IMPROVEMENTS IN APPARATUS FOR AND PROCESS OF PURIFYING GAS
Year: 1884

page_text: DIEUIFICATION.
I, ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents 66 Chancery
Lane in the County of Middlesex, Patent Agent, do hereby declare the nature of
my invention for IMPROVEMENTS IN APPARATUS FOR AND PROCESS OF PURIFYING
GAS, to be as follows:-
This invention embraces improvements in the scrubbers employed in the
purification of gas, and also an improved process or method of scrubbing gas
whereby the gas is not only purified by washing, but at the same time cooled to
such a degree as to be further purified by condensation.
The improvements in gas scrubbers relate to that class of scrubbers in which the
scrubbing surfaces are stationary, and arranged in several communicating chambers
wherein they are kept wetted by water or purifying liquor which is continually
pumped from the lower to the upper parts of said chambers and delivered upon
and caused to flow downward over the said surfaces, while the gas is passing
through the said chambers and in contact with the so wetted surfaces.
The scrubbing surfaces employed in carrying out the invention may be formed
of upright plates, or if intended to carry out our new process or method of scrubbing
and purification by condensation at the same time, the said surface should consist
of the outer surfaces of tubes or conduits through which a frigorific or cooling
liquid is caused to circulate for the purpose of artificially cooling them.
The improvements consist as follows:-
=
Firstly In the combination in a gas scrubber, of a number of chambers each
containing stationary scrubbing surfaces and provided with openings through which
they communicate with each other, alternately above and below said stationary
scrubbing surfaces, whereby the gas is caused to pass downward through one
chamber and upward through the next throughout the series, the said chambers
having also communication with each other by overflow boxes and traps for
maintaining a desirable level of the water or purifying liquor in the lower parts
thereof, and being furnished with pumps or other means of raising the water or
liquor from the bottom to the top thereof for delivery upon the scrubbing surfaces.
Secondly: In forming the communication between the lower parts of the said
chambers for the overflow of the water or liquor from one to another, by means of
openings in the outer sides of the chambers and overflow boxes arranged outside
of the chambers to form communication between the said openings in the adjacent
chambers.
Thirdly: In the construction of the said chambers in pairs, each pair forming
a distinct, separate and complete structure, and with its contained scrubbing

page_text: surfaces and necessary appurtenances constituting a complete scrubber, the several
pairs so constructed connecting with the adjacent pairs, only, by nozzles for the
passage of gas and by overflow boxes and traps for the passage of the purifying
water or liquor.
Fourthly: In the combination with two upright chambers containing stationary
scrubbing surfaces and having communication by overflow boxes and traps for
controlling the level of the water or purifying liquor within them, of a double
acting circulating pump with the opposite ends of whose cylinder the said chambers
are in communication below the said scrubbing surfaces by suction pipes and valves
and also in communication above the said surfaces by means of discharge pipes and
valves, whereby one pump is made to serve to produce the circulation of the water
or purifying liquor in the two chambers.
Fifthly: In the combination with two scrubbing chambers containing scrubbing
surfaces and connected by overflow boxes and traps and furnished with a double-
acting pump communicating with both chambers as hereinabove mentioned, of
pipes for forming communications between the gas spaces of the scrubbing chamber,
and stop cocks in said pipes by the opening of which the pumps will be caused to
merely draw gas from, and return it to, the said chambers when it is desired to stop
the circulation of water or purifying liquid in the said chambers.
Sixthly: In the combination in a gas scrubber, of a system of tubes or conduits,
the exteriors of which constitute scrubbing surfaces over and between which the
gas and the scrubbing water or liquor may be caused to flow or circulate, and
a pump or other means of producing a circulation of a frigorific or cooling liquid
through the said pipes or conduits for the purpose of artificially cooling their
surfaces, and thereby producing purification of the gas by condensation in the
scrubber as well as by the scrubbing action.
Seventhly: In the combination with a gas scrubber provided with a system of
tubes or conduits, the outer surfaces of which constitute wet scrubbing surfaces,
of tubes or conduits arranged outside of the said chamber, and means of circulating
a frigorific or cooling liquid through both said systems of tubes or conduits for
simultaneously producing cooling of the scrubber internally, and the cooling of the
atmosphere surrounding the scrubber.
