Improvements in Apparatus to be Used in the Purification of Coal Gas.
Year: 1888

page_text: Improvements in Apparatus to be Used in the Purification of
Coal Gas.
I, WILLIAM THOMAS WALKER of Bishopswood Road, Highgate in the County
of Middlesex, Esquire do hereby declare the naturo of this Invention to be as
follows:-
My Invention has reference to apparatus for purifying Coal gas in which apparatus
surfaces are alternately submerged in liquid and raised therefrom so that they, when
raised, present a freshly wetted surface to the gas to be purified passing in contact
therewith such for example as the apparatus described in the Specification of Letters
Patent No. 1478 of 1880.
Apparatus of this description is very liable to become clogged and inoperative by
the accumulation of dense matters, and it is the object of my Invention to overcome
this objection and to reduce the first cost of the apparatus and to simplify it and
generally render it better adapted for use.
According to my present Invention I make boxes preferably of cast iron to contain
the wetted surfaces the said boxes being open at bottom and I operate them in such a
way that the said boxes as they are reciprocated are at each downward movement
entirely submerged so that the liquid scours and washes the said surfaces and clears
them of any tarry matter which is carried freely from off them and discharged clear
of them. The surfaces contained in the said box I may make of any suitable material
but I prefer either plain iron plates or thin boards of wood which may be connected
together by bolts passing through all with distance pieces between the plates or boards
to keep the proper spaces between them. The said plates or boards are set vertically
and have a free way between them to allow the tarry matter to be washed freely from
them. The said spaces are entirely free and open at bottom and there is preferably
a space between the tops of the said plates or boards and the top of the box to allow
of the free passage of the washing liquid.
Thus arranged the apparatus is adapted for purifying the gas as it passes from the
condensers to the purifiers but I may make it suitable for use for purification either

page_text: at that stage or at the stage whereat the present mode of purification by oxide of iron
or lime is performed or at both stages. I effect this by isolating the interiors of the
superposed tanks from each other by a water-tight seal consisting of an inverted bell
or its equivalent which is secured to the operating shaft and dips into a vessel secured
to the tank and containing liquid so that the joint is maintained by the liquid as the
shaft reciprocates. The gas inlet passage to each tank is external to the said seal and
between the set of wetted surfaces and receives the gas preferably from a flat con-
necting passage between each tank and with a mouth at each side of the machine and
I provide a system of connections and valves to open and close communication with
each tank as desired so that if I chargé the tanks with purifying agents of kinds
suitable for removing various impurities I can by operating the valves pass the gas
as required through either or all of the tanks in any desired order or any number
of times.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus to be Used in the Purification of
Coal Gas.
I WILLIAM THOMAS WALKER of Bishopswood Road Highgate in the County
of Middlesex Esquire 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 :-
My Invention has reference to apparatus for purifying coal gas such for example as
the apparatus described in the Specification of Letters Patent No. 1478 of 1880 in
which apparatus surfaces are alternately submerged in liquid and raised therefrom by
a vertical reciprocating dipping movement, so that they when raised present a freshly
wetted surface to the gas to be purified which passes in contact therewith.
Apparatus of this description is very liable to become clogged and inoperative
by the accumulation of dense matters and it is the object of my Invention to over-
come this objection and to reduce the first cost of the apparatus and to simplify it
and generally render it better adapted for use as hereinafter described.
I will describe my Invention with reference to the accompanying drawings whereof
Figures 1 and 2 are elevations at right angles to each other (the lower parts being in
section) of an apparatus arranged according to my Invention. Figure 3 is an
enlarged section of a part of the same. Figure 4 is a horizontal section on the line 1. 2.
Figure 3 and Figure 5 is a vertical section on the line 3. 4 Figure 4.
According to my present Invention I make boxes B preferably of cast iron to
contain the wetted surfaces the said boxes being open at bottom and 1 operate them
by a reciprocating vertical dipping movement so that the said boxes as they are so
reciprocated are at each downward movement entirely submerged so that the liquid
scours and washes the said surfaces and clears them of any thick or dense matter
which is carried freely from off them and discharged clear of them. The surfaces con-
tained in the said boxes I may make of any suitable material but I prefer for the
purpose either plain iron plates or thin boards of wood as at which may be connected
together in groups by bolis as at 62 passing through all the plates or boards with
distance pieces between the plates or boards to keep the proper spaces between them.
They are supported at their ends upon the angle bars 6. The said plates or boards b
are set vertically and have a free way between them to allow the dense or thick matter
to be washed freely from them. The said spaces are entirely free and open at bottom
as shewn clearly at Figure 5 and there is preferably a space between the tops of the
said plates or boards and the top of the box B as at 3 in Figure 3 to allow of the free
passage of the washing liquid.
Thus arranged the apparatus is adapted for purifying the gas as it passes from the
condensers to the purifyers and I may make it suitable for use for purification either

