Note: Descriptions are shown in the official language in which they were submitted.
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~ield of the Invention
This invention relates to the field of fluid and solid
conditioning, for example for pollution abatement by chemical
or physical separation.
Background of the Invention
.
Fluid streams containing combinations of gases and liquids, and
with or without solidsr are conditioned in a variety of ways.
Undesirable elements contained in a fluid stream may be removed
by mechanical means or by chemical means. Often particulate is
used in the conditioner to enhance the operation of the
chemical or mechanical process.
Prior art devices of this kind have generally been concerned to
develop a reasonably compact efficient conditioner which allows
for sufficient contact between the fluid strearn and the
conditioning apparatus to properly condition the fluid stream.
Where conditioning is conducted with the use of particulate, it
is also important in many applications to provide means to
regenerate the particulate and means to prevent clumping of the
particulate. Means are ofteo provided to prevent channeling of
the fluid stream.
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One way to provide for this contact is to provide the
conditioning means in a columnar or tower form and to force the
fluid stream through. Generally in an apparatus of this type,
a relatively large amount of energy will be required to move
the fluid stream because of the depth of the particulate. Such
designs also make it difficult to provide for the removal and
regeneration of the particulate.
Another more common way is to provide for a long path during
which there is contact between the fluid stream and the
conditioning means. Such a long path requires a very large
conditioning apparatus unless means are taken to save space.
One method is to make the path helical.
Thus in United States Patent No. 2,688,807, Ginther, issued
September 14, 1954, a drying apparatus is disclosed in which a
gas stream passes along the length of a trough mainly
contacting the uppermost particles of the particulate contained
in the trough. However, in the Ginther apparatus, a relatively
smaller passage is provided for the gas than in the columnar or
tower configuration. This allows for a relatively smaller
volumetric flow of gas through the apparatus. In order to deal
with an efficient quantity of gas, a relatively higher gas
velocity must be utilized, thus decreasing the contact time
between the gas and the particulate.
Description of the Invention
Thus it is hoped in the present invention to avoid many of the
disadvantages of the columnar and helical trough type of
apparatus by providing in general a permeable helical trough
disposed about a cylindrical space. The fluid to be
conditioned passes through the permeable helical trough on
which may be disposed various conditioning means, such as
particulate. Alternatively the permeable trough may itself act
as a filter without the use of particulate.
Compared to helical dryirlg or conditioning devices known, this
apparatus in one of its aspects provides a relatively high
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volume, low velocity conditioner ~o that a greater contact
between the conditioning means, such as particulate matter, and
the fluid ~tream can be achieved in a lesser space.
In the embodiments utilizing a layer of particulates, the
apparatus may be provided with means to move the particulate
either vertically upward or downward along the trough. Means
may be provided to regenerate and recycle the particulate.
Means may be provided to wet the particulate to improve
conditioning. Means may be provided to vibrate the particulate
to minimize clumping of the particulate.
Thus the invention in one of its main aspects comprises:
a hollow vertical substantially cylindrical structure
comprising a surrounding helical side wall and helical baffle
and being closed at one end and open at the other end;
a helical trough, having a receiving end and a discharge
end and a permeable bottom~ said trough being interposed
between the helical side wall and the helical baffle;
the helical baffle connected to the trough and the said
side wall 50 that substantially the only conduit to channel gas
out of the cylindrical structure is through the permeable
trough bottom;
means for introducing a layer of particulate onto the
receiving end of the trough;
vibrating means for moving a layer of particulate along
the trough from the receiving end to the discharge end thereof;
means for transporting gas for conditioning into the
cylindrical structure and through the permeable trough bottom
and the layer of particulate thereon;
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means for applying a llquid to the layer of particulate
along the trough to enhance conditionlng of the gas;
means for removing the layer of particulate from the
trough;
means for regenerating the particulate; and
means for returning the particulate to the receiving end
of the ~rough.
PREFERRED EMBODIMENT
The features of the present invention will hecome apparent upon
a review of the preferred embodiments as shown in accompanying
drawings in which:
Figure 1 is a simplified representation of the preferred
embodiment of the present invention;
Figure 2 is a simplified view of another embodiment of the
present invention;
F'igure 3 i6 a fragmentary sectional view of a hellcal trough
member of another embodiment of the present invention;
Figure 4 is a front elevational view of the fluid conditioner
oE the present invention partially in section through the inner
and outer chambers thereof;
Figure 5 is a partial top sectional view of Figure 4 taken
along line 4 4.
