IMPROVED APPARATUS TO BE USED FOR BURNING COAL, ALSO IMPROVED APPARATUS TO BE USED FOR APPLYING HEAT TO EFFECT EVAPORATION OP CERTAIN SOLUTIONS
Year: 1845

page_text: TO ALL
HUNT, of Dodderhill, in the County of Worcester, Brickmaker, send greeting..
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Sixteenth day of January, in the eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Hunt, Her especial license, full power, sole privilege and authority,
that I, the said William Hunt, my exors, adiiors, and assigns, and such others
as I, the said William Hunt, my exors, adñiors, or assigus, should at any
time agree with, and no others, from time to time and at all times during
the term of years therein granted, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick upon
Tweed, my Invention of "IMPROVED APPARATUS TO BE USED FOR BURNING COAL,
ALSO IMPROVED APPARATUS TO BE USED FOR APPLYING HEAT TO EFFECT EVAPORATION
OP CERTAIN SOLUTIONS;" in which said Letters Patent is contained a proviso
obliging me, the said William Hunt, by an instrument in writing under my hand
and seal, particularly to describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, and to cause the same to be
inrolled in Her Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large annear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Hunt, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
My Invention of improved apparatus to be used for burning coal, also appa-
ratus to be used for applying heat to effect the evaporation of certain solutions,
consists, firstly, of an improved construction of furnace, by the use of which
I am enabled to effect the combustion of coal in such a manner as to generate
the utmost or nearly the utmost possible quantity of heat which can be pro-
duced therefrom; and, secondly, improved apparatus for effecting the evapora-
tion of saline solutions, and which apparatus are more particularly applicable
to the evaporation of brine or solutions of common salt, but may, with certain
modifications (to suit particular circumstances), be also employed for evaporating
other solutions. Figures 1, 2, 3, and 4, of the Drawings hereunto annexed
exhibit my improved construction of furnace for effecting the combustion of
coal; Fig being a longitudinal vertical section thereof; Fig. 2, a transverse
vertical section, taken through the dotted line a, b, of Fig. 1, looking to the
right; Fig. 3, a horizontal section, taken through the dotted line c, d, of Fig. 1,
that is, immediately above the fire bars; and Fig. 4, a horizontal section, taken
through the dotted line e, f, Fig. 1. In these several Figures the same letters
of reference are used to indicate similar parts. A is a chamber made with
inclined sides for the reception of coal, which is introduced through an
opening B, provided with a door or stopper for closing the same. C is a floor
or hearth on which the coal is supported. D is a series of bars forming what
may be called the grate of the furnace, through which a supply of atmospheric
air passes. This grate is formed of loose fire bars D, D, the upper ends of
which are hooked for the purpose of suspending them from the upper long
horizontal bar b, b, which is supported in slots or grooves c, c, made in the side
walls of this part of the apparatus, as seen in Fig. 1. The lower parts of the
fire bars rest against a similar long horizontal bar d, which is placed a little in.
advance of the upper bar b, and consequently holds the fire bars in an inclined
position. The ends of the bar d are also supported in slots similar to the
upper bar, and by moving these bars along the slots nearer to or further from
the lower end of the chamber A the thickness of the fire, and consequently
the quantity of coal in a state of ignition at one time, is diminished or increased,
as will sometimes be required, according to the nature of the coal and the
amount of draft. E is a passage by which the products of combustion pro-.

