IMPROVEMENTS IN APPARATUS FOR FREEING GASES FROM DUST AND OTHER PARTICLES OF MATTER FLOATING THEREIN, AND FOR CAUSING VAPOURS OR GASES TO BE ABSORBED BY LIQUIDS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Edward Alfred Cowper at the
Office of the Commissioners of Patents, with his Petition, on the 18th
September 1861.
I, EDWARD ALFRED COWPER, of 354, Great George Street, Westminster,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR FREEING GASES FROM DUST
AND OTHER PARTICLES OF MATTER FLOATING THEREIN, AND FOR CAUSING VAPOURS OR
GASES TO BE ABSORBED BY LIQUIDS," to be as follows:-
My improvements relate to a means of separating particles of dust from
gases of any kind, whether the same are in a pure or impure state, and
consists in causing a large extent of surface wetted with a liquid to be
exposed to the gas in a finely divided state in such a manner that every
minute portion of gas shall be brought into contact with such wetted surface,
whilst at the same time any vapour or gas that is capable of being absorbed
by the liquid shall be largely absorbed thereby.
I construct a cylinder of wire gauze or other material, having fine openings
with several concentric cylinders of like material inside it, they being all
closed at the ends, and cause the same to revolve in the liquid in which it is
partially immersed with the axis in a horizontal position, so as to become
wetted with the liquid, and then I pass the gas that requires to be cleansed
or condensed into the inside cylinder, and allow it to pass through the same
and the other cylinders, and to escape on the outside into a box or case which

page_text: encloses the whole, and from which the gas is conducted when desired; or T
make the whole of a conical form, or place a number of discs of wire gauze
or other material, having fine openings, inside a cylinder of metal or other
material, and pass the gas through from end to end in the direction of tho
axis of the cylinder, the same being partially immersed, and caused to revolve
in the liquid; or I fix the cylinder, and let the discs nearly touch it, and
cause them to revolvo without the cylinder. In certain cases, whero it is
desirable to increase the draught or motion of the gas, I use an ordinary
centrifugal fan to urge the gas through the apparatus, in which case I some-
times fix diaphragms or screens of wire gauze or like material in a radial
manner inside the fan caso, so that the gas may pass through them, the same
being kept wetted with liquid supplied by pipes; or I make the blades of the
fau itself in the same manner, and I supply liquid on to them by pipes, or I
fix a number of large screens of wire gauze or like material in a box or case,
and let the gas pass through them, the same being kept wet with liquid
supplied by pipes or thrown up by a small paddlo wheel revolving in the
liquid lying in the bottom of the box or case. The screens may be placed
horizontal, but I prefer to place them vertical or at an incline, so that the
dust or other particles deposited on them may be washed off by the liquid;
and in certain cases I construct a box or case with a number of such fixed
inclined screens one above the other, making them alternately incline to tho
right and to the left, so that whon a liquid is supplied on to the top screen or
shelf, it shall partly run across the screen as it runs through it, and shall thus
wash off any dust into a pocket placed at the lowest side to receive it, which
pocket I make deep enough to retain such deposit of dust, and yet allow of
the liquid there collected to overflow on to the highest side of the next screen
below, which is also provided with a like pocket, as aro all the rest, so that
there being a proper plug hole or opening to each pocket, it can be cleaned
out of any deposit at any timo without stopping the apparatus. Such an
apparatus may be filled with coke or breeze, or broken brick, or any material
in small pieces that will not be affected by the liquid or gases used, so as to
increase the surface exposed to tho gas, but such use of coke, breeze, or other
material forms no part of my Invention, and is similar to what is in common
use at gas works in tho "scrubber" or "breczo washer."
It is evident that a steam jet or blast, like that used in locomotive engines,
may be employed to urge the gas through the apparatus, or a numbor of fine
jets of liquid may be used to urge the gas to a slight extent, or a pump or a
blowing machino formed of two or more gas holders rising and falling may bo
used for the same purpose, or a spiral or helical-shaped pipe made to revolve

