IMPROVEMENTS IN THE MANUFACTURE OF BLEACHING PROVISIONAL SPECIFICATION
Year: 1871

page_text: LETTERS PATENT to Henry Larkin, of Theydon Gernon, in the
County of Essex, Andrew Leighton, of No. 16, South Castle Street,
Liverpool, in the County of Lancaster, and William White, of
No. 30, Thurlow Road, Hampstead, in the County of Middlesex, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF BLEACHING
PROVISIONAL SPECIFICATION left by the said Henry Larkin, Andrew
Leighton, and William White at the Office of the Commissioners of
Patents, with their Petition, on the 20th May 1871.
We, HENRY LARKIN, of Theydon Gernon, in the County of Essex,
ANDREW LEIGHTON, of No. 16, South Castle Street, Liverpool, in the
County of Lancaster, and WILLIAM WHITE, of No. 30, Thurlow Road,
Hampstead, in the County of Middlesex, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF BLEACHING
POWDER," to be as follows:-
In order to render the impure chlorine obtained by the action of
oxygen or heated chloride of iron suitable for the manufacture of

page_text: bleaching powder it is made to pass through suitable vessels or chambers,
in the first of which it is exposed to the action of cold hydrochloric
acid to remove the metallic impurities which accompany the chlorine,
and in the second to the action of cold water to absorb any hydrochloric
acid that may be carried over. These vessels or chambers also serve
to cool the heated chlorine as it passes through.
In order to cause chlorine to combine with lime to form bleaching
powder we place lime in a state of fine powder in a hopper or hoppers
situated over a chamber containing angular scattering bars in successive
rows or layers in its upper portion. By this means continuous streams
of powder in regulated quantities are made to fall upon the angular
ridges of the top row of bars, by which they are divided and scattered
upon the second row beneath, and so on in succession as many times
as may be necessary. Below the scattering bars there is a clear space
in the chambers through which the powder may then fall in a uniform
shower. At the lower part of this chamber there are apertures for the
introduction of the chlorine gas, either pure or diluted with nitrogen, as
when atmospheric air is used in its production. An opening in the
upper part of the chamber is also provided for the exit of any super-
fluous gas or gases. As the chlorine (or the mixture of chlorine and
nitrogen) rises in the chamber it is met by the descending lime powder,
which absorbs the chlorine with great avidity, and at last, when sufficiently
charged, falls into a chamber below, from which it may be removed by
means of a moveable bottom, or otherwise, without interrupting the
process
of manufacture. By properly proportioning the flow of the lime
powder to the supply of chlorine and the height of the scattering chamber
a very high degree of saturation may be readily obtained from a dilute
chlorine. The operation is also continuous, and the waste of chlorine
from the periodic opening of the chambers is avoided.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 3
filed by the said Henry Larkin, Andrew Leighton, and William
White in the Great Seal Patent Office on the 20th November 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
LARKIN, of Theydon Gernon, in the County of Essex, ANDREW
LEIGHTON, of No. 16, South Castle Street, Liverpool, in the County of 3

page_text: Lancaster, and William WHITE, of No. 30, Thurlow Road, Hampstead,.
in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of May, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Henry Larkin, Andrew Leighton, and
William White, Her special license that we, the said Henry Larkin,
Andrew Leighton, and William White, our executors, administrators,.
and assigns, or such others as we, the said Henry Larkin, Andrew
Leighton, and William White, our executors, 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 BLEACHING POWDER," upon the condition (amongst others) that we, the
said Henry Larkin, Andrew Leighton, and William White, our exe-
cutors or administrators, by an instrument in writing under our, or
their hands and seals, or under the hand and seal of one of us, or
them, 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 Henry Larkin, and William
White, on behalf of ourselves and the said Andrew Leighton, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
In order to render the impure chlorine obtained by the action of
oxygen on heated chloride of iron suitable for the manufacture of
bleaching powder it is made to pass through suitable vessels or chambers,
in the first of which it is exposed to the action of cold hydrochloric
acid to remove the metallic impurities which accompany the chlorine,
and in the second to the action of cold water to absorb any hydro-
chloric acid that may be carried over. These vessels or chambers also
serve to cool the heated chlorine as it passes through.

