va, the valve to compel
the circulation of steam through the pipes in blowing off.
Fig. 17 represents a long narrow concentrating boiler. $ 8, 88, are
steam spaces between the tube heads to break their continuity.

page_text: Fig. 18 represents a flask heater boiler. B is a cross section of the
boiler; fl, fl, are flask shaped condensers; and S P 1 is the horizontal
steam supply pipe.
"
Fig. 19 is a view of a tilting boiler. SP1 is the steam supply pipe,
and SP 2 the steam discharge pipe; bsp, is the brine supply pipe;
wp, the waste pipe; pi, pi, pivots of the boiler which rest on upright
standards; and GV, is the gate valve.
Figures 20 and 20%, Sheet III., represent in longitudinal and cross
sections the vacuum evaporator V E. dd, are doors at the ends of the
four compartments; S P1 is the steam supply pipe; S P 2, the steam 1
discharge pipe; and wp, the water pipe. In Fig. 20³ ws, is the water
space; ss, the steam space; ww, wooden ribs to which the false
bottom fb, of sheet iron is fastened.
Fig. 21 represents a tubular vacuum evaporator. TVE, SP1 is
the steam supply pipe, and S P 2 the steam discharge pipe; par, a 1
partition in the steam space; ss, and ttt, are steam tubes; wp, the
water pipe; R is a rod or shaft for working the combined scrapers,
scr; sh, sh, are hinged shovel scrapers for cleaning the bottom;
G V, is the gate valve, and SR, the salt receiver; ac, is an air cock,
and SP 3 a steam pipe to receiver; DP, is the discharge pipe, and 2
fi, a filter; at, is an attachment to support the system of tubes at the
right hand end, and gwp gwn, are galvanic wires.
Figures 22, 22, 22°, Sheet III., are various views representing the
retro-thermotor. Figures 22* represent a side and edge view of the air
channel A C. Fig. 22. is a sectional side view of retro-thermotor 2
and chimney flue to which it is attached; Fl, is the chimney flue;
HA, HA, are hot air passages; RT, is the retro-thermal structure
through which the hot air ascends and smoke descends in parallel
passages. The arrow h, s, indicates the hot smoke entering, and the
arrow cs, the cold smoke leaving the retro-thermotor; Ch, is the 3
chimney by which the smoke is expelled; re, the receptacle for smoke
as it comes from the smoke passages; CA, is the cold air chamber
communicating with the blower; co, is a cock for the discharge of
water condensed from the smoke. Fig. 22b is a sectional end view of
the box with its outer case removed from one face; CA, is the cold air 3
chamber, and HA, the hot air chamber; BP, is the pipe from the
blower; AP, the air passage to the flue of chimney; a, c, are air
channels, and sc, sc, smoke channels, and ff, is the grate frame.

page_text: Fig. 23 is a vertical section of the retro-thermotor apparatus and
furnace; B, is the pipe leading from the blower; R, the receptacle of
air from the blower; ap, ap, air pipes from the receptacle R passing
through the smoke pipes to the drum D; S m, is the smoke receptacle,
and Ch, a chimney for discharging the smoke from the smoke receptacle;
Bp, is a blow pipe from the drum D of the grate; W W, are the
walls of the furnace, and WC, W C, the inner and outer walls of the.
chimney; co, is a cock for the discharge of water, and nc, nc, a non-
conducting material for covering the walls.
Fig. 24, Sheet I., is a vertical section of a compound pump. No. 1 is
the brine pump leading to the boiler; No. 2 is a pump which is actuated
by the water of condensation from the boiler; No. 3 is the supply and
V V, are two way valves; pvpv, are poppet or self-
exhaust pump.
acting valves; pr, piston rod, and ph, are the pistons.
Fig. 25, Sheet II., represents a section of a generator. UMP, is
the upper main pipe, and LMP, the lower main pipe; ttt, are
vertical tubes placed between the upper and lower main pipes.
Fig. 26 represents the sectional generator in position. SS, are the
sections in place; and D the drum; and fp, is the fire-place. The
apparatus for carrying on these operations consists of a stcam generator
and a system of from five to twenty boilers mono-thermally connected
together and terminating in a vacuum evaporator and a condenser.
This apparatus operates upon brine that has been passed through a
purifier and is sustained in operation by a peculiar regenerative or rather
heat recovering furnace. The brine is first pumped into a suitable tank.
or reservoir in which its heterogeneous constituents are chemically
treated.
Preliminary Chemical Treatment.-Chloride of magnesium may be
removed by means of carbonate of soda which precipitates the magnesia
leaving chloride of sodium in its place. Chloride of calcium
may be.
decomposed by carbonate or sulphate of soda, thereby obtaining carbonate
and sulphate of lime which are removed by heat and filtration. The
above would be the cheapest process of purification, but the earthy
chlorides may be decomposed by phosphate of soda, either alone or in
combination with carbonate or sulphate of soda, or with sulphate of
ammonia to precipitate the ammonia magnesia phosphate; carbonate of
lime may be used as an adjunct to carbonate of soda in decomposing the
chloride of magnesium, and hydrate of lime may be employed in certain