page_text: in liquid may be used, or any other description of blowing machine may be
employed to urge the gas through the apparatus. In certain cases where the
gases are in a warm or hot state, when they are required to be cleansed, I
prefer, in order to save liquid, to cool them to some extent by making the
waste dirty liquid from the apparatus be supplied upon the outside of such
pipes as bring the gas to the apparatus, so that a very considerable cooling.
effect may be produced by evaporation, after the manner of surface evaporator.
condensers, as now used for steam engines, by Mr. Angier March Perkins,
Patent dated 21st September, 1858, No. 2124, and in cases where it is
wished to have the gas warm after the operation of cleansing has been
performed, I pass the pipe conveying the clean gas through or in contact
with the hot pipe, bringing the hot dirty gas to the apparatus so as to absorb
heat therefrom, and at the same time cool the hot dirty gas to some extent.:
In cases in which the gas is very dirty, I prefer to pass it first through a
common "scrubber" (or a scrubber constructed as before mentioned), or:
through a box or case in which liquid is in violent agitation, in consequence:
of its entering by a jet or jets with considerable force, or is being stirred up.
either by a paddle wheel or screw propeller, or a pair of wheels or frames
revolving in opposite directions in the same manner as churns are now made,
or by any other known means, so that a large portion of the dirt may be thus
first deposited; and I then, secondly, pass the gas through the apparatus.
before described, and I prefer to use the clean cold liquid first, for this last:
part of the process, than use it secondly for the first part of the process; and,
lastly, I apply it, if necessary, on to the outside of the hot pipes which bring
the hot gas to the apparatus, as before described. I use different materials
for the screens, shelves, cylinders, discs, and cones, according to the nature of
the gases to be cleansed; thus, for cleaning common atmospheric air, canvass
of an open texture will answer the purpose, or horsehair, cloth, or other like
material, but for air, smoke, or gases of high temperature, such as the gases
given off from the top of a blast furnace for smelting iron, it is desirable to
use wire gauze, perforated metal plates, or wires fixed very close to each
other, or other like materials; and for acid vapours or gases, it is desirable to
use such metals as are not acted on by them, or to use porcelain, earthenware,
or glass, which latter, finely perforated, is an admirable substance for the
purpose.
The above described apparatus may be employed not only for cleansing
gases or separating from them particles of dust or other impurities, but also
for causing liquids to be impregnated with certain gases. The proper liquid
to use in each case depends upon the result that it is wished to obtain; thus,

page_text: if it wished to impregnate any particular liquid with a certain gas, that liquid
must be used in the apparatus, and if it is wished to cleanse the gases given
off from the top of a blast furnace, then water is to be used, and, by prefer-
ence, it is to pass, as beforo said, in the opposite direction through the
apparatus to that taken by the gas, so that the water may bo economised, or
as little required as possible. Such gas, when so cleansed, will burn with a
clear flame without leaving any deposit, and is particularly well adapted for
burning under boilers or in hot blast stoves such as those for which Letters
Patent were granted to me, and bearing date tho 19th May, 1857, No. 1404,
or in common hot blast stoves or other places where heat is required.
I am aware that it has been proposed to forco gases beneath horizontal
plates or shelves, either perforated or not, and immersed in liquid, and such
apparatus might be used as a preparatory washing apparatus beforo using any
of the before described apparatus. In such cases I prefer to fix the plates or
shelves at a slight incline so as to allow the gas, when forced under them in
small streams, to rise slowly in small bubbles under the entiro length of the
inclino of the plate, so that these small bubbles may be exposed to the liquid
for. a much greater length of time than would be the case were they allowed
to ascend directly through the liquid. By this means also the small bubbles
are kept separated during the whole time they are immersed in the liquid,
instead of being allowed to join and form themselves into large bubbles, as is
the case when tho plates are horizontal.