Improvements in and relating to Scrubbing or Purifying of Gases, and in Apparatus therefor.
Year: 1895

page_text: Date of Application, 25th Mar., 1895-Accepted, 22nd June, 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Scrubbing or Purifying of Gases,
and in Apparatus therefor.
I, FRANK LEROY SLOCUM, a citizen of the United States of America, residing
corner of Linden Avenue and Reynolds Street, in the City of Pittsburgh, County
of Allegheny and State of Pennsylvania, one of the United States of America,
Chemist, 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 relates to the scrubbing or purifying of gases, such as the removal
of aminonia, tar, and other impurities from illuminating gas, or the removal of
benzole or other vapors from gases. The object of the invention is to provide for
the rapid and effective scrubbing and washing of the gases, and for that purpose
to bring the gases into contact with the absorbent liquid in such a way as to not
only insure the contact of the gases with the liquid but the breaking up of the
globules of tar and other extraneous matter, and also to prevent the diffusion of the
purified gases with those less purified, so as to provide for a more perfect scrubbing
and purifying of the gases.
To these ends my invention consists, generally stated, in forcing the gas through
a series of perforated disks set within one-half inch of each other and under such
pressure as to cause the gas passing through one disk to strike against the solid
portions of the next disk with impact sufficient to bring the gas into intimate
contact with the wetted surface and break up the globules of tar and other extraneous
matter contained in the gas, and forcing the layer of gas between one set of disks
through into the space between the next set of disks without permitting diffusion
between the layers of gas, as hereinafter more fully described.
It also consists in an apparatus for scrubbing or purifying the gas, having within
an enclosing case, a series of perforated disks mounted to rotate and dip into the
absorbent liquid, the disks being set within one-half inch of each other, and the
perforations of one disk being out of line with those of the adjoining disk, so as to
accomplish the results above briefly stated.
It also consists in so mounting the disks or plates that they travel sufficiently
close to the inner face of the casing to form a film joint therewith through the
employment of the liquid absorbent, and so prevent the passage of the gas around
the edges of the disks; as well as other improvements hereinafter set forth.
To enable others skilled in the art to practise my invention, I will describe the
same more fully, referring to the accompanying drawings, in which-
Figure 1 is a longitudinal vertical section of apparatus embodying my invention;
Figure 2 is a cross section on the line 2-2, Figure 1 ;
Figure 3 is a view showing the disks attached to the central shaft ;
Figure 4 is a full sized view of the upper end of some of the disks.
Like letters of reference indicate like parts in each.
The apparatus illustrated is well adapted for the carrying out of the method
hein described, and embodies all of the improvements in the scrubber which are
desired to be covered, though it is to be understood that the series of disks or
plates employed in practising the invention may be mounted to rotate in any desired

page_text: way so long as they embody and are adapted to carry out the principles of the
invention as above indicated.
In the said drawings, A is the casing, and in the upper part of the shell thereof are
the inlet port a and outlet port a' with which the gas pipes connect to carry the
gas to and from the scrubber. Mounted within the casing, which as shown is
cylindrical, so that the plates can fit close thereto, are a series of flat circular disks
or plates c, mounted on the central horizontal shaft C, which is in turn mounted
within the casing so that the lower parts of the disks are within the absorbent
liquid, while the upper parts thereof are in the gas chamber and in the course of the
gas through the scrubber, the portions of the disks within the gas space are
preferably held so close to the inner face of the casing as to form film joints
therewith by means of the liquid carried up by the disks, as hereinafter described.
The absorbent liquid is fed to the casing through suitable inlet and over-flow pipes,
so that the height of the liquid is maintained at about the level indicated by the
lines 5-5 Figure 1.
