US4222748A — Electrostatically augmented fiber bed and method …

Claim 1

Independent Claim 229 words

In a process for continuously removing particulates from a gas stream by flowing the gas sequentially through, first an electrostatic field to place a positive or negative charge on said particulates, and subsequently an irrigated packed bed collector wherein said charged particulates are collected, the improvement whereby even submicron particulates may be separated from the gas stream at high efficiency at high bed velocities while concurrently removing the collected solid particulates from the packed bed without interrupting the gas flow therethrough, which improvement comprises: (a) flowing said gas stream containing said charged particulates through a bed of fibers having an average fiber diameter of from 50 to 1000 microns, said fiber bed having a voidage of from 90 to 98%, while concurrently (b) irrigating said fiber bed with a liquid (i) at a liquid flow rate such that at least a sufficient portion of the fiber bed contains sufficient liquid to dissipate the electrical charge from the fiber bed and the collected particulates contained therein, and (ii) at least at a frequency such that no significant space charge is permitted to develop within the fibers and collected particulates in the fiber bed, and the collected solid particulates are removed from the fiber bed without substantial retention, (c) dissipating said electrical charge to an electrical ground, and (d) draining said liquid and the particulates contained therein from said fiber bed.

Claim 2

Dependent Claim 229 words

In a process for continuously removing particulates from a gas stream by flowing the gas sequentially through, first an electrostatic field to place a positive or negative charge on said particulates, and subsequently an irrigated packed bed collector wherein said charged particulates are collected, the improvement whereby even submicron particulates may be separated from the gas stream at high efficiency at high bed velocities while concurrently removing the collected solid particulates from the packed bed without interrupting the gas flow therethrough, which improvement comprises: (a) flowing said gas stream containing said charged particulates through a bed of fibers having an average fiber diameter of from 50 to 1000 microns, said fiber bed having a voidage of from 90 to 98%, while concurrently (b) irrigating said fiber bed with a liquid (i) at a liquid flow rate such that at least a sufficient portion of the fiber bed contains sufficient liquid to dissipate the electrical charge from the fiber bed and the collected particulates contained therein, and (ii) at least at a frequency such that no significant space charge is permitted to develop within the fibers and collected particulates in the fiber bed, and the collected solid particulates are removed from the fiber bed without substantial retention, (c) dissipating said electrical charge to an electrical ground, and (d) draining said liquid and the particulates contained therein from said fiber bed.

Claim 3

Dependent Claim 11 words

A process as in claim 1 wherein said irrigation is continuous.

Claim 4

Dependent Claim 41 words

A process as in claim 2 wherein after draining the liquid and solid particulates contained therein from the fiber bed, the solid particulates are at least partially separated from the liquid and the liquid is recirculated for irrigating the fiber bed.

Claim 5

Dependent Claim 54 words

A process as in claim 1 wherein the irrigating liquid is distributed within the fiber bed such that at least 50% of the liquid is initially distributed, after allowing for vicous drag thereon of the gas phase, within the upstream one-third of the depth of the fiber bed in the direction of gas flow.

Claim 6

Dependent Claim 11 words

A process as in claim 4 wherein said irrigation is continuous.

Claim 7

Dependent Claim 41 words

A process as in claim 5 wherein after draining the liquid and solid particulates contained therein from the fiber bed, the solid particulates are at least partially separated from the liquid and the liquid is recirculated for irrigating the fiber bed.

Claim 8

Dependent Claim 33 words

A process as in claim 1 further including providing a plurality of grounded electrodes in said first electrostatic field, and said grounded electrodes are at least intermittently cleaned to remove captured particulates therefrom.

Claim 9

Dependent Claim 17 words

A process as in claim 7 wherein said grounded electrodes are cleaned by irritating with a liquid.

Claim 10

Dependent Claim 15 words

A process as in claim 8 wherein said irrigation of the grounded electrodes is continuous.

Claim 11

Dependent Claim 15 words

A process as in claim 9 wherein said irrigation of the fiber bed is continuous.

Claim 12

Dependent Claim 54 words

A process as in claim 10 wherein the same liquid is used to irrigate both the fiber bed and the grounded electrodes, suspended particulates are at least partially separated from the liquid drained therefrom, and the liquid is recirculated for irrigating at least one of (a) the fiber bed and (b) the grounded electrodes.

Claim 13

Dependent Claim 39 words

A process as in claim 1 wherein the fibers of said fiber bed are at least partially oriented parallel to the vertical plane transverse to the direction of gas flow and less oriented across the face of such plane.

Claim 14

Dependent Claim 221 words

In an apparatus for continuously removing solid particulates from a gas stream comprising a housing having inlet and outlet ends, particulate charging section within said housing proximate said inlet and comprising a plurality of high voltage discharge electrodes connected to a D.C. voltage source at least one grounded electrode positioned and arranged with respect to said high voltage electrodes to create a substantially uniform electrostatic field therebetween, a packed bed collector for charged particulates disposed within said housing downstream of said particle charging section, and a means for irrigating said packed bed with a liquid, the improvement whereby even submicron particulates may be separated from the gas stream at high efficiency at high bed velocities while concurrently removing the collected solid particulates from the bed without interrupting the gas flow therethrough, which improvement comprises (a) said packed bed comprising fibers having an average fiber diameter of from 50 to 1000 microns, said fiber bed having a voidage of from 90 to 98%; (b) said irrigating means comprising means for a liquid flow such that at least a sufficient portion of the fiber bed contains sufficient liquid to dissipate the electrical charge from the fiber bed without permitting any significant space charge to develop within the fiber bed, and the collected solid particulates are removed from the fiber bed without substantial retention.