page_text: cases to precipitate carbonic acid and earthy carbonates, metallic
impurities, silica, phosphoric acid, organic matters, and magnesia.
Silicate of soda may also be used to precipitate lime and magnesia from
their chlorides. The sulphates of lime, soda, and magnesia may be
removed by carbonate of baryta, also by carbonate of lead, or by the
chlorides of these bases, but the absolute precipitation and removal of
the baryta or lead must be effected by sulphide of sodium. Sulphate of
soda may also be treated by the addition of its equivalent of chloride of
calcium and the application of heat in the purifying apparatus. This
will throw down sulphate of lime. Sulphate of magnesia may be
decomposed by chloride of calcium, and the resulting chloride of
magnesia precipitated by lime, by phosphates, or otherwise.. Such
operations may precede purification by heat or they may be used after
the removal of sulphate of lime, in which latter case it will be expedient
to pass the brine again through the purifier for the perfect removal of
the precipitates. If however the earthy chlorides or the sulphates of
soda or magnesia be present in large quantities it is cheaper to omit
these preliminary chemical processes and discharge the concentrated
solutions of the heterogeneous constituents (bitterus)- from the last boiler
of the monothermal series. In this case the boilers must be so con-
nected as to feed the brine from one boiler to another in regular
succession, in which case all the chlorides and other impurities will
accumulate in the last boiler and may be discharged at proper intervals
and used for the manufacture of certain merchantable salts. The several
Figures in the accompanying Drawings represent various views of the :
apparatus employed in the different operations.
To remove sulphate and carbonate of lime the brine is pumped
through a heating and cooling pipe BP, (Fig. 1, Sheet I.,) which may
be from eight to twelve inches in diameter and from six to twelve
feet long, and is filled with small tubes. The brine passes into the 3
purifier Pu, which is a cylinder two feet by five with an exterior
cylinder or current guide cg, about sixteen inches in diameter. This
rrangement produces an ascending current of sixteen inches in the
interior, and a descending current of four inches diameter in the exterior.
The brine being pumped into the upper end of the purifier descends in 3
the narrow annular space, and receives heat (as it passes) from a heating
coil of steam pipe hcho, thereby raising its temperature to about
three hundred and ten degrees Fahrenheit whereby the sulphate and

page_text: usually the carbonate of lime are rendered entirely insoluble, and are
precipitated and may be discharged from the bottom of the purifier
through a gate valve GV. The current of brine next passes up
through an extended cloth filter cfcf, and then through a filter of
sponge or other suitable material F, and will rise up the cylindrical
space cg to the small tubes in BP, by which it passes out, and in so
doing imparts its heat to the surrounding brine which is entering. This
exchange of heat is so effectual that the outgoing brine will be brought
down nearly to the temperature at which it entered, and the ingoing
brine so effectually heated as to require very little steam from the
coil h c, to raise it to three hundred and ten degrees. The brine goes
now to the discharging chamber dc, at the end. of BP, from which
it is pumped out through ep, while fresh brine enters at ip. The
formation of steam is prevented by want of room. A double-acting
pump is used with two separate connections, one for injecting the
crude, the other for withdrawing the purified brine. The inducting
channel ip may have self-acting flap or poppet valves while the
educting channel ep, requires its discharging pipe to be closed by the
proper movement of the valves as the brine enters the pump. The two-
way cock is a suitable valve for this purpose. When a discharge of
the calcareous precipitate is made from the purifier through the gate.
valve GV, steam will be developed in the upper part to replace the
amount discharged. To remove this a steam pipe SP.2 is extended
from the top of the purifier to the discharging chamber dc, and when
this passage is opened for a while by the cock co the steam is drawn
off by the pump. A glass tube being made a part of this connection
enables us to ascertain when the brine has taken the place of steam.
The purified brine thus obtained is conducted into a reservoir, from
which, by means of the compound pump shown in Fig. 24, Sheet II.,
each boiler supplies itself, or a steam pump may pump the purified brine
into a high-pressure chamber, from which the series of boilers may be
supplied either immediately through a pipe governed by an automatic
feeder or intermediately by feeding from one boiler to another through
the whole series, the transfer being governed by an automatic feeder
consisting of a ball floating in a small chamber connected with the
boiler, and attached to a lever by which it will open a feeding valve as
it descends with the level of the water. To prevent this ball float from
becoming in time water-logged by the slow entrance of water it is

