Gas/solids contacting device

A gas/solids contacting device provides a light-weight, easily installed unit for contacting gases with particulate solids and permits the removal of spent solids and introduction of replacement solids. A solids contacting chamber is maintained between a pair of generally parallel foraminous surfaces which are inclined at an angle greater than the angle of repose of the particulate solids to be confined in the solids-containing chamber. The devices may be connected in parallel or in series and will function with the gas flowing upwardly or downwardly through a bed of particulate solids within the solids-containing chamber. Gas distributor means are provided to promote uniform low velocity gas flow through the solids bed. Retractable or removable support legs may be included.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention concerns a device in which gases can be contacted with 
solids and more particularly to a device in which the solids can be 
intermittently replaced in whole or in part. 
2. Description of the Prior Art 
There are numerous processes in which gases are contacted with particulate 
solids in order to alter the composition of the gas stream. Examples 
include contacting a gas stream with particulate solids functioning as a 
catalyst to promote reaction of gaseous ingredients; contacting the gases 
with an absorbent or an adsorbent to remove selected components from the 
gas stream, e.g., contacting a moisture-containing gas with a dessicant 
such as silica gel to remove moisture from the gas stream, or contacting 
an acidic stream with alkaline solids to remove acid-containing 
ingredients from the gas stream, or contacting a stream with organic 
contaminants to remove the organic contaminants by contacting the gas 
stream with particulate activated carbon. There are other known processes 
for contacting gases with particulate solids in order to bring about 
desired changes in the composition of the particulate solids. The present 
invention is applicable to all such processes but is of particular 
interest to those processes where gases are treated by the solids to 
remove certain ingredients (moisture, acidic ingredients, organic 
ingredients) from the gas stream. 
Gas solids containing devices are known wherein a moving bed of particulate 
treating solids passes between screens, louvers or other gas permeable 
surfaces whereby the gas stream flows counter to or transversely to the 
direction of solids movement. The solids movement may be continuous or 
intermittent according to various processes known in the art. 
STATEMENT OF THE PRESENT INVENTION 
The present invention is concerned with a gas/solids contacting device 
confined within a portable container which provides for transverse gas 
movement through a static bed of particulate solids. The bed of solids is 
confined between generally parallel inclined foraminous surfaces which 
permit withdrawal and replacement of the particulate solids treating 
materials intermittently. The units may be provided in a range of sizes to 
accommodate the needs of a particular gas treatment installation. The 
units can be conveniently connected in parallel to increase capacity and 
can be connected in series to increase the efficiency of the gas/solids 
contacting process. 
One aspect of the invention is to provide the aforementioned inclined 
foraminous surfaces at an angle which is greater than the angle of repose 
of the particulate solids which form the treatment bed. By providing the 
foraminous surfaces at an angle greater than the angle of repose of the 
particulate solids, the solids may be readily withdrawn from the bed 
between the foraminous surfaces by opening appropriate discharge ports at 
the base of the particulate solids bed. In a preferred embodiment, the bed 
is provided with multiple discharge ports and is further provided with 
wedge-shaped flow directing guides to facilitate complete removal of the 
particulate solids when desired. At least one inlet port is provided for 
introducing fresh or regenerated treatment solids into the solids bed. 
Multiple inlet ports are preferred to facilitate uniform filling of the 
particulate solids bed. 
The particulate solids bed is confined within a generally rectangular 
casing which has a plenum chamber above and a plenum chamber below the 
particulate solids bed. Openings are provided into each plenum chamber to 
admit untreated gas into one of the plenum chambers and to discharge 
treated gas from the other of the plenum chambers. 
As a further improvement, either or both of the plenum chambers may be 
provided with a gas distribution manifold which attenuates and uniformly 
divides the forces of gas introduction and achieves a nearly uniform flow 
of incoming gas into one of the gas plenum chambers for uniform transit 
through the particulate solids bed. The distributor box preferably is 
provided with appropriate baffles and multiple gas outlets. A similar 
collection manifold reverses the procedure in the outlet plenum, to 
further promote uniform flow through the particulate solids bed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
One of the preferred applications for the present gas/solids contacting 
device is passing gases through a bed of activated carbon for selective 
removal of organic ingredients contained in the gas. 
