Improved Means for Effecting the Absorption of Chlorine Gas applicable in the Manufacture of Chlorates and Bleaching Liquor.
Year: 1896

page_text: Date of Application, 10th Sept., 1896
Complete Specification Left, 10th June, 1897--Accepted, 7th Aug., 1897
PROVISIONAL SPECIFICATION.
Improved Means for Effecting the Absorption of Chlorine Gas
applicable in the Manufacture of Chlorates and Bleaching
Liquor.
We, WILLIAM RANDAL CLARKE, Works Manager, and THE UNITED ALKALI COMPANY
LIMITED, both of G11 Exchange Buildings Liverpool in the County of Lancaster,
do hereby declare the nature of this invention to be as follows:-
No difficulty is found in absorbing, in milk of lime, or of magnesia, strong
chlorine gas uncontaminated with inert gas, by bringing the chlorine gas into
co. tact with the milk of lime, or of magnesia, when agitated.
When however chlorine gas contaminated with a large amount of inert gas, such
for instance as the chlorine gas produced by the Deacon process, has to be used the
difficulty of absorbing the chlorine is very great.
This Invention has for its object to provide means whereby the absorption of the
chlorine from such contaminated gases is effected in a satisfactory manner.
According to this Invention we employ a chamber or tower of considerable height
relatively to its width or horizontal sectional area, its height being say from
15 to 20 times greater than its width. This chamber or tower is provided with a
number of shelves or partitions slightly inclined to the horizontal, and permitting
the gases to ascend in a zigzag direction through the chamber or tower by apertures
in, or at the sides of, each shelf, or partition so that the apertures in successive
shelves, or partitions, are at opposite sides of the chamber, or tower, or are
alternately in the middle and sides of the shelves or partitions.
At the bottom of the said chamber, or tower, we provide an outlet for the milk of
lime, or of magnesia, and just above that we provide an inlet, for the gases, from
which the chlorine is to be absorbed. At the top of the chamber or tower just
above the top partition or shelf, we provide an outlet for the inert gases, and just
below that we provide an inlet for the milk of lime or of magnesia.
We draw the gases from which the chlorine is to be absorbed through the
chamber or tower which may be done by means of a steam jet or other forcing
device and we force the milk of lime, or of magnesia, in through the inlet at the
top of the chamber or tower. We find it advisable to have about 1 cubic foot of
milk of lime cr of magnesia and from 50 to 100 cubic feet of the gases passing
through the chamber or tower during a given time.
The milk of lime or of magnesia can flow from the bottom of the chamber, or
tower, into a receiving tank provided with an agitator and be pumped from this
receiving tank again to the top of the chamber or tower and be kept circulating in
this manner until it has absorbed sufficient chlorine gas.
In order to prevent the liquid from becoming too hot we refrigerate the milk of
lime or of magnesia on its way to the tower which may be done for example by
passing it through piping immersed in cold water.
When the lime or magnesia has thus been transformed into chlorate, we may
employ it for the manufacture of other chlorates in the well known manner.
If bleaching liquor is to be made the operation may be carried out as hereinbefore

page_text: described but care must be taken not to fully saturate the milk of lime with the
chlorine gas.
In order to avoid loss of chlorine we may take the gas from the top of one
chamber, or tower, and cause it to pass through a second similar chamber, or tower,
wherein fresh milk of lime, or of magnesia, is kept circulating the milk of lime or
of magnesia from this second chamber, or tower, being afterwards used in the first
chamber, or tower. Two such chambers, or towers, will generally be sufficient to
absorb all the chlorine from gases such as are furnished by the Deacon process, but
more than two such chambers, or towers, may be used if required.
We may provide hermetically closable doors in the sides of the chambers, or
towers, for giving access to the partitions, or shelves, for cleaning, or other purpose.
Dated this 10th day of September 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improved Means for Effecting the Absorption of Chlorine Gas
applicable in the Manufacture of Chlorates and Bleaching
Liquor.
We, WILLIAM RANDAL CLARKE, Works Manager and THE UNITED ALKALI COMPANY
LIMITED both of G 11 Exchange Buildings Liverpool, in the County of Lancaster, do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
No difficulty is experienced in absorbing in milk of lime, or of magnesia, strong
chlorine gas uncontaminated with inert gas, by bringing the chlorine gas into
contact with the milk of lime or of magnesia, when agitated.
When however chlorine gas contaminated with a large amount of inert gas, such
for instance as the gases produced by the Deacon process, has to be used, the
difficulty of absorbing the chlorine is very great.
This Invention has for its object to provide means whereby the absorption of the
chlorine from such contaminated gases is effected in a satisfactory manner, there
being obtained a good production of chlorate and a concentrated solution, resulting
in considerable economy in raw materials and labour. According to this Invention
we employ a chamber, or tower, of considerable height relatively to its width, or
horizontal sectional area, its height being say from ten, or fifteen, to twenty times
greater than its width. This chamber, or tower, is provided with a number of
shelves, or partitions, slightly inclined to the horizon and permitting the gases to
ascend in a zig-zag direction through the chamber, or tower, by apertures in, or
at the sides of, each shelf, or partition, so that the apertures in successive shelves,
or partitions, are at opposite sides of the chamber, or tower, or are alternately in
the middle and at the sides of the shelves, or partitions. At the bottom of the
said chamber, or tower, we provide an outlet for the milk of lime, or of magnesia,
and just above that we provide an inlet for the gases from which the chlorine is to
be absorbed. At the top of the chamber, or tower, just above the top partition,
or shelf we provide an outlet for the gases and just below that we provide an inlet
for the milk of lime, or of magnesia. We draw the gases from which the chlorine
is to be absorbed through the chamber, or tower, which may be done by means of
a steam jet, or other forcing device, and we force the milk of lime, or of magnesia,
in through the inlet at the top of the chamber, or tower. We find it advisable to