page_text: necessary that its cavity should communicate with the atmosphere
through a tubular perforation in the lever.
The evaporation of this purified brine is effected in a monothermal
series or combination of boilers in which the salt-making boilers operate
only on saturated brine, and this saturated brine is prepared for them by
a series of concentrating boilers, the number of which is proportioned to
the weakness of the brine. If the brine be half saturated one half of
the boilers will be devoted to concentrating or evaporating half of the
water, and the other half to completing the process. The monothermal
series then is composed of concentrators and precipitators, the number
of the latter corresponding to the amount of water in excess over
saturation. Brine that is nearly saturated will require precipitators
only.
As it is desirable to precipitate in the boilers of the lowest pressure
the high-pressure boilers will act as concentrators, (see Fig. 2, CB,) and
the low-pressure boilers as precipitators (see Fig. 2, PB), the boiler at
the lowest pressure will work nearly at atmospheric pressure.
The details are as follows:-A high-pressure boiler or generator com-
posed mainly of small water tubes takes up the heat of the regenerative
furnace. If the brine is very strong this boiler will carry pure water only,
and will furnish steam heat to the boilers, the water of condensation re-
turning by gravity to the generator. If the brine be weak the
expense
of one boiler may be saved by using the generator to concentrate the
brine while furnishing from this brine steam for the series which as it
condenses will be discharged. The generator is constructed of a sufficient a
number (say twelve or fifteen) horizontal pipes five or six inches in
diameter, with projections two inches apart, into which two inch pipes
of proper length are screwed. They may be arranged parallel, as shewn.
in Fig. 3ª, Sheet II., so as to form by reason of the different lengths of
the two-inch tubes an arch over the fire. Fig. 3 shews on a larger scale 3
how each main pipe MP is occupied by a horizontal injecting tube ip,
from which circulation tubes ct, ct, descend nearly to the bottom of
each boiling tube. The injecting tubes are all connected with a pipe
from the pump IP, by which they are supplied, and another pipe EP,
connected with the pump withdraws from each main pipe any excess of 3
water. A cross connection between the main pipes cc maintains their
equilibrium. In the operation of the generator the tubes are protected
from overheating and expelling their contents by the constant supply of

page_text: water at their lower ends through the circulation tubes ct, ct, and the
pump which maintains this circulation requires but little power. The
_steam from this generator goes to a pipe or drum five or six inches in
diameter and five or six feet long, which is connected with either the
end or the middle of each main pipe, and supplies steam (preferably from
each end) to the first boiler of the monothermal scries in which it is con-
densed. If the generator acts on fresh water the water condensed from
its steam in the first boiler is returned to it by a pipe from the bottom
of the boiler to the pipe EP. If (as is desirable, with very weak brines)
the generator acts on salt water the pump which maintains its circula-
tion will discharge what it receives from the generator to a tank, and
will inject only fresh liquid drawn from the tank of purified brine.
When it is not convenient to maintain the circulation by a steam pump
the generator is constructed on a very simple plan, as shewn in Fig. 25,
Sheet II. The main pipe U M P, is extended down at its ends to another
horizontal tube below the vertical tubes which are connected with the
two horizontal tubes above and below. A circulation of steam and
water takes place up the small tubes and down the lateral main pipes,
as indicated by the arrows. This arrangement, which constitutes one
section of the generator, delivers its steam at SP 2, and receives its water
by wp. The generator is composed by combining together in any
convenient way a sufficient number of these sections. A very convenient
method of doing so consists in placing the sections parallel to each
other in a furnace, as shewn in Fig. 26, Sheet II.
With such a generator we may cheaply and safely obtain saturated
steam of four hundred degrees to five hundred degrees temperature,
which may be passed into the first concentrator series, Fig. 2, Sheet I.,
CB, CB, which consists of boilers containing steam condensers, as in
B¹, Fig. 6, Sheet I., or in Fig. 4, Sheet II. The condensers may consist
of tubes or cylinders of any convenient shape, and the condensing tubes
of each successive boiler are supplied with steam from the evaporation
caused by the heat of the condensing tubes in the preceding boiler (see
Fig. 6, Sheet I.).
When the concentrating boilers are horizontal the steam condensing
tubes are inserted at each end in a substantial head opening at both
ends into a steam space between the tube head and the boiler (see
Fig. 4). These tubes are not more than two inches in diameter, and
one inch or one inch and a half apart. They nearly fill the interior

page_text: of the boiler, leaving only a small area above for a steam space, from
which the steam is removed by a pipe or pipes leading to a suitable
drum (D, Fig. 4, DDD, Fig. 5).
D, Fig. 4, is a section of a cylinder thirty inches in diameter and ten or
twelve inches deep, which gives a broad area for the insertion of a wire
sieve to arrest any spray in the steam drum D; Fig. 5 is an elongated
cylinder, eight or ten inches in diameter, and of any convenient length
which may also contain small spray screens. From each drum or vessel
D steam is delivered to the condensing tubes of the next boiler in the
series, in which the same operations are repeated, and so on to the end
of the monothermal series of boilers (see Figures 5 and 6, Sheets I.
and II.). The steam enters at one end of the boiler (which may be ten,
twenty, thirty, or more feet in length), occupies the steam space next
the boiler head (see Fig. 4, ss,) from which it passes through the tubes
to the steam space at the other end, as in Fig. 4, (or to the ends of the
tubes, as in Fig. 6,) and is condensed by the inferior temperature of the
boiling brine around the tubes, which by boiling at thirty degrees or
forty degrees lower temperature takes up the heat of the condensing
steam at the rate of about nine hundred equivalents per hour, per square
foot for every degree of difference of temperature. The concentrator
boilers which are of lower pressure may be of lighter construction than
the others, and as their steam is more voluminous they will require larger
steam passages. Boilers of the highest pressure may be narrow and
long, in which case the tubes may be subdivided longitudinally by
additional steam spaces as shewn in Fig. 17, Sheet II. The steam con-
densed in the tubes flows out as water from one or both ends of the
boiler, from the bottoms of the steam spaces, its discharge being regulated
by a float valve which closes as soon as the water is expelled, and thereby
retains the steam. The heat of the water thus discharged should be
utilized by imparting it to incoming brine, after passing through a
compound pump, (see Fig. 24, Sheet I.,) its expulsive force being sufficient
in operating this pump for the injection of a corresponding amount of
brine, and the injection of brine to take the place of that which having
been concentrated is to be discharged. The supply of brine to the
concentrating boilers may however be regulated by an automatic feeder,
consisting of a float attached to a lever which opens a valve as the
water level descends and allows a supply to enter from a high-pressure
feeding reservoir, in which it is maintained at a high pressure by the