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Figure 6 is an enlarged fragmentary perspective view of a
portion of the trough and the particulate layer supported
thereon as shown in Figure 4;
Figure 7 is an enlarged fragmentary sectional view of the
5 trough and particulate layer of Figure ~;
Figure 8 and Figure 9 are enlarged fragmentary sectional views
of modified forms of the invention in which the fluid passes
through a series of troughs and particulate layers supported
thereon.
In reference to Figure 1, the perferred embodiment of the
present invention is shown with a fluid stream 1 entering fluid
inlet 2 as defined by the upper collar member 3. The fluid
stream 1 may be introduced into the inner chamber 4 of the
cylindrical body 5 by either pressure or vacuum means (not
shown), the selection of which would be determined by the
design parameters for the particular application. The inner
chamber is defined at its lower end by lower closure member 14.
Upon entering the inner chamber 4, the fluid passes throu~h a
trough 6 helically wound about the axis 7 of the cylindrical
body 5. Vertically inclined baffle ~ is helically disposed
about axis 7 and connected with outer wall 9 of trough 6 to
comprise a substantial portion of the side wall of the
cylindrical body 5. The perforated floor 10 of the trough
provides a helically wound surface through which the fluid
stream 11 may exit from the inner chamber of the body. Inner
wall 12 of the trough 6 provides a barrier preventing any
previously collected material from falling over the inner edge
of floor 10 and back into the inner chamber. Any heavy
entrained particles or other impurities in the fluid stream
will fall to the floor 15 of the cylindrical body.
An alternate embodiment of the apparatus provides a porous
floor in the helical trough to remove dry solid particles from
a gas stream. The porous floor may be made from a pliable,
textured cloth membrane of sufficient density to capture and
retain the impurities. Vibrating means may be provided to
dislodge minute impurities from the cloth membrane and move the
deposited filter cake along the helical trough to the discharge
end thereof. Continuous cake removal would permit the filter
apparatus to continuously condition the gas stream.
In Figure 2, another embodiment of the present invention is
shown wherein a fluid stream 21 enters the inner chamber 24
through an inlet 22 provided in lower closure member 23. The
cylindrical body 25, having axis 27, has its outer walls
defined by a helically wound inclined baffle member 28 which
joins corresponding inner wall portion 32 and outer wall
portion 29 of trough 26. More specifically, the inclined
baffle member is inclined upwardly and outwardly from the inner
wall 32 to the corresponding wall 29 of trough 26, whereas in
Figure 1, the inclination from inner to outer wall is upwardly
and inwardly between corresponding walls. Top plate 34 and the
side walls of the body enclose the inner chamber 24.
Perforated floor 30 provides a helically wound surface which
acts as a fluid exit means for fluid stream 31. This
configuration may be used in filtering applications where it is
desirable to remove solid impurities. This embodiment may also
be used where the directional flow of the fluid would be
reversed relative to that represented in Figure 2. In
reversing the fluid flow, it would be necessary to introduce
~he ~luid from an outer body (not shown) down~ard through the
perforated floor 30, into the chamber 24, and out through the
opening identified previously as inlet 22.
Other modifications to the embodiment shown in Figures 1 and 2
include the addition of a layer of particulate material (not
shown in Figures 1 and 2) onto the porous floor 30 of trough
26. Depending upon its chemical and physical properties, the
particulate layer may be used as a filtering aid, absorbent or
adsorbent. Still other applications may provide for the
addition of a wetting liquid to enhance mass transfer processes
such as gas-liquid absorption.
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Still another embodiment of the invention provides for the
chemical conditioning of a fluid stream by contacting the fluid
stream with a reactive particulate layer transported along the
helical trough. In such an embodiment, a catalyst or reactive
chemical in granular form would move along the helical trough
as a layer of particulate contacting the active gas and
generating the desired reaction.
In Figure 3, for example, a fluid stream 1 passes from the
inner chamber 4 and into the channel defined by inclined baffle
8, inner wall 12 and outer wall 9 of the trough. The fluid
stream is wetted by a li~uid spray 39 produced by spray
assemblies 38. The wetted fluid passes through a layer of par-
ticulate material 35 supported by mesh or grate members 36 in
perforated floor 10. The mesh or grate members must be suffic-
iently closely spaced to retain the particulate material. Thewetted fluid stream 1 contacts the particulate, which is also
wetted9 is conditioned by chemical or physical means and there-
after exits through perforations 37 as conditioned fluid 11.