The disks are placed sufficiently close to each other to obtain the peculiar result
aimed at, namely, such impact of the gases passing through one disk against the
other as to ensure the contact of the gases with the wetted surface of the disk in
front of the one through which it passes and the absorbing of the ammonia or other
vapors from the same, the breaking up of the globules of tar or other extraneous
matter, and the carrying of the gases through the apparatus without permitting
diffusion of the gas between one set of disks or plates with the gas between the
adjoining sets. For this purpose I find by actual practice that it is necessary the
disks be placed no farther apart than one-half inch, and that to produce the best
results the disks should be placed even closer than that, such as about within one-
fourth inch of each other. The disks are also secured upon the driving shaft in
such manner that the perforations in the one disk are out of line with the
. perforations in the adjoining disks, so that the gas passing through the perforations
in one disk will be projected against the solid portions of the adjoining disk in
order to produce the results above referred to. The disks may be secured upon the
driving shaft in any suitable way, the several disks forming the series being shown
as placed around the driving shaft with collars d between them, and the collars being
the proper width to form the spacings between the disks and hold them in proper
line. It is desirable that the disks and collars be keyed to the driving shaft and
locked together, and for this purpose the driving shaft is preferably formed with a
groove c¹, and both collars and disks have V-shaped projections d¹ fitting in such
groove; and besides this the disks and collars having perforations formed therein
in line with each other in which pins or blocks e fit, the blocks corresponding in
diameter to the perforations, and preferably having a length equal to the thickness
of one of the collars and two of the disks, so that when placed in such
perforations the blocks or pins will pass through one collar and the two adjoining
disks and be held in place by the solid bodies of the collars on the other side of the
disks, and so act to lock the disks to that particular collar. In this way all of the
disks and collars are locked together, and one disk is locked to the collar on one
side at one point and to the collar on the other side at another point, so that the
entire series of collars are united together by means of pins or blocks extending
through and confined between them. The shaft C has a collar or nut e' at one
end thereof against which the end disk of the series bears, and at the other end
of the series near the outer end of the shaft the shaft is threaded, as at e², and a
nut engages with such thread and forces the several disks and collars firmly into
contact with each other, so firmly binding the collars and disks upon the shaft.
The disks are also connected together at suitable points near their outer edges, the
construction employed for this purpose being bolts extending through the disks at
such points, and ferrules f¹ placed between the disks around the collars, such
ferrules corresponding in length to the thickness of the collars d, and the whole
being clamped together by means of the bolts.
The disks are provided with numerous small perforations which are bored or

page_text: stamped therein throughout their entire surface, through which perforations the
gas passes, as above referred to, and the disks being so secured upon the shaft that
the perforations in one disk are opposite the solid portions of the other, or are out of
line with the perforations in the other to produce the action above referred to, the
perforations also serving to carry up the water or other absorbent liquid which holds
to the surface of the disks and within such perforations by capillary action, the
water within such perforations being forced from the same by the gas passing
through the perforations, which is thus brought into intimate contact with the
water and is one means of absorbing the soluble vapors therefrom. The shape of
the perforations may be varied if desired, being circular or of slot form, the former
being found more desirable. The perforations are made comparatively small, so
that as the gas passes through them there will be such a compression of the gas as
to cause it to pass with considerable velocity through the perforations and insure
its being projected against the surface of the adjoining disk, the necessary pressure
to produce this result being obtained for the reason that the surface area of the
perforations in the disks is not as great as that of the inlet port of the casing. That
the gases might flow around the outer edges of the disks, or at least escape contact
with the absorbing liquid, suitable means for preventing this are provided by forming
a practically gas tight joint between the series of disks or plates and the upper
part of the washer through which the gas passes.
C
For this purpose I provide an accurately turned close joint between the outer
edges of the plates and the body of the casing, so that the plates may be brought
in such close proximity with the walls of the casing that a water film joint may always
be maintained between the plates and casing. This is accomplished in the
following way:
As shown in Figures 1 and 4 the upper part of the casing A (which casing can
be divided into any number of sections desired) is turned accurately from a point
at the line of the central shaft C throughout the entire upper portion thereof, this
being done by suitable machinery so as to bring the same accurately to the desired
size and curve for the face k thereof. The lower part of the casing A, which is
filled with the absorbent liquid, is not turned to such face but leaves space for the
flow of the liquid around the ends of the plates, a depression being formed
around that portion of the case, and the lower part of the casing being divided
into a series of compartiments by the partitions k². The outer edges of the plates
which are to form the joints with the casing are also accurately turned to the
proper size after they are mounted upon the central shaft so as to bring them to
the exact size required, that is, to such size as will enable the plates to fit so close
to the face k that a film of water or other absorbent liquid will always be
maintained between the edge i of the plates and the inner face k of the casing.
