WO1995003875A1

WO1995003875A1 - Dynamic packed chamber scrubber

Info

Publication number: WO1995003875A1
Application number: PCT/US1994/008777
Authority: WO
Inventors: William J. Carr
Original assignee: Carr William J
Priority date: 1993-08-03
Filing date: 1994-08-02
Publication date: 1995-02-09

Abstract

A liquid media scrubber (10) for gases utilizes a chamber (12) having an inlet (18) and an outlet, each capable of passing fluids therethrough. A packed container (48) is located within chamber (12), possessing a distinct inlet (52) and outlet (54). A liquid injector (60) delivers and disperses liquid from a liquid storage (38) to packed container (48) and within chamber (12) at inlet portion (52) to packed container (48). Pressure source (118) imposes a negative pressure on chamber (12). Packed container (48) and liquid injector (60) are rotated within chamber (12) to increase the efficiency of the scrubbing process. Liquids are returned to liquid storage (38) after contact with the gases being scrubbed for disposal. Scrubber (10) may also include a demisting compartment (108) located outside of chamber (12) for effecting further removal of the liquid from the liquid gas mixture generated within chamber (12).

Description

DYNAMIC PACKED CHAMBER SCRUBBER BACKGROUND OF THE INVENTION

The present invention relates to a novel gas scrubber utilizing a dynamic packed chamber.

Many manufacturing and production facilities generate toxic gases which are considered to be undesirable at the least. For example, the heavy industry, waste processing plants, biotechnology facilities, utility generation, small operations such as dry cleaning, ground soil remediation, and the like, fall into this category. In addition, food and tobacco industries generate dust and exhaust gases which also must be controlled. Certain exhaust gases are harmful only in large quantities, while other gases are extremely poisonous and must be strictly controlled. In the latter category, gases such as silane, phosphine, tetraethyl, orthosilicate, and the like, produced in the electronics fabrication field, must be removed and carefully disposed.

Prior scrubbing processes have encountered great difficulty in eliminating toxic gases from waste stacks. In this regard, reference is made to United States Patent 5,185,016 which was a notable advance in waste gas scrubber technology. Prior systems have also used static packed bed scrubbers. However, such scrubbers tend to "channel" the exhaust effluent, requiring this type of scrubber to be built in large sizes in order to achieve acceptable efficiencies. Along these lines, large scrubbing devices are often placed on the exterior of a building such as the roof. In many cases additional roof supports are required to support such equipment. Also, high pressure water lines and other peripheral items are necessary to operate such equipment, which can be quite expensive. Further, in addition to the initial expense of purchasing static bed scrubbers, water consumption during operation is quite high and maintenance is extremely costly. For example, internal cleaning of solidified residues and removal of heavy sludges is often required in such prior art devices. Moreover, prior art devices often require secondary containment systems, such is double blowers, to prevent catastrophic releases of hazardous waste gases. Many prior art gas removal mechanisms are not compatible with secondary containment systems.

The gas scrubbing apparatus which achieves an exceptional efficiency in removing waste gases from a variety of industries would be a great advance in the field of air pollution control.

SUMMARY OF THE INVENTION

In accordance with the present invention, a novel and useful waste gas scrubber is herein provided.

The scrubber of the present invention utilizes .a chamber having an inlet and an outlet, each capable of passing fluids therethrough. Exhaust gases may pass through the inlet to the chamber for treatment within the same. Gases may be a mixture of relatively inert gases, such as nitrogen, as well as poisonous gases such as silane. The chamber may be contiguous with a liquid storage portion in the form of a sump. Pressure means is employed to impose at least a partial vacuum or negative pressure on the chamber such that exhaust gases are pushed into the chamber and drawn out of the same at a proper rate.

A packed container is located within the chamber. Such container is capable of receiving exhaust gases, processing the same, within the packed container, and causing the gas to egress the outlet. Means is included for turning or rotating the packed container within the chamber. Such turning means may take place along an axle which is motivated by a motor lying outside the chamber.