page_text: have about one cubic foot of milk of lime, or of magnesia, for every fifty, to one
hundred, cubic feet of the gases passing through the chamber, or tower, during a
given time. The milk of lime, or of magnesia, can flow from the bottom of the
chamber, or tower, into a receiving tank provided with an agitator and be pumped
from this receiving tank again to the top of the chainber or tower and be kept
circulating in this manner until it has absorbed sufficient chlorine gas. In order to
prevent the liquid from becoming too hot we refrigerate it on its way to the tower
which may be dono for example by passing it through piping immersed in cold
water, circulated over the coil or renewed as frequently as required.
When the lime, or magnesia, has thus been transformed into chlorate we may
employ it for the manufacture of other chlorates, in the well known manner. For
the manufacture of chlorates the milk of lime, or of magnesia, may be made of such
concentration that the finished liquor tests afterwards, from 50° to 60° on Twaddel's
hydrometer. If bleaching liquor is to be made, the operation may be carried out
as hereinbefore described but care must be taken to not fully saturate the milk of
lime with the chlorine gas otherwise chlorate is liable to form. It is also advisable
not to use for this purpose too strong a solution of lime. Good results have been
obtained with milk of lime testing 70 on Twaddel's hydrometer. In order to avoid
loss of chlorine we may take the gases from the top of one chamber, or tower, and
cause them to pass through a second similar chamber, or tower, wherein fresh milk
of lime, or of magnesia, is kept circulating, the milk of lime, or of magnesia, from
this second chamber, or tower, being afterwards used in the first chamber, or tower.
Two such chambers, or towers, will generally be sufficient to absorb all the chlorine
from gases such as are furnished by the Deacon process, but more than two such
chambers, or towers, may be used if required.
We will now describe, with reference to the accompanying drawings, the best
arrangement of apparatus with which we are acquainted for carrying this Invention
into practical effect, but we promise that we do not limit ourselves to the precise
details of the arrangement illustrated.
Figure 1 is a diagrammatic elevation and Figure 2 a diagrammatic plan of the
apparatus. Certain parts which are shewn in the plan are not repeated in
the elevation to avoid confusion of what is shewn in Figure 1.
In Figure 1 part of the tower or chamber A is broken away to shew the
arrangement of the plates or shelves a therein.
Two chambers, or towers, A A are shewn in this arrangement as hereinbefore
mentioned.
The said chambers, or towers, may be provided with hermetically closable doors
in their sides for giving access to the partitions, or shelves, for cleaning, or other
purpose. B1 B2 are the outlets for milk of lime, or of magnesia, and E' E, are the
inlets for the same, they passing through the top of the towers, as shew in dotted
lines on the tower A, and through the first plate, or division a, so as to terminate
over the. second plate, or division. J is a steam jet, or other suitable forcing device,
by which the gases from a Deacon decomposer, for example, are drawn through the
inlet C' into the tower A¹ up which they pass and thence pass by the outlet D¹
pipe j and inlet C into the tower A up through the tower A' and thence through
the outlet D and pipe j and device J, to the place of discharge. The said gases
pass alternately in opposite directions over the shelves, or partitions, in the towers,
the milk of lime, or of magnesin passing down, over the said shelves or plates (in
the reverse direction to the gases) entering at E and E and leaving at B¹ B
11 13 I are receiving tanks provided with agitators, driven by an engine F.
G G G are pumps for passing the liquid through the various portions of the
apparatus as hereinafter described. K is a refrigerator for cooling the liquid by its
passing through a coil of piping immersed in cold water in the said refrigerator.
The tanks 112 constitute one pair connected with each other and with the suction
of a pump G by a pipe H¹ provided with valves A³, and the tanks I I' constitute
another pair connected with each other and with the suction of a pump G* oy a
pipe H provided with valves 'h' and all the said tanks are connected together

