A CERTAIN METHOD OF MANUFACTURING SALT
Year: 1823

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSIAII
PARKES, of Manchester, in the County Palatine of Lancaster, Civil Engineer,
send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, by His
Letters Patent, under the Great Seal of Great Britain, bearing date at West-
minster, the Fourth day of December, in the fourth year of His reign, did,
for Himself, His heirs and successors, give and grant unto me, the said
Josiah Parkes, His special licence that I, the said Josiah Parkes, my exors,
adiñors, and assigns, or such others as I, the said Josiah Parkes, my exors,
adñiors, 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, and also within all His Majesty's
.Colonies and Plantations abroad, my Invention of "A CERTAIN METHOD OF
MANUFACTURING SALT;" in which said Letters Patent there is contained a
proviso, obliging me, the said Josiah Parkes, 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 enrolled in His Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said recited
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.

page_text: NOW KNOW YE, that my method of manufacturing salt from brine
consists in combining a boiler with a vessel or, chamber attached beneath it
and below the action of the fire, the construction of the boiler and its connec-
tion with the vessel or chamber being such that the salt may be deposited
within the vessel or chamber as it is produced, and may be withdrawn there-
from without interrupting the evaporation of the brine, or without opening tho
boiler, if a covered one is made use of; also in cooling the salt collected in
such vessel or chamber, previous to withdrawing it, by the use of cold brine.
The boiler may be made of wrought iron, or of any other suitable material.
The figure which I prefer is that of a truncated cone inverted, and a good
proportion of parts, for a boiler of any given power, is to make the small
diameter of the cone one-fifth of the large diameter, or base, and the height
or length of the side equal to the large diameter; but notwithstanding that,
I give the preference to the conical figure; any other form which permits the
salt to fall into the vessel or chamber hereafter described, without resting on
the sides of the boiler, will answer the same end. This boiler opens below
into a vessel or chamber, which I prefer to have of a cylindrical shape, its
diameter being equal to that of the boiler at its lower end, at which part it is
joined to the said cylindrical vessel. The lower end of this cylindrical vessel
opens into a short inverted cone, to the point of which is attached a stop-cock.
The length of the cylindrical vessel may be twice its diameter: It is not,
however, essential that this vessel or chamber should be of the cylindric
form, nor that it should be a distinct vessel joined to the boiler, as it may be a
prolongation of the boiler itself. The boiler, if a close one is made use of, is
covered with a doom of metal, which opens at top into a short cylindrical box,
the cover of which is moveable; this box serves as a man-hole to the boiler,
and a pipe or pipes open into it, through which the steam produced by the
evaporation of the brine is discharged; the safety valve also of the boiler is
attached to the aforesaid box. The several pieces of apparatus aforesaid, con-
sisting of the box, the dome, the boiler, the cylindrical vessel, with its conical
termination and stop-cock (reckoning them in order from above downwards),
are coniiected with each other by rivets, nuts, and screws in the usual way,
and open freely into one another. The whole metallic structure thus connected
is supported partly by a strong plate of cast iron, on which the cylindrical
vessel aforesaid rests, and partly by the brickwork or masonry which surrounds
the upper part of the boiler. This iron plate has a round hole cut through it,
to the under side of which is secured the cone with its stop-cock. Round the
outside of the cylindrical vessel, at its upper extremity, is a flaunch which
the grate bars, rest by one of their ends; the other end rests on a ring of iron
upon