:
Eighthly In so arranging within a gas scrubber, a system of pipes which
constitute the scrubbing surfaces, and through which a frigorific or cooling mixture
is caused to circulate as herein above mentioned, that the lower part of the said
system is immersed in the washing or scrubbing liquor which collects in the lower
part of the scrubber, and so made to cool the said collected liquor.
Ninthly In the combination with a gas scrubber in which the scrubbing surfaces
are the exterior surfaces of tubes or conduits, and a pump for circulating a cooling
liquid through said tubes or conduits, of an external cooling apparatus for
refrigerating the said cooling liquid.
Tenthly In the improved process or method of scrubbing gas herein above
explained, that is to say, causing both the gas and the washing or scrubbing liquor
to pass in contact with artificially cooled surfaces.
Eleventhly: In the improved method of operating a gas scrubber herein above
explained, that is to say, circulating or passing the gas, and washing or scrubbing
liquor, over surfaces contained in the scrubber; and simultaneously and artificially
cooling or refrigerating those surfaces and the atmosphere surrounding the
scrubber.

page_text: I ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents, 66 Chancery
Lane in the County of Middlesex, Patent Agent do hereby declare the nature of
my invention for "IMPROVEMENTS IN APPARATUS FOR AND PROCESS OF PURIFYING
GAS," and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention embraces improvements in the scrubbers employed in the
purification of gas and also an improved process or method of scrubbing gas
whereby the gas is not only purified by washing, but at the same time cooled to
such a degree as to be further purified by condensation.
The improvements in gas scrubbers relate to that class of scrubbers in which the
scrubbing surfaces are stationary and arranged in several communicating chambers
wherein they are kept wetted by water or purifying liquor which is continually
pumped up from the lower to the upper parts of said chambers and delivered upon
and caused to flow downwards over the said surfaces; while the gas is passing
through the said chambers and in contact with the so wetted surfaces.
The scrubbing surfaces employed in carrying out the invention may be formed of
upright plates, or if intended to carry out our new process or method of scrubbing
and purification by condensation at the same time, the said surfaces should consist
of the outer surfaces of tubes or conduits through which a frigorific or cooling
liquid is caused to circulate for the purpose of artificially cooling them.
The improvements consist as follows:-
Firstly In the combination in a gas scrubber, of a number of chambers each
containing stationary scrubbing surfaces and provided with openings through which
they communicate with each other alternately above and below said stationary
scrubbing surfaces, whereby the gas caused to pass downward through one
chamber and upward through the next throughout the series, the said chambers
having also communications with each other by overflow boxes and traps for
maintaining a desirable level of the water or purifying liquor in the lower parts
thereof, and being furnished with pumps or other means of raising the water from
the bottom to the top thereof for delivery upon the scrubbing surfaces.
Secondly: In forming the communication between the lower parts of the said
chamber for the overflow of the water or liquor from one to the other by means of
openings in the outer sides of the chambers, and overflow boxes arranged outside of
the chambers to form communication between the said openings in the adjacent
chambers.
Thirdly: In the construction of the said chambers in pairs, each pair forming a
distinct, separate and complete structure and with its contained scrubbing surfaces
and necessary appurtenances constituting a complete scrubber, the several pairs so
constructed connecting with the adjacent pairs only by nozzles for the passage of
gas and by overflow boxes and traps for the passage of the purifying water or
liquor.
Fourthly: In the combination of two upright chambers containing stationery
scrubbing surfaces and having communication by overflow boxes and traps for
controlling the level of the water or purifying liquor within them, of a double
acting circulating pump with the opposite ends of whose cylinder the said
chambers are in communication below the said scrubbing surfaces by suction pipes
and valves, and also for communicating above the said surfaces by means of
discharge pipes and valves whereby one pump is made to serve to. produce the
circulation of the water or purifying liquor in the two chambers.

page_text: :
Fifthly In the combination with two scrubbing chambers containing scrubbing
surfaces and connected by overflow boxes and traps and furnished with a double
acting pump communicating with both chambers as hereinabove mentioned, of pipes
for forming communications between the gas spaces of the scrubbing chambers and
the pump, and stop cocks in said pipes by the opening of which the pumps will be
caused to merely draw gas from and return it to the said chambers when it is
desired to stop the circulation of water or purifying liquid in the said chambers.
