IMPROVEMENTS IN THE MANUFACTURE OF SALT AND AN IMPROVED SYSTEM AND APPARATUS EMPLOYED THEREIN
Year: 1884

page_text: We JOHN EDWARD HIGGIN and THOMAS HOUSMAN HIGGIN, both of 33, Tower
Buildings West, Water Street, Liverpool, in the County of Lancaster, Salt
Merchants do hereby declare the nature of the said Invention for IMPROVEMENTS
IN THE MANUFACTURE OF SALT AND AN IMPROVED SYSTEM AND APPARATUS
EMPLOYED THEREIN to be as follows:-
This Invention has for its object certain improvements in the manufacture of
salt, in which the essential feature which constitutes our Invention is
The application of a confined blast, or quick moving body of hot air as the direct
agent of heat for evaporating the brine.
The improved system, which we employ in the manufacture of the salt consists
in the mode of heating and applying the air used therein; and consists in first
heating the air in a furnace, as hereinafter described and then passing such heated
air under the pan, or pans, hereinafter described, and conveying such air after use
under the pan, or pans, back to the heating furnace for re heating and re-use.
The improved apparatus consists as follows
In the air heating furnace, which may be in any suitable position in relation to
the evaporating pan. Between the pan and the furnace are provided suitable
culverts, or leads. The air heating furnace consists of a number of pipes, or
retorts, or passages, which are placed in or over a furnace, and through which the
air is forced, or driven and the furnace is fired with coal, or other suitable.
combustible.
The pan is mounted on brickwork walls at its sides and ends and the space
within the walls forms an open furnace or hot air chamber. The bottom of this.
bot air chamber is inclined and a regulating outlet is provided at one end and the
hot air blast is forced into the bottom of and through the chamber and along the
bottom of the pan to the outlet; from whence it is brought back and repassed
through the heating apparatus, or it may be led to a second pan and there operate
in a like manner and then brought back and re passed through the heating
apparatus. In some cases the hot air blast may be obtained by forming the heating
furnace in, or in connection with the brickwork of the pan and forcing the air
through the furnace and up and under the pan, as above described.

page_text: The apparatus we employ for forcing, or driving and circulating the air, consists
of a fan, or. blower, driven by any suitable known mechanical means, and in which,
when in operation the air is drawn from the exits of the pans, through suitable
leads, or culverts and re forced through the heating furnace. An opening, or valve
is provided in the fan, for the admission of fresh air to make up for leakage and
for any other desirable purposes.
By the Improvements above set forth a more even evaporation of the brine
under treatment takes place and a comparatively greater amount of salt is produced
for a given quantity of fuel, and the salt, thus precipitated will contain com-
paratively fewer impurities in the shape of pan scale" and "sand scale."
The use of our Invention enables the brine pan to be constructed of thinner iron
and of inferior quality than is used in ordinary salt pans, and fired in the ordinary
manner.

page_text: COMPLETE SPECIFICATION.
We JOHN EDWARD HIGGIN and THOMAS HOUSMAN HIGGIN, both of 33 Tower
Buildings West, Water Street, Liverpool in the County of Lancaster, Salt
Merchants do hereby declare the nature of the said invention for IMPROVEMENTS
IN THE MANUFACTURE OF SALT AND AN IMPROVED SYSTEM AND APPARATUS
EMPLOYED THEREIN and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following 'statement:-
This Invention has for its object certain improvements in the manufacture of
salt from brine. The essential features which constitute our Invention are the
application of a confined blast, or body of heated air under the pan for evaporating
the brine and a system of heating air and applying such heated air. According to
one modification of our system, we heat the air in a furnace and pass such heated
air under the pan, or pans, the air being supplied by suitable blowing apparatus
above atmospheric pressure and after having been forced under the pan, or pans is
repassed through the heating apparatus, which also heats the fresh supply of air
that may be introduced. This method however of employing the heated air under
pressure we do not find to be nearly so advantageous in practice as the method
referred to in the last part of our Provisional Specification wherein the hot air
blast is obtained by forming the heating furnace in, or in connexion with the
brickwork of, or supporting the pan and forcing the air through the furnace up
and under the pau, or pans in the manner we will now proceed to describe by the
aid of the Drawings annexed, like letters and figures being used to denote like, or
corresponding parts throughout the various views.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan showing an arrangement of apparatus we employ in carrying,
out the system according to our Invention.
Figure 2 is a sectional elevation of the arrangement of apparatus set forth with
reference to Figure 1 of the drawings.
Figure 3 is a section through X X Figure 1.
Figure 4 is a sectional elevation of a furnace according to our Invention as set
forth with reference to Figure 1.
Figure 5 is an end.view partly in section of Figure 4.
Figure 6 is a plan of fire bearer according to our Invention.
Figure 7 is an end view showing salt pan with our apparatus applied thereto.
Figure 8 is a sectional elevation of Figure 7.
.
With reference to the Drawings A is the pan which is supplied and filled with
brine. B are furnaces provided with close doors b close ashpits L having the close
doors and roofs 6' which are preferably made of fire brick and which protect the
bottom of the pan directly above the furnace from burning. C is a pressure fan, or,
other blower. Dis the air delivery main. d are branches from the main to the
furnaces B. E is the escape flue. F.is a flue which conveys the waste heated.

