IMPROVEMENTS IN THE MANUFACTURE
Year: 1872

page_text: LETTERS PATENT to Arthur McDougall, of the Firm of McDougall
Brothers, Manufacturing Chemists, Manchester & London, for the
TX
MOD MANATE OF COMMON SALT"
PROVISIONAL SPECIFICATION left by the said Arthur McDougall at
the Office of the Commissioners of Patents, with his Petition, on
the 31st January 1872.
I, ARTHUR MCDOUGALL, of the Firm of McDougall Brothers, Manu-
facturing Chemists, Manchester & London, do hereby declare the nature
of my said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF COMMON
SALT," to be as follows, that is to say :-
In the ordinary methods employed in the manufacture of common
salt great destruction of plant results from the burning of the plates of
the salt pans owing to the deposition of the scale and salt.. Messrs.
Thompson, of Northwich, Cheshire (Patent No. 2251, 1859), attempted
to obviate this inconvenience by passing steam or heated gases through
flues or conduits of heat of considerable diameter placed in the body

page_text: the process was slow, and no great turn out of salt could be obtained by
the process.
My improvements consist in the use of high-pressure steam con-
tained in pipes of small diameter for the evaporation of brine to produce
common salt.
-The
The following is one method of carrying out my Invention:—
brine is run into a tank or pan of convenient size, say thirty feet long,
eight feet wide, and eight feet deep, until the brine stands about one
foot from the top of the tank. About one foot below the surface of the
brine a number of cross bars are fixed, and upon these a series of iron
pipes in gridiron fashion is placed, so constructed that steam being
admitted at one end of the series passes through the whole of the pipes.
The water produced in these pipes by the condensation of steam is
allowed to escape by means of a simple but effective steam trap, and is
pumped at a boiling heat into the steam boilers which supply the steam
to the pipes. These steam boilers are constructed on any of the most
approved and economical principles, and when working should carry a
pressure of about eighty pounds per square inch. The tank or pan
being provided with a tight moveable cover,
the vapour
which is pro-
duced from the brine by evaporation is collected in one or more large
pipes which are made to pass through an elevated cistern containing
brine. By this means all the brine required to keep the liquid in the
tank or pan at a nearly constant level is supplied in a considerably
heated state.
Any vapour not condensed by this means is carried
forward in a continuation of the large pipes to the stoves or drying
houses, which it serves to heat.
In the practical working of the above described apparatus the tank
or pan, and also the cistern, being filled with brine, the steam from the
boiler is turned on to the pipes, which soon brings the brine to a rapid
boil near the surface, and the salt falls to the bottom of the tank as
quickly as formed. This is continued until the tank is almost filled
with salt. The steam is then turned off and the remaining brine
removed, and the pipes are lifted out by means of a suitable crane.
The salt can then be shovelled out on to drainers.
J
If any scale has formed upon the pipes it can be chipped off, and

page_text: when the pipes have been put back into the tank or pan a fresh quantity:
of bring con he run in and the whole oneration repeated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur McDougall in the Great Seal Patent Office
on the 26th July 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
M° DOUGALL,. of the Firm of McDougall Brothers, Manufacturing
Chemists, Manchester and London, send greeting.
,
WHEREAS Her most. Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of January, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give.
and grant unto me, the said Arthur McDougall, Her special license that
I; the said Arthur Me Dougall, my executors, administrators, and assigns,
or such others as I, the said Arthur Me Dougall, my executors, adminis-
trators, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term 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 MANU-
FACTURE OF COMMON SALT," upon the condition (amongst others) that I, the
said Arthur McDougall, my executors or administrators, by an instrument
in writing under my hand and seal, 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
Scal Patent Office within six calendar months next and immediately.
after the date of the said Letters Patent.
NOW. KNOW YE, that I, the said Arthur McDougall, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, that is to say :-
In the ordinary methods employed in the manufacture of common
salt great destruction of plant results from the burning of the plates

page_text: х потреб,
to obviate this inconvenience by passing steam or heated gases through
flues or conducts of heat of considerable diameter placed in the body of
the brine, but as only low pressure and waste steam was employed the
process was slow, and no great turn out of salt could be obtained by the
process.
My improvements consist in the use of high-pressure steam contained
in pipes of small diameter for the evaporation of brine to produce
common salt.
The following is one method of carrying out my Invention:-The
brine is run into a tank or pan of convenient size, say thirty feet long,
eight feet wide, and eight feet deep, until the brine stands about one
foot from the top of the tank. About one foot below the surface of the
brine a number of cross bars are fixed, and upon them a series of iron
pipes in gridiron fashion is placed, so constructed that steam being
admitted at one end of the series passes through the whole of the pipes.
The water produced in these pipes by the condensation of steam is
allowed to escape by means of a simple but effective steam trap, and is
pumped at a boiling heat into the steam boilers which supply the steam
to the pipes. These steam boilers are constructed on any of the most
approved and economical principles, and when working should carry a
pressure of about eighty pounds per square inch. The tank or pan
being provided with a tight moveable cover the vapour which is pro-
duced from the brine by evaporation is collected in one or more large
pipes which are made to pass through an elevated cistern containing
brine. By this means all the brine required to keep the liquid in the
tank or pan at a nearly constant level is supplied in a considerable
heated state. Any vapour not condensed by this means is carried
forward in a continuation of the large pipes to the stoves or drying
houses, which it serves to heat.
In the practical working of the above described apparatus the tank or
pan, also the cistern, being filled with brine, the steam from the boiler
is turned on to the pipes, which soon brings the brine near the surface
to a rapid boil, and the salt falls to the bottom of the tank as quickly
as formed, the brine being kept at a constant level by regulated supply
from the elevated cistern, as herein-before described. This is continued
until the tank or pan is almost filled with salt. The steam is then

page_text: turned off and the remaining brine removed, and the pipes are lifted out
by means of a suitable crane. The salt can then be shovelled out on to
drainers.
If any scale has formed upon the pipes it can be chipped off, and
when the pipes have been put back into the tank or pan a fresh quantity
of brine can be run in and the whole operation repeated.
By these means a great saving in fuel, labour, and wear and tear is
effected.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is, the
employment in the production of salt from brine of high pressure steam
in conjunction with pipes of small diameter, substantially in the manner
herein-before described.
In witness whereof, I, the said Arthur McDougall, have to this my
Specification set my hand and seal, this Twenty-fourth day of July,
One thousand eight hundred and seventy-two.
ARTHUR M'DOUGALL. (L.S.)