Rotating with the packed container in the chamber is liquid injector means for delivering and dispersing liquid from the liquid storage of the chamber. The injector may take the form of an elongated member having a first port for sending the liquid to the interior of the rotating packed container and a second port for delivering liquid to the chamber just outside the inlet to the rotating packed container. Rotation of the packed container and the liquid injector together insures a thorough mixing of the exhaust gases sent into the chamber of the liquid found in the packed container, as well as in the area just adjacent the inlet to the packed container. The liquid injector may include a plurality of apertures for this purpose. In addition liquid may be delivered to the injector from one end of the elongated member which lies outside the chamber, but within sealed ante-chamber which does not rotate.

Gases mixed with the dispersed water in the chamber are sent from the chamber to a demisting compartment which is located adjacent the chamber. Packing material may also be found in the demisting compartment. Liquid holding waste gas exiting the chamber but not entering the demisting chamber, is sent back to a liquid disposal sump. In addition, liquid recovered in the demisting compartment is fed back to the liquid disposed sump through appropriate conduit. Gases leaving the demisting compartment are considered to be scrubbed or cleansed and are sent to the outward environment or through secondary containment chambers for application of further assurance measures against contamination of the atmosphere.

It should also be noted that the rotating packed container contacts the liquid storage within the compartment and further disperses liquid for mixture with the exhaust gases entering the chamber. The rotational speed of the packed container also serves to regulate the flow of gases into and out of the same within the chamber since the inlet and outlet of the packed container includes plates that have a multiplicity of apertures. For example, rapid turning of the packed container will reduce the flow rate of gases thereinto, in this regard.

It may be apparent that a novel and useful scrubber for waste gases has been described. It is therefore an object of the present invention to provide a scrubber for gases which is compact in size and exhibits a very high efficiency in the removal of noxious gases from the manufacturing or production process.

It is another object of the present invention to provide a scrubber for gases which exhibits high reliability and eliminates complex peripheral equipment associated with prior art static bed scrubbers.

A further object of the present invention is provide a scrubber for gases which is compatible with secondary liquid containment systems.

A further object of the present invention is to provide a scrubber for gases which is economical to operate since extremely reduced water consumption and power is required.

Yet another object of the present invention is to provide a scrubber for gases which eliminates the effort associated with internal cleaning of solidified residues and sludges.

Yet another object of the present invention is to provide a scrubber for gases which is easily integrated into production and manufacturing waste streams since the scrubber of the present invention is easily adjustable to specific waste flow rates.

The invention possesses other objects and advantages especially as concerns particular characteristics and features thereof which will become apparent as the specification continues.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a side elevational view of the scrubber of the present invention with the waste gas inlet, a gas treatment and liquid recovery portions shown in section. -

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1.

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1.

Fig. 4 is a sectional view taken along line 4-4 of Fig. 1.

Fig. 5 is a right end view of the scrubber of the present invention taken along line 5-5 of Fig. 1.

For a better understanding of the invention references made to the following detailed description of the preferred embodiments thereof which should be taken in conjunction with the prior described drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various aspects of the present invention will evolve from the following detailed description of the preferred embodiments thereof which should be referenced to the previously described drawings.

The invention as a whole is depicted in the drawing by reference character 10. Gas scrubber 10 includes as one of its elements a chamber 12 which is formed as a portion of housing 14. With reference to Figs. 1 and 2 it may observed that housing 14 includes a cylindrical end portion 16 providing an inlet 18 to chamber 12. Process gases are directed through conduit 20, in this regard. Chamber 12 is divided into a first portion 22 and a second portion 24. Plate 26 having circular opening 28, serves to divide chamber 12 into portions 22 and 24. Support wall 30 functions as a mounting surface for cylindrical end portion 16 through a plurality of fasteners 32, shown in exemplar form on Fig. 2. Support wall 30 rests on base 34 which may also serve as secondary containment for processed gases encapsulated in liquid originating in liquid body 36 within liquid storage portion 38 of chamber 12. It should be noted that liquid body 36 may be water or other liquids capable of recovering waste gases. A plurality of hollow bosses 40 permits scrubber 10 to be affixed to a pallet or runners (not shown) . Drain opening 42 accesses the interior of base 34 to effect removal of waste gas contaminated liquids. Ring-shaped flange 44 provides outlet 46 to chamber 12. It should be noted that cylindrical end portion 16 and connected flange 44 are fastened to support wall 30. Such connections within housing 14 are achieved by welding or other suitable means.