Sixthly In the combination in a gas scrubber of a system of tubes or conduits
the exteriors of which constitute scrubbing surfaces over and between which the
gas and the scrubbing water or liquor may be caused to flow or circulate, and a
pump or other means of producing a circulation of a frigorific or cooling liquid
through the said pipes or conduits for the purpose of artificially cooling their
surfaces and thereby producing purification of the gas by condensation in the
scrubber as well as by the scrubbing action.
:
Seventhly In the combination with a gas scrubber provided with a system of
tubes or conduits the outer surfaces of which constitute wet scrubbing surfaces, of
a system of tubes or conduits arranged outside of the said scrubber, and means
of circulating a frigorific or cooling liquid through both said systems of tubes or
conduits for simultaneously producing cooling of the scrubber internally and the
cooling of the atmosphere surrounding the scrubber.
Eighthly: In so arranging within a gas scrubber a system of pipes which
constitute the scrubbing surfaces and through which a frigorific or cooling mixture
is caused to circulate as hereinabove mentioned, that the lower part of the said
system is immersed in the washing or scrubbing liquor which collects in the lower
part of the scrubber and so made to cool the said collected liquor.
Ninthly In the combination with a gas scrubber in which the scrubbing
surfaces are the exterior surfaces of tubes or conduits, and a pump for circulating
a cooling liquid through said tubes or conduits, of an external cooling apparatus
for refrigerating the said cooling liquid.
:
Tenthly In the improved process or method of scrubbing gas hereinabove
explained, that is to say causing both the gas and the washing or scrubbing
liquor to pass in contact with artificially cooled surfaces.
Eleventhly: In the improved method of operating a gas scrubber hereinabove
explained that is to say circulating or passing the gas and washing or scrubbing
liquor over surfaces contained in the scrubber and simultaneously and artificially
cooling or refrigerating those surfaces and the atmosphere surrounding the
scrubber.
Sheet I of the drawing exhibits a scrubber which illustrates the first, second,
third, fourth and fifth parts of the invention, the scrubbing surface of said scrubber
being in the form of upright plates.
Sheet II of the drawings exhibits a scrubber which is both a scrubber and a
condenser and which may be termed a "condenser scrubber" the scrubbing surfaces
consisting of the outer surfaces of conduits through which a frigorific or cooling
liquid is caused to circulate for the purpose of cooling the said surfaces, and
thereby effecting what is known in the gas manufacture as condensation. This
illustrates all the features of the invention.
In Sheet I Figure 1 is a partly sectional elevation, Fig: 2 is a vertical section in
the dotted line xx of Fig: 1 Figure 3 is a plan partly in section. Figures 4 and 5
are sectional views on a larger scale than Figures 1. 2. and 3 showing the method
of forming the groups of metal plates for the scrubbing surfaces.
Similar letters of reference designate corresponding parts in all these Figures.
A designates upright chambers which may be of any size and shape desired, and
of which any number may be connected in a series to form a scrubber of the
desired size and capacity. These chambers are represented as formed in pairs, each
pair constituting a distinct and separate structure, which may be made of cast or
wrought iron. The two chambers of each pair are separated from each other by a
partition A¹

page_text: Within the chambers A are arranged plates B of any suitable material preferably
thin sheet metal which are arranged very near together and which almost entirely
fill the chambers, as shown in Figure: 3.
The plates are secured together as represented in Figures 4 and 5 in groups by
rivets a and have washers a¹ interposed between them to hold them at the desired
distance apart. The plates may however be secured in groups in any suitable way.
As here represented, the groups of plates B are arranged in three banks or tiers
and are supported on girders B¹; but more or less than three tiers may be used,
according to the height of the scrubber.
C designates the gas inlet which communicates with the chamber A at one end
of the scrubber above the plates B therein, and C¹ designates the gas outlet leading
from the chamber at the opposite end of the scrubber above the plates therein.
In each partition A' which separates the chambers of each pair, is a hole or
opening b below the plates in the chambers, and through which the chambers
communicate directly by means of nozzles or openings d with the chambers of
adjacent pairs above the plates B in the chambers. The several chambers may all
rest upon the same foundation as shown and may have inclined bottoms, as shown
in Figure 2 so that the tar will all drain to one side and each chamber communicates,
through a pipe c provided with a valve or cock c¹ with a common conduit D for
carrying off the tar.
The means employed for producing the circulation of the ammoniacal liquor in
the scrubber may be to some extent varied, those represented and which constitute
part of the invention are as follows.
