US3926587A — Electrostatic filtration in panel bed

Claim 1

Independent Claim 383 words

THE METHOD OF TREATING A GAS INVOLVING THE SEPARATION AND REMOVAL OF PARTICULATE MATERIAL BY MEANS OF A FILTER OF GRANULAR MATERIAL WHICH COMPRISES: A. ARRANGING AN ELECTRICALLY CONDUCTING GRANULAR MATERIAL IN A PANEL BED HAVING A PULRALITY OF TRANSVERSELY DISPOSED UPWARDLY SPACED GAS ENTRY PORTIONS SEPARATED BY INTERPOSED ELECTRICALLY CONDUCTING GROUNDED SUPPORTING MEMBERS HAVING OUTER AND INNER EDGES WITH RESPECT TO THE BED WHEREIN SAID GAS ENTRY PORTIONS HAVE GAS ENTRY FACE SUBSTANTIALLY CONTIGUOUS WITH SAID OUTER EDGES AND WHEREIN SIAD BED HAS GAS EXIT PORTIONS SPACED FROM SAID INNER EDGES; B. PRODUCING A CORONA DISCHARGE OF ELECTRICITY OUTSIDE OF SAID PANEL BED AND IN PROXIMITY TO SAID GAS ENTRY PORTIONS; C. FORWARDLY FLOWING GAS TO BE TREATED IN A SUBSTANTIALLY CONTINUING FLOW DURING ITS TREATMENT IN PROXIMITY TO SAID CORONA DISCHARGE OF ELECTRICITY TO CHARGE ELECTRICALLY THE PARTICULATE MATERIAL IN THE GAS AND THEREBY TO CREATE A FORCE OF ATTRACTION BETWEEN SAID PARTICULATE MATERIAL AND SAID GRANULAR MATERIAL, AND FORWARDLY FLOWING THE GAS THROUGH SAID GAS ENTRY PORTIONS OF THE GRANULAR MATERIAL BED AND OUTWARDLY FROM THE GAS EXIT PORTIONS TO SEPARATE ANAD ACCUMULATE PARTICULATE MATERIAL AT SAID GAS ENTRY FACES; D. STOPPING THE FLOW OF SAID GAS; E. CAUSING A TRANSIENT FLOW OF GAS TO MOVE IN THE DIRECTION IN REVERSE TO THE FLOW OF SAID GAS IN (C); F. SAID TRANSIENT REVERSE FLOW PRODUCING FIRST A RISE AT A GIVEN RATE OF RISE AND SUBSEQUENTLY A FALL IN THE PRESSURE DIFFERENCE BETWEEN SAID GAS EXIT PORTION AND SAID GAS ENTRY PORTION, SAID DIFFERENCE PRODUCED BY SAID TRANSIENT REVERSE FLOW REMAINING GREATER THAN A FIRST CRITICAL MINIMUM DIFFERENCE FOR A TIME INTERVAL LESS THAN ABOUT 150 MILLISECONDS, SAID FIRST CRITICAL DIFFERENCE BEING THAT DIFFERENCE AT WHICH A STEADY FLOW OF GAS IN SAID REVERSE DIRECTION JUST PRODUCES A LOCALIZED SPILL OF GRANULAR MATERIAL FROM SAID GAS ENTRY FACES, AND SAID DIFFERENCE PRODUCED BY SAID TRANSIENT REVERSE FLOW PEAKING TO A TOP VALUE BEYOND A SECOND CRITICAL MINIMUM DIFFERENCE FLOW OF GAS IN SAID REVERSE DIFFERENCE AT WHICH A TRANSIENT FLOW OF GAS IN SAID REVERSE DIRECTION PRODUCING SAID PRESSURE DIFFERENCE AT SAID RATE OF RISE JUST INITIATES A BODY MOVEMENT OF THE GRANULAR MATERIAL TOWARD SAID GAS ENTRY FACES TO SPILL A PORTION OF THE GRANULAR MATERIAL FROM THE BED.