page_text: ceed from the furnace; the exit of this passage should be considerably
narrowed, in order to give good eflect to the draft and to facilitate the com-
bustion of the gases.
F is a narrow channel or air passage, open to the
atmosphere, and communicating with the passage E. Through this channel a
proper supply of atmospheric air is admitted to effect the combustion of gases
proceeding from the coal. This channel is furnished with a regulating
damper G, by the use of which the quantity of atmospheric air admitted may
be increased or diminished as required. I prefer to construct this apparatus
of fire bricks, and to inclose the upper part of it in a casing of iron plates,
marked H, in order to prevent the escape of the gases which are generated
by the coal in the chamber A, becoming heated, and apply luting to the
stopper B for the same purpose. When I use my improved furnace for burning
coal to generate steam in steam boilers, I prefer to have a double casing of
iron plates, forming a water and steam chamber, inclosing the upper portion
of my furnace, and to have this chamber connected with the steam boiler to
which my improved furnace is applied. I commence using my improved
furnace by placing a quantity of burning coal on the floor C, and I then intro-
duce a further supply of coal through the opening B on to the top of the
I then close the
already ignited fuel until the chamber A is nearly filled.
opening B, and air obtaining access to the burning coal on the floor C through
or between the grate or fire bars, the coal undergoes combustion, and as it
becomes consumed a further portion of coal descends from the chamber A.
I provide a sufficient space between the lower ends of the bars D and the
floor C to admit of clinkers and ashes being withdrawn from the furnace
when requisite. The passage E serves to conduct the flame and heated air
produced by the ignited fuel into contact with a steam boiler, evaporating
vessel, or other apparatus in which heat is required to be applied, and a suitable
draft is obtained by means of a chimney, or by other means, as is well under-
stood. It will be perceived that my improved furnace provides for having a
considerable quantity of coal in its chamber at one time, and for a regular
supply of this coal being furnished to the place of combustion as the consump-
tion proceeds; as a consequence of this arrangement, the quantity of of coal
undergoing combustion is nearly uniform, and the quantity of air required to
effect this combustion, and for consuming the gases produced from the coal, is
very nearly equal at all times, and the proper admission of this latter quantity of
air can be regulated by the use of the damper G. I construct the passage E of small
dimensions as respects its depth, in order that the current of air passing through
the channel may become more thoroughly mixed with the gases proceeding
from the burning coal. In using my improved furnace I prefer to introduce

page_text: therein that kind of coal which has not the property of "soldering" together
when heated, and to have this coal in pieces not exceeding the size of a man's
fist. One of the principal advantages resulting from the use of this improved
method of effecting the combustion of coal is, that by the peculiar construction
of the apparatus the gases and other products of combustion are or may be
effectually consumed without at the same time reducing the 'temperature by
the admission of cold air immediately in contact or contiguous with the sur-
faces that it is required to heat, as is the ease in most ordinary furnaces;
whereas in my improved apparatus the atmospheric air is admitted through
the opening F into the passage E, where it enters into the midst of the gases,
and owing to the intense heat of the red hot brickwork, its temperature is imme-
diately raised, and the passage E being flat, a perfect admixture and consequent
perfect combustion of the gases takes place, and a flame of intense heat rushes
out from the contracted opening of the passage E to the place where the heat
is to be applied; but if the atmospheric air is caused to mix with the gases
in a situation where the contiguous surfaces are comparatively cool, the tem-
perature of this part of the apparatus would not be suflicient to cause a perfect
combustion of the gases; whereas by the employment of brickwork, which I
allow to get red hot, the gases are as effectually consumed when con-
tiguous to these surfaces as they would be in the centre of the passage or
flame itself. I will now describe my improvements on apparatus for effecting
the evaporation of saline solutions, as I construct and apply the same for
evaporating brine in manufacturing common salt. One of the objects in this
part of my Invention is to prevent the access of currents of cold air from the
atmosphere underneath pans, used for evaporating saline solutions, which
access of air (otherwise than through the fires) I find to act very prejudicially
to economy in applying heat to effect such evaporation, as it sometimes very
considerably reduces the temperature of the pans. To effect this object I
employ certain improved arrangements of apparatus, which I will now proceed
to describe:-Fig. 5 is a section of part of a salt pan, with one of my improved
plans for preventing the access of cold air underneath such pans attached
thereto. A is a portion of a salt pan. B is a wall of brickwork supporting
the pan, and having a set ofl; as shewn at ; C is a bent plate extending the
whole length of the pan, and resting on the set off b. D is a clamp or hook
of iron attached to the plate C, and tying this plate to the brick wall B. I use
a number of these clamps, attaching one of them to the plate C, at distances
of about two feet from each other. E is a plate of pliable or flexible metal,
such as lead, zinc, or copper, extending the whole length of the pan, and
attached by its lower part to the plate C, and having its upper part turned

