IMPROVEMENTS MUT MANUFACTURE of Bleaching LIQUOR
Year: 1872

page_text: LETTERS PATENT to Henry Deacon, of Widnes, in the County of
Lancaster, Alkali Manufacturer, for the Invention of “IMPROVEMENTS
MUT MANUFACTURE of Bleaching LIQUOR."
T
Sealed the 31st December 1872, and dated the 7th November 1872.
PROVISIONAL SPECIFICATION left by the said Henry Deacon at the
Office of the Commissioners of Patents, with bis Petition, on the
7th November 1872.
I, HENRY DEACON, of Widnes, in the County of Lancaster, Alkali
Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OP BLEACHING LIQUOR," to be as
follows:-
Bleaching liquor is usually formed by causing a mixture of caustic
lime and water to absorb chlorine, and the reaction may be represented
by the following formulæ :-
Ca Olg
2 Ca O+Cl+x H₂ O= {Ca Cl, O₂
+x H₂O,

page_text: but if the caustic lime be replaced by carbonate of lime then the reaction
may be represented as follows:-
:―
Ca CO,+C+x H₂O= CO₂+H, Cl₂ O₂+Ca Cl,+(x-1) H, O,
and the result may be described as a mixed solution of chloride of
calcium and hypochlorous acid with liberation of carbonic acid. This
solution may be used for bleaching purposes instead of the ordinary
bleaching liquor, or it may be used for the production of pure chlorine
by the addition to it of hydrochloric acid, or it may be converted into
ordinary bleaching liquor by the addition of caustic lime, as shewn in
the following formula :—
bleaching liquor, or it may be used for the production of pure chlorine
by the addition to it of hydrochloric acid, or it may be converted into
ordinary bleaching liquor by the addition of caustic lime, as shewn in
the following formula :—
Cl
Ca O+H¸ Cl₂ O̟₂+ɑa Cl₂+(x-1) H₂ O= {Câ C₁₂ 0;
+x H, O.
Now my Invention consists in using certain kinds of carbonate of
lime to replace wholly or in part the caustic lime usually employed.
One of the kinds of carbonate of lime I employ is that procured in a
state of fine division by causticising solutions of the carbonates of soda
or of potash. This finely divided material is usually a mixture of
caustic lime with carbonate of lime, and may be used with water
instead of caustic lime and be impregnated with chlorine in the usual
bleaching liquor making apparatus, too well known to need description.
The other kind of carbonate of lime I employ is chalk or limestone in
lumps. I fill towers or columns or other vessels constructed of stone
or other suitable materials with such lumps of chalk or limestone, which
are continually moistened with water or with weak liquor produced in
the course of the manufacture, and I pass chlorine gas or gases con-
taining chlorine through the apparatus amongst the lumps of chalk or
limestone. Carbonic acid gas is evolved and escapes, and a solution is
obtained which may be described as containing free hypochlorous acid
and chloride of calcium, which can be used as a bleaching liquor, or it
may be used for the production of pure chlorine by the addition to it of
hydrochloric acid, or be converted into ordinary bleaching liquor by the
addition of lime, as before described.
This improvement is especially applicable to the manufacture of
bleaching liquor by the aid of chlorine gas when mixed with carbonic
acid gas or otherwise diluted.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Deacon in the Great Seal Patent Office
on the 1st May 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DEACON, of Widnes, in the County of Lancaster, Alkali Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of November, 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 me, the said Henry Deacon, Her special license that
I, the said Henry Deacon, my executors, administrators, and assigns,
or such others as I, the said Henry Deacon, my executors, admini-
strators, 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 MANUFACTURE
OF BLEACHING LIQUOR," upon the condition (amongst others) that I,
the said Henry Deacon, 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 Seal Patent
Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Deacon, 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:
Bleaching liquor is usually formed by causing a mixture of caustic
lime and water to absorb chlorine, and the reaction may be represented
by the following formulæ :—
2 Ca 0+0+ H₂ O=
Ca Cl₂
Ca Cl, O₂+x H. O,

page_text: but if the caustic lime be replaced by carbonate of lime then the reaction
may be represented as follows:-
Ca CO,+C+ H₂ O=CO₂+H, Cl₂ O₂+Ca Cl₂+(x-1) H₂ O,
and the result may be described as a mixed solution of chloride of
calcium and hypochlorous acid with liberation of carbonic acid. This
solution may be used for bleaching purposes instead of the ordinary
bleaching liquor, or it may be used for the production of pure chlorine
by the addition to it of hydrochloric acid, or it may be converted into
ordinary bleaching liquor by the addition of caustic lime, as shown in
the following formula :-

page_text: To prevent loss and retard the decomposition of the volatile hypo-
chlorous acid the production of the bleaching liquor should be carried
on at low temperatures, and in order to prevent loss of bleaching power
the production should be performed quickly as an aqueous solution of
hypochlorous acid is gradually changed into a solution of. chloric and
hydrochloric acids. This change may be retarded as is well known
by saturating the acid with an equivalent of caustic lime, or of some
other alkaline base, and weak liquids so treated may be used in this
manufacture instead of water in order to obtain liquors of greater
strength.
Bleaching liquor so produced may also be used for the manufacture
of chlorate of potash, and for this purpose I saturate the bleaching liquor
obtained as before mentioned with lime as above described, but the
subsequent reactions are the same whether this saturation takes place
before or after the also herein-before described change of hypochlorous
acid into chloric and hydrochloric acids.
For the production of chlorate of potash therefore some advantage
will result from leaving the before-mentioned bleaching liquor produced
according to my Invention in contact with limestone or cheap carbonate
of lime, as the hydrochloric acid produced from the hypochlorous acid
will thus be neutralized by the cheap carbonate of lime, and the quantity
of more expensive caustic lime or base needed to complete the saturation
will be lessened in an equivalent degree, and obviously an effect of the
same kind will be produced if the time occupied by, the process of
absorbing the chlorine be prolonged.
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,—
First. The use of carbonate of lime, such as lumps of limestone or of
chalk, or of carbonate of lime in a state of fine division, such as that
which is obtained by causticising solutions of the carbonates of soda
and of potash by means of lime for the absorption of chlorine, as herein
described.

page_text: Second. The employment of carbonates of lime in a similar manner
for the purpose of absorbing chlorine when the chlorine is mixed with
carbonic acid gas, or is otherwise diluted.
In witness whereof, I, the said Henry Deacon, have to this my
Specification set my hand and seal, this Twenty-fifth day of April, 5
One thousand eight hundred and seventy-three.
HENRY DEACON. (L.S.)