Within chamber 12 is found a container 48 filled with packing material such as multiplicity of spheres 50. Of course, packing material may also take the form of other known packing configurations such as media balls, Raschig rings, Berl saddles, and the like. Packed container 48 is located within second portion 24 of chamber 12. With reference to Figs. 2 and 3, it may be observed that packed container 48 includes an inlet plate 52, Fig. 2, and an outlet plate 54. Plates 52 and 54 include plurality of apertures 56 and 58, respectively, which are sufficient to permit the passage of fluids, yet retain multiplicity of spheres 50 within container 48.

Liquid injector means 60 is also found in the present invention in the form of an elongated tube 62 which extends into chamber 12. Elongated tube is formed with a plurality of openings or ports 65 to permit the passage of liquid from liquid body 36, the path of which will be discussed hereinafter in detail. Elongated tube 62 is fastened to a tube 64 of reduced diameter that extends through elongated tube 62. Tube 64 of reduced diameter connects to bearing housings 66 an 68. Tube 64 and bearing housing 66 and 68 isolate a shaft 70, therewithin, against contact with any gases or liquids within chamber 12. However, shaft 70 is keyed such that tube 64 and elongated tube 62 turn with shaft 70. In this regard, turning means 72 is provided in the form of a wheel 74 which is held to shaft 70 outside of chamber 12. Shaft 76 is turned by motor means 78. Journaled end 80 of shaft 76 includes a pulley 82 which connects to pulley wheel 74 through a belt 84. Injector is connected to container 48 such that turning means 72 is capable of turning injector 60 as well as packed container 48.

Liquid is fed from liquid storage portion 38 through conduit 86 and to pump 88. The outlet 90 of pump 88 sends liquid into a sealed ante-chamber 92. Elongated tube 62 turns within chamber 92 formed by a manifold housing 94. Manifold 94 is held to a support wall 96 by a circular flange 98 welded thereto, Figs. 1 and 4. Large openings 100 through elongated tube 62 permits liquid from chamber 92 to enter tube 62 and pass to multiplicity of apertures 65 in elongated tube 62, without contacting shaft 70. Seals 102 and 104 prevent the passage of liquid from chamber 92 into chamber 12.

Again turning to Figs. 1 and 4, grid 106 contacts liquid having encapsulated waste gases exiting chamber 12. A portion of this liquid is set to liquid disposal sump 10.. Conduit 109 is employed to remove liquid holding waste gases. Grid 106, Figs. 1 and 4 also contacts any gas and liquid mixture traveling into a demisting chamber or compartment 108. Combined gas and liquid effluent passing through grid 106 are directed by partition 110 to pass through grid 112 and, eventually, through grid 114 into transition duct 116. A plurality of spheres 118 intercept the liquid and gas mixture between grid 112 and 114. This contact serves to further capture liquid from the mixture, which then returns through grid 106 and to sump 107.

De-watered and cleaned gas is then passed through blower 118 to the exterior environment or to a secondary contamination chamber. Blower 118 is operated by motor 78 whose output shaft 120 turns pulley 122 through belt 124 and blower shaft 126. It should be observed that shaft 120 is also capable of operating pulley 128 which is linked to pulley 130 through belt 132. Thus, shaft 76 is also operated by motor 78, Fig. 5.

