IMPROVEMENTS IN APPARATUS FOR EXTRACTING TAR AND IMPURITIES FROM GASES OR VAPOURS."
Year: 1880

page_text: LETTERS PATENT to Percy John Wates, of the Brooklands, Bedford Hill,
Balham, in the County of Surrey, Civil Engineer, for an Invention
of "IMPROVEMENTS IN APPARATUS FOR EXTRACTING TAR AND
IMPURITIES FROM GASES OR VAPOURS."
OTHER
PROVISIONAL SPECIFICATION left by the said Percy John Wates at
the Office of the Commissioners of Patents on the 13th October 1880.
PERCY JOHN WATES, of the Brooklands, Bedford Hill, Balham, in the County
of Surrey, Civil Engineer. "IMPROVEMENTS IN APPARATUS FOR EXTRACTING TAR
AND OTHER IMPURITIES FROM GASES OR VAPOURS."
This Invention has for its object to facilitate the extraction of tar and other
impurities from gases or vapours, particularly from coal gas. For this purpose I
cause the gas or vapour to pass through a rectangular box or casing, across which
are set a series of frames one behind the other. Each of these frames carries a
screen or screens composed of parallel wires; the screens do not occupy the whole
width of the frame, but spaces are left between them; the passage of gas through
At a short distance
these spaces is prevented by their plates fixed to the frame.
behind each screen is a fixed plate against which the fine streams of gas passing
through the screens impinge; the surfaces of these plates against which the gas
strikes may be kept wetted by any liquid which has an affinity for the impurity
sought to be extracted or may be left dry. The gas is thus caused, first, to pass
through screens, then to strike against plates, again to pass through other screens
and against other plates, and so ou, any desired number of screens and plates being
used. The wires forming each screen surface all run in one direction, except at
intervals where a cross wire is used to hold and keep them at equal distances
apart. Between the wires comb teeth are passed, or the wires are passed through
perforated or slotted plates. The combs or plates are carried by frames which can,
from time to time, be moved to and fro in a direction parallel with the wires of the
screen, so as to cause the combs or plates to traverse along the spaces between the
wires and prevent these spaces from becoming clogged and closed by impurities.

page_text: When it is desired that the surface of the plates against which the streams of gas
are caused to impinge should be kept wetted, this may be effected by means of a
continuous band of steel or other material passing over rollers mounted across the
box or casing near the top and bottom. The band may carry buckets to raise liquid
from a tank formed at the bottom of the box and deliver this liquid into a small
trough at the top of the plates, from which the liquid can flow through a fine slit
on to the surface of the plate; this slit may be kept clear by means of pins moved
to and fro, from time to time, along it. In place of using fixed plates with liquid
trickling down over their surface, continuous bands of cotton, sail cloth, or other
such like fabric passed over rollers at the top and bottom of the box or casing may
be used, the lower part being immersed in water or other purifying liquid, and the
rollers being continuously rotated a fresh wetted surface will constantly be
presented for the gas to impinge against.
In place of the box or casing being rectangular in cross section, it might be
circular; the frames carrying the sieves would then be of a corresponding form, and
with the wires forming the screen surface in concentric circles around the centre of
the frame. All the frames might be mounted on an axis passed centrally through
them; the comb pins or clearers might be carried by a series of radial arms
projecting from the axis. By turning the axis in one direction the comb pins
would be carried around the sieve surface until the comb came against any fixed
part which prevented further movement of the combs relatively to the sieve, the
sieve frame would then turn with the combs if the axis continued to turn.
The radial arms in addition to carrying comb teeth, which serve to clean the
wires of one screen, also serve as dash plates for the streams of gas which have
passed through the screen next in front of it to impinge against.
The circular screens might be caused to revolve continuously by the central axis
being revolved continuously, and the lower part of the box or casing might be
kept filled with liquid so that the surfaces of the screens and dash plates are always
kept moistened, or the dash plates only might be revolved in water or other liquid
and the screens be stationary; in this case they may be cleaned by combs which
are independent of the dash plates.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Percy John Wates in the Great Seal Patent Office on the 12th
April 1881.
