Improvements in Coal Gas Scrubbers.
Year: 1899

page_text: Date of Application, 10th Apr., 1899
1
1000
A
1000
Improvements in Coal Gas Scrubbers.
I, GEORGE ERNEST STEVENSON, of Airedale, Sale, in the County of Cheshire,
Gas Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to coal gas scrubbers which are used for freeing
coal gas from impurities such as ammonia, carbonic acid and sulphuretted
hydrogen.
My improved scrubber is one of the kind known as "Tower" scrubbers, but
instead of the gas passing up from the bottom to the top of the tower as is the
case with other tower scrubbers at present in use, the gas, in my invention, is
made to travel in a zig-zag direction from side to side of the tower in its ascent.
In order to effect this I prefer to make the tower of rectangular form and about
twice as wide in one direction as in the other direction (but I do not limit myself
to any particular proportions) and I insert within the tower at certain distances
apart trays made of perforated iron or steel plates. These trays are stopped
short of the wall of the tower at opposite ends alternately so that the gas is com-
pelled to pass from side to side of the tower in its ascent. Between the trays I
provide rows of wood of canvas screens or the like made in the same manner as
those used in other tower scrubbers but instead of being placed one on the top
of the other in a crossed position as in other tower scrubbers I arrange the rows
of wood boards or canvas sheets in the same direction, namely in the direction
of the greatest width of the tower and each row is made to rest on packing bars
placed on the row below so that there is a small space between each row. At the
top of the tower is provided an arrangement for distributing a shower of water
or ammoniacal liquor, or any other liquid purifying agent passing through the
tower. This arrangement is similar to the arrangement used in other tower
scrubbers.
The liquid shower falls straight down the tower passing through the perfora-
tions in the iron trays and preventing the gas from ascending through them.
The gas travels longitudinally across the liquid shower from side to side of the
tower and amongst the screens and comes in contact with their wetted surfaces.
The advantage of my invention above described is that the gas has a travel
of about three times the length of the tower and is all the while in contact with
the wetted surfaces of the screens and exposed to the shower of liquid.
The efficiency of the tower is therefore three times as great as a tower scrubber
of the same size, or an equivalent efficiency of my improved tower may be made
about one third the height of the ordinary tower scrubber thus saving a large
proportion of the cost of the apparatus.
Dh 7th day of Amil 1500

page_text: Improvements in Coal Gas Scrubbers.
1, MARIANA STANLEY STEVENSON, of Airedale, Sale, in the County of Cheshire,
Widow and Sole Executrix of the late George Ernest Stevenson, of Airedale,
aforesaid, Gas Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement: -
This invention has reference to coal gas scrubbers which are used for freeing
coal gas from impurities such as ammonia, carbonic acid and sulphuretted
hydrogen.
My improved scrubber is one of the kind known as "Tower" scrubbers, but
instead of the gas passing up from the bottom to the top of the tower as is the
case with other tower scrubbers at present in use, the gas, in my invention, is
made to travel in a zig-zag direction from side to side of the tower in its ascent.
I will describe this invention by referring to the accompanying drawings on
which Fig. 1 is a sectional elevation of a coal gas scrubber constructed in accord-
ance with this invention; Fig. 2 is a sectional side elevation of the same;
and Fig. 3 is a plan on an enlarged scale of a portion of one of the perforated
trays of the said scrubber.
in carrying out this invention I build up the tower A of cast iron plates in
the usual way and prefer to make the tower of rectangular form in plan and
about twice as wide from side to side (see Fig. 1) as it is from back to front
(see Fig. 2) but I do not limit myself to any particular proportions, and I insert
within the tower at a certain distance apart, one above the other, trays of per-
forated iron or steel plates. In the scrubber represented in my drawing there
are eight of these perforated trays and they are marked respectively B1, B2, B³,
B³, 15, 136, 137 and Bs. The plates forming the said trays can conveniently be
made of No. 12 B.W.G. in thickness and perforated with holes one-eighth of an
inch in diameter and two inches from centre to centre arranged in rows one inch
apart. The said trays are carried by end brackets C cast on the walls of the
tower and by cross girders D arranged crosswise of the tower from front to back..
The said trays are stopped short of the wall of the tower at opposite ends alter-
nately, that is to say, the trays B1, B3, B5, B are as shewn stopped off short
of the right hand wall (Fig. 1) and the trays B2, B4, B6, 18 are stopped off
short of the left hand wall so that as indicated by the arrows in Fig. 1 the gas
which enters the tower by the pipe E is compelled to pass from side to side of
the tower in a zig-zag manner in its ascent. F is the outlet pipe down which
the gas passes after it has left the scrubber.
Between the said trays I provide rows of wood or canvas screens or the like
made in the same manner as those used in other tower scrubbers but instead of
being placed one on the top of the other in a crossed position as in other tower
scrubbers I arrange the rows of wood boards or canvas screens in the same
direction namely in the direction of the greatest width of the tower and each row
is made to rest on packing boards placed on the bottom row below so that there
is a small space between each row. This arrangement of the boards or screens
will be clear by an examination of my drawing by which it will be seen that over
each tray and arranged longitudinally from side to side of the scrubber in the
same direction as the gas travels there are five rows of boards marked respect-
ively G1, G2, G3, G4, G each row consisting of boards on edge with a short
distance between each the bottom row resting on the tray and the other rows
resting on packing strips h which are placed on the row below and extend from

page_text: front to back of the tower. At the top of the tower is provided an arrangement
for distributing a shower of water or ammoniacal liquor or any other liquid
purifying agent passing through the tower. This arrangement is similar to the
arrangement used in other tower scrubbers and which being well known I need
not describe.
The liquid shower falls straight down the tower wetting the rows of boards G¹.
G³, G³, G, G³ and passing through the perforations in the trays B', B2, B3,
B, B5, B6, B7, B8 and preventing the gas from ascending through the perfora-
tions. The gas in rising up the tower travels as indicated by the arrows in Fig. 1
longitudinally across the liquid shower from side to side of the tower passing
between the boards and coming in contact with their wetted surfaces.
The advantage of my invention above described is that the gas lias a consider-
ably increased length of travel in passing from the bottom to the top of the tower
and is all the while in contact with the wetted surfaces of the boards or screens
and exposed to the shower of liquid.
The efficiency of the tower is therefore three times as great as a tower scrubber
of the same size or an equivalent efficiency of my improved tower may be made
about one third the height of the ordinary tower scrubber thus saving a large
proportion of the cost of the apparatus. .
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
In a coal gas scrubber of the kind known as a "tower" scrubber the employ-
ment of perforated metal trays arranged horizontally in the tower one above the.
other and stopped off short of the opposite walls of the tower alternately, said
trays carrying boards on edge or canvas screens or the like arranged in the
direction which the gas travels, in combination with a shower of liquid purify-
ing agent falling down the tower and through the perforations and wetting the
boards or screens the arrangement being such that the gas in rising up the tower
travels to and fro over the trays in a zig-zag manner from side to side and
between the wetted surfaces of the boards or screens and is prevented from rising
up through the perforations in the trays by the liquid which is falling through
the perforations, all substantially as set forth.
Dated this 6th day of February 1900.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.