IMPROVEMENTS IN APPARATUS FOR THE PURIFICATION OF COAL GAS
Year: 1880

page_text: LETTERS PATENT to William Mann, of Wellesley Road, Gunnersbury, and
William Thomas Walker, of Highgate, both in the County of Middlesex, for
an Invention of "IMPROVEMENTS IN APPARATUS FOR THE PURIFICATION OF
COAL GAS."
PROVISIONAL SPECIFICATION left by the said William Mann and William
Thomas Walker at the Office of the Commissioners of Patents on the 10th
April 1880.
WILLIAM MANN, of Wellesley Road, Gunnersbury, and WILLIAM THOMAS
WALKER, of Highgate, both in the County of Middlesex. "IMPROVEMENTS IN
APPARATUS FOR THE PURIFICATION OF COAL GAS."
Our Invention relates to that description of apparatus for the purification of coal
gas in which plates or equivalent scrubbing devices are employed forming elongated
passages for the gas, the said plates or their equivalents being caused to present a
constantly fresh wetted surface to act upon and intercept the impurities in the gas
as it passes along the same.
In carrying out our Invention we construct the scrubbing devices of a series of
rods of wood or other suitable material, and of any convenient section, arranged
side by side, and in rows with intervening distance picces, so as to form elongated
passages for the gas. Wo then take scrubbing devices, made either in this manner
or in the form of plates of any suitable shape, and arrange the same in sets upon a
beam or rocking lever over troughs or receptacles containing purifying liquid in
such a manner that the plates or their equivalents may be alternately immersed in
the liquid and raised out of the same, one set being in the liquid while the other
set is out. Theso plates or their equivalents and their troughs or receptacles may
be either arranged in tiers one above the other, or horizontally, or both arrange-
ments may be employed in conjunction if found desirable.
By means of our Invention a small amount of motive power only is required to
effect the immersion and elevation of the scrubbing devices, as the plates or their
equivalents at opposite ends of the beam or rocking lever are in equilibrio, one set
being arranged to balance the other.
The gas inlet pipes may be arranged so that their upper orifice shall be at or
above the level of the purifying liquid, the scrubbing devices surrounding the said
pipes. The overflow from the several tanks may be also taken from the bottom of
the troughs or receptacles, that is to say, the lower strata of the fluid may be
discharged from chamber to chamber.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Mann and William Thomas Walker in the Great Seal Patent
Office on the 9th October 1880.
WILLIAM MANN, of Wellesley Road, Gunnersbury, and WILLIAM THOMAS
WALKER, of Highgate, both in the County of Middlesex. "IMPROVEMENTS IN
APPARATUS FOR THE PURIFICATION OF COAL GAS."
Our said Invention relates to that description of apparatus for the purification of
coal gas in which plates or equivalent scrubbing-devices are employed forming.
olongated passages for the gas, the said plates or their equivalents being caused to
present a constantly fresh wetted surface to act upon and intercept the impurities
in the gas as it passes along the same.
It is well known that a large extent of surface filmed over with wator will, when
exposed to the flow of a gas containing ammonia, cause the water to become impreg
nated with this impurity, so that when it flows out of the vessel in which the
absorbing action is set up it is an ammoniacal liquor of strength commensurate
with the completeness of the arrangement. It is also generally known that any
liquid reagent presented in a similar manner will remove any impurity for which
it has an affinity, and that the more this reagency or absorbing power can be
exercised by extension of surface without interruption to the flow of the gas, the
more adaptable to the purposes of the gas manufacturer will be the apparatus..
Again the more tortuous and numerous the ways are through which the gas has to
travel, provided that they are properly supplied with absorbing or reacting Huid,
the more potent will be the absorbing or reacting power of the said fluids when
exposed to the flow of the gas.
Now our said Invention has reference partly to improved scrubbing devices,
whereby we obtain a very large amount of wetted surface within a small compass,
and at the same time reduce the cost of the apparatus by reason of the inexpensive
construction of the said devices. Our said Invention however also comprises
improvements in the general arrangement of the purifying apparatus, and also in
the mode of withdrawing the overflow from the several tanks so as to maintain the
same free from tarry or other denso matter.
In carrying out our said Invention we construct the scrubbing devices of a series
of rods or bars of wood or other suitable material, and of any convenient shape or
section, arranged side by side and in rows with intervening distance pieces, so as to
form elongated passages for tho gas.
These scrubbing devices we mount in tiers upon vertical rods or spindles in a
superposed series of tanks containing purifying liquid, and we employ two or more
of such vertical rods or spindles, with their scrubbing devices arranged in connection
with each other in such a manner that the scrubbing devices are alternately
immersed in the liquid and raised partially out of the same, one set being in course
of depression or immersion when the other set is in course of elevation or
emersion. For the purpose of operating the scrubbing devices we connect the
vertical rods or spindles to a rocking beam or lover driven by a steam engine or
other suitable prime mover, in order to obtain the required continuous alternating
motion.