page_text: at that stage or at the stage whereat the present mode of purification of oxide of iron
or lime is performed or at both stages. I effect this by isolating the interiors of the
Superposed tanks A from each other by a water-tight seal consisting of an inverted
bell or its equivalent which is secured to the casting B and that in turn is secured
to the operating shaft D and the said bell C dips into a vessel E secured to the tank
and containing liquid so that the joint is maintained by the liquid as the shaft D
reciprocates vertically. The gas inlet passage to each tank is at F external to the
said seal and between the opposite sets of wetted surfaces and receives the gas to
be purified preferably from a flat connecting passage & beneath each tank A and with
a mouth at each side of the machine one for the attachment of the branch. from the
inlet main and the other (at g) for facilitating cleaning.
The machine thus having each of its superposed tanks A isolated one from the
other and so constructed as to bring its inlets and outlets to its exterior, can be
arranged with a system of connecting pipes and valvular arrangements enabling the
gas which is to be purified to be brought into communication with any chemical
agent in either or any of the tanks in any order desired. Thus the gas after having
its tar extracted in the lowermost portion of the machine may be conducted from
No. 1 tank through all the tanks above to No. 6 tank or either of the tanks may be
byepassed or the gas may be conducted so as to work right round in a circuit for
example it may be conducted first to tanks Nos. 5 and 6 and thence to tanks
Nos. 1. 23 and 4.
Or for a special process of purification such for example as that of Claus the gas
may after having the tar extracted in the washing chamber in the lowermost part by
means for example of the apparatus made according to my prior Patent No. 3619
of 1881 be conducted thence successively to tanks Nos. 15, 2, 3, 4 and 6 to be
brought in contact with particular chemical agents contained in the said tanks for
effecting the purification of the gas from impurities such as carbonic acid, sulphuretted
hydrogen, hydrocyanic acid, bisulphide of carbon, and ammonia. These connections
and valves as shown in Figures 1 and 2 are as follows.
X is the general inlet main having a branch and a valve to each tank (leading
into the passages G).
Y is the general outlet main having a branch y and valve y² to each tank.
W is a main for working or byepassing any of the tanks the said main having inlet
branches and valves w outlet branches and valves and bye pass valves u to each
tank.
T is the return main for conveying the gas from No. 6 tank at the top to No. 1
tank at the bottom and t is its valve.
S is a pipe for conveying the gas from No. 5 tank to No. 2 tank and s are its
valves.
R is a pipe for conveying the gas from No. 1 tank to No. 5 tank and is its
valve.
Qis the general bye pass main for bye passing the whole of the tanks and q is its
valve.
Pare the liquor overflow pipes for conveying the purifying liquids from one
chamber to another and p are their valves.
The gas inlet is shewn by the arrows in the lower part of Figure 1.
N is the tar well-M is the apparatus for reciprocating the boxes B.
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.
1st. In apparatus of the kind referred to surfaces which are wetted for contact-of
the gases consisting of holders or boxes having a reciprocating vertical dipping action
and open at bottom and at each end with vertical or approximately vertical plates boards
or the like offering a free way for the liquid in the tank so that the surfaces are cleansed
as the plates boards or the like are operated substantially as described and shewn.

page_text: 2nd. In apparatus of the kind and worked in the manner referred to the arrange-
ment of gas passages G under the tanks A and therefrom to the inner part of the
boxes B and of a liquid seal C. E. situated in the centre and surrounding the operating
shaft substantially as and for the purpose described and substantially as illustrated.
3rd. The arrangement in combination with apparatus of the kind and worked in
the manner referred to of the system of passages and valves for controlling the
passing of the gas to be purified into the chambers, or tanks as desired substantially
as hereinbefore described and shewn in Figures 1 and 2 of the accompanying
drawings.
Dated this 96th day of November 1888