page_text: <
gases to a fresh air heating stove G. H is the main through which the fresh air
passes from the stove G to the fan, or blower C. The pan A is supported upon
columns a and brickwork sides and ends N The space J within the walls N forms
an open hot air chamber. The bottom of this hot air chamber J is inclined as
shown and regulating outlet valve m is provided. The heating stove G consists of
a nest of tubes n. The heated gases pass from the duct F into the stove G and up
around the tubes n and escape by the outlet n¹ which is provided with a valve n³.
The air to be heated is drawn by the blower C through the tubes n and is thus
heated. The ducts for the heated air and gases are lagged with any known bad
conductor of heat.
In Figures 2 and 3 there is shown provided a chimney O having a damper
valve o; also a duct P having a damper valve p. We utilize the chimney as a
means of carrying away the waste gases in cases where our whole system is not
required, in which case the ducts F and P are dispensed with and in cases where it
is desired to lead the residual gases from the chamber J to an ordinary salt drying
stove (not shown in the Drawings) they may be led by the duct P in which case,
the duct F and chimney O are dispensed with.
The fire bearers illustrated in detail at Figure 4 are made of metal plates
perforated with small holes such as circular holes of about of an inch diameter.
We use this form of fire bearer having found it to be a good one when using
"slack" coal.
We have found that salt pans worked under a forced blast with and in an open
chamber such as J are more effective in producing salt than with the ordinary flue
and chimney draught. But such chambers are not so effective in producing salt,
when working with the usual chimney draught.
In operation air is forced by the blower C and delivered under pressure into the
ashpit L below the fire bearers upon which a thin fire 12 of about 1 to 2 inches
thick is made and maintained by feeding fuel thereto in frequent small and evenly
distributed quantities. The advantages of keeping only a comparatively thin
stratum of fuel in combustion is obvious, because the combustion is more perfect
and little, or no waste of fuel is caused by wasteful evolution of carbonic oxide.
The air is forced up through this fire 2 through holes ³ in the bearers into the
furnace B in a greater quantity than the proper amount necessary to support
combustion of the fuel. Thus the whole quantity of air is heated as it is forced
through the fuel. It then passes in that state from the furnace into the space C
and along under the pan A. It having given up a greater part of its heat to the
pan passes to the outlet E which is regulated to maintain a pressure by the
damper m. After passing the damper m the gases may be made to travel along
the duct Finto the air heating stove G where their heat is to a certain extent
given up to the fresh air which is drawn in through the tubes n by the blower C,
or they may be made to travel by the duct P or chimney O.
In Figures 4. 5 and 6 the construction of the furnace B with its attendant parts
are shown in detail to a larger scale, namely the fire bearer / close door b furnace
roof 61 close ashpit L close ashpit door air duct D and branch d. It will be seen
that the door is hung on inclined hinges so that its own weight tends to close it
and keep it close when shut. The ashpit floor is made inclined in order to
facilitate the withdrawal of ashes therefrom.
In Figures 6 and 7 are shown a complete assemblage and arrangement of parts
and general construction of apparatus according to our Invention for working one
salt pan without the re heating stove G. In this case the air forcing device is a
"Korting" Blower which delivers air direct into the air duct D, the capacity of
which decreases for each succeeding furnace, as shown.
By the method and system of manufacturing salt and the use of apparatus as
above set forth the following advantageous results are obtained. A more even
evaporation of the brine under treatment takes place and a comparatively greater
amount of salt is produced for a given quantity of fuel, also a greater amount of
salt is produced for a given quantity of brine..

page_text: The desideratum of a salt of finer grains, or crystals is obtained when making
"fine salt" than by the usual method.
tt
The salt produced will contain comparatively fewer, impurities in the shape of
pan scale" and "sand scale." Also the amount of scale made and adhering to the
pan is greatly reduced comparatively with that produced in the ordinary method
of evaporating brine in the manufacture of salt.
A greater amount of salt per pan is produced than by the usual method.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is
First In the employment of salt pans constructed as herein described heating
then by the agency of a confined body or blast of heated air forced through a
heating furnace, above atmospheric pressure and caused to act upon the bottom of
the pan or pans substantially as set forth.
Second The combination in connection with salt pans such as are herein described
of a blower which maintains a pressure of air above atmospheric pressure below
the fire bearers on. which a thin stratum of burning fuel is maintained substantially
as set forth.
Third The use in combination with salt pans (such as A) worked as described,,
of heat chambers (such as J) in the manner and for the purposes substantially as
set forth,
Fourth The use in combination with a salt pan (such as A) of close ashpit
chambers (such as L) air pipes, or ducts (such as d) blower, or blowers (such as C)
and close furnaces (such as B) as set forth and operating as described.
Fifth The use in combination with a salt pan such as A of doors chambers L
pipes, or ducts & (for supplying air under pressure) fire bearers furnaces B doors b
roof 6, chamber J and a regulated escape flue E as set forth and operating as
described.
'
Sixth The manufacture of commercial salt of superior quality by evaporating
brine by means of pans and heating apparatus constructed and operating
substantially as herein described.