We also take the overflow from the several tanks from the bottom thereof in
order to maintain the same free from tarry or other dense matter, the lower strata
of the fluid being discharged from tank to tank.
And in order that our said Invention may be fully understood we shall now
proceed moro particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a horizontal section of one
half of a scrubbing device constructed according to our said Invontion; Figure 2

page_text: is a transverse section of the same; and Figure 3 is a detail horizontal section
drawn to the natural size of a portion of the scrubbing device; Figure 4 is a
vertical section of a series of superposed tanks with two sets of the scrubbing
devices applied thereto; Figure 5 is an end view of the same; and Figure 6 is a
detail hereinafter referred to; Figure 7 is a vertical section of a portion of the
apparatus illustrating a modification.
Referring to Figures 1, 2, and 3 the scrubbing device consists of any suitable
number of rows of rods or bars a of wood, or other suitable material, which may
be either round, as shewn, or square, or of any other suitable shape and section, the
rods or bars of each row being placed in intimate contact or a short distance apart
from each other, whilst the several rows are maintained separate the one from the
other by means of distance pieces b so as to leave a series of narrow passages c for
the gas. The rods or bars with their distance pieces thus arranged are secured in
a frame d which is closed at the top and on the sides e, e, but is open at the
ends e, e; the frame is provided with a boss for attachment to the vertical
spindle g carrying and actuating the scrubbing devices.
Figures 4 and 5 illustrate the mode of applying these devices for effecting tho
purification of coal gas. A are a series of tanks arranged one above the other, and
containing water (for example), the supply of which is so regulated as to maintain
the approximately constant level indicated at 1, 1. Within these tanks are placed
two sets of scrubbing devices carried respectively on rods or spindles g, g', two of
the scrubbing devices being contained in each tank of the apparatus. The upper
ends of the rods or spindles g, g', (passing to the exterior through stuffing boxes)
are connected to a rocking beam or lever B which is mounted outside upon a centre
or fulcrum C at the top of the apparatus, and receives motion through the inter-
vention of a crank disc D from a steam engine or other suitable prime mover.
The two sets of devices are so arranged that when one set is submerged beneath
the liquid in the tanks the other set will be partially raised out of the liquid, the
two sets being alternately immersed in the liquid and elevated under the continuous
rocking motion of the beam or lever, by which continuous motion the full area of
the gas passages is constantly maintained without check, that is to say, there is no
moment of time in which the thoroughfare or passage is not maintained equal in
area to the inlet or supply pipe.
The gas is admitted at the bottom at E, and passing up through the branch
pipes E, E, enters the central spaces d' of the bottom scrubbing devices d of
both sets in the lowest tank. The current of gas is then divided to the right and
left hand sides of the central spaces of both of the lowest scrubbing devices passing
between the wetted rods or bars, and giving up a portion of its ammonia it thence
ascends the pipes E' and E' of the tank next above, and passes through the wetted
rods or bars as before described, and so on in succession throughout the whole
series of tanks A until it arrives at the top, whence it finally escapes at G in a
purified condition. The arrows in Figure 4 indicate the course of the gas.
In order to adapt the apparatus to suit the different production of gas in winter
and summer the crank pin h and the connection of the spindles g, g', with the
rocking beam or lever B are made adjustable, so that the lift or stroke which gives
the quantity of wetted surface of the scrubbing devices may be varied, whilst the
position at the bottom of the stroko remains unaltered. In our Drawings we havo
shewn two holes i, i, in the crank disc D for the crank pin h, and two holes k, k¹,
are provided in the head of each of the spindles g, g', for their attachment by
means of a bolt to the rocking beam or lever B so as to admit of the spindles being
practically lengthened or shortened as required.
In the position of the parts shown in Figures 4 and 5, the crank pin h is inserted
in the hole i of the crank disc D, and the connecting bolts of the spindles are
passed through the holes k of the spindles, the scrubbing devices therefore receive
the full stroke necessary to adapt them to operate upon the maximum quantity
of gas required for consumption in winter. By removing however the crank pin h,
and the connecting bolts of the spindles from the holes i, k, and inserting them

page_text: Mann & Walker 8 improvements in apparatus for me urgication of Gout crus.
in the holes i,, respectively, the stroke of the spindles is reduced, and they with
their scrubbing devices are lowered bodily (see Figure 6), the scrubbing devices in
their lowest positions will then be submerged beneath the liquid, and when in their
highest position they will be elevated to a reduced height, so as to expose only a
sufficient surfaces for operating upon the diminished quantity of gas required for
summer consumption. Or we accomplish the same result by means of a screw
motion, or its equivalent, the centre bearing of the beam being made adjustable,
and thereby raise or lower the beam as required.