FIG. 1 illustrates the present gas/solids contact device comprising a box 
10 containing a top wall 11, bottom wall 12, side walls 13, 14 and end 
walls 15, 16. The box 10 contains three distinct chambers including a gas 
manifold chamber 17, a gas manifold chamber 18 and a solids-containing 
intermediate chamber 19. The solids-containing intermediate chamber 19 is 
confined between a pair of foraminous surfaces 20, 21 which comprise 
essentially flat surfaces having openings sufficiently small to preclude 
any significant passage of solid materials through the surface but 
admitting free passage of gases through the surfaces. 
The top foraminous surface 21 extends from the one side wall 13 to the 
other side wall 14 and commences along the top wall 11 adjacent to the 
intersection 22 of the top wall 11 and the end wall 15. The foraminous 
surface 21 extends to the end wall 16 above the intersection 23 of the end 
wall 16 and the bottom wall 12. The bottom foraminous surface 20 likewise 
extends from the side wall 13 to the side wall 14 and extends from the 
back wall 15 adjacent to and below the intersection 22 toward the 
intersection 23 of the bottom wall 12 and the end wall 16. As illustrated 
in FIG. 1, the bottom foraminous surface 20 terminates exactly at the 
intersection 23. In other embodiments, the termination of the bottom 
foraminous surface 20 could be along the bottom wall 12 or along the end 
wall 16 in the region of the intersection 23. 
It will be observed that the angle of inclination, indicated by the numeral 
24, between the bottom wall 12 and the foraminous surface 21 is at least 
equal to the angle of repose of the solid material which will be deposited 
in the intermediate solids-containing chamber 19. For activated carbon 
having a particle size from 2 to 50 U.S. Sieve, the angle of repose is 
about 30 degrees for dry material, about 25-35 degrees for visibly moist 
material, depending on the amount of liquid between particles. 
The end wall 16 is equipped with one or more outlet ports 25 through which 
spent treatment solids can be removed from the solids-containing chamber 
19. In a preferred embodiment, flow directing devices 26 are positioned in 
the solids-containing chamber 19 to direct the spent treatment solids into 
the ports 25. The flow directing devices 26, which are illustrated in FIG. 
10, also reduce the volume of non-functioning contacting-solids within the 
solids-containing chamber 19. Solids inlet ports 27 are provided in the 
top wall 11 to admit treatment solids into the solids-containing chamber 
19. Appropriate closure members (not shown in FIG. 1) are provided for the 
outlet ports 25 and the inlet ports 27. With the bottom in a generally 
horizontal plane, spent solids will readily flow out from the 
solids-containing chamber 19 so long as the angle 24 exceeds the angle of 
repose of the solids. 
The box 10 is provided with one or more gas flow ports 28 communicating 
with the plenum chamber 17 and one or more gas flow ports 29 communicating 
with the plenum chamber 18. In operation the gas/solids contacting device 
10 receives gas to be treated through a gas flow port 28. The gases passes 
through the solids-containing chamber 19 where it encounters the treatment 
solids; the treated gas is recovered from the plenum chamber 18 through 
the gas flow port 29. It is possible to reverse the flow so that the gas 
to be treated enters the gas flow port 29 and passes from the plenum 
chamber 18 through the solids-containing chamber 19 into the plenum 
chamber 17 and out through a gas flow port 28. 
As thus far described, the present gas/solids contact device can be quickly 
installed where needed and can be easily serviced by removing spent 
treatment solids and replacing fresh treatment solids in the 
solids-containing chamber 19. The units can be fabricated in generally 
rectangular configuration of sufficient sizes to meet normally anticipated 
gas flow conditions. Easily handled boxes 10 can be fabricated as cubes 
with edges of 2 feet by 2 feet by 2 feet up to 5 feet by 5 feet by 5 feet 
for rapid installation. The outer surfaces of the box 10 preferably are 
fabricated from light gauge metals such as steel sheets of 20 gauge 
through 10 gauge. The foraminous surfaces 20, 21 are preferably formed as 
illustrated in FIG. 2 wherein a sturdy grating 30 is formed from 
perpendicularly presented ribs 31 in the form of a "subway grating". The 
grating 30 is covered with appropriate screen, mesh, fabric or other 
foraminous surface 32, preferably stainless steel wire mesh. The screen 32 
will be presented on the interior surface of the solids-containing chamber 
19. 