Claim 2

Independent Claim 383 words

THE METHOD OF TREATING A GAS INVOLVING THE SEPARATION AND REMOVAL OF PARTICULATE MATERIAL BY MEANS OF A FILTER OF GRANULAR MATERIAL WHICH COMPRISES: A. ARRANGING AN ELECTRICALLY CONDUCTING GRANULAR MATERIAL IN A PANEL BED HAVING A PULRALITY OF TRANSVERSELY DISPOSED UPWARDLY SPACED GAS ENTRY PORTIONS SEPARATED BY INTERPOSED ELECTRICALLY CONDUCTING GROUNDED SUPPORTING MEMBERS HAVING OUTER AND INNER EDGES WITH RESPECT TO THE BED WHEREIN SAID GAS ENTRY PORTIONS HAVE GAS ENTRY FACE SUBSTANTIALLY CONTIGUOUS WITH SAID OUTER EDGES AND WHEREIN SIAD BED HAS GAS EXIT PORTIONS SPACED FROM SAID INNER EDGES; B. PRODUCING A CORONA DISCHARGE OF ELECTRICITY OUTSIDE OF SAID PANEL BED AND IN PROXIMITY TO SAID GAS ENTRY PORTIONS; C. FORWARDLY FLOWING GAS TO BE TREATED IN A SUBSTANTIALLY CONTINUING FLOW DURING ITS TREATMENT IN PROXIMITY TO SAID CORONA DISCHARGE OF ELECTRICITY TO CHARGE ELECTRICALLY THE PARTICULATE MATERIAL IN THE GAS AND THEREBY TO CREATE A FORCE OF ATTRACTION BETWEEN SAID PARTICULATE MATERIAL AND SAID GRANULAR MATERIAL, AND FORWARDLY FLOWING THE GAS THROUGH SAID GAS ENTRY PORTIONS OF THE GRANULAR MATERIAL BED AND OUTWARDLY FROM THE GAS EXIT PORTIONS TO SEPARATE ANAD ACCUMULATE PARTICULATE MATERIAL AT SAID GAS ENTRY FACES; D. STOPPING THE FLOW OF SAID GAS; E. CAUSING A TRANSIENT FLOW OF GAS TO MOVE IN THE DIRECTION IN REVERSE TO THE FLOW OF SAID GAS IN (C); F. SAID TRANSIENT REVERSE FLOW PRODUCING FIRST A RISE AT A GIVEN RATE OF RISE AND SUBSEQUENTLY A FALL IN THE PRESSURE DIFFERENCE BETWEEN SAID GAS EXIT PORTION AND SAID GAS ENTRY PORTION, SAID DIFFERENCE PRODUCED BY SAID TRANSIENT REVERSE FLOW REMAINING GREATER THAN A FIRST CRITICAL MINIMUM DIFFERENCE FOR A TIME INTERVAL LESS THAN ABOUT 150 MILLISECONDS, SAID FIRST CRITICAL DIFFERENCE BEING THAT DIFFERENCE AT WHICH A STEADY FLOW OF GAS IN SAID REVERSE DIRECTION JUST PRODUCES A LOCALIZED SPILL OF GRANULAR MATERIAL FROM SAID GAS ENTRY FACES, AND SAID DIFFERENCE PRODUCED BY SAID TRANSIENT REVERSE FLOW PEAKING TO A TOP VALUE BEYOND A SECOND CRITICAL MINIMUM DIFFERENCE FLOW OF GAS IN SAID REVERSE DIFFERENCE AT WHICH A TRANSIENT FLOW OF GAS IN SAID REVERSE DIRECTION PRODUCING SAID PRESSURE DIFFERENCE AT SAID RATE OF RISE JUST INITIATES A BODY MOVEMENT OF THE GRANULAR MATERIAL TOWARD SAID GAS ENTRY FACES TO SPILL A PORTION OF THE GRANULAR MATERIAL FROM THE BED.

Claim 3

Dependent Claim 16 words

The method of claim 1 in which said time interval is less than about 50 milliseconds.

Claim 4

Dependent Claim 43 words

The method of claim 1 in which said particulate material is fly ash from the combustion of pulverized coal and wherein said gas comprises combustion products from said combustion and wherein said corona discharge of electricity is negative in respect to the ground.