Practice shows that this joint, while not that of actual contact and friction, can be
made so close that the water carried up by the edges of the plates will always
maintain a film or water joint between the plates and the face k of the casing, so
that the gases cannot pass around the same. It is evident, however. that in the
erection of the machine, it will be practically impossible to bring the parts into
that exact position; and to enable this to be accomplished, instead of making the
bearings m for the shaft C rigid with the casing, I form the same adjustable therein
so that after the closing of the casing the shaft can be raised and bring the edges
of the plates into the exact position proper for maintaining the joint between the
edges thereof and the face k. This is shown in the drawings, Figure 1, in which
the bearing block m is secured to the end wall A¹ of the casing by the flanges m¹
through which bolts pass, the casing having the shoulder n below the seat on the
flange m¹ of the bearing and through said shoulder n the set screw * extending so
as to bear against the flange of the bearing m and provide for the accurate
adjustment of the same. Suitable metal or packed joints may be employed
between the casing and flange m' of the bearing so as to prevent leakage of the
gas. The bearings m are also made closed and gas tight so that there can be no

page_text: leakage through the bearings, this being preferred, and the power being applied to
rotate the shaft C in another way, so as to overcome the necessity of stuffing boxes
and the necessity of such tight packing for the shaft as would create friction in the
rotation of the same. The bearings m may contain suitable brasses or bearing
blocks m² and the oil may be fed thereto through the oiling cup m³. After the
casing has been closed around the shaft and when the machine is ready to be put
in operation, the shaft is accurately adjusted within the casing by the loosening of
the bolts connecting the bearings to the casing and the adjustment of such bearings
through the set screws n² so as to form such exceedingly close joint_between_the
plates and the inner face k of the casing, the shaft being raised and adjusted to
give this result.
It is evident that another source of leakage of the gas from these rotary
scrubbers is found in the driving of the main shaft thereof through the stuffing
boxes just above alluded to, and also that it is easier to maintain a water tight
joint than a gas tight joint, and for that purpose I have arranged to drive the
central shaft C in the following way:
Upon the same 1, place the gear wheel p which meshes with the gear wheel pl
upon the shaft p² which shaft extends through the stuffing box 3 in one of the end
plates A and below the water line of the scrubber. The shaft p² is mounted in
suitable bearings formed in the frame R which is secured to the foundation B of
the machine, and within which frame R is the worm wheels, which is secured to
the shaft p², said worm wheel being driven by the worm sl mounted in the frame B ;
while to the shaft carrying said worn, power can be applied by any suitable means,
either directly by the engine, or by connections from any other suitable source of
power. In this way, even in a large scrubber, it is found that the same can be
driven at the expenditure of practically no power, the different plates clamped
upon the main shaft being arranged to practically balance each other, and said
shaft being mounted in the bearings generating little or no friction and the power
being applied to the same through a joint which does not require to be more than
usually tight, while the outer edges of the plate form close joints with the inner
face of the casing but do not actually contact therewith, and there is practically
no friction in the rotation of the series of plates. I generally prefer to separate
the lower part of the casing into a series of chambers by the vertical partition
plates 2, and at the bases of the chambers so formed are pockets t to receive any
iar or like condensable matters which can be conducted from the same through the
pipes t¹.