page_text: supply pump and by high-pressure steam. Each boiler if supplied by an
automatic feeder may keep itself filled from the preceding boiler of the
series which has necessarily a higher pressure. In this case the first
boiler must be supplied either by a pump or by a steam feeder operated
by condensing steam. It will be expedient to protect the automatic
feeders between the precipitator boilers by inserting filters in the con-
necting pipes to prevent the transmission of salt. When the concen-
trating boilers are placed upright (as seen at Fig. 6, Sheet I.), the
condensing tubes rise from the lower steam space, and are connected
with an upper steam space which stands below the water level which is
very strong and well stayed. If this upper steam chamber be used the
inducting steam pipe is connected directly with it alone to facilitate
the expulsion of any accumulation of air from the condensation which
takes place. A somewhat better plan is to connect each of the tubes
in one half of the boiler with a corresponding tube in the other half
(by bending or by elbows), so that when the corresponding halves of
the steam chamber below are separated by a partition, the steam shall
ascend on one side and descend on the other (see B¹, Fig. 6), thus
facilitating the expulsion of air from the tubes and promoting by circu-
lation the transfer of caloric. In boilers of great vertical length it will
be expedient to leave one-third of their area either at the circumference
or the centre clear of the tube to facilitate a returning or descending
current from that raised by the ebullition, and a thin partition between
the currents will also be useful. The brine being sufficiently concen-
trated is to be removed by the compound pump (Fig. 24) and replaced
by the injection of fresh brine by the same pump. It is then taken up
by the compound pumps of the precipitating boilers. The precipitating
boilers being of lower pressure are of lighter structure, and may be
made of thin iron or of wood properly jointed and hooped. Their
evaporating surfaces may be cylinders or tubes. It is preferable that
the tubes should be vertical to facilitate the removal of the salt by its
gravity, but this is not indispensable (a horizontal precipitator is shown.
in Fig. 21).
The vertical tubular precipitator boilers may be formed as shewn in.
Fig. 6, B 3. The tubes are arranged in two or more concentric circles,
so as to leave a central channel for the descent of the salt. The tubes
are connected with horizontal annular pipes at the top and bottom,
and receive their steam by the upper pipe, and discharge their water

page_text: through the lower by wp. The currents of ebullition bring down the
granulated salt in the central channel (after ascending along the tubes),
and as it falls it passes through the open gate valve G V 1 into the salt
receiver SR, the thin partitions par, par, serves to separate the
ascending and descending currents. When the receiver S is full this
gate valve GV is closed, and a current of steam is thrown into it by
the injecting pipe SP 3, which serves to expel the brine by the dis-
charging pipe DP to the boiler above, from which the valve V prevents
its return, and an additional valve may be located at the connection
with the boiler. A sponge or other suitable filter fi may be inserted
at the connection of DP with the salt receiver. The brine having
thus been expelled the lower gate valve GV 2 is opened until the salt
escapes, the cock on SP 3 allowing only enough steam to pass to
exclude air from the receiver. The salt when discharged is received by
a travelling screw or belt, and conveyed to the drying cylinder from
which it is dropped into barrels. The gate valve being closed and the
cock of SP 3 shut, brine may be readmitted by gradually opening
GV 1, while an air cock ac may be opened by way of precaution
until the receiver is full. The evaporative power of this boiler may be
considerably increased by adding an exterior shell, so as to make a
steam space or steam jacket sj around it as shewn in Fig. 6, B 3.
The additional evaporating surface in this case amounts to about one
hundred and seventeen square feet. The expulsive force of the water
from each of the boilers operating on the compound pump (Fig. 24)
supplies each with the proper quantity of brine.
The cylindrical condenser precipitating boiler is constructed as
follows: In a boiler (which may be vertical or horizontal) is placed a
set of concentric steam spaces each composed of two parallel cylinders
with an interval of an inch or two between them to contain steam in
the close cavity, forming thus a compact steam heater (see Fig. 10,
Sheet II). These steam heaters (from one to five or more in each
boiler), which may be from one to four inches apart concentrically
arranged and of any expedient height, will fill the interior of the boiler,
excepting the space for the steam at the top, and the space circum-
scribed by the smallest cylinder. The spaces between them being
occupied by the boiling which rapidly ascends, descending again in the
circumscribed space just mentioned. The currents thus produced may.
be sufficient for the removal of the salt and its delivery to the descend-