A further improvement of the present gas/solids contacting device is 
illustrated schematically in FIG. 3 having corresponding numerals and 
illustrating gas distribution housings 33, 34 which are presented in the 
plenum chambers 17, 18 respectively. The purpose of the gas distribution 
housings 33, 34 is to attenuate the force component of gases and retard 
any flow channeling tendencies within the plenum chambers 17, 18, without 
inducing significant flow resistance. 
One gas distribution housing element 33 (34) is illustrated in FIG. 4 as 
having a top surface 35 and a side surface 36. Gas flow ports 28 introduce 
gas into the interior of the distribution housing 33 whence multiple gas 
flow ports 37 communicate with the plenum chamber 17 to distribute 
incoming gas uniformly. In a preferred embodiment, the interior of the gas 
distribution housing 33 (34) may be provided with appropriate sheet 
baffles as illustrated in FIG. 6. The incoming gas enters through one or 
more gas flow ports 28 and encounters overlapping baffle surfaces 38 and 
exit from the gas distribution housing through gas flow ports 37 at a 
uniform velocity. 
Another feature of the gas distribution housing 33 (34) illustrated in FIG. 
5 provides curved surfaces 39 on the plenum chamber side of the gas ports 
37 to intercept force components of the gas and further diminish 
turbulence within the plenum chamber. 
The present gas/solids contacting device can be employed with gas flow in 
either direction with housings 33, 34 acting to distribute/collect or 
collect/distribute gases. Accordingly the units can be conveniently 
assembled in series for optimum recovery efficiency as illustrated in 
FIGS. 7, 8, 9. In FIG. 7, the two devices 10A, 10B function identically. 
Incoming gases enter the plenum chamber 17A and are exhausted from the 
plenum chamber 18A through a conduit 40 into a plenum chamber 17B. Treated 
gases are withdrawn from the plenum chamber 18B. In FIG. 7, the gas flow 
is upwardly through both of the solids-containing chambers 19A, 19B. 
In FIG. 8, incoming gases enter the device 10C through the plenum chamber 
17C and are withdrawn from the plenum chamber 18C through a conduit 41 to 
the plenum chamber 18D of the device 10D. Treated gases are withdrawn from 
the device 10D from the plenum chamber 17D. In the arrangement shown in 
FIG. 8, the gases flow upwardly through the solids-containing chamber 19C 
and flow downwardly through the solids containing chamber 19D. 
FIG. 9 presents the same flow arrangement as that illustrated in FIG. 8 
except that the gases are introduced and withdrawn through side walls 
instead of end walls. The gas enters the device 10E through gas flow port 
28E and is delivered by a circuit 41' to the device 10F whence the treated 
gas is withdrawn from the plenum chamber 17F through a conduit (not 
shown). 
FIGS. 7, 8, 9 collectively illustrate the versatility of the present 
gas/solid contacting device and its ability to provide substantial 
gas-solids contact time in relatively small space. 
The present gas/solids containing devices can be connected in parallel to 
increase the throughput of any installation and thereby avoid the need for 
oversize units to achieve a desired low gas velocity through the 
solids-containing chambers 19. 
Typically the solids-containing chambers 19 will have a thickness (distance 
between the two foraminous surfaces 20, 21) of about 10 to 30 inches. 
Alternative solids feed and discharge devices are illustrated in FIG. 11. 
FIG. 11 is a perspective illustration of an alternative embodiment of the 
present invention illustrating a hinged cover 42 in the top wall 11 of the 
device. Hinges 43 permit the hinged cover 42 to expose the interior of the 
solids-containing chamber 19 for rapid introduction of fresh treating 
solids into the solids chamber 19. 