In practising my invention with the apparatus above described, where it is
desired to remove ammonia from the ordinary illuminating gas, water is fed through
the lower part of the casing, a proper current being maintained for carrying the
water as it is charged with the ammonia, and the water being preferably fed to the
apparatus in such way that the water passes in the opposite direction to the gas,
so that the gases are always passing into contact with purer water carried up by
the disks. Where oil or other absorbeut liquid, such as for the absorption of
benzole, is employed, it is introduced in the same way. The liquid is preferably
maintained to the height just under the lower edge of the driving shaft. The gas
passes into the casing through the inlet opening a and it strikes against the first
one of the perforated disks, and in order to pass through the perforations of such
disk its speed is accelerated because the sum o the area of such perforations
through which such gas can pass is not equal to the area of the inlet port, and
for this reason the gas will pass with considerable velocity through the perforations
and it will be projected against the surface of the adjoining disk; the same
acceleration of speed being maintained throughout the entire series of disks as the
gas passes through them in succession. As the disks rotate within the casing they
pass down into the liquid and are coated thereby, and the perforations in the disk
are filled or nearly filled with the liquid, the liquid being held within the
perforations and adhering to the surface of the disk by capillary action, so that a

page_text: large body of liquid is carried up by the disks at each revolution of the driving
shaft. As the gas passes through the perforations of the disks it is of course
brought into intimate contact with the liquid in the perforations, and it is in some
cases necessary that the gas shall even force the liquid out of the perforations in
order to pass through the same, and in this way the gases are brought into such
contact with the liquid as to absorb the soluble vapors therefrom, while at the
same time the forcing of the liquid from the perforations also acts to maintain, as
it were, a shower of liquid between the disks, which has practically the same effect
as the spraying of water, so that the liquid thus displaced descends in a fine spray
through the gases into the body below. As the disks are close to each other, the
distance, as above stated, being one-half inch, or less, and as the gases are
compressed and forced with accelerated speed through the perforations, it is evident
that in passing through such short distance the gas will be projected in fine jets
against the next adjoining disk, and as the perforatious of one disk are opposite
the solid portions of the other, these jets of gas will strike against the next
adjoining disk with considerable force, so that the gas is projected against the
wetted surface of the adjoining disk, and all the particles of gas are thus brought
positively into intimate contact with the wetted surface of such disk, so insuring
the absorbing of the ammonia or other vapors therefrom. At the same time, by
being projected with such speed against the adjoining disk, any globules of tar or
other extraneous matter contained in the gas are broken up by contact with the
solid surface of the disk and are deposited thereon and carried down into the
absorbent liquid, where the tar or such matter gathers, and from which it can be
removed. It is found that to produce this peculiar result it is necessary that the
perforations in the disks shall be placed at least within one-half inch of each other,
and that the tar cannot be removed and the vapors are only very imperfectly
eliminated unless the disks are set within such distance of each other, because
under the ordinary pressure at which the gas is carried throughout the apparatus
the speed of the jets of gas would not be sufficient to bring the gas with such force
against the adjoining disk as to break up the globules of tar, or other matter, or
to bring the gases into such intimate contact with the wetted surface of the disks
to insure the absorbing of the vapors therefrom, but, as the gas spreads as soon as
it passes through the perforations, it would become diffused through the gas held
between the disks, as the force would not be sufficient to bring it into contact with
the opposite disk. Where the disks are placed so close to each other, however,
the gases are projected against the disks with sufficient force to produce this action,
and it is preferable to place them even closer, such as within one-fourth of an inch,
so that the gas will vibrate back and forth against the surface of the two disks, so
being brought again and again in contact with the wetted surface thereof.