page_text: ing current toward the salt receiver if the channels are sufficiently
narrow and elongated, but to make it sure in all cases the evaporating
surfaces of the heaters should be traversed by reciprocating scrapers,
composed of rods bearing scrapers sustained by springs as shewn at
Fig. 126, Sheet I. A revolving scraper of which the springs are attached
to upright rods fastened to horizontal arms and revolving around a
central shaft (passing up through the top of the boiler) might be used
but would be less desirable.
For the tubular heaters the proper style of scraper is shewn in Figures
8, 8ª, and 21, Sheet III. A double ring (the two halves connected at
three points) embraces cach tube. Its sharp edges serve as scrapers.
The rings are arranged in planes one or two feet apart and are connected
by rods and the whole operated by a rod (which passes through the end
of the boiler) with a reciprocating motion. An equally good or better
form has each chain of rings composed of two halves attached together
by a spring as in Fig. 8. (scr, scraper rings in two halves; spr,
springs to press the halves together.)
When the boiler is a simple cylinder with but one evaporating surface,
as in Fig. 11, Sheet II., a spiral scraper or screw (sp) will be the
appropriate method of clearing it from salt. A salt receiver should be
affixed to its lower end if vertical (as in Fig. 6), or to one side if
horizontal (as in Fig. 21, Sheet III.) Instead of such mechanical expe-
dients for removing the salt we may depend upon currents in the brine
propelled by ebullition and the power of a pump. Thus in Fig. 10,
Sheet II., the boiler contains two cylinder, heaters, and a current is
rapidly propelled over their surfaces, which may be from half an inch to
an inch apart, by the rotary pump R, P, which receives the brine as it
descends the central channel to the salt receiver SR. The brine
returns through the pump after depositing a portion of its salt. This
receiver should be of sufficient depth to hold twenty or thirty bushels
of salt and has its lower portion formed like the salt receiver of Fig. 6,
and is controlled in the same manner by two gate valves, a steam-pipe,
and a discharging pipe. The steam supply of these cylinders should be:
received at the top, as shewn in Fig. 10, (unless revolving scrapers are:
used, in which case it should be received at the bottom) and the outlets
at the bottom wp will discharge their water of condensation and when
necessary any air or gas accumulated in them. The efficiency of the.
ebullition currents in removing and conveying the salt may be greatly
B 2

page_text: increased by elongating the channels for the ascending steam and brine,
as by making long narrow vertical boilers, or by adding an ascending
and descending channel, as in Fig. 9, Sheet II., AC, DC. The
ascending channel AC may be ten or twenty feet long. The steam
which produces the ascensive tendency is given off to a pipe or drum at
its upper end and the water, clear of steam, descends in the channel
DC to a salt chamber of sufficient size and depth. The brine returns
from this chamber to the ascending current over the tubular evaporating
surfaces in the boiler.
In Fig. 9 a central steam heater No. 1 is surrounded by two con-
centric heaters Nos. 2 and 3 so as to leave three annular spaces a little
less than an inch wide through which the current will be extremely
rapid even without the assistance of a pump. In addition to scraping
and the use of ebullition currents and pump currents for the removal
of saline accumulations the process of redissolving may be employed, for
which purpose the monothermal twin series of boilers and the mono-
thermal reversible series may be used.
The twin series may be formed as shewn in Fig. 13, Sheet II., by
connecting together at the base two vertical boilers, one of which has
the salt receiver at its lower end, the brine is fed into the other boiler,
and as the brine becomes sufficiently concentrated it necessarily passes
into the second or salt making boiler. In using the twin boilers I may
change the connection as often as necessary, and by feeding the fresh
brine to the boiler in which the salt has accumulated or incrusted its
resolution will be affected. The twin boilers may also be arranged
concentrically as shewn at Fig. 13ª, Sheet II., one being placed inside
the other, and by turning the two-way cock to the brine may be
conducted to either boiler. The reversible series is shewn at Fig. 14,
Sheet I., and is formed by making double connections between all the
boilers of the monothermal series so that if the series consists of seven
boilers the first may be connected with the generator and the seventh
with the vacuum evaporator, or by reversing the connection the seventh
may be connected with the generator and the first with the vacuum
evaporator, the transfer of caloric taking place in opposite directions.
This change converts the precipitatory boilers into concentrators and
removes their accumulations of salt. This plan involves the necessity of
constructing all the boilers alike and in the strongest manner. It also
involves the necessity of making the brine supply reversible if the boilers

page_text: feed from each other, which is effected in this case by giving the auto-
matic feeders af, af, double connections, so that they may communi-
cate in either direction.
To prevent saline accumulation all the evaporative surfaces may
be enamelled so as to diminish the saline adhesion, or an electric
condition may be maintained in the metallic evaporative surfaces un-
favourable to deposits.
An electric current produced by a battery of large plates connected
by its wires with the upper and lower ends of the evaporating structures
in Fig. 6 and Fig. 10 (see g wp, gwn,) is the best mode of preventing
saline deposits..
Having described the entire monothermal series operating above two
hundred and twelve degrees it remains to explain the method of evapora-
tion below that point. The steam from the last boiler operating at or
near atmospheric pressure is utilized in horizontal evaporators of which I
recommend two forms, the flat and the tubular. The first is a wooden
vessel or box which may be thirty inches wide, ten or twelve feet long
(see Fig. 20, Sheet III.), four feet high, and subdivided horizontally
into four compartments (by tight wooden floors) each of which holds
and evaporates brine. There is a false bottom to each made of sheet
iron screwed or bolted firmly to longitudinal ribs six or eight inches
apart. Between this sheet iron and the wooden bottom is a space one or
two inches deep, in which the steam from the last boiler is condensed as
it evaporates, the brine resting on the sheet iron. The evaporation
continues slowly until salt is deposited several inches deep (of a coarser
grain than salt from boiling) and is wholly or partially dried when it is
raked out through the doors which are opened at the end. These doors
are hinged and close on a rubber margin so tightly as to hold the liquid
contents of the compartments. The steam is supplied for evaporation
by steam tubes near one end (S P 1) and the vapour evolved is carried
by pipes SP 2 to a suitable condenser. The brine may be supplied by
cocks turned by hand, and rushes into the compartments by atmospheric
pressure; a water guage or a glass strip set in the walls of each compart-
ment shews the height of the water. The water of condensation passes
off by pipes wp to be discharged into the condenser, the arrangement.
of which it is not necessary to describe. The other form is shewn in
Fig. 21 in which we see a horizontal boiler with a steam space at one
or both ends filled with steam-condensing tubes which are embraced by