page_text: Jet into the wall of the grate; the plan of the fire place is therefore a circular
area, surrounding and in contact with the boiler where it joins the cylindrical
vessel. The ash-pit of the grate is formed round about the cylindrical vessel,
the ashes falling on the iron plate. A vertical feed pipe communicates with
the cylindrical vessel by means of a horizontal branch pipe, which enters it
laterally near the bottom, and it communicates also with the boiler by means
of another horizontal pipe, which enters it at about the line of union of the
cone and dome. Each of the horizontal pipes above-mentioned is furnished
with a stop-cock. The boiler and cylindrical vessel being charged with brine,
by turning the cock of the upper branch of the feed pipe, and a fire being
made in the fire place, the brine in the boiler will be brought into a state of
strong ebullition, and steam will pass off through the pipes intended for that
purpose, as aforesaid. Grains of salt will be produced in proportion to the
evaporation of the watery part of the brine, which grains being prevented from
adhering to the side of the boiler (partly on account of the steep slope of such
side, and partly on account of the rapidly-ascending currents of heated brine
adjacent to the side), will sink through the less agitated portion of brine about
the axis of the boiler into the cylindrical vessel. The brine in this vessel,
on account of its being below the level of the grate, and consequently out
of the direct action of the fire, will have acquired very little increase of
temperature, and will therefore cool down to a certain degree the hot
grains of salt that descend into it, being itself thereby proportionally heated.
When the evaporation of the brine has continued a certain time (an hour
is the time that I find most convenient), a suitable. quantity of salt will
have been deposited in the cylindrical vessel; I then open the cock upon the
lower horizontal branch of the feed pipe, and let in cold brine to the amount
of about the bulk of salt collected in the cylindrical vessel, the consequence
of which will be that the brine, which had been warmed by the heat given off
from the salt, will be raised above the salt (the cold brine being specifically
heavier than the warm brine), and the salt itself will be brought down in
a temperature nearly to that of the cold brinc. The cock at the bottom of the
conical termination of the cylindrical vessel is then to be opened, upon which
the salt, mixed with a small quantity of cold brine, will be expelled by the
superincumbent pressure of the brine and steam into a basket or strainer,
placed to receive and retain the salt; the salt having thus been discharged, the
cock is to be closed till another deposit of salt shall have taken place in the
cylindrical vessel, which is to be discharged in a similar manner, and so on
with each successive deposit. The abstraction of heat from the salt may also
be accomplished by applying a casing to the exterior of the vessel or chamber,

page_text: and so connecting it with the feed pipe that the brine supplying the boiler
may flow through the casing. It is of importance to keep the surface of the
brine in the boiler at the same height as nearly as possible, to effect which the
cock of the upper horizontal branch of the feed pipe is in general to be kept
open to such a degree as that the continual supply of brine shall equal the
continual loss by evaporation. A gage must be attached to the boiler, in order
to shew at any time the height of the liquor contained therein, which height
or level may be maintained about six inches above the line of union of the
conical boiler and dome, the space contained, within the dome above the level
of the brine acting as a steam chamber. The supply of brine may also be
regulated by any of the methods now in use for feeding the boilers of steam
engines. The boiler may or may not be inclosed in a metallic casing according
as it may be most advantageous to heat the brine by the direct application of
the fire to the boiler, or through the medium of steam, of water, or of any
other liquid. If the latter mode be preferred the casing must be applied, and
the steam, water, or other liquid by means of which the heat is to be conveyed
to the brine must occupy the space between the boiler and the casing. It is
not essential to my improved method of manufacturing salt that the brine in
the boiler should be heated by means of fuel of any kind burnt in a grate
surrounding the lower part of the boiler, in the manner already described, for
I can and do employ the spare heat produced in the fire place of one boiler, as
well as the heat of the steam generated in such boiler, to heat and evaporate
brine contained in a second boiler or series of boilers, which boiler or boilers
differ in no wise from that already described, except in certain additions of
flues, pipes, and other vessels in which the heated air and steam are contained,
which flues, pipes and other vessels may be infinately varied, and to the application
of which as a mode of heating and evaporating brine I lay no claim. It is
impossible to state the comparative capacity of the boiler, and of the cylindrical
vessel beneath it, farther then that the latter must be large enough to receivo
all the salt that may be deposited in the interval between one discharge of salt
and the next. I at present prefer to discharge once in an hour, but circum-
stances may render it expedient to discharge once in half an hour, or only once
in two hours; in which cases the size of the cylindrical vessel, as compared
with that of the boiler, will require to be varied accordingly. It is also evident
that the intervals, between the discharges of the salt, must in some measure
depend upon the strength of brine under operation. The dimensions above
assigned to the cylindrical vessel are calculated sufficiently exact for the use of
a saturated brine; it is also practicable so to adjust the relative proportions of
the cylindrical vessel or chamber and of the boiler that a cock or funnel,

page_text: having some given aperture, may be kept continually open, and the salt would
then flow out in a continual stream. The Drawing, with letters of reference
annexed to this Specification, is for the purpose of shewing one of the forms of
apparatus and of the modes of combining the same, whereby my method
of manufacturing salt from brine may be effected. It is that which upon the
whole I prefer, but my claim is not restricted to the particular form here
represented, but includes all other forms of apparatus and modes of combining
the same, which possess the principles and properties whereby the object claimed
in the foregoing Specification may be accomplished.
In witness whereof, I, the said Josiah Parkes, have hereunto set my
hand and seal, this
in the year of our
day of
Lord One thousand eight hundred and twenty-four