US3430420A - Gas sorption unit - Google Patents

Description

March 4, 1969 w. E. GROSS 3,430,420

GAS SORPTION UNIT Filed May 18, 1967 Sheet of 3 0 ob o\o/o 0 o o v Him INVENTOR. WILLIAM E. G ROS S BYg/ \ ATTORNEYS w. E. GROSS GAS SORPTION UN IT March 4,

= Sheef.

Filed lay l8 1967 enoss United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE A gas sorbent container, having a pair of compositely formed walls for containing sorption material therebetween and convoluted from one side of a housing to the other and sealed or otherwise attached to cover and base at upper and lower edges. Finger plates are inserted from front and rear to hold convolutions in shape. During filling of the container with gas sorbent material, prior to installation of the top cover, magnetic elements may be used to bow wall segments outward to increase the capacity, the subsequent insertion of finger plates operating to further compact the sorption material.

The invention relates to an improved gas sorption unit (gas filter) for cleaning ventilating air of gaseous and vaporous deliberate contaminants, often referred to as chemical biological and radiological agents which are likely to be used in warfare or to incidentally result therefrom, and those resulting from industrial pollution.

Devices presently available are bulky, wasteful of space and have a low etliciency in the utilization of sorbent material. The design of the conventional unit requires a multiplicity of seals and is subject to the hazards of leakage. Further, the unique construction described herein prevents the granules of sorbent material from plugging the openings in perforated walls, which results in increased air flow resistance. Some available gas sorption sorbent units utilize fiat surfaced fines retainers alone, which themselves have an inherent resistance to air flow. Further, in some types of construction the perforated plates sometimes pull loose from the wooden frames to which they are attached. The sorbent is then spilled causing failure of the unit and a hazard to the area where protection is sought. Further, failure may result under severe service conditions where shock and vibration are characteristic of the environment. In some types of construction the sorbent material moves in shear in relation to the walls containing it, causing grinding action against itself and the walls. Further, there is failure due to the seeping of contaminated gases past gaskets and seals, and in some cases along the walls, because of inadequate compensation for wall effect.

The object of the invention is to eliminate the failures from the above-outlined causes, and provide a device which meets each problem and provides a solution. The necessity for a multiplicity of seals is eliminated. Seals are necessary only at top and bottom of a continuous convoluted baflle element. A sorption unit of maximum capacity, maximum efiiciency is provided which also occupies a minimum of space.

A further object of the invention is the provision of a sorption device and method of constructing the device, which achieves the optimum air flow distribution throughout the unit and its sorbent bed, and which also possesses high efiiciency in utilization of sorbent material.

A still further object of the invention is the provision of a sorbent unit utilizing a combination of woven screen, such as fiber glass fibers and a fines retainer such as random unwoven web formed of textile or glass fibers, or woven cloth. The woven screen permits more even distri- 3,430,420 Patented Mar. 4, 1969 bution of air flow at the interfaces between the sorbent and its perforated retaining wall.

A further object of the invention is the achievement of a high degree of compaction of sorbent material, together with uniformity in bulk density.

A still further object of the invention is the provision of a device wherein the sorbent container walls are protected from contact with chemically reactive sorbent and corrosion and failure of the device are prevented.

Further, the device is resistant to shock forces and severe vibration and requires a minimum of labor in its construction and assembly, and is less costly and more durable than available items.

The device further can be duplicated and placed in parallel in unlimited numbers to obtain any air flow rate required without increase in total resistance to air flow; or, again, may be joined in series to achieve a doubling of capacity or air fiow rate without causing excessive total resistance to air flow. Logistics are thus simplified because only one item of equipment which meets all requirements need be stocked. Joining of conventional units in this manner results in increased resistance to air flow.

In the drawings:

FIGURE 1 is a perspective view of the unit;

FIGURE 2 is a schematic top plan view of the device with the top cover removed and showing the convolutions of the sorbent containing wall;

FIGURE 3 is a schematic horizontal cross sectional view showing the angle of the convolutions of the continuous baffie and sorption container element greatly expanded;

FIGURE 4 is a vertical fragmentary cross section taken substantially on the line 4-4 of FIGURE 2, showing the intermediate finger plates, and the baflle configuration on the inside of the cover;

FIGURE 5 is a vertical fragmentary cross section showing the character of the finger plates;

FIGURE 6 is a detail fragmentary cross section of adjacently lying segments of the sorbent container walls;

FIGURE 7 is a view of reinforcing plate embossments sometimes used in the sides of the unit; and

FIGURE 8 is a view showing the configuration of the baffle elements on the side of the cover and bottom, see arrows 88 in FIGURE 4.

The figures of the drawing are schematic, exemplary and are not drawn to scale.

Referring more in detail to the drawings:

The completely assembled gas sorption unit is designated by the numeral 10. Its exterior is formed by sides 12 and 14, a base 16, a top or cover 18. It is open at front and rear for entrance and exit flow. Flow can be in either direction.

The sorption element 20 has, in addition, a bafile function. Air entering is redirected through the walls to the sorption material. The effective length is increased by its convoluted form, and its capacity increased while being contained in an extremely small space. It is comprised of a pair of composite sorbent container walls 21, extending in convoluted or pleated form from one side 12 to the other 14. It is sealed or otherwise attached to the sides, note 13, FIGURE 3, and each composite wall is sealed or merely attached at its edges as desired and throughout its convoluted length to the base 16, see FIGURE 6. The upper end is left open for the filling operation later described.

