CERTAIN IMPROVEMENTS IN THE PROCESS OF EFFECTING THE DECOMPOSITION OF MURIATE OF SODA OR COMMON SALT
Year: 1836

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Jonn
SWINDELLS, of Manchester, in the County Palatine of Lancaster, Manufacturing
Chemist, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-first day of December, in the seventh year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said John Swindells, His special licence, full power, sole privilege and
authority, that I, the said John Swindells, my executors, administrators, and
assigns, and such others as I, the said John Swindells, my executors,
administrators, and 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 "CERTAIN
IMPROVEMENTS IN THE PROCESS OF EFFECTING THE DECOMPOSITION OF MURIATE OF
SODA OR COMMON SALT;" in which said Letters Patent is contained a proviso
that I, the said John Swindells, 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 His 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 bad, will more
fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Swindells, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in the explanation thereof, that is to say :-
My improvement in the process of effecting the decomposition of muriate
of soda is principally intended to counteract and prevent the injurious escape
of the hydrochloric acid gas into the atmosphere as it arises during the
ordinary process of decomposing muriate of soda in open reverberatory furnaces.
Presuming the usual manner of effecting the decomposition of muriate of soda
or common salt to be generally understood, I have only to state the variation
I propose as my improvement (and which I have found to answer with con-
siderable effect), in order to comply with the object of these presents. Having
first prepared in convenient situations closed vessels of stone or other suitable
substances, and of any desirable capacity, charged with the materials usually
employed in this process of decomposition, namely, the respective atomic pro-
portions of muriate of soda and sulphuric acid, I effect the decomposition in
the following manner:-The closed vessels containing the materials to be
acted upon are furnished with steam or hot air pipes, which are suitably con-
nected with ordinary steam boilers or hot air furnaces, and are also fitted with
an internal agitator in order to keep the whole of the materials in motion
during the process of decomposition; the steam or heated air is now to be
admitted into the interior of the vessels, by opening the communication from
the steam or hot air generators, and allowed to fill the vessels, continuing the
supply until the whole of the hydrochloric acid is expelled and conducted to the
condensors through exit pipes, arranged in connection with the decomposing
vessels for that purpose. Great advantages will be found to arise from this
internal application of steam into the decomposing vessels,―
Firstly, in the production of pure hydrochloric gas, being of course entirely
free from the coal gas and vapours arising from the usual process of decom-
position; and,
Secondly, in an effectual and ready method of propelling the hydrochloric
gas through the water in the condensors as it is in connection with the steam,
and blows off with it through the exit pipes arising from the top of the decom-
posing vessels. This method which I propose of driving the hydrochloric acid
gas with the exit steam through water in order to obtain its condensation, will
be found entirely to prevent the great nuisance of the admission of the hydro-
chloric acid gas into the atmosphere through the flues of the open reverberatory
furnaces in the common manner. The sulphate of soda (the residuum which
will be found in the decomposing vessels) is then to be run into a furnace and

page_text: dried clown in the usual manner, and finished for use as heretofore. I wish it
to be perfectly understood that I do not intend to claim any description or
arrangement of apparatus by which my improvement is to be carried into
practical effect, as the materials, dimensions, and construction of the same
must necessarily be circumstantially arranged by the operator, but I do claim
as my Invention the application of steam or heated air into the decomposing
vessels (whether open or closed), in order to effect the decomposition of
muriate of soda or common salt, as above described.
In witness whereof, I, the said John Swindells have hereunto set my
hand and seal, this Seventeenth day of June, in the year of our Lord
One thousand eight hundred and thirty-seven.