E designates the steam or motor cylinder of a direct acting engine and F
designates double acting pump cylinders, one of which is employed in connection
with each pair of chambers. The pistons of the steam engine and pumps are or
may be all attached to a common piston rod e. Each pump is double acting and
the ends of its cylinder are connected by suction pipes f with the lower portion of
the two chambers of each pair and by the discharge pipes g with the upper part of
both chambers of said pair.
In the suction pipes fare check-valves f¹ provided with screws, whereby they
may be more or less throttled or held close together or with ordinary stop cocks;
and in the discharge pipes are valves or cocks g¹. The upper end of each
discharge pipe g enters the chamber and has a horizontal extension g3 which is
perforated and the perforations are preferably in the top or upper side thereof so
that the liquor will be discharged with considerable velocity against the top
of chamber and thereby sprayed over all the groups of the plates B. The liquor
trickles down over said plates and keeps their surfaces constantly wet and returns
again to the bottoms of the several chambers. The gas enters at the inlet C and
passes downward through and among the groups of plates in the first chamber;
thence through the opening b to the other chamber of the pair and upward through
and among the groups of plates of that chamber, thence through the nozzle or
opening d to the first chamber of the next pair, and so on, until it makes its exit
at the outlet pipe C¹. It will be seen that in its passage through the scrubber the
gas passes again and again over the constantly wet surfaces of the plates B and is
freed from its sulphur and other impurities which the ammoniacal liquor will
remove. Each chamber has upon its side a cover or bonnet A³ and when the cover
is removed access is afforded to all the groups of plates in the chamber and they
may be removed for cleaning or for renewal and as readily replaced.
From the chamber A which is provided with the gas inlet C there extends
a discharge or outlet pipe h for the concentrated ammoniacal liquor, and in order to
maintain the desired quantity in the several chambers the chamber at the opposite
end of the scrubber is provided at the top with the inlet pipe 2.
On the sides of the several chambers A are overflow openings or apertures ; and
the openings or apertures of adjacent chambers are connected by overflow boxes G
bolted to the exteriors of the sides of the chambers so that they may be readily

page_text: i
'removed in case they become clogged, or for any other purpose, without breaking
any other joints:
As best shown in Figure: 1 the several overflow boxes G are set at different levels
grading from the right downward toward the left, and thereby the liquor is made
to flow towards the left in its passage through the scrubber, while the gas flows in
.the opposite direction, or toward the right, hence the gas as it enters comes first in
contact with the most highly concentrated liquor.
The overflow boxes G are provided with central partitions k which enable them
to serve as traps and so prevent gas from blowing through and compelling the gas
to pass upward and downward through the chambers for treatment successively by
weaker and weaker liquor.
In order to vary or control the degree of concentration which takes place in the
several chambers, the speed of the engine may be increased or diminished or
the amount of liquor raised by the pumps may be varied by opening or closing
the valve f¹ in the suction pipe f. In case it is desirable to put one pump or either
end of same entirely out of action, we provide each pump F with a pipe Z
connecting its ends and communicating with a pipe which leads from the gas
space of the scrubber, it being attached to the upper part of one of the overflow
boxes G or to the chamber below the plates B. In the pipe are cocks or valves [*
and by closing the valve f' in the suction pipe f, and g¹ in the discharge pipe g and
opening the valves the pump will be made to draw gas from the scrubber and
deliver it through the pipes thus pumping gas instead of liquor.
It will be seen that any number of chambers or pairs of chambers may be
'combined to form a scrubber and at any time other chambers can be bolted onto
the nozzles d and connected with the existing chambers and with each other by
overflow boxes G. Thus provision is made for very readily increasing the size of
the scrubber.
If more chambers are added at any time each pair of chambers should be
provided with a pump cylinder F and the piston thereof should be connected with
the common piston rode or each chamber may have its own pump.
The "condenser scrubber" represented in Sheet II differs in construction from
that shown in Sheet I and already described, in having its scrubbing surfaces
composed of artificially cooled tubes instead of being simple plates and in having
combined with it means for cooling the atmosphere surrounding it.
In Sheet II of the drawing Figure 6 is a partly sectional elevation of the
"condenser scrubber" and its appurtenances, and Figure 7 is a plan of the same.
Similar letters of reference indicate corresponding parts in these Figures.