Claim 5

Dependent Claim 23 words

The method of claim 1 wherein said corona discharge of electricity is interrupted for the duration of said reverse transient flow of gas.

Claim 6

Dependent Claim 33 words

The method of treating a gas containing both particulate matter and an odor in which said electrically conducting granular material of claim 1 is an active carbon adsorptive in respect to said odor.

Claim 7

Dependent Claim 19 words

The method of claim 5 in which said corona discharge of electricity is positive in respect to the ground.

Claim 8

Independent Claim 470 words

The method of treating a gas involving the separation and removal of particulate material by means of a filter of granular material which comprises: a. arranging an electrically conducting granular materiAl in a panel bed having a plurality of transversely disposed upwardly spaced gas entry portions separated by interposed electrically conducting grounded supporting members, a typical said member having an upper and a lower surface each having outer and inner edges with respect to the filter bed wherein said surfaces are articulated at an edge joint at their respective inner edges and wherein said gas entry portions have gas entry faces substantially contigous with said outer edges of said upper surfaces and wherein a line drawn through a said outer edge of a said lower surface and also through said inner edge joint to the next subjacent member forms an angle less than about 60* from the horizontal and wherein said filter bed has gas exit portions spaced from said inner edge joints; b. producing a corona discharge of negative electricity outside of said panel bed and in proximity to said gas entry portions; c. forwardly flowing gas to be treated in a substantially continuing flow during its treatment in proximity to said corona discharge of negative electricity to charge electrically the particulate material in the gas and thereby to create a force of attraction between said particulate material and said granular material, and forwardly flowing the gas through said gas entry portions of the granular material bed and outwardly from the gas exit portions to separate and accumulate particulate material at said gas entry faces; d. stopping the flow of said gas; e. causing a transient flow of gas to move in the direction in reverse to the flow of said gas in (c); f. said transient reverse flow producing first a rise at a given rate of rise and subsequently a fall in the pressure difference between said gas exit portions and said gas entry portions, said difference remaining greater than a first critical minimum difference for a time interval less than about 150 milliseconds, said first critical difference being that difference at which a steady flow of gas in said reverse direction just produces a localized spill of granular material from said gas entry faces, and said difference produced by said transient reverse flow peaking to a top value beyond a second critical minimum difference, which is the pressure difference at which a transient flow of gas in said reverse direction producing said pressure difference at said rate of rise just initiates a body movement of the granular material toward said gas entry faces to spill a portion of the granular material and accumulated particulate material from the bed; and, g. supplying fresh granular material to said bed to replace material spilled from said gas entry portions.

Claim 9

Independent Claim 470 words

The method of treating a gas involving the separation and removal of particulate material by means of a filter of granular material which comprises: a. arranging an electrically conducting granular materiAl in a panel bed having a plurality of transversely disposed upwardly spaced gas entry portions separated by interposed electrically conducting grounded supporting members, a typical said member having an upper and a lower surface each having outer and inner edges with respect to the filter bed wherein said surfaces are articulated at an edge joint at their respective inner edges and wherein said gas entry portions have gas entry faces substantially contigous with said outer edges of said upper surfaces and wherein a line drawn through a said outer edge of a said lower surface and also through said inner edge joint to the next subjacent member forms an angle less than about 60* from the horizontal and wherein said filter bed has gas exit portions spaced from said inner edge joints; b. producing a corona discharge of negative electricity outside of said panel bed and in proximity to said gas entry portions; c. forwardly flowing gas to be treated in a substantially continuing flow during its treatment in proximity to said corona discharge of negative electricity to charge electrically the particulate material in the gas and thereby to create a force of attraction between said particulate material and said granular material, and forwardly flowing the gas through said gas entry portions of the granular material bed and outwardly from the gas exit portions to separate and accumulate particulate material at said gas entry faces; d. stopping the flow of said gas; e. causing a transient flow of gas to move in the direction in reverse to the flow of said gas in (c); f. said transient reverse flow producing first a rise at a given rate of rise and subsequently a fall in the pressure difference between said gas exit portions and said gas entry portions, said difference remaining greater than a first critical minimum difference for a time interval less than about 150 milliseconds, said first critical difference being that difference at which a steady flow of gas in said reverse direction just produces a localized spill of granular material from said gas entry faces, and said difference produced by said transient reverse flow peaking to a top value beyond a second critical minimum difference, which is the pressure difference at which a transient flow of gas in said reverse direction producing said pressure difference at said rate of rise just initiates a body movement of the granular material toward said gas entry faces to spill a portion of the granular material and accumulated particulate material from the bed; and, g. supplying fresh granular material to said bed to replace material spilled from said gas entry portions.