page_text: derived from the excess of pressure in the condensing tubes over that
of the boiler..
The machinery for moving the valves needs no description. I would
only observe that the valves have the form of longitudinal sections of a
cylinder, as shewn in the Drawing, and operate as a two-way cock to
open and close alternately the passages into two channels. The valves
for injection of the boiler by pump No. 3 need only be the common
self-acting flap or poppet valves. Pumps. Nos.. 1 and 2 must be equal,
as the quantity of brine to be injected must. be the same as the amount
lost by evaporation.. Pump No. 3 throws into the boilers at each
up stroke the same quantity of liquid which it removes in the down
stroke, it has no effect on the boiler: The quantity of brine thrown by
No. 1 corresponds to the amount of evaporation. The quantity removed
by No. 3 bears the same ratio to the amount removed by No. 1 as the
volume of brine nearly saturated does to the amount of water above,
saturation in the brine that is used.. Hence the sizes of these pumps
should be different.. If the brine used be just half saturated the
volumes of water for the two pumps should be equal, but as No. 3.
injects only by the up stroke while No. 1 is double acting for injection
the area of No. 3 should be twice as great to move the same volume;
and if the brine be two-thirds saturated pump No. 3 will have twice.
the diameter of No. 1.
'
In Fig. 2 the compound pump is shewn in its connection with
a concentrator boiler tank of pure brine. T1, and tank of concen-
trated brine T.2. Each concentrator boiler has the same arrangement,
but each precipitator boiler has only Nos. 1 and 2 of the compound
pump. The piston rods of these pumps must extend through the
cylinder heads at each end alike to equalize the capacities of the two
chambers.
In conclusion I shall describe some other forms of boilers belonging,
to this Invention, which are under some circumstances desirable.
The concentric. boiler has the advantage of great compactness for a
monothermal series. It is formed by placing the boilers of a series one
within another, as shewn in Fig. 15. The interior boiler (B1) may-be
heated by steam tubes, as shown in the Drawing; boiler No. 2 surrounds
it, and a circle of steam pipes in it supplies its heat. These steam pipes
are supplied by a pipe from the steam space of No. I. It is necessary
to prevent the direct passage of heat from boiler to boiler that each

page_text: should have a double shell. The inner shell of No. 1 holds its water,
and a space of one inch between the inner and outer shells is filled
with steam. Thus the outer boiler No. 2 has an evaporating surface in
the shell just mentioned as well as in its tubes. The boilers succes-
sively added around each other are arranged exactly as in No. 2, and
as they may be constructed with three inches water space and one inch
steam space a series of seven can be constructed with a diameter of
sixty-five to seventy inches. The operation of the boilers as to receiving
steam, discharging their water, and supplying themselves by the com-
pound pump, is the same as described for other monothermal series.
It is not necessary that the concentric boilers should all be of equal
evaporative capacity, but this equality may be attained by varying the
number of their tubes.
Another form of boiler which has its merits, but which is less safe
and economical than the steam tubular, is the water tube shown in
Fig. 12. In this form an upper and lower water space are connected
by water pipes (in which ebullition occurs), which are surrounded by
_steam occupying the entire area between the upper and lower water
spaces. In this case I propose to insert in each water pipe a circulation
tube, by which the water ascending in the water tubes and loaded with
salt from evaporation may descend to the lower water space, as shown.
These tubes are armed with two sharp longitudinal ridges (like the
dorsal fin of a fish) on two opposite sides, by which the inner surface of
the water pipe is scraped and salt removed as the inner tube turns on
its axis. Its rotation is effected by a small crank. The cranks of all
the tubes are attached to a common frame fr and supported by a
common bearing be, and this common frame is rotated by a crank
turned by an exterior pulley above the boiler head so as to give a
common movement of rotation to all the tubes by which the salt is
détached and finally carried below by the circulation tube to reach a
salt receiver, as lieretofore described.
There are threc other forms of boilers embraced in my Invention of
sufficient value to merit description. The compound tubular boiler
Fig. 16 has all the tubes inserted, not in a steam head but bent down
and connected with a horizontal pipe which supplies steam and carries
off the water. A partition in this horizontal pipe compels the circulation
of steam through the pipes when we desire to blow out. This partition
is the valve va.