Claim 15

Dependent Claim 221 words

In an apparatus for continuously removing solid particulates from a gas stream comprising a housing having inlet and outlet ends, particulate charging section within said housing proximate said inlet and comprising a plurality of high voltage discharge electrodes connected to a D.C. voltage source at least one grounded electrode positioned and arranged with respect to said high voltage electrodes to create a substantially uniform electrostatic field therebetween, a packed bed collector for charged particulates disposed within said housing downstream of said particle charging section, and a means for irrigating said packed bed with a liquid, the improvement whereby even submicron particulates may be separated from the gas stream at high efficiency at high bed velocities while concurrently removing the collected solid particulates from the bed without interrupting the gas flow therethrough, which improvement comprises (a) said packed bed comprising fibers having an average fiber diameter of from 50 to 1000 microns, said fiber bed having a voidage of from 90 to 98%; (b) said irrigating means comprising means for a liquid flow such that at least a sufficient portion of the fiber bed contains sufficient liquid to dissipate the electrical charge from the fiber bed without permitting any significant space charge to develop within the fiber bed, and the collected solid particulates are removed from the fiber bed without substantial retention.

Claim 16

Dependent Claim 60 words

An apparatus as in claim 13 further comprising conduit means for carrying liquid and solid particulates contained therein from the bottom of said fiber bed to a liquid treating means for at least partially separating said liquid from said solid particulates, and conduit means for returning at least a portion of the treated liquid to said fiber bed irrigating means.

Claim 17

Dependent Claim 47 words

An apparatus as in claim 13 wherein said fiber bed irrigation means is such as to distribute at least 50% of the liquid within the upstream one-third of the depth of the fiber bed, in the direction of gas flow from said inlet to said outlet end.

Claim 18

Dependent Claim 59 words

An apparatus an in claim 15 further comprising conduit means for carrying liquid and solid particulates contained therein from the bottom of said fiber bed to a liquid treating for at least partially separating said liquid from said solid particulates, and conduit means for returning at least a portion of the treated liquid to said fiber bed irrigating means.

Claim 19

Dependent Claim 23 words

An apparatus as in claim 13 further comprising means for at least intermittantly cleaning collected particulates from said at least one grounded electrode.

Claim 20

Dependent Claim 24 words

An apparatus as in claim 17 wherein said means for cleaning collected particulates from said at least one grounded electrode comprises an irrigating means.

Claim 21

Dependent Claim 71 words

An apparatus as in claim 18 further comprising conduit means for carrying liquid and solid particulates contained therein from the bottom of said fiber bed and the bottom of said electrostatic field means to a liquid treating means wherein said liquid is at least partially separated from said solid particulates, and conduit means for returning at least a portion of the treated liquid to at least said fiber bed irrigating means.

Claim 22

Dependent Claim 24 words

An apparatus as in claim 19 further comprising conduit means for returning a portion of the treated liquid to said grounded electrode irrigating means.

Claim 23

Dependent Claim 82 words

An apparatus as in claim 13 wherein each of said high voltage electrodes comprises a plurality of needles projecting from the front and back of a supporting rod when viewed parallel to the direction of gas flow, said needles being spaced substantially equidistant with respect to each other along the length of said rod, with th needles on the back of said bed being staggered with respect to the needles on the front of said rod substantially one half the distance therebetween.

Claim 24

Dependent Claim 37 words

An apparatus as in claim 21 wherein said at least one grounded electrode comprises a plurality of grounded plates at least 12 centimeters wide in the direction of gas flow from said inlet to said outlet end.

Claim 25

Dependent Claim 57 words

An apparatus as in claim 22 further comprising conduit means for carrying liquid and solid particulates contained therein from the bottom of said fiber bed to a liquid treating means to separate said liquid from said solid particulates, and conduit means for returning at least a portion of the treated liquid to said fiber bed irrigating means.

Claim 26

Dependent Claim 51 words

An apparatus as in claim 21 wherein said fiber bed irrigation means is constructed and arranged such as to distribute at least 50% of the liquid within the upstream one-third of the depth of the fiber bed, in the direction of gas flow from said inlet and to said outlet end.

Claim 27

Dependent Claim 60 words

An apparatus as in claim 24 further comprising conduit means for carrying liquid the solid particulates contained therein from the bottom of said fiber bed to a liquid treating means for at least partially separating said liquid from said solid particulates, and conduit means for returning at least a portion of the treated liquid to said fiber bed irrigating means.

Claim 28

Dependent Claim 33 words

An apparatus as in claim 21 further comprising irrigating means for at least intermittantly flushing collected solid particulates with a liquid from said at least one grounded electrode in the electrostatic field means.

Claim 29

Dependent Claim 70 words

An apparatus as in claim 26 further comprising conduit means for carrying liquid and solid particulates contained therein from the bottom of said fiber bed and the bottom of said electrostatic field means to a liquid treating means for at least partially separating said liquid from said solid particulates, and conduit means for returning at least a portion of the treated liquid to at least said fiber bed irrigating means.

Claim 30

Dependent Claim 24 words

An apparatus as in claim 27 further comprising conduit means for returning a portion of the treated liquid to said grounded electrode irrigating means.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1983-09-16	1984-03-17	1984-09-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1987-09-16	1988-03-17	1988-09-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1991-09-16	1992-03-17	1992-09-16	$7700.00	Window Closed / Lapsed

Electrostatically augmented fiber bed and method of using

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