Claim 10

Dependent Claim 16 words

The method of claim 7 in which said time interval is less than about 50 milliseconds.

Claim 11

Independent Claim 508 words

The method of treating a gas involving the separation and removal of particulate material and also involving the removal of an odor by means of a filter-contactor of granular material which comprises: a. arranging an electrically conducting active carbon in granular form that is adsorptive in respect to said odor in a panel bed having a plurality of transversely disposed upwardly spaced gas entry portions separated by interposed electrically conducting grounded supporting members having outer and inner edges with respect to the bed wherein said gas entry portions have gas entry faces with outer edges substantially contiguous with said outer edges of said supporting members and wherein a typical supporting member is gently curved and inclines downwardly and inwardly from its outer edge and then upwardly and inwardly toward its inner edge and wherein the inner edge of a typical supporting member is either above the inner edge of the gas entry face supported by the member or, when below, a line drawn through these edges is inclined at an angle of less than about 45* to the horizontal and wherein said bed has gas exit portions spaced from said inner edges of said supporting members; b. producing a corona dischArge of electricity outside of said panel bed and in proximity to said gas entry portions; c. forwardly flowing gas to be treated in a substantially continuing flow during its treatment in proximity to said corona discharge of electricity to charge electrically the particulate material in the gas and thereby to create a force of attraction between said particulate material and said granular carbon, and forwardly flowing the gas through said gas entry portions of the granular carbon bed and outwardly from the gas exit portions to separate and accumulate particulate material at said gas entry faces and to adsorb and remove said odor; d. stopping the flow of said gas; e. causing a transient flow of gas to move in the direction in reverse to the flow of said gas in (c); f. said transient reverse flow producing first a rise at a given rate of rise and subsequently a fall in the pressure difference between said gas exit portions and said gas entry portions, said difference remaining greater than a first critical minimum difference for a time interval less than about 150 milliseconds, said first critical difference being that difference at which a steady flow of gas in said reverse direction just produces a localized spill of granular material from said gas entry faces, and said difference produced by said transient reverse flow peaking to a top value beyond a second critical minimum difference, which is the pressure difference at which a transient flow of gas in said reverse direction producing said pressure difference at said rate of rise just initiates a body movement of the granular material toward said gas entry faces to spill a portion of the granular material and accumulated particulate material from the bed; and g. supplying fresh granular material to said bed to replace material spilled from said gas entry portions.