page_text: and with the suction of a pump G by a pipe H provided wi
valves h
and . The delivery of the pump G is connected by a pipe gl to one end of the
coil in the refrigerator K, the other end of the said coil being connected by a
pipe g2 to the inlet for milk of lime, or of magnesia, to the tower A¹. The delivery
ef the pump G is connected by a pipe g directly to the inlet for milk of lime, or of
magnesia, to the top of the tower A2. The delivery of the pump G³, has three
branches g g of controlled by valves. The branch y is connected to the inlet
pipe of the coil in the refrigerator K, the branch g' to the inlet pipe g, to the
tower A', and the branch to a reservoir, indicated at M, for receiving the finished.
chlorate liquid, or bleaching liquid as the case may be.
It is also necessary to have a storage tank (not shewn) for fresh milk of lime, or
of magnesia, situated at a sufficient elevation to allow the contents to flow into
either of the tanks I 12 13 14.
Across each pair of tanks 11 and 1 1 is a trough L L each provided with
two outlets and which are controlled by plugs. The outlets for liquid from
the bottoms of the towers A A aro connected respectively with these troughs by
the pipes b¹².
The working of the apparatus is as follows:-the tank 12 is presumed to contain
milk of lime, or of magnesia, already partially satarated with chlorine. By opening
the valve and closing the valve A the liquid is passed by the pump G³ from the
tank 1 through the pipes H and g' and through the coil in the refrigerator K,
wherein it is cooled and passes by the pipo g2 into the top of the tower A' and as
it descends over the plates, or partitions, a, in the said tower it absorbs more
chlorine from the gas passing up through the said tower. The liquid then flows
out by the outlet B and pipe 6 into the trough L and through the opening l
(from which the plug is removed) into the tank I from which the said liquor
flows back into the tank 1 by the pipe H' the valves A and being both open
and the valve h° closed. Thus the liquid circulates through the tower A1 and
refrigerating tank K until it is nearly saturated. Then the valves are closed
and the contents of the tank 12 are pumped through the tower A1 into the tank I¹.
When the tank I is full the valve A is closed and the valve A is opened and
the liquid is now circulated from the bottom of the tank 1' through the refrigerator K
and through the tower A back to the tank I and this operation is continued
until the analysis of a sample of the liquid shews that it is fully saturated when
the pump G' is stopped and the valve A' is closed. The suction pipe of the pump Ga
is then by opening the necessary valves put in communication with the tank I
which contains milk of lime, or of magnesia, which has been circulated through the
tower A, and contains some chlorine. The delivery [pipe branch g, is put in
communication with the inlet of the coil in the refrigerator K, so that the pump G³
delivers the contents of the tank 13 through the tower A1 into the tank 12 the
opening in the trough L being open for the purpose, and that at being closed.
When the tank 1 is filled again the pump G³ is stopped the valve A is opened and
the pump G¹ put in operation and the liquid from the tank 1 is pumped through
the refrigerator and passes through the tower A' and back to the tank I. In the
meantime the tank 11 has been put in communication with the suction of the
pump G³ (the valves 2 and h being opened and the valve he closed) and the contents
of the said tank I pumped through the pipe g' into the tank M. As soon as the
tank I is empty the liquid is circulated as first described from the tank I through
the refrigerator K and tower A¹ into the tank I' and from thence back to the
tank I².
The fresh milk of lime, or of magnesia, contained in the tank I is similarly
pumped by the pump G through the tower A and flows therefrom by the pipe b
into the trough L and through the opening into the tank 1 and by the pipe H
back to the tank I the valves being suitably set as will be readily understood.
Whilst the tank Is is being emptied to supply the tower A' fresh milk of lime, or
of magnesia, is allowed to flow from the reservoir therefor into the tank I.
By this means a continuous flow of liquid through both towers can be maintained

page_text: to ensure a complete absorption of chlorine gas and the full saturation with chlorine
of the milk of lime, or of magnesia.
Although we have illustrated two towers, as these will generally be sufficient to
absorb all the chlorine from gases such as those furnished by the Deacon process,
yet more than two such towers may be used if desired.
The comparatively fresh milk of lime, or of magnesia, which meets the gases in
the second tower ensures complete absorption of the chlorine and prevents the
discharge of noxious gases into the atmosphere. By the addition of extra connecting
pipes and valves it will be evident that the system can be so arranged that either
tower can be made the first of the series.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. For effecting the absorption of chlorine gas in the manufacture of chlorate
and bleaching liquor a tower having inlets and outlets for the absorbent liquid and
for the gases from which chlorine is to be absorbed and provided with plates or
partitions down over which the liquid passes and meets a stream of gases containing
chlorine substantially as hereinbefore described and illustrated in the accompanying
drawings.
2. For effecting the absorption of chlorine gas in the manufacture of chlorates
and bleaching liquor, the combination with a tower, such as is claimed under the
preceding claiming clause, of a refrigerator and a pair of tanks and a pump all
connected and operating substantially as hereinbefore described and illustrated in
the accompanying drawings.
3.
3. For effecting the absorption of chlorine gas in the manufacture of chlorates
and bleaching liquor the combination of two or more towers, such as that claimed
under the first claiming clause each provided with a pair of tanks and a pump, and
one being provided with a refrigerator, there being a pump or pumps between the
towers so that liquid which has absorbed chlorine from partially spent gases in a
tower or towers can be passed through the first tower to become saturated with
chlorine from the gases as they first enter the apparatus and pass through the first
tower; substantially as hereinbefore described and illustrated in the accompanying
drawings.
4. The arrangement and combination of parts constituting apparatus for effecting
the absorption of chlorine gas substantially as herein before described and illustrated
in the accompanying drawings.