page_text: In order to cause the chlorine to combine with lime to form bleaching
powder we place lime in a state of fine powder in a hopper or hoppers
situated over a chamber containing angular scattering bars in successive
rows or layers in its upper portion. By this means continuous streams
of powder in regulated quantities are made to fall upon the angular
ridges of the top row of bars, by which they are divided and scattered
upon the second row beneath, and so on in succession as many times as
may be necessary. Below the scattering bars there is a clear space in
the chambers through which the powder may then fall in a uniform
shower. At the lower part of this chamber there are apertures for the
introduction of the chlorine gas, either pure or diluted with nitrogen, as
when atmospheric air is used in its production. An opening in the
upper part of the chamber is also provided for the exit of any super-
fluous gas or gases. As the chlorine (or the mixture of chlorine and
nitrogen) rises in the chamber it is met by the descending lime powder,
which absorbs the chlorine with great avidity, and at last, when
sufficiently charged, falls into a chamber below, from which it may be
removed by means of a moveable bottom, or otherwise, without inter-
rupting the process of manufacture. By properly proportioning the
flow of the lime powder to the supply of chlorine and the height of
the scattering chamber, a very high degree of saturation may be readily
obtained from a dilute chlorine. The operation is also continuous, and
the waste of chlorine from the periodic opening of the chambers is
avoided.
Having thus described the nature of our Invention, we will proceed
to describe more fully the manner in which we prefer to carry the same
into effect, reference being made to the Drawings hereunto annexed and
to the letters and figures marked thereon.
Figures 1 and 2 of the Drawings shew vertical sections and Figure 3
a horizontal section of apparatus for manufacturing bleaching powder
by causing a continuous stream of lime in a state of powder to fall in
a divided state through chlorine gas as above described.
The lime slacked and in a state of fine powder is placed in the hopper a
situated over a chamber 6 containing scattering bars c in successive
rows or layers in its upper portion. By this means and by the action
of a revolving pinion d, Figure 1, and a slide e for opening and closing
the aperture a continuous stream of powder in regulated quantities is
made to fall upon the top bar, by which it is divided and scattered upon

page_text: the second row beneath, and so on in succession as many times as may
be necessary. Below the scattering bars there is a clear space ƒ through
which the powder may fall in a sufficiently distributed shower. At the
lower part of this chamber there is an aperture g for the introduction
of the chlorine gas, either pure or diluted, as when atmospheric air is
used in its production. An opening h is also provided in the upper part
of the scattering chamber for the exit of any superfluous gas or gases.
As the chlorine (or the mixture of chlorine and nitrogen) rises in the
chamber it is met by the descending lime, which absorbs the chlorine
with great avidity. As the lime by this mixing operation becomes
sufficiently charged with chlorine, and thus converted into bleaching
powder it falls into a box or other suitable receptacle i provided to receive
it. When the receiving box becomes filled with bleaching powder the
moveable bottom k, Figure 1 is pushed in as shewn at Figure 3. By
opening the door the full box may then be removed without stopping
the process, and an empty box put in its place. The door is then again
closed and the movable bottom k withdrawn, when the operation will
proceed as before.
By properly proportioning the flow of the lime to the supply of
chlorine and the height of the scattering chamber a very high degree
of saturation may be readily obtained from a dilute chlorine. The
operation being also continuous the waste of chlorine from the usual
periodic opening of the chambers is avoided; m is a settling chamber
through which the superfluous gas or gases pass from the aperture h to
the exit flue n; o, o, o, are a series of funnel-shaped boxes into which
any powder which may be carried over by the draught is allowed to
settle, and which may be removed by opening the trap doors p, p, p.
When undiluted chlorine is used the aperture and settling chamber
are not required.
When the chlorine used in the manufacture of bleaching powder is
obtained by the action of oxygen on heated chloride of iron we cleanse
and cool it by passing it through suitable vessels or chambers, in the
first of which it is exposed to the action of hydrochloric acid to remove
the metallic impurities which accompany the chlorine, and in the second
to the action of water to absorb any hydrochloric acid that may be
carried over. An arrangement similar to the ordinary acid condensing
towers is convenient and suitable for this purpose. The acid and water
are made to flow in at the top as cold as practicable, and as they meet

page_text: the upward current of the chlorine gas and issue in a heated condition
from below they are passed through any suitable cooling apparatus,
after which they are again conveyed to the top to be again used as
before. By this arrangement the same acid may be used many times,
and any chlorine absorbed by the water is prevented from running to
waste.
Having thus described the nature of our Invention, and the manner
in which we prefer to carry the same into effect, we would have it
understood that what we claim as our improvements in the manufacture
of bleaching powder is,.-
1. The combined arrangement of apparatus for the manufacture of
bleaching powder, substantially as herein described, whereby a continuous
stream of lime in powder is caused to fall in a divided state through
chlorine gas, either pure or diluted, and whereby the bleaching powder
produced can be drawn off from time to time without interrupting the
process of manufacture.
2. The manufacture of bleaching powder by subjecting lime to the
action of chlorine gas obtained by passing oxygen or atmospheric air
over or amongst heated chloride of iron and purified by submitting it
first to the action of hydrochloric acid and then to the action of cold
water.
In witness whereof, we, the said Henry Larkin and William
White, have hereunto set our hands and seals, this 20th day of
November, in the year of our Lord One thousand eight hundred
HENRY LARKIN.
(L.8.)
WILLIAM WHITE. (L.S.)