IMPROVEMENTS THE
Year: 1872

page_text: LETTERS PATENT to James Hargreaves, of Widnes, in the County
of Lancaster, Chemist, and Thomas Robinson, of the same Place,
Ironfounder, for the Invention of "IMPROVEMENTS IN THE MANU-
PROVISIONAL SPECIFICATION left by the said James Hargreaves and
Thomas Robinson at the Office of the Commissioners of Patents,
with their Petition, on the 29th August 1872.
We, JAMES HARGREAVES, of Widnes, in the County of Lancaster,
Chemist, and THOMAS ROBINSON, of the same Place, Ironfounder, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF HYDROCHLORIC ACID AND IN APPARATUS EMPLOYED THEREIN,"
to be as follows:-
The main objects of our Invention are, (1), to more perfectly
condense hydrochloric acid from gases evolved during the manufacture
of sulphate of soda or potassa, or of chlorine; (2), to separate arsenic
and sulphurous acid from such gases; and (3), to provide efficient
combined and compact condensing apparatus. For these purposes we
pass the gases evolved during the manufacture of soda or potassa or of
chlorine through a condensing tower packed with coke or other suitable
material and supplied with a stream of weak hydrochloric acid or water,
or both, thence through a series of connected multitubular syphons or

page_text: bent pipes arranged side by side and made by preference of earthenware.
These syphons or bent pipes serve to cool the gases and condense another
and further portion of hydrochloric acid. After leaving the said series
of multitubular syphons the gases are passed through a second tower
filled with coke or other suitable material to scrub the gases and separate
any remaining fine particles of hydrochloric acid solution. The said
gases are next passed through a third similar tower provided with a
stream of water so as to separate the last. particles of hydrochloric acid.
The weak acid obtained from the third tower is or may be used in the
first tower and be there converted into strong acid; it may also be used
to furnish water vapour for the series of multitubular cooling syphons.
To separate arsenic and sulphurous-acid from the hydrochloric acid
aforesaid we cause a sufficient quantity of sulphide of hydrogen to mix
with the aforesaid evolved gases before passing them into the condensers.
The said sulphide of hydrogen on coming into contact with chloride of
arsenic causes the formation of sulphide of arsenic which is insoluble,
and which may be collected from time to time; or if sulphurous acid or
chlorine be present the said sulphide of hydrogen causes the precipitation
of sulphur, which may be collected as required.
The apparatus consists of the towers and multitubular syphons above
described in combination, and of the connected side by side series of
multitubular syphons or bent pipes for condensing hydrochloric acid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Hargreaves and Thomas Robinson in
the Great Seal Patent Office on the 28th February 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
THOMAS ROBINSON, of the same Place, Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen. Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of August, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said James Hargreaves and Thomas Robinson,
Her special licence that we, the said James Hargreaves and Thomas.
Robinson, our exccutors, administrators, and assigns, or such others

page_text: 5.
as we, the said James Hargreaves and Thomas Robinson, our exe-
cutors, administrators, and 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 MANUFACTURE OF HYDROCHLORIC ACID AND IN APPARATUS EMPLOYED
THEREIN," upon the condition (amongst others) that we, the said James
Hargreaves and Thomas Robinson, our executors or administrators, by
an instrument in writing under our, or their, or one of their, or one
of our hands and seals, 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 Seal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent..
NOW KNOW YE, that we, the said James Hargreaves and Thomas
Robinson, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described.
and ascertained in and by the following statement, reference being had
to the accompanying Sheet of illustrative Drawings, and to the figures
and letters marked thereon, that is to say :—
The main objects of our Invention are, (1), to more perfectly
condense hydrochloric acid from gases evolved during the manufacture
of sulphates of soda or potassa or of chlorine; (2), to separate arsenic
and sulphurous acid from such gases; and (3), to provide efficient
combined and compact condensing apparatus. For these purposes we
pass the gases evolved during the manufacture of sulphate of soda or
potassa or of chlorine through a condensing tower packed with coke or
other suitable material and supplied with a stream of weak hydrochloric
acid or water, or both, thence through a series of connected multitubular
syphons or bent pipes arranged side by side and made by preference of
earthenware. These syphons or bent pipes serve to cool the gases and
condense another and further portion of hydrochloric acid. After leaving
the said series of multitubular syphons the gases are passed through a
second tower filled with coke or other suitable material to scrub the
gases and separate any remaining fine particles of hydrochloric acid
solution. The said gases are next passed through a third similar tower
provided with a stream of water so as to separate the last particles of..