PERCY JOHN WATES, of the Brooklands, Bedford Hill, Balham, in the County of
Surrey, Civil Engineer. "IMPROVEMENTS IN APPARATUS FOR EXTRACTING TAR
AND OTHER IMPURITIES FROM GASES OR VAPOURS."
This Invention has for its object to facilitate the extraction of tar and other
impurities from gases or vapours, particularly from coal gas; for this purpose I
cause the gas or vapour to pass through a rectangular box or casing, across which
are set a series of frames one behind the other; each of these frames carries a
screen or screens composed of parallel wires. The screens do not occupy the whole
width of the frame, but spaces are left between them. The passage of gas through
At a short distance
these spaces is prevented by thin plates fixed to the frame.
behind each screen is a fixed plate, against which the fine streams of gas passing
through the screens impinge. The surfaces of these plates against which the gas
strikes may be kept wetted by any liquid which has an affinity for the impurity
sought to be extracted, or may be left dry. The gas is thus caused first to pass
through screens, then to strike against plates, again to pass through other screens and
against other plates, and so on, any desired number of screens and plates being used.
The wires forming each screen surface all run in one direction except at intervals
where a cross wire is used to hold and keep them at equal distances apart.
Between the wires comb teeth are placed, or the wires are passed through perforated
or slotted plates. The combs or plates are carried by frames which can from time
to time be moved to and fro in a direction parallel with the wires of the screen so
as to cause the combs or plates to traverse along the spaces between the wires, and
prevent these spaces from becoming clogged and closed by impurities. When it is
desired that the surface of the plates against which the streams of gas are caused to
impinge should be kept wetted, this may be effected by means a continuous band of
steel or other material passing over rollers mounted across the box or casing near
the top and bottom. The band may carry buckets to raise liquid from a tank
formed at the bottom of the box, and deliver this liquid into a small trough at the
top of the plates, from which the liquid can flow through a fine slit on to the
surface of the plate; this slit may be kept clear by means of pins moved to and fro
from time to time along it. In place of using fixed plates with liquid trickling down
over their surface continuous bands of wire gauze, or cotton, sail cloth, or other such
like fabric passed over rollers at the top and bottom of the box or casing may be
used, the lower part being immersed in water or other purifying liquid, and the
rollers being continuously rotated a fresh wetted surface will constantly be presented
for the gas to impinge against.
In place of the box or casing being rectangular in cross section, it might be
circular; the frames carrying the screens would then be of a corresponding form,
and with the wires forming the screen surface in concentric circles around the
centre of the frame. All the frames might be mounted on an axis passed centrally
through them. The comb pins or clearers might be carried by a series of radial
arms projecting from the axis; by turning the axis in one direction the comb pins
would be carried around the screen surface until the comb came against any fixed
part which prevented further movement of the combs relatively to the sieve, the
sieve frame would then turn with the combs if the axis continued to turn.
The radial arms in addition to carrying comb teeth which serve to clean the
wires of one screen, also serve as dash plates for the streams of gas which have
passed through the screen next in front of it to impinge against.

page_text: The circular screens might be caused to revolve continuously by the central axis
being revolved continuously, and the lower part of the box or casing might be kept
filled with liquid, so that the surfaces of the screens and dash plates are always
kept moistened, or the dash plates only might be revolved in water or other liquid
and the screens be stationary; in this case they may be cleaned by combs which
are independent of the dash plates.
Having thus described the nature of my Invention, I will proceed to describe
more fully the manner of performing the same.
Figures 1, 2, 3, and 4 show various views of apparatus arranged as herein before
described. Figure 1 is a transverse vertical section showing the screens; Figure 2
is a part longitudinal vertical section. Figure 3 is a transverse vertical section
showing the dash plates; Figure 4 is a plan view partly in section of a portion of
the apparatus.