page_text: over the edge of the pan A, and caused to descend about three inches
therein. (but I prefer that this plate E should not descend so low as to
touch. the brine contained in the pan A). The pliable or flexible plate E
adapts itself by its own weight to the upper edge of the pan A, and its
pliability admits of the pan A moving or rising to a certain extent upon the
brick work..B, without permitting the access of an injurious quantity of air
between the upper edge of the pan and the pliable plate E, and the free access.
of. air underneath the pan (which would otherwise take place when the pan
moves or rises upon the brickwork, and which would tend to reduce the tem-
perature thereof,) is thereby prevented. Fig. 6 is a section of part of a salt
pan with another of my improved apparatus for preventing the access of air
underneath such pans attached thereto. A is a portion of a salt pan. Bis a
wall of brickwork supporting the pan. C is an iron plate attached to the lower
part of the pan, extending its whole length, and projecting about one foot below
the bottom of the pan.. D is an iron plate extending the whole length of the pan, ;
and secured in the floor E of the salt pan house. F is a connecting piece, formed.
of some pliable or flexible material (such as canvas or lead), which serves to
connect the plate C with the plate D. The connecting piece F is attached to.
the plates C and D by means of screw pins or cotters passing through the
plates, also through a strip of iron, or wood placed over the pliable material:
and extending its whole length. The width of this connecting piece F is such
as to admit of its lying in folds between the two plates C and D, and thereby
to provide for the pan A moving or rising on the brickwork B, and the texture
of the said connecting piece is sufliciently close to prevent the access of an,
injurious quantity of air underneath the pan, which would otherwise take place;
when the said pan rises or moves on the brickwork, and thereby creates an
opening between the pan and brickwork. Fig. 7 is a section of part of a salt.
pan with another of my improved apparatus for preventing the access of air
underneath such pans attached thereto. A is a portion of a salt pan. Bis
the floor of the salt pan house. C is an iron plate attached to the lower part
of the salt pan, extending its whole length, and projecting about two feet below
the bottom of the pan. D is a bent iron plate attached to the plate C, and
extending its whole length. E is a wall of brickwork supported on the plate D,
and serving to protect the plate C from the action of the flame passing under.
the pan. Frepresents a mound or quantity of flue dust or ashes placed against
the plate D to prevent the access of air from the atmosphere under this plate,
but which mound of flue dust or ashes does not prevent the pan from moving or
rising on its seating. In this arrangement the salt pan is supported on pillars
of brickwork or iron, in the same manner as such pans are frequently supported.
.
°

page_text: I have described my improvements in preventing the access of air under salt
pans as applied to only one part of such pans, but it will be obvious that to
obtain the desired effect it will be necessary to apply these improvements or
some of them to the lower part of the said pans wherever cold air from the
atmosphere may obtain access underneath the same; and although I have
described the best means with which I am acquainted of carrying this part of
my Invention into effect, I do not mean or intend to confine myself rigorously
and exclusively thereto, as the means I have shewn may doubtless be varied in
detail without departing from the nature or principle of my Invention. Another
of my objects in the second part of my Invention, or that which relates to the
evaporation of saline solutions, is to communicate heat to the saline solution
which I wish to evaporate previously to the solution being introduced into the
evaporating pan, the heat so communicated being derived from the heat passing
through the flues conducting from the fire-place under the evaporating pan to
the chimney. I effect this object by means of certain improved apparatus,
which I will describe as I use the same for the evaporation of brine or solution
of common salt. Fig. 8 is a longitudinal section, and Fig. 9, a transverse
section of a salt pan having this part of my Invention applied thereto. A is
the salt pan. B is the fire-place. C is the flue under the salt pan. D is the
flue leading from the salt pan to the chimney. E is an annular vessel, formed
of two cylinders, into which cold brine is introduced by means of a pipe F.
The heated air passing from under the salt pan A surrounds the vessel E, also
passes through its interior cylinder, and thereby communicates heat to the brine
contained therein. G is a pipe through which the heated brine is conducted
into the salt pan A, at such part thereof as may be preferred. It will be
obvious that the object of this part of my Invention can be effected by having
a number of tubes placed in the flue D, these tubes being supplied with cold
brine, and having an arrangement to conduct the heated brine into the salt pan A;
also that these tubes or the vessel E may be placed in that part of the flue which
is immediately under the salt pan, but I prefer to effect this object by means of
the arrangement of apparatus exhibited in Fig. 8 and Fig. 9 of the Drawings
hereunto annexed. Another of my objects in the second part of my Invention
is to diminish the quantity of salt which adheres to that part of pans used for
evaporating saline solutions which is situated over the fire-place, and which
adhesion occasions the formation, in evaporating brine, of what is called "pan-
scale or pan scratch." I effect this object by means of an improved arrange-
ment of apparatus, which is also exhibited in Fig. 8 and Fig. 9 of the Drawings
hereunto annexed. A is a salt pan. B is the fire-place. H is a closed vessel,
placed in the salt pan, and supported upon feet, so as to keep its bottom