Claim 12

Independent Claim 508 words

The method of treating a gas involving the separation and removal of particulate material and also involving the removal of an odor by means of a filter-contactor of granular material which comprises: a. arranging an electrically conducting active carbon in granular form that is adsorptive in respect to said odor in a panel bed having a plurality of transversely disposed upwardly spaced gas entry portions separated by interposed electrically conducting grounded supporting members having outer and inner edges with respect to the bed wherein said gas entry portions have gas entry faces with outer edges substantially contiguous with said outer edges of said supporting members and wherein a typical supporting member is gently curved and inclines downwardly and inwardly from its outer edge and then upwardly and inwardly toward its inner edge and wherein the inner edge of a typical supporting member is either above the inner edge of the gas entry face supported by the member or, when below, a line drawn through these edges is inclined at an angle of less than about 45* to the horizontal and wherein said bed has gas exit portions spaced from said inner edges of said supporting members; b. producing a corona dischArge of electricity outside of said panel bed and in proximity to said gas entry portions; c. forwardly flowing gas to be treated in a substantially continuing flow during its treatment in proximity to said corona discharge of electricity to charge electrically the particulate material in the gas and thereby to create a force of attraction between said particulate material and said granular carbon, and forwardly flowing the gas through said gas entry portions of the granular carbon bed and outwardly from the gas exit portions to separate and accumulate particulate material at said gas entry faces and to adsorb and remove said odor; d. stopping the flow of said gas; e. causing a transient flow of gas to move in the direction in reverse to the flow of said gas in (c); f. said transient reverse flow producing first a rise at a given rate of rise and subsequently a fall in the pressure difference between said gas exit portions and said gas entry portions, said difference remaining greater than a first critical minimum difference for a time interval less than about 150 milliseconds, said first critical difference being that difference at which a steady flow of gas in said reverse direction just produces a localized spill of granular material from said gas entry faces, and said difference produced by said transient reverse flow peaking to a top value beyond a second critical minimum difference, which is the pressure difference at which a transient flow of gas in said reverse direction producing said pressure difference at said rate of rise just initiates a body movement of the granular material toward said gas entry faces to spill a portion of the granular material and accumulated particulate material from the bed; and g. supplying fresh granular material to said bed to replace material spilled from said gas entry portions.

Claim 13

Dependent Claim 16 words

The method of claim 9 in which said time interval is less than about 50 milliseconds.

Claim 14

Dependent Claim 30 words

The method of claim 9 in which said gas is odoriferous air containing micron-size particulate material and wherein said corona discharge of electricity is positive in respect to the ground.

Claim 15

Dependent Claim 530 words

An electrostatic panel bed gas filter comprising a pair of upwardly extending horizontally spaced-apart electrically conducting perforate retaining walls; a ground in electrical communication with said perforate walls; a gas inlet compartment adjacent and in communication with the perforations of the first of the perforate walls; an elongated electrically conducting electrode element within said gas inlet compartment and substantially coextensive therewith; a source of high electrical tension biassed with respect to said ground and in electrical communication with said electrode element; a gas outlet compartment in communication with the perforations of the second of the perforate walls; closure means about the space between the first and second perforate walls closing said space against the passage of gas except through the perforations of said perforate walls; feed means for supplying a loose electrically conducting solid particulate material into the space between the perforate walls; a plurality of support members each adjacent a perforation of said first perforate wall, said support members being arranged to extend outwardly from below their adjacent perforations and into the inlet compartment to support and expose to the inlet compartment a plurality of free surfaces of particulate material, said support members being arranged cooperatively to support the particulate material and retain the material within said space; an inlet for admitting a gas into the inlet compartment for passage in proximity with said electrode element and into the free surfaces and through the particulate material to the outlet compartment; an outlet for discharging gas from the outlet compartment; means for periodically effecting a body movement toward the inlet compartment of at least those pOrtions of the particulate material including said free surfaces and which are retained on said supporting members, said body-movement means comprising means for effecting a transient flow of gas into said outlet compartment and thence across said perforate walls and through said particulate material in said space and from said free surfaces into said inlet compartment to produce first a rise and subsequently a fall in the pressure difference between said outlet compartment and said inlet compartment, said means for effecting said transient flow including a. means for moderating the rate of said rise in said pressure difference, b. means for moderating said transient flow so that said pressure difference remains greater than a first critical minimum difference for a time interval less than about 150 milliseconds, said first critical difference being that difference at which a steady flow of gas from said outlet compartment to said inlet compartment just produces a localized spill of particulate material from said free surfaces into said inlet compartment, and c. means for moderating said transient flow so that said pressure difference produced by said transient flow peaks to a top value beyond a second critical minimum difference, which is the pressure difference at which a transient flow of gas from said outlet compartment to said inlet compartment producing said pressure difference at said rate of rise just initiates a body movement of the particulate material toward said free surfaces to spill a portion of the particulate material from said free surfaces; and means for discharging from the inlet compartment material which is spilled thereinto by the body-movement means.

