IMPROVEMENTS IN THE MANUFACTURE OF SALT
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPHI
HALL, of Over, in the County of Chester, Plumber, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirteenth day of September, in the second year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Joseph
Hall, Her especial license, full power, sole privilege and authority, that I, the
said Joseph Hall, my exors, admors, and assigns, or such others, as I, the.
said Joseph Hall, my exors, admors, or assigns, should at any time agree.
with, and no others, from time to time and at all times during the term of
years therein expressed,, should and lawfully might make, use, exercise, and.
vend, within England, Wales, and the Town of Berwick-upon-Tweed; my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF SALT;" in which said
Letters Patent is contained a proviso, that I, the said Joseph Hall; shall
cause a particular description of the nature of my said Invention, and in what
manner the same is to be performed, to be inrolled in Her said 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 appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said.
Joseph Hall, do hereby declare the nature of my Invention, and the manner
in which the same is to be performed, are fully described and ascertained in

page_text: and by the following statement thereof, reference being had to the Drawings
hereunto annexed, and to the figures and letters marked thereon, that is to
say:-
The first part of my Invention relates to the construction and application of
a moving pan; this is made to revolve on a pivot from the centre and pass
over the fire, which imparts a regular heat to the whole of the pan and equalizes
its wear and tear. The pan is supported by a flanch being attached to its edge
all round, to which friction rollers are fastened, passing through a water lute
joint, the trough of which is fixed upon a brick wall immediately under the
periphery of the pan; by this means the pan will more regularly and easily
move round, upon the application of any mechanical power being applied to its
circumference or any other convenient part, and the flanch being immersed in
the water will prevent any smoke or flue heat from the furnace escaping round
the edges of the pan. If the above be used as a covered pan for the purpose
of preserving the steam for other purposes, it will be necessary to construct it
with a pocket all round the circumference of the pan, into which the salt may
be raked or scraped by means of a scraper or scrapers affixed to bars attached
to a fixed vertical shaft passing through the cover of the pan, and which part
ought to extend with a curve from the centre of the pan towards the pocket, in
which as the pan revolves the salt is of course deposited, from whence it may
be removed in the usual manner.
DESCRIPTION OF THE DRAWING.
Sheet 1: Figure 1 is a section, and Figure 2 a plan, of the above-described
apparatus; whereof A is the pan; B, the pocket; C, the wheel which prevents
the salt from forming in the centre of the pan, whence it would be difficult to
remove; D, D, the centre and step on which the pan revolves; E, the salt-
scrapers; F, the scrapers for removing the pan scale; G, G, the arms of the
vertical fixed shaft to which the scrapers F, F, are attached; H, H, the water.
lute joint, with friction rollers supporting the pan rim; J, a cast-iron cylinder
protecting the pivot from the action of the fire. Although I prefer a round
pan with revolving motion as best suited to pass over the action of the fire, and
also on account of its being more easily moved, yet I do not confine myself to
this motion, as for instance, the same might be moved partly round and back
again; nor do I confine myself to the shape, as an oblong might be made. to
pass to. and fro; but what I claim as this part of my Invention is, a pan being.
made to move whilst salt is forming in it, or, technically speaking, "whilst the
pan is at work," and whether the same be covered or not.
. My second improvement consists of a mode of constructing and using salt

page_text: pans having a semicircular form, or that of any other portional part of a circle,
having a pocket or receptacle for the salt formed on its straight side (diameter
or radius), into which the salt is moved by a scraper or scrapers working with.
a reciprocating motion from a vertical shaft placed in the middle of such straight
side, thereby sweeping the salt from the pan bottom into the pocket, thence to
be removed in the usual manner. The method of communicating motion to
my scrapers will be by any well known mechanical means, as I only claim as
my Invention the form of the pan and the causing the scraper or scrapers to
pass from the semi-diameter of the pan marked A' to that marked B¹, and by
reversing the motion from B' to A', thus extracting all the salt from under-
neath the cover, thereby enabling me to preserve the steam produced from the
boiling brine for application to ulterior purposes.
Sheet 2 Figure 1 is a section, and Figure 2 a plan, of a pan constructed.
according to the second part of my Invention. A is the pan; B, the pocket,
into which the scrapers deposit the salt; C, C, the scrapers; D, D, the rods to
which the scrapers are attached; E, E, the pinions which move the scrapers ;-
F, vertical shaft; G, reciprocating rack to move pinions, which may be worked
by any known mechanical power.
My third improvement is an apparatus by which the pan scratch formelin
that part of the pan more immediately over the fires, and where it is productive-
of most mischief, may be in a considerable degree removed without having
recourse to the usual expedient of entirely emptying the pan and knocking off
the scale with hammers; this I propose to accomplish by constructing a frame
or frames to traverse over the surface of the pan bottom. In these frames are
placed stones or other material of sufficient hardness to rub off the
pan scratch
so often as may be found convénient; the frame or frames to be put in move-
ment by any mechanical means constructed for that purpose.
And in order to explain this part of my Invention I have shewn two modes
of carrying the same into effect.
Sheet 3: Figure 1 is a section, Figure 2 a plan, of an apparatus applicable to
a pan worked by two fires. A, pan; B, frame for carrying the stones to be
moved backwards and forwards by the crank and rod C. Sheet 2: Figure 3
is a section shewing a method of removing the pan scale from the surface of
the pan by stones fixed in a revolving frame. A is the pan; F, frame to.
contain the stones; B, arms to which the framing is affixed; D, a wheel
affixed to the upright shaft E; G, a pinion which takes into the wheel D; the
pinion G is affixed upon a shaft, which may be turned by any suitable power.
What I claim as new is, the reduction or grinding down the pan scale by the
substances already alluded to without so often emptying the pan for this pur-