A designates upright chambers constructed in pairs with a partition A¹ between
those of each pair and connected in a series of any number by nozzles d d an
opening b being provided in each partition A' all as shown in and described with
reference to the Figures in Sheet 1. The means provided for the circulation of the
ammoniacal liquor over the scrubbing surfaces of this scrubber, and the means
provided for the overflow of the said liquor from one chamber to another are also
the same as those shown in and described with reference to Sheet I and are
designated by similar letters of reference and therefore need no further description.
The tubular scrubbing surfaces consist of inclined rows, or tiers of parallel
tubes B which are connected by headers B' on opposite sides of each chamber.
These headers and parallel tubes constitute extensive passages or conduits for the
circulation of any cooling or refrigerating liquid or agent and present externally a
large extent of scrubbing and cooling surface to the gas. They extend downward
into the liquor which collects at the bottoms of the chambers.
H designates a cooler which may be of any suitable character. It may contain
ice or have the brine from an ice machine circulated within it and the upper ends
of the systems of pipes or tubes B B¹ in the several chambers are connected with it
by a pipe m outside of the scrubber chamber.
F designates a pump cylinder, the piston of which may be attached to the
piston rod eor operated by a separate motor. The suction pipe n of this pump

page_text: extends from the cooler H, and its discharge pipe o communicates through short
branch pipes furnished with stop cocks of with the lower ends of the tube systems
B B¹ in the several chambers, so that the pump may keep up a circulation of the
cooling liquid through the pipes B B¹ and the cooler H, the said liquor passing
from the pipe o through the stop cocks o' to B B¹, and leaving the latter by the
pipe m through which it returns to the cooler H.
pp designate a system of pipes which are connected with the discharge pipe o
on opposite sides of a valve o', and which extend through the room wherein the
scrubber is situated. In the pipes p plare valves p³. When the valves p³ are
closed and the valve o' is open, the cooling or refrigerating fluid is circulated by
the pump through the pipe o, thence upward through the systems of tubes B B¹,
and thence from their upper ends through the pipe m to the cooler. H. When the
valve o' is closed, and the valves p' are open the cooling or refrigerating fluid is
circulated first through the system of pipes p p' throughout or around the room
wherein the scrubber is situated and then through the several systems of tubes in
the several chambers If the scrubber is situated conveniently to an ice machine or
other artificial refrigerating machine the cooling fluid may be brine circulated by
the brine pump of the machine, or circulation may be produced by an elevated
reservoir for liquid.
In lieu of the scrubbing surfaces within the chambers consisting of tubes they
may be made of any hollow form so that they may be artificially cooled or
refrigerated in any suitable way. As shown, the system of the tubes B B' extends
downward into the liquor which collects in the lower parts of the chambers, and
the said liquor is thereby cooled or refrigerated. The desired result might be
effected by cooling the liquor in the bottom of the chambers only; but it is
preferable to also cool the tubes B B₁ or other analogous scrubbing surfaces over
which the liquor or water trickles and with which the gas comes in contact in
passing through the scrubber.
If desired the cooling fluid may be circulated through the system of pipes p p¹
around the room, and through the systems in the chambers independently of each
other.
The circulation through the system of pipes B B¹ hereinabove described is from
the pipe o through each system independently and from each system independently
through the pipe m to the cooler; but there is also represented in the drawing
provision for the circulation of the cooling liquid through the several systems B B¹
one after another in succession which will now be explained.
The connection between the upper ends of the systems B B¹ with the pipe m is
by short branch pipes furnished with stop cocks m¹. Between each of these stop
cocks m¹ and the scrubber, except as to the scrubber chamber nearest the cooler,
there is connected with the branch pipe in which the cock is situated, the upper
end of one of a series of pipes 8 the lower end of which connects with the lower
end of the system B B¹ in the next chamber of the scrubber and in the upper part
of each pipe 8 is a stop cock 8'.
When it is desired to circulate the cooling liquid through the several cooling
systems B B one after the other, all the cocks o' are closed except the one furthest
from the cooler, all the cocks m³ are closed except the one nearest the cooler and
all the cocks 8 are opened. The circulation is then from the pump along the pipe o
to the system B B' in the chamber furthest from the cooler, upward through that
system and out through the cock 8 and pipe 8, and down through the said pipe to
the system B B' in the next chamber, and so on successively through the systems
in all the chambers to the cooler.
To make the circulation through the cooling systems in the several chambers
successively as first described the cocks 8' are all closed and those o' and m¹ are
opened.