I am also enabled by holding the gas in a thin sheet between the disks to carry
forward the gas in sheets or layers without permitting the diffusion of the gas
between one set of disks with the gases between the adjoining disks, and in this
way to prevent the intermingling of the less purified gas with that which has been
subjected to a greater purifying action, the pressure of the gas passing into the
space between the disks forcing the other gas ahead of it without diffusing with it,
so that each layer of gas is carried in practically a separate sheet or body further
through the apparatus and into contact with cleaner water. The preventing of the
diffusion of the gas in the spaces between the disks is of very great importance in
the scrubbing or purifying thereof, because in case of such diffusion, gas which has
reached a more advanced state of purification may be contaminated by the less
purified gas, and there is no surety that the gas passing from the scrubbers is pure
and free from tar, vapor, or other extraneous matter. By means of the close film
joint between the plates or disks and the interior of the casing, passage of gas
around the edges of the plates is prevented, unless the pressure thereof is sufficient
to overcome the film joint, in which case the gas is necessarily brought into direct
contact with the liquid, while there is no actual contact and no friction between the
plates and casing; and by introducing the power shaft below the water line and

page_text: mounting the main shaft in enclosed bearings, the necessity of gas tight joints is
overcome, leakage is prevented, and the friction reduced to a minimum.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein-described method of removing tar globules from, and purifying
gas, consisting in forcing the gas in jets across a short space against a solid surface
wetted with absorbent liquid, with sufficient velocity to break up the tar globules
and bring the gas into intimate contact with the wetted surface, substantially as and
for the purposes set forth.
2. The herein-described method of purifying gas consisting in forcing the gas
through a series of perforated disks set within one-half inch of each other and
coated with an absorbent liquid, under such pressure as to cause the gas passing
through one disk to strike against the solid portions of the adjoining disk with
impact sufficient to break up the globules of tar or other extraneous matter con-
tained in the gas, and forcing the layer of gas between one set of disks through
into the space between the next set of disks without permitting diffusion between
the layers of gas, substantially as and for the purposes set forth.
3. In gas washing or scrubbing apparatus, the combination of an enclosing case
having inlet and outlet ports, a series of perforated disks mounted to rotate and dip
into liquid, the disks being set within one-half inch of each other and the
perforations of one disk being out of line with those of the adjoining disk,
substantially as and for the purposes set forth.
4. In gas washing or scrubbing apparatus, the combination of an enclosing case
having inlet and outlet ports, a horizontal rotary shaft mounted therein, and a series
of plates secured to that shaft within the casing and held sufficiently close to the
inner face of the casing to form a film joint between the said plates and the inner
face of the casing, substantially as set forth.
5. In gas washing or scrubbing apparatus, the combination of an enclosing case
having inlet and outlet ports, a horizontal rotary shaft mounted therein, a series of
plates secured to that shaft within the casing and held sufficiently close to the inner
face of the casing to form a film joint between the said plates and the inner face of
the casing, and bearings for said horizontal shaft made separate from the casing and
adjustable thereon, substantially as set forth.
6. In gas washing and scrubbing apparatus, the combination of an enclosing case
having inlet and outlet ports, a horizontal shaft mounted therein a series of plates
or disks secured to said shaft, said shaft being mounted in closed bearings and
carrying a gear wheel, and a driving shaft extending within the case below the
liquid line thereof and carrying a gear wheel meshing with the gear wheel of the
shaft, substantially as and for the purposes set forth.
7. In gas washing and scrubbing apparatus, the combination of an enclosing case,
a horizontal shaft mounted therein and carrying a series of plates or disks, said
plates or disks being supported sufficiently close to the inner face of the case to
form a film joint therewith, bearings formed separate from and secured to the end
plates, said bearings having flanges, and the end plates having seats for said flange,
and shoulders below the flanges through which set screws extend to engage with
the flanges, substantially as and for the purposes set forth.
8. The combination of a shaft and a series of disks and collars fitting around said
shaft, said disks and collars alternating with each other and having perforations
formed therein in line with each other and pins or blocks extending through the
perforations in one collar and the perforations in two said disks, substantially as set
forth.
9. The combination of a shaft and a series of disks and collars fitting around said
shaft, said disks and collars alternating with each other and having perforations
formed therein in line with each other and pins or blocks extending through the
perforations in one collar and the perforations in two said disks, the disks being

page_text: connected in this way to the collars on both sides thereof, substantially as set
forth.
Dated this 25th day of March 1895.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.