It is obvious that the rocking beam employed may consist of a lever of an order
different to that shewn in Figures 4, 5, and 6, such for example as is indicated in
Figure 7.-
This Figure also illustrates a modification in the arrangement of the scrubbing
devices in which the gas inlets are at one end of which device in lieu of at the
centre, as in the arrangement previously hereinbefore described, and the gas passes
from the space d' through the spaces c to the single open end e' of each device, the
tubes and sealing caps m being provided for the purpose of maintaining a tight
joint without friction. In this example also the holes, , to admit of the adjust-
ment of the connection of the spindles y, g', with the rocking beam or lever B are
shown as formed in links h¹ depending from the beam or lever.
In order that the liquid required for purification may be maintained at a
uniform level in the tanks, it is requisito to discharge the overflow or surplus from
the tanks. As however the tarry or other dense inatter settles at the bottom,
we provide at the bottom of each tank an opening and-pipe 2, which conducts
the lower strata containing the tarry or dense matter into a pipe 3, which turning
upwards ascends to the level of the interior height of the fluid entering a receiver
box 4, and then descends to the tank immediately below, and so on in succession
throughout the series of tanks to the bottom tank, whence the liquid containing
the tarry or dense matter is finally discharged. Or the same object may be
obtained by means of a vertical receiver box 5 (shewn at the central portion of
Figure 5), the liquid entering from the tank at the bottom ascends to the
necessary height, and thence descends by the central tube G to the tank immediately
below, and so on in succession throughout the series of tanks, as hereinbefore
explained.
The liquid in the tanks is thus maintained clear and free from dense matter,
which result cannot be attained by discharging the overflow or surplus from the
top, as in that case the clear liquid is drawn off whilst the dense matter
accumulates in the tanks.
The arrangement lastly herein before described in which the overflow from one
tank is discharged into the tank immediately below, and the overflow from that
tank to the tank next below, and so on in succession throughout, the series of tanks
is generally suitable when one and the same liquid reagent is employed in all the
tanks. When however it is required to use different reagents, and in other cases
where found advantageous the tanks may be divided into sets, the tanks of each set
being connected together in the manner herein before described, so that the dense
matter is drawn off from the bottom and discharged from tank to tank through-
out the set.
For examplo, all the alternate tanks may be connected together, thus forming
two sets, or each third tank may form one of a separate set, the residual matter
from the tanks of each set being thus kept separato in lieu of its being allowed to
commingle, as would be the case if such matter were conducted through the whole
of the tanks of the apparatus in succession.
We also prefer to regulate the supply of liquid to the tanks by means of a
hydrometer, so arranged in connection with a balanced vessel or float in a cistern
containing the liquid which has flown from the washer, that as the specific gravity
of the liquid in the tanks varies the hydrometer will cause the balanced lever to
rise or fall, more or less, and acting on the supply valve or cock will thus regulate
the supply of liquid according to the requirements of the operation,

page_text: By the use of our said Invention the gas is operated upon under conditions
the most advantageous for effecting its purification. The current of gas is finely
divided by being caused to pass through a large number of narrow elongated
passages, each of which form the mode of construction adopted, presents a wetted
surface of a largo aroa for contact with the gas, whilst the whole is contained
within a small compass, and is capable of being cheaply produced.
Having now described and particularly ascertained the nature of our said
Invention and the manner in which the same is or may be used or carried into
effect, we would observe in conclusion that what we consider to be novel and original
and therefore claim as the Invention secured to us by the hereinbefore in part
recited Letters Patent is,-
First. The employment in apparatus of the description hereinbefore referred to
for the purification of coal gas of scrubbing devices, consisting of a series of rods or
bars arranged side by side, and in rows with intervening distance pieces,
substantially as hereinbefore described.
Second. An apparatus for the purification of coal gas constructed with two or
more sets of scrubbing devices which are alternately immersed in a purifying liquid,
the said apparatus being so arranged that the scrubbing devices shall be constantly
maintained in a wetted condition, substantially as herein before described.
Third. The mode of withdrawing the overflow or surplus liquid from the several
tanks by discharging the lower strata of liquid from tank to tank, in order to
maintain the liquid in the tanks practically free from tarry or dense matters,
substantially as hereinbefore described.
Fourth. The general arrangement and combination of parts constituting an
apparatus for the purification of coal gas, substantially as hereinbefore described
and illustrated in the accompanying Drawings.
In witness whereof, the said William Mann and William Thomas Walker,
have to this our Specification set our hands and seals, the Sixth day of
October, One thousand eight hundred and eighty.