The gas may be taken into this artificially cooled scrubber directly from the
hydraulic main or from the hot scrubber if a hot scrubber be used; or the

page_text: artificially cooled scrubber make take the place of both an ordinary scrubber and
an ordinary condenser.
The process of scrubbing and condensing carried out in this "condenser scrubber"
by cooling the scrubbing surfaces artificially constitutes a very important feature
of this invention and when it enables the separate condenser commonly used to be
dispensed with, it effects an important saving in the cost of apparatus and in the
production of gas. It also enables a smaller scrubber to be used effectively because
it requires no larger scrubber for summer than is sufficient for winter while
heretofore it has, been necessary to provide a scrubber larger than required for
winter use in order that it should be large enough for summer use. This also effects
a saving in the cost of apparatus and in the room occupied. It also produces a
highly concentrated ammoniacal liquor of greater value than that produced by the
operation of an ordinary scrubber. All the above results are augmented by
artificially cooling the room wherein the scrubber is situated.
In the operation of gas scrubbers heretofore there have been no means of
regulating or controlling the temperature except by varying the quantity of washing
water used and in warm weather the quantity used is enormous.
'This invention effects a great saving in the quantity of water used.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1 The combination in a gas scrubber of a number of chambers each containing
stationary scrubbing surfaces and provided with openings through which they
communicate with each other directly alternately above and below said surfaces,
whereby the gas is caused to pass downward through the plates of one chamber
and upward through the next chamber throughout the series, overflow boxes or
openings for maintaining the desired level of liquor in the several chambers and
means for raising liquor from the bottom to the top of said chambers, substantially
as and for the purpose herein described.
2nd The communications between the several chambers of the scrubber formed
by openings in the outer sides of the chambers and overflow boxes arranged outside
of the chambers to form communications between the said openings substantially
as herein described.
3rd The combination of the chambers containing the stationary scrubbing
surfaces and constructed in pairs, each pair forming a complete structure and
communicating with the next one by openings or nozzles for the passage of gas
and by overflow boxes and traps for the passage of the purifying water or liquor
all substantially as herein described.
4th The combination with two upright chambers containing stationary scrubbing
surfaces and provided with overflow boxes for controlling the level of the
purifying liquor in them of a double acting circulating pump with the opposite
ends of whose cylinder the said chambers are in communication below said scrubbing
surfaces by suction pipes and valves, and also in communication above said surfaces
by means of discharge pipes and valves whereby one pump is made to serve for
both chambers substantially as and for the purpose herein described.
5th The combination with two chambers of a scrubber connected by overflow
boxes and traps and furnished with a double acting liquid circulating pump serving
for both chambers, of pipes for forming communications between the gas spaces
of the chambers and the pump, and stop cocks in said pipes substantially as and
for the purpose herein described.
6th The combination in a gas scrubber, of a system of tubes or conduits the
exteriors of which constitute scrubbing surfaces, over, between and in contact with
which the gas and the scrubbing liquor may be caused to flow or circulate, and
means of producing a circulation of a frigorific or cooling fluid through said pipes
or conduits and thereby artificially cooling the same substantially as and for the
purpose herein described.
u
'
7th The combination with a gas scrubber containing a system of tubes or

page_text: conduits the outer surfaces of which constitute scrubbing surfaces, of a system of
tubes or conduits outside of said scrubber and means for producing the circulation
of a frigorific or cooling liquid through both said systems of tubes or conduits
substantially as and for the purpose herein described.
8 The arrangement of the system of tubes or conduits which constitute the
artificially cooled scrubbing surfaces in such manner within the scrubbing
chambers that the lower parts of said system are immersed in the scrubbing liquor
which collects at the bottoms of said chambers substantially as herein described.
9th The combination with the gas scrubber and its contained system of tubes or
conduits constituting scrubbing surfaces and a pump for circulating a cooling liquid
through said tubes or conduits, of an external cooling apparatus for refrigerating
said cooling liquid substantially as herein described.
10th The improved method of scrubbing gas consisting in causing both the gas
and the scrubbing liquor to pass in contact with artificially cooled surfaces
substantially as and for the purpose herein described.
11th The improved method of operating a gas scrubber consisting in circulating
or passing the gas and washing or scrubbing liquor over surfaces contained in
the scrubber, and in simultaneously and artificially cooling or refrigerating such
surfaces and cooling or refrigerating the atmosphere surrounding the scrubber
substantially as and for the purpose described.