page_text: The compound flask heater, Fig. 18, has also a horizontal pipe of about
four inches in diameter, to which are firmly connected by their necks
two or three inches apart certain hollow vessels or flasks which serve as
the condensing steam heaters.
The tilting boiler, Fig. 19, consists of two vessels, as shewn in the
Drawing, bolted together with a steam space between them, and with a
top terminated by a gate valve, the whole is supported on pivots pp so
that it may be turned over to empty its contents through the valve, and
has its steam pipes SP 1, and SP 2 with its water pipe wp, and its
brine pipe bp, so that it may be used separately or as part of a
monothermal series, being specially adapted to small operations and
occasional use for pharmaceutic, domestic, and agricultural purposes.
To perfect the economy of this apparatus it is necessary that no caloric
should be wasted. The boilers should all be enveloped in non-conductors
of which soft paper is preferable for cheapness and efficiency, the exterior
layers being made incombustible and the great waste of caloric from all
furnaces by their chimneys and walls should be prevented. The walls
of the furnaces should be protected with non-conducting materials, such
as sawdust or dry fine coal ashes several inches thick, and the heat
passing off in the products of combustion should be recovered and
restored to the fire by the air which supports combustion. Two of my
plans for this purpose are illustrated in Figures 22 and 23.
In Figures 22, 22ª, 22b, and 22° are displayed the structures by which
the products of combustion are carried off in downward currents between
the ascending currents of cold air going to the fire. A sheet iron pipe
twelve or fifteen inches in diameter and ten feet long, more or less, is
flattened until its cavity is from half an inch to an inch wide (see
Fig. 22.) The ends are flared or flanged in such a manner that when
it slides into the iron frames above and below, it is firmly held in place,
these frames are constructed as if a solid plate of iron had been cut like
a comb, a slit three-quarters or one inch wide and eighteen inches deep
being cut out at intervals of an inch and a half or two inches. The
flattened pipe or air channel sliding into and occupying this slit rests
its flange on the inch and a half or two inch bars (and at the outer
margin it may be locked in and its flange supported by a transverse
bar) upon which bars they are tightly compressed and held by another
corresponding grate frame ff, (Fig. 22b.) The lower ends are inserted
and held between grate frames in the same way, and these grate frames

page_text: (which are screwed together) are held in position by four rods at their
corners. These grate frames and the air channels which they carry are
enclosed in a box fitting closely (Fig. 22b), which encloses a hot-air
chamber above (HA,) and a cold air chamber below. each about ten
inches deep. The sides of this box should be hinged, so as to admit of
being opened. The flue from the furnace receives a pipe or pipes from
the hot-air chamber, which passing down through the smoke delivers the
hot air at the grate. The cold air chamber receives fresh air from the
blower which passes up through the air channels to the hot-air chamber
heated on its way by the surrounding smoke which enters the box at
hs, and leaves it cold after descending to cs, passing up the chimney.
It is so effectively cooled on its way by passing between the air channels
that its moisture is precipitated and passes off by the cock co.
In the other structure Fig. 23 the chimney or flue should be made of
good non-conducting materials, and an exterior chimney around it also
constructed of non-conducting materials, encloses a concentric flue or
intermediate channel down which the smoke is compelled to descend,
and from which it passes by the channel sm to the chimney ch. A
rapid current of cold air is sent by the pipe B from the blower to
the receptacle R, from which it passes by numerous tubes up the outer a
and down the inner flue (taking up the heat of the smoke) to the
drum D, from which it passes to the fire. The vapor condensed from
the smoke as it passes down is discharged by a cock from the bottom of
the exterior flue.
The arrangement of the tubes descending the main flue to give a
large amount of surface is shown in the horizontal section Fig. 23*. The
effect of these regenerative or heat absorbent arrangements when suffi-
cient surface is used is to reduce the smoke to about one hundred
degrees Fahrenheit, condensing its vapor and thus recovering about
twenty-five per cent. of the total caloric which is usually lost. This 3
recovery of heat is so effective as to make a rapidly accumulative
heating furnace, which if its heat be not consumed by the boiler soon
becomes white hot and destroys everything metallic about it. Hence it
is advisable that the hot-air pipes near the fire be enamelled to prevent
oxidation, and if high temperatures are to be maintained the pipe nearest 3
the fire should be of fire-clay, bauxite, or some other very refractory.
substance. As this structure prevents the waste of caloric, a very trivial
fire will maintain its heat when the machinery is not in operation. As

page_text: this apparatus carries back to the fire the heat that usually escapes I
call it a retro-thermomotor or retro-thermal apparatus.
To convey the heat of this furnace in tubes without the high and
dangerous pressure of steam, I resort to other caloriferous media as certain
liquids which have great capacities for holding and carrying caloric
without great pressure. Saturated solution of caustic soda, maintains
the temperature of a low red heat with very little pressure of vapor.
Purified petroleum tar will convey a temperature sufficient to carbonize
wood, and prepared oil of turpentine will carry a temperature very near
to a red heat, while its vapors have a carrying capacity for caloric
which may be estimated as five to ten times greater than that of steam.
This preparation of oil of turpentine is made by subjecting it to continued
heat for a varying time from four or five hours to two or three days,
raising it gradually to the highest temperature to be borne. The change
is promoted and a better result produced by mixing it with carbonate of
soda, or potash, or chloride of zinc, or an equal quantity of sulphuric acid
while being heated. Fluoride of boron (less than two per cent.) effects
the same change almost instantly. The products of the heating process
are not homogeneous, and are known by different names, as colophine,
isoterebene, meta-terébenthene, meta-austra-terebenthene, which have
their boiling points at six hundred and eighty degrees. Other terebene
liquids are produced of slightly different composition and higher boiling
points and others more volatile, as terebenthene or austrabene, boiling
at four hundred and thirty-two degrees. (For further accounts of these
liquids sce Watts's Dictionary of Chemistry.) Caustic soda solutions,
purified petroleum, tar, and colophene may be used in liquid circulation
in coils of pipe by a pump to carry heat from the furnace. The
turpentine products may all be used to carry heat by their vapors instead
of steam, and having all very great specific capacities they require very
close joints and the use of the best cements.
Having now described the Invention that has been communicated to
me by my foreign correspondent, and having explained the manner of
carrying the same into effect, I claim as the Invention secured to me by
Letters Patent as aforesaid,-
'
C
First. The manufacture of salt by the evaporation of brine by means
of high-pressure steam at temperatures between three hundred degrees
and six hundred degrees Fahrenheit, and the transmission of caloric
from these high temperatures by successive evaporations through a