Like letters indicate the same parts throughout these Figures; c is a rectangular
box or casing to which gas is admitted at one end and allowed to pass off at the
opposite end; a, a, are light iron frames carrying a pair of wire sieves b and a
plate of sheet metal between them, so that the only passage for gas is through the
sieves; d, d, are dash plates carried by other frames; they come behind the sieves b,
as shown; e, e, are combs, the teeth of which are inserted between the wires of
the sieves; the combs are fixed to rods f which pass out through stuffing boxes g;
by these rods the combs can from time to time be moved up and down to keep the
spaces between the wires of the sieves from becoming clogged or choked with
impurities.
In place of the dash boards and sieves being ranged vertically, as above
described, they might be placed horizontally, and the rods fto which the combs
are attached be then passed out through stuffing boxes at one side of the rectangular
box or casing c.
In Figures 1 to 4 the dash boards are shown as being used dry; if it is desired
that the face of the dash boards should be kept moistened with any liquid, I
modify the apparatus in the manner shown at Figures 1, 3, and 14. In these
Figures n is a trough running along the top of the dash plates, but placed at a
little distance from them, so as to leave between the dash plate and the bottom of
the troughs a narrow groove o, through which liquid may run down from the
troughs over the surface of the dash plates. The grooves o can be kept clear by
means of a pin p carried on a rod q, which can from time to time be moved
end wise to traverse the pin p along the groove and keep it open. The troughs
can be kept supplied with liquid in any suitable manner.
At Figures 7 and 8 I have shewn how the dash plates d may be formed of
continuous bands of sack cloth or other porous material passed over rollers i, i, at
top and bottom, the lower roller being immersed in water or other liquid. The
rollers are carried on shafts j, j, which are made to rotate from the outside of the
box or casing o.
At Figures 9, 10, 11, and 12 I have shewn various ways of forming the cleaning
combs; k, k, are plan views of parts of the combs, and I, 1, transverse sections;
these Figures clearly shew the various ways in which the combs may be made.
Figures 15 and 16 show enlarged views of parts of the wire sieves; the wires
are attached to the frame by being soldered or brazed to them or by other suitable
means.
Figures 5 and 6 show an arrangement of the apparatus in which the box or
casing is circular in cross section. In the apparatus, shewn in these Figures, each
frame a carries a series of sieves 6 placed alternately with dash plates d. The
combs care attached to the dash plates. The alternate frames are keyed to a
central shaft h whilst the others are loose upon it,

page_text: In cases where it is not required that the surfaces of the dash plates should be
kept moistened, the alternate frames which are loose upon the shaft h may be
retained from turning in any suitable manner, and when the sieves require to
be cleaned a partial turn may be given to the shaft h, first in one direction and
then in the opposite, and be then again brought back into the position shewn in
the Drawing, so that the dash plates shall be behind the sieves." In cases where
it is desired that the surfaces of the dash plates should be kept moistened, the
lower part of the box or casing might be filled with water or other liquid and the
shaft h caused to turn continuously. In this case the combs would be carried
along the edges of the dash plates, and when the sieves require to be cleaned the
shaft would be turned a distance backwards to move the combs along the sieves
and clean them; the shaft would then again be revolved continuously in the
former direction. Or, as previously explained, arrangements might be made for
revolving the dash plates only whilst the screens remain stationary.
Having thus described the nature of my Invention and the manner of performing
the same, I would have it understood that I claim,-
First. The combination of a series of screens formed of parallel wires to admit
of their being readily cleaned, and dash plates ranged one behind the other across
a box or casing through which a stream of gas or vapour is caused to pass,
substantially as herein before described.
Second. The combination of apparatus for extracting tar and other impurities
from gas and vapours, substantially as herein before described with reference to
Figures 1, 2, 3, and 4.
Third. The combination of apparatus for extracting tar and other impurities
from gas and vapours, substantially as herein before described with reference to
Figures 5 and 6.
Fourth. The combinations of apparatus substantially as hereinbefore described,
in which the surfaces of the dash plates are kept moistened with the liquid.
In witness whereof, I, the said Percy John Wates, have hereunto set my
hand and seal, this Ninth day of April, in the year of our Lord One
thousand eight hundred and eighty one.
P. J. WATES. (L.S.)