The spray assembly in Figure 3 may be installed as a discreet
arrangemen~ of nozzles located at various points along the
trough, or alternatively, as a trickle tube type assembly
~uspended alony the length of the trough.
Various embodiments of a fluid conditioning device of the
pre~ent invention are shown in Figures 4 to 9 of the drawings.
~5 Although most applications of the embodiments therein disclosed
are more readily adaptable to gas purification, alternate uses
may relate to conditioning fluids of various compositions.
Fluids containing mixtures of gas, solids and liquids may be
treated chemically or physically by passing these fluids
through an embodiment of the present invention. For example,
the operation of gas absorption or gas adsorption transfer
operations depend upon the appropriate selection of liquid
sprays and/or particulate material. Similarly, if the desired
result is the treatment of a moving layer of particulate, this
may be carried out by selecting yet ano~her appropriate fluid
stream component, and if necessary, a suitable liquid for the
spraying operation.
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The fluid conditioning apparatus of the present invention may
be modified in several ways to more efficiently condition
specific gas streams, regenerate the purification material
and/or control the humidity and temperature of the purified
gas. ~or instance, it is preferable to have one or more spray
nozzles mounted in the inlet to the substantially cylindrical
body, in such a position as to spray water or another suitable
liquid across the path of the incoming gas stream. Such
spraying not only scrubs the incoming gas but also will wet the
gas and particulate thus enhancing the removal efficiency of
the particulate. With such a modification it may be desirable
to maintain a liquid sump at the bottom o~ the inner chamber of
sufficient height to close the bottom of the inner chamber.
If the apparatus is to be used continuously it is desirable to
have included therein a particulate regeneration passageway or
zone, one end of which is operably connected to the discharge
end of the helical trough and the other end of which is
operably connected to the receiving end of the helical trough.
The passageway will have an applicator therein for continuously
applying a regeneration media to the particulate.
Typically the regeneration media will be a liquid which is
capable of washing the captured impurities frorn the particulate
or a flame of sufficient temperature to burn the impurities off
the particulate. Travel of the particulate through the
passageway may be effected by gravity or forced movement such
as by a screw conveyor. While the passageway may be positioned
adjacent to but separate of the outer chamber, space can be
conserved and a more compact unit obtained by positioning the
regeneration passage way within the outer chamber but separate
from the inner chamber.
The humidity and/or temperature of the purified outgoing gas
may be controlled by interposing a humidity control means e.g.
a condensor and/or a temperature control means e.g. a heater or
refrigeration coil, across the outlet of the outer chamber~
If the incoming gas is not under sufficient pressure a fan may
be mounted in the inlet to the inner chamber to force the gas
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stream into the inner chamber. Similarly the outlet of the
outer chamber may also be fitted with a fan to draw the gas out
of the outer chamber. For a better understanding of the
present invention, a fluid conditioning device is described in
reference to Figures 4 to 9.
As sho~n in Fig. 4 and Fig. 5 the preferred embodiment of the
fluid conditioning apparatus of this invention comprises a
vertically disposed inner chamber 51 of general cylindrical
shape having a cylindrically shaped inlet duct 52 at its upper
end and being open at its lower end. The inlet 52 is flexibly
and sealably connected to inner chamber 51 by rubber seals 41
and has a constriction 50 which increases the velocity of the
incoming fluid. Chamber 51 is entirely enclosed by vertically
disposed outer chamber 53 the lower portion of which is of
cylindrical shape and the upper portion of which is frustocon-
ically shaped. The frustoconical shape of the outer chamber
helps keep the velocity of the fluid constant to control the
pressure drop across the perforated trough. This shape is not
essential, but is preferable for the particular embodiment
shown in Figure 4. A toroidally shaped skirt 59 of rectangular
cross section is rigidly connected to the lower portion of the
vertical wall of chamber 51 and extends radially outward there-
from but separable from side 55 of chamber 53. The outer
chamber 53 has an outlet duct 54 extending through side 55 and
adjacent to the ~lpper horizontal side 56 thereof. Inlet 52
25 al50 extends through the horizontal side 56. A toroidally
shaped condensor 44 is positioned at the upper end of chamber
53 adjacent to and below outlet duct 54 and extends across the
space between side 55 and the vertical side of inlet duct 52.