page_text: hydrochloric acid. The weak acid obtained from the third tower is or
may be used in the first and second towers and be there converted into
strong acid; it may also be used to furnish water vapour for the series
of multitubular cooling syphons.
To separate arsenic and sulphurous acid from the hydrochloric acid
aforesaid we, cause a sufficient quantity of sulphide of hydrogen to mix
with the aforesaid evolved gases before passing them into the condensers.
The said sulphide of hydrogen on coming into contact with chloride of
arsenic causes the formation of sulphide of arsenic which is insoluble,
and which may be collected from time to time; or if sulphurous acid.or
chlorine be present the said sulphide of hydrogen causes the precipitation
of sulphur, which may be collected as required.
The apparatus consists of the towers and multitubular syphons above
described in combination, and of the connected side by side series of
multitubular syphons or bent pipes for condensing hydrochloric acid.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a plan partly in section; and Fig. 2 a longitudinal clevation.
partly in section of our improved apparatus employed in the condensation
of hydrochloric acid. In both views like letters denote the same parts.
1 are flues conveying uncondensed hydrochloric acid gas into the
tower 2, where it is scrubbed in its passage by pieces of coke placed
therein; 3, down take pipes which serve also as coolers to convey the
scrubbed hydrochloric acid gas to the bent syphon coolers 4. The
uncondensed gas passes through the syphon coolers as shown by the
arrows, while the condensed gas or hydrochloric acid solution passes off
by the channels or troughs 5 through the beaks 6 into the way 7, thence
into any desired receptacle; all the lower ends of each transverse row of
syphon coolers 4 dip into a channel or trough 5. Any hydrochloric acid
gas not yet condensed passes from the final syphon cooler 4* into the
flue 7, thence by the flues 8 into the tower 9, where it meets in its
passage therethrough a shower of water supplied from the cistern 10.
If any hydrochloric acid gas remains still uncondensed it passes through
the pipe 11 into the second condensing tower 13 constructed similar to 9.
Both towers are filled with pieces of coke, bricks, or like material to
give greater surface of contact to the water and uncondensed gas. To
resist the outward pressure of the coke the sides of the towers are built

page_text: concave and secured by tie rods. The acidified water from the towers 9
and 13 is led off by the pipes 14. The water supplied to the towers from
the cistern 10 first passes to the distributors 15, which rocking on the
pins 16 alternately throw the water from one side to the other of the
tanks 17 so as to prevent a few of the tubes 18 from taking all the water,
which would be the case if the supply of water was small and any of the
tubes 18 slightly lower than the rest.
Fig. 3 shows an enlarged view in vertical section of the perforated
wood tank 17 with corks 19 and glass tubes 18. The sulphide of
hydrogen is admitted amongst the hydrochloric acid gas between the
sulphate apparatus and the condensing appliances above described.
Having now described the nature of our said Invention, and par-
ticularized the same, we claim,―
First. Passing the gases evolved during the manufacture of sulphate
of soda or potassa or chlorine through a condensing tower packed with
coke or other suitable material, thence through a series of connected
multitubular syphons for the purposes set forth.
Second. Separating arsenic and sulphurous acid from gases evolved
during the manufacture of sulphate of soda or potassa by the employ-
ment of sulphide of hydrogen, substantially in the manner set forth.
Third. The towers and multitubular syphons in combination, and also
the connected side by side series of multitubular syphons for condensing
hydrochloric acid, as set forth.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and seal, this Twenty-fourth day of February, in
the year of our Lord One thousand eight hundred and seventy-
In the presence of,
JAMES JOHNSON,
Clerk to J. T. King,
Liverpool.
JAMES HARGREAVES. (L.S.)