The device 10 shown in FIG. 11 also provides one or more hinged openings 
44, 45 in the end wall 16 for removing spent treating solids from the 
solids-containing chamber 19. A large hinged cover 44 may be pivoted 
through hinges 48 to open an area in the end wall 16 which communicates 
the solids-containing chamber 19 for rapid removal of spent solids. 
Alternatively, smaller hinged covers 45 may be opened individually or 
together to discharge spent solids. The device 10 of FIG. 11 also may be 
filled through a port 53 in side wall 13 or a port 54 in the end wall 15. 
A further feature of the present invention is illustrated in FIG. 12 
wherein the device may be equipped with convenient leg members 51 formed 
from an angle strip having multiple openings 52 and having a base plate 
47. This side wall 13 and end wall 15 join in an edge 48. Appropriate 
brackets 49 are secured to the walls 13, 15 respectively to provide a 
slide connection for receiving the leg member 51. One or more pin 
receiving opening 50 is provided in the walls 13 and/or 15 to receive a 
pin or threaded fastener to secure the leg member 51 at a selected 
elevation within the brackets 49. During shipment, the leg member 51 will 
be positioned such that the base plate 47 does not significantly protrude 
from the box during shipment. 
A further alternative embodiment of the device is illustrated in FIG. 13 
wherein the side wall 13 of the device is formed from a pair of triangular 
plates 62, 63 and a cover plate 60 which is secured by fasteners such as 
screws 61 to the triangular plates 62, 63. The removable cover plate 60 
facilitates cleaning the interior of the device. Appropriate gasketing is 
provided between the cover plate 60 and the mounting seams to preclude gas 
entry or discharge through the seams. By removing the cover plate 60, the 
operator can have access to the screens and grating elements within the 
device for maintenance if required. 
FIGS. 14, 15, 16 and 17 illustrate an alternative construction for 
supporting legs to elevate the device above a base surface. As shown in 
FIG. 14, a lower corner of the device is formed from a side wall 13, an 
end wall 15 and a bottom wall (not seen) 12. A length of channel 65 is 
secured to the bottom wall 12 in any appropriate fashion as by welding, 
bolting, et cetera. The channel 65 has a generally square cut-out 66 in 
its flange and is provided with a pin-receiving opening 67 in the channel 
legs. The supporting legs can be a rectangular cross-section tube 68 (FIG. 
15) or a channel 69 (FIG. 16). The leg 68 of FIG. 15 is provided with 
pin-receiving openings 70 and is secured to a base plate 71. The leg 69 of 
FIG. 16 is provided with pin-receiving openings 72 in its channel legs and 
is secured to a base pad 73. The assembly of the supporting structure is 
illustrated in FIG. 17 wherein the leg member 68 is inserted through the 
flange opening 66 of the channel 65. A pin 74 is inserted through aligned 
opening 66 (of the channel 65) and 70 (of the leg 68). Leg members as 
shown in FIGS. 14, 15, 16 and 17 can be employed not only at the corners 
of the device but also, if desired at spaced locations along one or more 
edges of the bottom wall 12. The channels 65 can extend entirely across 
the width of the bottom wall and function as skids for the device. 
A further alternative embodiment of the present invention is illustrated in 
FIG. 18 which is similar to FIG. 3 except that the lower foraminous sheet 
20a intersects the bottom wall 12 and one or more discharge ports 25a is 
provided in the bottom wall 12. In the embodiment of FIG. 18, solids which 
are introduced into the chamber 19a may be discharged through the bottom 
wall discharge port 25a. The design also permits a steeper angle of the 
foraminous sheets 20a, 21a. 
SUMMARY 
The present invention provides a light-weight, portable, gas/solids 
containing device which can be quickly and conveniently filled, emptied 
and refilled with treatment solids. A preferred treatment solid is 
activated carbon. However other solids may be employed such as catalysts, 
dewatering agents, molecular sieves and other gas treating materials. The 
foraminous surfaces which define the solids-containing chamber are 
presented at an inclination angle which exceeds the angle of repose of the 
particular solids to be contained in the chamber, thus facilitating 
charging and removing treatment solids.