Year: 1898

page_text: I, JOSEPH EMERSON DOWSON, of 39, Old Queen Street, Westminster, London,
Member of the Institution of Civil Engineers, do hereby declare the nature of
this invention to be as follows:-
The chief object of this invention is the removal of tar and condensable pro-
ducts, as well as coal dust and other impurities, from what is technically known
as water gas, generator gas, or producer gas. It may also be used for other
kinds of gas or gaseous products such for instance as the products of combustion
and the unburnt gases given off from furnaces and the like.
The above effect is produced by passing the unclean gas through a horizontal
diaphragm or screen in which there are small holes or openings, while at the
same time water is allowed to flow on to the upper surface of said diaphragm
or screen that is to say in the opposite direction to the currents of gas. Some
of the water passes through the holes in the diaphragm or screen, but the
ascending currents of gas in a state of fine division check the flow of water, and
cause it to be agitated and split up. There is thus an intimate mixture of the
gas and water, and the tar and condensable products, as well as other impurities
in the gas, are removed by the water. To prevent the water heaping up more
than is desired, on the diaphragm or screen, a suitable overflow is provided
which can be adjusted to give any depth of water required above the diaphragm
or screen.
The apparatus consists of a hollow vertical casing (preferably a cylinder),
having a perforated diaphragm or screen, at a convenient height above the lower
end of the said casing. The top and bottom of the casing are closed, but the
gas inlet may pass through the bottom, or through the side of the casing. The
gas outlet may pass through the top, or through the side of the casing, but the
latter is preferred. The top of casing is bolted or otherwise fastened to the
casing, so that it can be easily removed.
By lifting off the said top of the casing the diaphragm or screen can then be
easily removed to be cleaned, and afterwards replaced. Attached to the said
top there is a suitable contrivance by means of which sufficient pressure can be
put on the outer edge of the said diaphragm or screen, to insure its sitting closely
on the ledge or rim provided for it inside the casing. This provision is desir-
able to prevent water passing between the diaphragm or screen and its seating.
The casing is provided with a suitable water supply, sealed so as to prevent an
escape of gas. The overflow pipe inside the casing is sealed in a cup, or in any
other convenient way, and the overflow water is allowed to escape in any suitable
manner.

page_text: I, JOSEPH EMERSON DOWSON, of 39, Old Queen Street, Westminster, London,
Member of the Institution of Civil Engineers, do hereby declare the nature of
this invention, and in what manner the same is to be performed to be particu-
Jarly described and ascertained in and by the following statement:—
The chief object of this invention is the removal of tar and condensable pro-
ducts, as well as coal dust, ash, and other impurities, from what is technically
known as water gas, generator gas, or producer gas. It may also be used for
other kinds of gas or gaseous products such for instance as the products of com-
bustion and the unburnt gases given off from furnaces and the like.
The above effect is produced by passing the unclean gas through small holes
or openings in a horizontal diaphragm or screen, while at the same time water
is allowed to flow on to the upper surface of said diaphragm or screen, in the
opposite direction to the current of gas, so that the gas must pass through water
after it has passed through the holes or openings in the said diaphragm or screen.
Some of the water escapes downwards through the holes in the diaphragm or
screen, but the ascending currents of gas in a state of fine division not only
cause the water to be agitated and split up but they check its flow through the
said holes. There is thus an intimate mixture of the gas and water, and the tar
and condensable products, as well as other impurities in the gas, are taken up by
the water. To prevent the water heaping up more than is desired, on the dia-
phragm or screen, a suitable averflow is provided which can be adjusted to give
any depth of water required above the diaphragm or screen, and the bulk of the
foul water which contains the impurities from the gas is removed in this way.
In the drawings accompanying this specification, Fig. 1 represents a vertical
section and Fig. 2 a sectional plan of the said apparatus. It consists of a hollow
vertical casing a (preferably a cylinder), having a horizontal perforated dia-
phragm or screen 6, at a convenient height above the lower end of the said
casing. The top and bottom d of the said casing are closed. The gas inlet
may be at e through the bottom d or it may be through the side of the casing a.
The gas outlet may be at f through the side, or it may be through the top of
the said casing. The top c should be bolted or otherwise fastened to the
casing a so that it can be easily removed. The perforated diaplíragm 6 should
rest on a ring or other convenient projection inside the casing a, and passing
through the top c, there is a rod g with two or more legs h and ring i, with a
nut or other convenient contrivance at n so that the ring i may be pressed down-
wards on the top of diaphragm b, to prevent water passing between
the said diaphragm and the ring j. Any other convenient way may
be adopted for preventing the passage of water between the said diaphragm b
and the ring j. Attached to the casing a is a syphon k for admitting water above
the top of diaphragm b. In the middle of the said diaphragm b, or in any other
position preferred is an overflow and seal cup m for regulating the depth of
water required on the upper surface of the said diaphragm b. It is obvious that
a suitable water overflow can be arranged in various ways, inside or outside the
casing a, and I do not limit myself to the particular overflow shown in Fig. 1.
This is given rather as an indication of what has been found to answer the
purpose.
A suitable size for the holes in the diaphragm 6 is about one sixteenth of an
inch diameter, and the number of holes should be proportioned approximately
to the volume of gas to be passed through the apparatus in a given time. When

page_text: the volume of gas is to be considerably less than the maximum for which the
apparatus is made; it is better to place a plate or ring over part of the
diaphragm b so as to reduce the total area of the openings through which gas
can pass.
Small adjustments of this kind are not necessary, but plates or rings
are convenient for reducing the maximum area 25 or 50 per cent.
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. A gas washer having a perforated diaphragm so placed that the gas to be
washed has to pass through small holes therein, the said holes being of such size
that water above the diaphragm is upheld by the currents of gas passing through
the perforations of the diaphragm, while at the same time there is an intimate
mixture of the gas and water.
2. A gas washer having a perforated diaphragm arranged horizontally and
provided with means for the admission of water above the diaphragm, there being
an overflow at such height as to maintain the depth of water required on the
said diaphragm.
3. In a gas washer having a perforated diaphragm on which a desired depth
of water may be maintained as described, means for holding the said diaphragm
in place, and for preventing the water escaping round the edge of the said dia-
phragm substantially as described.
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, London, W.C.