page_text: monothermal series of boilers to evaporators at gradually decreasing
temperatures, as herein set forth.
Second. The use of high-pressure steam condensing tubes, as and
for the purposes herein set forth, and the combination with such tubes:
of mechanical scrapers and of galvanic currents to remove saline in- t
crustations.
Third. The use of concentric cylinders as steam condensing vessels, as
herein set forth, and the combination therewith of reciprocating or
rotary scrapers to remove incrustations from their surfaces.
Fourth. The removal of incrustations from the evaporating surfaces I
by enamelling such surfaces and keeping them actively swept by strong..
currents produced by a pump or by ebullition currents in a boiler of long
ascending and descending channels, as shewn and described.
Fifth. The combination of annular steam spaces and steam tubes for
evaporation by the heat of condensation.
Sixth. The combination of a brine filtering vessel with a heating
apparatus and parallel inducting and educting brine passages leading to
and from a pump which controls the induction pressure by its valves
for the purpose of precipitating and removing the sulphate of lime.
Seventh. The removal of salt from the boilers by means of a salt 2
receiver attached below, constructed and arranged as shown, with valves
above and below, and pipes for the injection of steam, the expulsion of
brine back to the boiler, and for the expulsion of air.
Eighth. The combination of concentrated and precipitator brine boilers
so as to produce salt from saturated or nearly saturated brine, and to 2
evaporate the excess of water over saturation in high-pressure boilers
without precipitation.
Ninth. The combination of concentrator and precipitator boilers in a
monothermal twin series, as and for the purposes described.
Tenth. The combination of brine boilers of a monothermal series in a 3
reversible manner as described, so as to allow the induction of steam
and of brine by either end of the series.
Eleventh. The construction of a high-pressure steam generator com-
posed of pipes and tubes, in which the tubes exposed to the fire are
supplied by a pump and interior circulation tubes with a steady current 3
of water at their lower ends, as described, and the use of such a
generator as the first of a monothermal scries of brine boilers.

page_text: Twelfth. The combination with brine boilers of a compound pump so
constructed and connected that the expulsive force of the water of cọn-
densation shall propel into the boiler an equal amount of brine, and also
extract the proper quantity of concentrated brine and inject an equal
quantity in its place.
Thirteenth. The three forms of brine boilers for a monothermal series
respectively described as the tilting boiler, the flask heater, and the com-
pound tubular boiler.
☐☐ Fourteenth. The insertion in a water tube brine boiler of a returning
tube to produce a descending current, and the addition to the tube of
scraping edges, and an apparatus for rotation to remove the incrustation
of the adjacent evaporating surfaces.
Fifteenth. The vacuum brine evaporator, as described, with condensing
tubes, scrapers, and a salt receiver.
Sixteenth. The combination with a monothermal series of brine
evaporators of the vacuum evaporator, consisting of alternate horizontal
compartments for condensing steam and evaporating brine, as described.
Seventeenth. The retro-thermotor consisting of an arrangement of
ascending air passages and descending smoke passages to secure the
entire refrigeration of the products of combustion and the precipitation
and discharge of their watery vapor.
Eighteenth. The arrangement (for a retro-thermotor) of long narrow
air passages sliding in and out of a metallic frame in a close box, so
as to be conveniently inserted and removed on opening the box, as
described.
Nineteenth. The combination with a monothermal series of brine
boilers of a spiral scraper for removing the salt.
Twentieth. The combination with a monothermal series of brine
boilers of chemical thermal and mechanical processes and apparatus for
purifying the brine by first precipitating the heterogeneous constituents
or impurities by means of chemical re-agents, then precipitating the
sulphate of lime by means of a high temperature and a process of
filtering.
Twenty-first. The use of a saturated solution of caustic soda, purified
petroleum tar, prepared oil of turpentine; or of any other equivalent
liquid as specified, for the purpose of transferring high temperatures for
brine evaporation.

page_text: Twenty-second. The combination of boilers in a monothermal series
with intermediate automatic feeders, so as to supply each boiler auto-
matically with brine from its next neighbour in the series.
-
In witness whereof, I, the said William Edward Newton, have here-
unto set my hand and seal, the Twenty-first day of April, in the
year of our Lord One thousand eight hundred and seventy-one.