After the filling and compaction operations have been completed the cover 18 is applied, and sealed or merely attached, as found desirable. Each wall strip 20 is comprised of a plurality of elements, of which three are shown. The number of layers of material and their composition may be varied within the scope of the invention. The three elements are: an outer member 22 which may be perforated and may be of any of a variety of types of perforated metal; a woven screen element 24 of fiber glass mesh or comparable material; and third, a liner member or fines retainer 26 which, as constructed, is nonwoven glass. Woven materials can also be used. A fourth element may be an additional woven screen element 28.

The figures of the drawing are schematic and are for illustrative purposes only. In FIGURE 3, the angle of the convolutions is widened to show construction and the size of the space 27 for containing the sorption material is not shown to any scale.

The edges of the fines retainer 26, together with elements 24 and 22 may be sealed or otherwise attached to the base 16 or as the situation requires, attached by any competent means 32-, as shown in FIGURE 6. As shown in FIGURE 5, the screen 24 may be terminated short of the base 16 and the fines retainer 26 bonded to the outer element 22 below it by a suitable bonding agent. The space 27 is filled with charcoal, or other suitable sorptive material.

The effective length of the sorption element 20 is increased by its convoluted form.

Two sets of brace plates or finger plates 30 and 31 are equipped with wedge shaped fingers having flanges as shown at 34 in FIGURE 4 for fitting to the convolutions of the sorbent container 20. One set of plates, say 30, may be permanently installed before the filling operation, for the bracing of one wall only. The other wall may be temporarily deformed, that is bowed outward to increase the capacity of the container so that the sorbent material introduced into it can be later compacted. The deformation of the walls may be effected, for example, by inserting into the tapered space, between convolutions, wedges equipped with gripping devices such as magnets, to grip and deform the walls as noted above. The wedge devices are removed after the filling operation has been completed. Vibration may be applied for compacting the sorbent material. The second set of finger plates 31 may now be inserted from the opposite side and the deformity of the wall segments removed by inward pressure. A high degree of compaction is desirable.

Another method of filling may be used. Both sets of plates 30 and 31 can be installed and the device filled by gravity as, for example, by methods disclosed in applicants patents: 2,332,512, Oct. 6, 1943; 2,614,741, Oct. 21, 1952; or 2,631,770, Mar. 17, 1953. A compacting process for this purpose is shown in applicants Patent No. 2,142,- 127, issued Jan. 3, 1939.

Excess sorbent can be removed by suitable scrapers or vacuum devices, care being taken not to disturb the compacted material.

For the purpose of dealing with the creeping of gaseous material along surfaces of any extent, an effect known as wall effect, a ridge 42 is soldered or otherwise secured to the plate 40 which forms the cover 18 and bottom 16 and conforms in extent and shape to the convoluted shape of the sorbent container. It extends into the charcoal bed, interrupting any creeping flow along the wall that may occur.

Although the invention has been illustrated and described in terms of a preferred embodiment thereof, it will be apparent to those skilled in the art that certain 4 changes, alterations, modifications and substitutions, particularly with respect to the construction details, can be made in the arrangement and location of the various elements without departing from the true spirit and scope of the appended claims.

Having thus set forth and disclosed the nature of my invention, what I claim and desire to secure by Letters Patent of the United States is:

1. A device for the sorption of gaseous contaminants, comprising a housing having two opposite sides, a base, a cover an open front and an open rear for the entrance and exit flow of gaseous material, a sorption element for containment of sorption material, ridge means attached to said cover for retarding creeping wall gases, said sorption element comprising a pair of continuous strips of composite layered material spaced throughout their length and having continuous sorption material therebetween, said strips positioned vertically and attached to the base throughout their length, said strips extending alternately to the front and to the rear of said unit to form a cont ainer element having convoluted. wall segments capable of containing sorbent material, each of said strips comprising a plurality of layers of elements, including a perforated plate, a woven fiber glass element, a fibrous nonwoven element operating as a fines retainer, and a woven glass fiber element in contact with the sorbent.

2. In a device as claimed in claim 1, a pair of plates, each provided with Wedge shaped finger sections conforming to the shape of adjacently lying wall segments, one plate insertable from the front and the other from the rear of said device, to brace said wall segments.

3. In a device as claimed in claim 1, an element secured to and depending from the inner side of said cover and formed to conform to the shape of and extend the length of said sorption element and to extend into the sorption material contained therein for retarding creeping gases, and compensating for wall effect.

4. The method of filling and compacting a sorbent container unit of convoluted form, said method comprising the steps of magnetically deforming the convoluted wall segments of said container outwardly, filling the sorbent container unit with sorption material, compact ing the material within the container by applying wedging pressure to said segments to return them to normal contour.

References Cited UNITED STATES PATENTS 2,904,945 9/1959 Kerr 5324 3,069,831 12/ 1962 Young et al. 55521 3,217,471 11/1965 Silverman 55-387 3,222,850 12/1965 Hart 55521 3,319,401 5/1967 Bogardus 55387 3,344,590 10/1967 Smith et al. 55521 3,354,622 11/1967 Murphy 55521 FOREIGN PATENTS 1,012,257 12/ 1965 Great Britain.

REUBEN FRIEDMAN, Primary Examiner.

CHARLES N. HART, Assistant Examiner.

U.S. Cl. X.R. 53--24; 55-521

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