page_text: about two inches above the bottom of the salt pan. The vessel H extends the
whole length of the fire-place B, and its bottom is pierced with three rows of
holes (of, about one sixteenth of an inch in diameter) in the direction of its
length, these rows of holes being about three inches distant from each other,
Cand the holes themselves being also about three inches distant from each other.
Jis a pipe attached to the vessel II, through which brine (either in a cold or
heated state) is supplied to the vessel H, and this brine escapes through the
said holes in the bottom of the vessel H on to that part of the bottom of the
pań A which is placed over the fire, and thereby prevents, to a certain extent,"
tlie.adhesion of salt on the said part of the evaporating pan. If it be thought
desirable to introduce heated brine into the vessel II, this object is effected by
conducting the pipe G from the annular vessel E in the flue D, and connect-
ing it either directly to the said vessel H, or furnishing it with a cock or tap,
whereby a regular quantity of brine may be run out from the said pipe G into.
the funnel at the upper end of the pipe J, as seen in Fig. 8. Another of my.
objects in the second part of my Invention, or that which relates to the,"
evaporation of saline solutions, is to collect the steam which is produced by the
evaporation of saline solutions at a boiling temperature, and to apply such
steam to effect the evaporation of saline solutions at a lower temperature. L
Ceffect this object by means of certain improved arrangements of apparatus, or
some of them, which I will describe, as I construct and apply these for manu-
facturing that description of common salt which is produced by evaporating brine"
at a boiling temperature, and is known as "fine salt," also that description of.
common salt which is produced by evaporating brine at a temperature below
boiling heat, and is known as "broad salt." Fig. 10 is a transverse vertical
section of one of my improved arrangements of apparatus, by means of which
I effect this object of my Invention. A is a salt pan, in which "fine salt" is
manufactured by causing brine to be evaporated at a boiling temperature. Bis
a vessel forming a steam collector, which incloses nearly the whole surface of
the brine contained in the pan A, but leaving a long, narrow, open space on
cach side of the pan, and into which spaces the crystallized salt is raked from
time to time, previous or preparatory to removing it from the pan, as hereafter
described. C is a pipe for conveying steam from the steam collector B to
evaporating pans containing brine, and which are constructed in the sam
manner as the evaporating pans which are commonly used for manufacturing
"broad salt, by the application of heat derived from steam. The steam col-
lector B is, represented in the Drawings as being constructed of iron plates
covered witli wood, the latter being applied for the purpose of decreasing the
amount of condensation occasioned by the transmission or radiation of heat
.

page_text: from the steam through the iron plates when exposed to the atmosphere. Cis
a strong piece of timber supported upon the walls of the salt pan house.
D, D, are moveable pieces, forming the sides of the steam collector B. These
sides are attached to the pieces C by means of hinges, and are counterbalanced
by weights hanging over pullies, as shewn in the Drawings. The hinges adinit
of the sides D, D, being lowered, so that their lowest part becomes immersed
in the brine contained in the pan A (as shown in Fig. 10), or of these sides
being raised so that workmen may obtain access to the pan A to withdraw salt
therefrom or for other purposes (this position of the sides is shewn by dots in
Fig. 10). The ends of the steam collector are attached to the piece C, and
rest upon the bottom of the salt pan A. The sides D, D, are connected to the
ends by means of a flexible canvass joint, which is made in such a manner as
to admit of these inclined sides being raised to the position shown by dots in
Fig. 10. This canvass joint is made for the purpose of rendering the sides as
steam-tight as possible, and opens and shuts in a similar manner to a pair of
bellows. A canvass covering (shewn by dots, and marked F, F,) is also used to
complete the joint between each of the sides D, D, and the piece C, and to render
these joints sufficiently steam-tight for the purpose required. These connections of
canvass F, F, are sufficiently pliable to admit of the sides D, D, being moved,
as herein-before described. G, G, are iron gutters attached to the interior
of the inclined sides D, D, for the purpose of collecting the water produced by
the condensation of steam against these sides, and for conducting such water
beyond the salt pan A by means of a pipe, as will be easily understood by any intel-
ligent manufacturer. Figures 11 and 12 represent longitudinal and side eleva-
tions of another plan of constructing the steam collector, being in fact a modifica-
tion of the plan just described. Instead of the inclined sides D, D, a flat lid, top,
or covering is supported from cross pieces C, C, which are suspended from the
roof above. Moveable flaps or doors E, E, are hinged on to the flat lid, top, or
covering, and the joint is covered over with canvass or some other suitable flexible
material, as shewn at F, for the purpose of preventing the escape of the steam.
The moveable flaps or doors are connected to the end pieces by means of
flexible canvass joints II, as in the other plan, so as to allow the doors or flaps
to be lifted up, as shewn by dots in Fig. 12. The doors are counterbalanced
by weights attached to cords passing over pullies, as seen in Fig. 12; and
in order as far as possible to prevent the condensation of the steam, the flat
covering D is covered over with a layer or bed of coke ashes or other substance
which is a bad conductor of heat. G is the steam pipe for conducting off the
steam arising from the evaporating pan from the steam collector to other
evaporating pans, as above mentioned. When it is required to rake up the