page_text: pose, in doing which a large quantity of hot and fully saturated brine is wasted
and time lost.
My fourth improvement is by preparing the brine in a vessel having separate
and distinct fires from the one in which it is converted into salt, and in which
separate vessel the brine can be raised to the "boiling" point, purified by raising
and taking off the "scum" in the usual manner, and allowed to remain therein
until by the precipitation of earthy matters not taken up by the scum, it
becomes purified and ready to be run off into pans or vessels usually employed
in making salt. The advantages I propose to derive from this system are,
first, a saving in fuel and wear and tear by always firing on bare plates in
the preparing pan, as it may be cleansed so often as the brine is racked off
into the working pans; whereas on the usual mode of operating much fuel is
wasted and great injury done to the pan bottoms in raising the brine from the
temperature of the reservoir (50° to 60°), to the point necessary to its working
(180° to 200°), there being a thick scale on it during a considerable portion of
the time the pans are kept working without its being removed, or what is
technically called "picking," occupying usually from fourteen to twenty days.
Secondly, a saving in time, as the pans will make more salt in the same time
with the assistance of the preparing pan than without it, inasmuch as the time
now occupied in warming up the brine may be employed in making salt.
My fifth improvement consists in placing a thin stratum of the well-known
easily fusible metallic compound of lead, tin, and bismuth on those parts of the
bottoms of salt pans most exposed to the action of the fire, which may be done
by the pan being made an inch or two deeper in that part, or by raising a rim
inside the pan
to contain this alloy, thereby in a great measure preventing the
injurious effects of the pan scratch or scale by keeping the brine immediately
over the action of the fire from coming in contact with the iron, so that what-
ever scale or scratch might form would be on the alloy, whence it is easily
removeable.
My sixth improvement consists in making that part of salt pans immediately
over the fires more shallow than the remaining part of the pan, so that instead
of letting the brine run to waste when the pan requires to be picked, only so
much need be drawn off as will lay bare this shallow part, being that portion
of the pan which requires most frequent picking, thereby saving a. large
quantity of hot saturated brine. The pan shewn at Figure 3, Sheet III., 'is
made according to this part of my Invention.
My seventh improvement is a method of supplying at intervals fuel to the
furnaces of vessels employed in the manufacture of salt, by means of a machine
shewn at Figures 3, 4, 5, and 6, Sheet III. a is a box placed at the front

page_text: of the fire-place; the top of the box is surmounted by a hopper ; fuel is
delivered from the hopper 6 by means of the cylinder c, which has a groove
formed in its surface in the direction of its axis; this cylinder is driven by' a
strap working on the pulley d, or any other convenient arrangement; when the
groove comes to the upper side the fuel falls into it from the hopper and the ro-
tation of the cylinder causes the fuel which it has received from the hopper to be
delivered on to the delivering plate e, which works on pivots at the end nearest
the fire-place; fis an eccentric placed on the axis of the cylinder c, the object
of which is to raise and lower the rod h; a short lever i is affixed on one of the
pivots of the delivering plate, and a projection from the rod h, coming against
the lever i, depresses it to the position shewn in the Drawing. An inclined
plane on the rod h then comes in contact with the fixed stud j, which forces
the rod h off the lever i, and allows the weight k, which is connected
with the pivot of the delivering plate by a lever and cord, as shewn in the
Diagram, suddenly to raise it, which thus spreads the fuel it has received
from the cylinder c upon the surface of the grate. It is obvious that the same
motion may be given to the delivering plate by a spring as well as the weight
described. The time of the revolution of the cylinder c is so arranged as to
supply the proper quantity of fuel at regular periods.
My eighth improvement consists in constructing a second or false bottom
extending over either the whole or part of a salt pan, the space between such
bottoms to be filled with water or any other liquid whose temperature at the
boiling point equals or exceeds that of water, or by the metallic fusible com-
pound described in my fifth improvement, as shewn at Figure 7, Sheet 3. I
claim as the benefit to arise from this Invention a saving in the wear and tear
of the salt pans, inasmuch as the pan bottom cannot exceed the temperature
of the interposed fluid or metallic compound.
My ninth and last improvement consists in the application of perforated
grate bars for the furnaces of salt pans, through which a current of atmospheric
air is allowed to pass so as to increase the combustion of the fuel in the grate.
The forced air may be obtained in various ways, but the double action bellows,
either that employed at a smith's forge or that used for feeding the wind-chest
of organs, worked by any mechanical power, will perhaps be the best.
In witness whereof, I, the said Joseph Hall, have hereunto set my hand
and seal, this Thirteenth day of March, One thousand eight hundred
and thirty-nine.
JOSEPH (L.S.) HALL.

page_text: AND BE IT REMEMBERED, that on the Thirteenth day of March, in
the year of our Lord 1839, the aforesaid Joseph Hall came before our said
Lady the Queen in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Thirteenth day of March, in the year of our Lord One-