The lower side 57 of chamber 53 is inclined to the horizontal
and at the lowest point thereof has an outlet drain 58 which is
fitted with a valve. Fans tnot shown) are positioned in the
inlet duct 52 and the outlet duct 54 to force the fluid into
the former and out of the latter. Spray nozzle 49 is
positioned centrally in inlet 52 slightly above constriction 50
such that its spray field is directed radially and downwardly.
The spray nozzle is operably connected by pipe 48 to the outlet
of pump 47.
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A vertical spiral perforated trough 63 spirals about the
vertical side of chamber 51 from the top to the bottom thereof
and openly communicates therewith. Supported on trough 53 is a
layer of particulate 64.
The type of particulate used in this invention will depend upon
the impurities which are to be removed from a fluid, such as
gas. For instance cork may be used for dust; foam rubber for
metal chips, saw dust for oily aerosols and charcoal or porous
carbon for odours~ Other materials include crushed rock, sand,
Berl saddles and Raschig rings. In all instances the particle
size of the material should be such that it will not pass
through the perforations of the trough. The perforations in
the helical trough may be of virtually any shape~
Chamber 51 is resiliently supported by four vertically
positioned coil springs 60 (two are not shown), the individual
tops of which are rigidly connected to base plates 43 mounted
rigidly on the bottom of skir~ 59 and spaced equidistant about
the circumference thereof. The bottom of each coil spring 60
is mounted on a support plate 61 which extends radially
inwardly from side 55 and is rigidly connected thereto.
The helical trough is resiliently supported such that it is
capable of restricted movement in all directions. Inasmuch as
the trou~h will usually be mounted on the vertical wall(s) of
the substantially cylindrical body, it is convenient to merely
resiliently support the entire cylindrical body (including the
helical trough ~ounted thereon). Such support may be
accomplished by suspending the cylindrical body on coil springs
~rom the upper lateral surface of the outer chamber or mounting
it on coil springs af~ixed to the lateral base of the enclosing
chamber or support plates rigidly connected to the vertical
wall of the outer chamber. The helical trough is used to
project the particulate along the length of the helical trough
in a series of short hops or trajectories. Such d2vices are
essentially so called "directional throw units". The capacity
of the device is determined by the magnitude of helical trough
displacement, frequency of this displacement, angle of
displacement, slope of helical trough and the ability of the
material to receive and transmit through its mass the force
exerted by the helical trough.
The trough vibrations may be generated by known mechanical,
electrical, pneumatic or hydraulic devices such as by directly
connected hinged rocker arms, eccentrically loaded wheels,
pulsating electromagnets or pneumatic or hydraulic cylinders.
One of the simplest and most readily adaptable to the gas
purifying apparatus of this invention comprises a pair of
electrically driven motors having eccentrically weighted rotors
and housings directly coupled to the cylindrical body. Such
motors involve roller masses rotating about bearings so that
the masses generate centrifugal forces which are reactively
opposed by the bearings. The bearings are supported on the
housing and in response to the aforesaid centrifugal forces
exert a periodic inertial force to the housing and thus to the
helical trough.
With reference to Figure 4, a pair of electrically driven
vibration generators 65 are rigidly coupled to the vertical
side of chamber 51 close to the bottom thereof, but above the
level of liquid 62. The generators 65 are positioned dia-
metrically opposite each other on the vertical side of chamber
51 and their axes of rotation are angularly displaced from each
other. The eccentrically weighted rotors of the generators 65
rotate in the same direction e.g. counterclockwise.
Chamber 51 extends downwardly to a position relatively close to
the lower side 57 and when the outer chamber 53 has been filled
with liquid 62 to a level just above the lower edge of the open
bottom of chamber 51 the liquid 62 prevents the fluid in
chamber 51 from entering chamber 53 via the open bottom of
chamber 51. The level of liquid 62 is regulated by float
valves 46. The inlet of pump 47 is connected to liquid 62 by
pipe 45.
A vertical regeneration passageway 66 is positioned adjacent to
the side 55. A series of overlapping baffles 67 which are
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alternatlngly lnclined positively nnd negatively relative to
horizontal are positioned on passageway 66 and are alternating-
ly rigidly conne~ted to side 55 and the outer side of passage-
way 66. Spray nozzles 68 are positioned opposite each of the
5 unsupported ends of the baffles 67 and are operably connected
by pipe 48 to the outlet of pump 47. The upper ~discharge) end
of trough 63 extends through side 55 ~nd into the upper end of
passageway 66 and the lower end of passageway 66 feeds onto the
lower (receiving) end of trough 63 from outlet 69.