page_text: salt that has been deposited on the bottom of the pan, the inclosed sides D of
Fig. 10 or the hanging flaps of Figures 11 and 12, are to be raised into the
position shewn by dots in the several Figures, and then the attendants can rake
the salt from the middle up to the sides of the pans, where a space is left for
that purpose. When the raking is completed the sides are let down again,
and the salt can be removed at leisure from the edges of the pan by the
attendants while a further deposition is going on in the pan. Figures 13, 14,
and 15, represent different views of an improved mode of raking up the salt
that is deposited at the bottom of the pan, without the necessity of raising any
part of the covering, so as to admit of an escape of steam and reduction of
temperature. Fig. 13 is a longitudinal section; Fig. 14, a transverse or
cross section; and Fig. 15, a horizontal section or plan view, the upper
covering or lid of the pan being removed. A, A, is the salt pan; B, the fire-
place or furnace; C, the flue; D, D, the lid or covering of the pan, which is
supported in its place from timbers or bearing picces E, E, but is to be con-
sidered as a fixture, it being firmly secured to the pan; but as it will be
occasionally found necessary to have access to the interior of the pan, this is
provided for by having doors D, D*, Fig. 15, made in the front end largo
enough for a man to enter. The raking instrument consists of a number of
small rakes a, a, a, a, a, a, a, a, Fig. 15, mounted on a horizontal rod or
shaft b, b, b, b, which is furnished at each end with small wheels or rollers c, c,
which run on peculiarly constructed railways d, d. This raking instrument
is moved backwards and forwards in the salt pan by means of the screwed
shaft c, e; the inner end of this shaft is furnislied witli two stop pieces f and y, as
seen best in the enlarged detached views, Figures 16 and 17, and passes through
and works in a hole made in the bridle piccc h; when the instrument is pushed
forward the stop piece f bears against the bridle piece h, and the stop piece g
bears against a long horizontal bar i, i, which passes under the small rakes and
parallel with the shaft b, b. It will now be understood that as the raking
instrument advances, the screwed shaft c, c, pushes forward and raises up the
horizontal bar i, i, and by that means raises the 'rakes out of the brine; but in
order further to insure that the racks should be raised out of the brine, a
railway d, d, Figures 13, 14, and 15, is made on each side of the pan. The
end pieces of these railways are mounted on centres, and form inclined planes
to conduct the small rollers c, c, up to the fixed stationary rail above and down
from the top rail to the other one immediately below. The centre of one of
these end pieces is at 1, and the centre of the other is at 2; the latter piece is
made or counterbalanced in such a inanner that it will always remain level
with the fixed.part d'of the railway, and when the rollers of the raking instru-