In operation, the process gases to be cleaned are sent through duct conduit 20 and into inlet 18 of chamber 12. Turning means 72 rotates liquid injector 60 and connected packed container 48 via the operation of motor 78. Liquid is then pumped from liquid body 36 within liquid storage portion 38 of chamber 12 and into sealed liquid chamber 92. Liquid passes through large openings 100 of elongated tube 62 and disperses outwardly from injector 62 through multiplicity of apertures 65 therein. Simultaneously, dispersed liquid flows into first portion 22 of chamber 12 as well as into packed container 48. It should be noted that packed container 48 also scoops water from liquid body 36 within container 12 during its rotation. Such thoroughly mixed liquid and gas is then passed through from packed container outlet plate 54 to grid 106, and demisting chamber or compartment 108. The rate of rotation of packed container 48, determines the residence time of the liquid gas mixture. Grids 106, 112 and 114 as well as plurality of spheres 136 in demisting compartment 108 serve to separate the water encapsulating the waste gases from purified air. The clean air then passes into transition duct 116, through blower 118, and outwardly from scrubber 10. It should be noted that blower 118 also serves as means 134 for imposing a negative pressure on scrubber 10, especially within chamber 12. It has been found that scrubber 10 is extremely compact and efficient since the liquid 36 and the waste gases entering inlet 18 to chamber 12 are thoroughly mixed therewithin. Liquid containing waste gases are then drained from scrubber 10 through conduit 109. Thus, scrubbing may take place on a continuous basis.

While, in the foregoing, embodiments of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those of ordinary skill in the art that numerous changes may be made in such details without departing from the spirit and principles of the invention.

Claims

WHAT IS CLAIMED IS

1. A scrubber for gases utilizing a liquid, comprising; a. a chamber; said chamber including an inlet and an outlet each capable of passing fluids therethrough; b. a packed container located within said chamber, said packed container including an inlet and an outlet capable of passing fluids therethrough; c. turning means for rotating said packed container within said chamber; d. liquid injector means for delivering and dispersing liquid from a liquid storage to said chamber; e. pressure means for imposing at least a partial vacuum on said chamber; and f. conduit means for permitting drainage of liquid after contact with said gases within said chamber.

2. The scrubber of claim 1 in which said liquid injector means includes first port means for delivering liquid to the interior of said rotating packed container, and second port means for delivering liquid to said chamber outside said rotating packed container.

3. The scrubber of claim 2 in which said turning means further comprises means for rotating said liquid injector.

4. The scrubber of claim 3 in which said turning means further includes means for rotating said packed container and said liquid injector together.

5. The scrubber of claim 1 in which said liquid injector includes a hollow elongated member extending into said chamber said elongated member including a liquid inlet and said first and second port means comprises a plurality of outlet apertures communicating with said packed container and said chamber outside said packed container.

6. The scrubber of claim 1 which additionally includes a compartment communicating with said outlet of said chamber, said compartment including packing material, a first outlet for direction scrubbed gases therefrom and a second outlet or directing liquid to said chamber.

7. The scrubber of claim 1 in which said inlet to said packed container includes a plate having a multiplicity of apertures.

8. The scrubber of claim 7 in which, said outlet from said packed container includes a plate having a multiplicity of apertures.

9. The scrubber of claim 6 in which said liquid injector means includes first port means for delivering liquid to the interior of said rotating packed container, and second port means for delivering liquid to said chamber outside said rotating packed container.

10. The scrubber of claim 9 in which said turning means further comprises means for rotating and liquid injector.

11. The scrubber of claim 10 in which said turning means further includes means for rotating said packed container and said liquid injector together.

12. The scrubber of claim 11 in which said liquid injector includes a hollow elongated member extending into said chamber said elongated member including a liquid inlet and a plurality of outlet apertures communicating with said packed container and said chamber outside said packed container.

13. The scrubber of claim 1 which further comprises a liquid disposal sump for liquid after contact with the gas in said chamber, said conduit means communicating with said liquid disposal sump.

14. The scrubber of claim 6 in which said compartment possesses packing material and a plurality of grids for contacting liquids and gases within said compartment.