In operation, unconditioned fluid enters inlet duct 52 where
nozzle 49 sprays the fluid with liquid 62 causing large solid
particles in the fluid to be entrapped by the droplets of
liquid 62, which by force of gravity drop down through chamber
51 to the sump of liquid 62. As shown in Fig. 4 and Fig. 6 the
vertical side of chamber 51 is so contoured in the vicinity of
trough 63 that as the fluid enters chamber S1 from inlet duct
52 the fluid is drawn by the suction from the fan positioned in
outlet duct 54 downwardly into the trough 63 and through the
particulate layer 64. Since the fluid is wet with liquid 62
when it impinges upon the partic~late layer 64, the liquid 62
in the fluid tends to condense upon the particulate layer 6~.
As shown in Fig. 7, the motion of these particles relative to
one another from the vibration of trough 63 causes the
condensed liquid to foam. In addition to the inherent
absorbent propertles of particulate layer 64, this interGtitial
foaTn also provides an efficient medium for entrapping
impurities. The bottom of the trough 63 consists of a
plurality of parallel, equidistant bars 75. The size of the
slot perforations 76 will determine the size of the particles
supported on the trough. Particles which have broken ~own with
use will fall through the slots 76 and into the liquid sump
62. Perforations in the trough floor may be provided in
alternative patterns, such as mesh or grids ~not shown). The
choice of a pattern may affect the throw capacity of the
vibrating trough. The purified fluid exits from trough 63
through the slot perforations 76 into chamber 53. Any liquid
62 which has condensed on particulate layer 64 as the fluid
passes therethrough tends to form droplets 77 which ultimately
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fall from trough 63 into the sump of liquid 62 at the bottom of
chamber 53. From chamber 53 the fluid passe~ through condensor
44, where excess liquid is removed, and out of the apparatus
via outlet duct 54.
The vibrations of trough 63 cause the particles of layer 64
thereon to be continuously projected upwardly along the path of
trough 63. These vibrations also afford the advantages of
keeping material 64 distributed uniformly on trough 63,
providiny maximum exposure of particulate layer 64 to the fluid
and preventing the particulate layer of 64 from agglomerating
and compacting. It is to be understood that it is equally
possible to provide means to actuate the trough to move the
layer of particulate downwardly along the path of the trough.
The selection of the appropriate direction in some cases depend
upon energy saving considerations. The impurities absorbed by
or entrapped in particulate layer 64 are removed therefrom by
depositing material 64 from the upper end of trough 63 onto the
uppermost baffle 67 in regeneration passageway 66~ The
particulate 64 cascades down the series of baffles 67 and is
washed and cleaned by a spray of liquid 62 from no~zles 680
The thus cleansed particulate collects at the bottom of the
passageway 66 and is returned to the lower end of trough 63 by
outlet 69.
Fig. 8 and Fig. 9 show modifications of the apparatus of E~ig. 4
and Fig. 5 which involve a plurality of layers of particulate
supported on multiple layered troughs. These modifications are
especially advantageous where fluid contains a variety of
impurities, the removal of which reguires two or more different
layers of particulate or more than a single pass. Fig. 8
illustrates a modification wherein a second trough 80,
identical in construction to trough 63 and on which is support-
ed a particulate layer 81, which may be the same or different
from particulate layer 4, is posi~ioned directly below and
parallel to trough 63 such that the fluid first passes into
trough 63 and throuyh particulate 64 and then into ~rough 80
and through particulate 81 before exiting into chamber 53.
Fi~. 9 shows a modification wherein a second vibrating chamber
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82 and trough 83, identical in construction to chamber 51 and
trough 63 except as regards circumferential size, are
positioned annularly to chamber 51 and trough 63. The fluid
first passes from chamber 51 into trough 63, through
particulate 64 and into chamber 82 and then into trough 83 and
through particulate 84, which is supported on trough 83, before
exiting into chamber 53.
It is to be understood that the foregoing description is not
intended to limit the invention, since changes and
modifications may occur to those skilled in the art which do
not depart from the spirit of the invention and which come
within the scope of the appended claims.