page_text: ment pass the centre 2 of the end piece, this latter will tip over and assume
the inclined position shown in Fig. 13, until the rollers c, c, quit it at
bottom, when it will immediately rise up again and resume its original position,
that is, level with the other part of the railway. By this means this part of
the rail allows the rollers c, c, to pass under it. When the raking instrument
is drawn back for the purpose of raking or gathering up the salt the rollers c, c,
pass along the lower rail k, k, under the upper rail, and the action of drawing
the screwed shaft back withdraws the stop piece from under the horizontal
bar i, i, and allows the small rakes a, a, to drop down on to the bottom of the
pan, which they will do by their own weight; then by continuing to draw back
the screwed shaft, the raking instrument will advance, gathering up in its
progress the deposited salt, and is guided along the pan by the rollers c, c,
When the rollers c, c, arrive
running on the lower rail k, as before mentioned.
at nearly the end of their return course, they come into contact with the under
sides of the inclined end of the upper railway, which being hung on a centre
at 1, as before mentioned, is raised up by the rollers c, c, in order to let them
pass, and as soon as they have passed, these inclined ends assume their original
position; and upon pushing back the screwed shaft the rollers c, c, will run up
the inclined ends d, d, of the railway to the upper rail d, as has been already
mentioned. The raking operation will only be wanted to be carried on occa-
sionally, and when the raking instrument is not in use it must be passed up
the inclined end of the upper railway and pushed on to about the middle of the
latter, where it will remain until again required for use. When pans of large
dimensions are used it will require more power than one man can exert to
work this raking instrument with facility; it is therefore necessary that some
mechanical means should be devised to assist the workman; a variety of
mechanical contrivances may be suggested to effect this object, but I have
shewn in the Figures one which I consider will answer the purpose very well,
although do not mean to confine myself exclusively thereto. The plan 1
have adopted consists in employing a screwed rod e, and passing it through a
box or nut fixed in standards 7, 7. As the shaft will vary slightly in inclination
as it enters or leaves the pan, it is necessary that the screw box at 1, 1, should
be mounted in shackles, so as to suit itself to the inclines of the shaft. The
screw box is mounted on a centre pin, which slides up and down in a slot
made in the standards 1, 1, as seen in Fig. 18; and two handles or arms are
connected to the screw box, so that by turning these handles one way or the
other the screwed rod e, and consequently the raking instrument, are made to
advance or recede at pleasure. I would observe that the screwed rode passes
through a hole at m made in the back of the covering for that purpose, and

page_text: that the steam arising from the evaporation of the brine is conducted ofl
through the steam pipe at the opposite end for the purpose of heating the brine
in another pan.
。
I have herein particularly described and, ascertained the nature of my
Invention, and the manner in which I prefer to construct and apply the
various apparatus constituting the same; and I have also indicated various
inaterials which I consider best adapted to construct the same, but I do
not confine myself to the use of these materials, nor to the precise arrange-
ments herein indicated, as these may be varied to some extent without
departing from the nature of my Invention; and although in order to avoid
confusion I have thought it more desirable to describe and illustrate all my
various improvements separately, yet it will be evident to every intelligent
manufacturer that they can all be employed and applied collectively. I do not,
however, think it will be necessary for me to enter into any further explanation
on this point, as it must always be left to individual manufacturers, who will be
guided by circumstances. Jclaim as the Invention secured to me by the
herein before in part recited Letters Patent, first, the peculiar arrangement
and construction of apparatus shewn and described in reference to Figures 1,
2, 3, and 4, or any modification thereof, for effecting the regular and econo-
mical combustion of coal, and thereby obtaining an intense heat, which may
be applied to various useful purposes, such object being effected by regularly
supplying fuel to the grate and atmospheric air to the gases at a part of the
apparatus which is kept constantly at a red heat. Secondly, I claim also the
construction of apparatus for preventing the access of cold air underneath pans
for evaporating saline solutions, in which apparatus such access of cold air is
prevented by the use of shields or guards made of such pliable materials as I
have herein described for such purpose, or by the use of fluc dust, ashes, or
other similar material applied in the manner I have herein described for such
purpose. Thirdly, I claim the use of tubes or other closed vessels for commu-
nicating heat to saline solutions previously to these solutions being introduced
into pans for evaporation. Fourthly, I claim the mode above described of pre-
venting the injurious effects of the fire on that part of the pan situated imme-
diately above the fire by causing a continuous supply of fresh brine to enter
in small streams into the pans through boxes or shields perforated with holes,
so that fresh brine is continually flowing on to and over the bottom of that part
of the pan situated immediately above the fire, and the deposit of salt thereby
prevented. Fifthly, I claim constructing the covers of evaporating pans in
such a manner that I am enabled to collect and carry off the steam therefrom,
and employ it for evaporating solutions in other pans, while I can also at any

page_text: time have access to the open pan for the purpose of removing the salt therefrom,
or for other purposes, such objects being effected by being enabled to raise a
portion or the whole of the cover when access to the pan is required, and the
escape of the steam is prevented by means of the flexible joints when the pan
is closed. Sixthly and lastly, I claim the apparatus above shewn, or any modi-
fication thereof, whereby a pan can be properly raked and the salt collected
without the necessity of raising the cover or getting open access to the pan.
In witness whereof, 1, the said William Hunt, have hereunto set my
hand and seal, this Sixteenth day of July, in the year of our Lord
One thousand eight hundred and forty-five.
Jurolled the same Sixteenth day of July, in the year above written.