Claim 16

Dependent Claim 530 words

An electrostatic panel bed gas filter comprising a pair of upwardly extending horizontally spaced-apart electrically conducting perforate retaining walls; a ground in electrical communication with said perforate walls; a gas inlet compartment adjacent and in communication with the perforations of the first of the perforate walls; an elongated electrically conducting electrode element within said gas inlet compartment and substantially coextensive therewith; a source of high electrical tension biassed with respect to said ground and in electrical communication with said electrode element; a gas outlet compartment in communication with the perforations of the second of the perforate walls; closure means about the space between the first and second perforate walls closing said space against the passage of gas except through the perforations of said perforate walls; feed means for supplying a loose electrically conducting solid particulate material into the space between the perforate walls; a plurality of support members each adjacent a perforation of said first perforate wall, said support members being arranged to extend outwardly from below their adjacent perforations and into the inlet compartment to support and expose to the inlet compartment a plurality of free surfaces of particulate material, said support members being arranged cooperatively to support the particulate material and retain the material within said space; an inlet for admitting a gas into the inlet compartment for passage in proximity with said electrode element and into the free surfaces and through the particulate material to the outlet compartment; an outlet for discharging gas from the outlet compartment; means for periodically effecting a body movement toward the inlet compartment of at least those pOrtions of the particulate material including said free surfaces and which are retained on said supporting members, said body-movement means comprising means for effecting a transient flow of gas into said outlet compartment and thence across said perforate walls and through said particulate material in said space and from said free surfaces into said inlet compartment to produce first a rise and subsequently a fall in the pressure difference between said outlet compartment and said inlet compartment, said means for effecting said transient flow including a. means for moderating the rate of said rise in said pressure difference, b. means for moderating said transient flow so that said pressure difference remains greater than a first critical minimum difference for a time interval less than about 150 milliseconds, said first critical difference being that difference at which a steady flow of gas from said outlet compartment to said inlet compartment just produces a localized spill of particulate material from said free surfaces into said inlet compartment, and c. means for moderating said transient flow so that said pressure difference produced by said transient flow peaks to a top value beyond a second critical minimum difference, which is the pressure difference at which a transient flow of gas from said outlet compartment to said inlet compartment producing said pressure difference at said rate of rise just initiates a body movement of the particulate material toward said free surfaces to spill a portion of the particulate material from said free surfaces; and means for discharging from the inlet compartment material which is spilled thereinto by the body-movement means.

Claim 17

Dependent Claim 93 words

The electrostatic panel bed gas filter of claim 12 wherein a typical said support member is arranged to extend outwardly and downwardly in a gentle curve from below its adjacent perforation and then to extend further in a gentle curve upwardly and into the inlet compartment and wherein the inner edge of said typical support member is either above the inner edge of the said free surface supported by the member or, when below, a line drawn through these edges is inclined at an angle of less than about 45* to the horizontal.

Claim 18

Dependent Claim 62 words

The electrostatic panel bed gas filter of claim 12 wherein said perforate retaining walls are hexagonal when viewed in plan and where said gas inlet compartment is within said first perforate wall and said gas outlet compartment is without said second perforate wall and where said electrode element is a wire hanging vertically at substantially the center of said gas inlet compartment.

Claim 19

Dependent Claim 113 words

The electrostatic panel bed gas filter of claim 12 wherein a typical said support member has two surfaces articulated at an edge joint substantially adjacent and below the member''s respective perforation and wherein the lower of the two surfaces is arranged to extend outwardly and downwardly from said edge joint and into the inlet compartment and wherein the upper of the two surfaces is arranged to extend outwardly and upwardly from said edge joint and into the inlet compartment and wherein a line drawn through the outer edge of a typical said lower surface and the edge joint of the next subjacent member forms an angle less than about 60* from the horizontal.

Claim 20

Dependent Claim 29 words

The electrostatic panel bed gas filter of claim 15 wherein said moderating means (b) moderates said transient flow so that said time interval is less than about 50 milliseconds.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-12-15	1979-06-16	1979-12-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-12-15	1983-06-16	1983-12-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-12-15	1987-06-16	1987-12-16	$7700.00	Window Closed / Lapsed

Electrostatic filtration in panel bed

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