US3854902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of filtering gas
Assignee: ZELCRON INDUSTRIES Inc A DE CORP
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Filing: 1973-08-22
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Granted: 1974-12-17
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Expires: 1993-08-22
Abstract
Abstract High temperature dirty gas is filtered in an axial direction through granular material in superimposed narrow filter chambers, and the granular material may be backwashed by pulses of high pressure air.
Inventors
- 👤 B Kalen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:05
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
207 words
A METHOD OF FILTERING HIGH TEMPERATURE DIRTY GAS COMPRISING THE STEPS OF PASSING THE DIRTY GAS RADIALLY INWARDLY THROUGH DISCRETE INLET SCREENS COAXIAL WITH A CENTER CHAMBER TO DISCRETE SUPERIMPOSED ANNULAR FILTER CHAMBERS CONTAINING GRANULAR MATERIAL OCCUPYING LESS THAN THE TOTAL VOLUME OF THE ANNULAR FILTER CHAMBERS SO AS TO LEAVE AN UNOCCUPIED SPACE AT THE TOP OF EACH FILTER CHAMBER, MINIMIZING THE EFFECT OF THE ANGLE OF REPOSE OF THE GRANULAR MATERIAL BY USING HORIZONTAL FILTER BEDS WHOSE RADIAL WIDTH IS BETWEEN 1/5 AND 1/6 OF THE OUTER DIAMETER OF THE FILTER CHAMBERS, FILTERING OUT PARTICULATE FROM THE DIRTY GAS BY PASSING THE GAS IN AN AXIAL DIRECTION WITH RESPECT TO THE FILTER CHAMBERS THROUGH THE GRANULAR MATERIAL, COLLECTING THE CLEANED GAS WITHIN THE CENTRAL CHAMBER RADIALLY INWARDLY OF THE FILTER CHAMBERS, DISCHARGING THE CLEANED GAS FROM THE CENTER CHAMBER IN AN AXIAL DIRECTION THEREOF, AND BACKWASHING SAID GRANULAR MATERIAL IN EACH FILTER CHAMBER INTP THE UNOCCUPIED SPACE ABOVE EACH FILTER CHAMBER BY INTRODUCING PULSES OF HIGH PRESSURE AIR INTO SAID CENTER CHAMBER WITH THE HIGH PRESSURE AIR DISCHARGING THROUGH SAID SCREEN,S AND PREVENTING LOSS OF THE GRANULAR MATERIAL BY USING SCREENS HAVING TRANSVERSE DIMENSIONS WHICH ARE LESS THAN THE TRANSVERSE DIMENSIONS OF THE GRANULAR MATERIAL.
Claim 2
Independent Claim
207 words
A METHOD OF FILTERING HIGH TEMPERATURE DIRTY GAS COMPRISING THE STEPS OF PASSING THE DIRTY GAS RADIALLY INWARDLY THROUGH DISCRETE INLET SCREENS COAXIAL WITH A CENTER CHAMBER TO DISCRETE SUPERIMPOSED ANNULAR FILTER CHAMBERS CONTAINING GRANULAR MATERIAL OCCUPYING LESS THAN THE TOTAL VOLUME OF THE ANNULAR FILTER CHAMBERS SO AS TO LEAVE AN UNOCCUPIED SPACE AT THE TOP OF EACH FILTER CHAMBER, MINIMIZING THE EFFECT OF THE ANGLE OF REPOSE OF THE GRANULAR MATERIAL BY USING HORIZONTAL FILTER BEDS WHOSE RADIAL WIDTH IS BETWEEN 1/5 AND 1/6 OF THE OUTER DIAMETER OF THE FILTER CHAMBERS, FILTERING OUT PARTICULATE FROM THE DIRTY GAS BY PASSING THE GAS IN AN AXIAL DIRECTION WITH RESPECT TO THE FILTER CHAMBERS THROUGH THE GRANULAR MATERIAL, COLLECTING THE CLEANED GAS WITHIN THE CENTRAL CHAMBER RADIALLY INWARDLY OF THE FILTER CHAMBERS, DISCHARGING THE CLEANED GAS FROM THE CENTER CHAMBER IN AN AXIAL DIRECTION THEREOF, AND BACKWASHING SAID GRANULAR MATERIAL IN EACH FILTER CHAMBER INTP THE UNOCCUPIED SPACE ABOVE EACH FILTER CHAMBER BY INTRODUCING PULSES OF HIGH PRESSURE AIR INTO SAID CENTER CHAMBER WITH THE HIGH PRESSURE AIR DISCHARGING THROUGH SAID SCREEN,S AND PREVENTING LOSS OF THE GRANULAR MATERIAL BY USING SCREENS HAVING TRANSVERSE DIMENSIONS WHICH ARE LESS THAN THE TRANSVERSE DIMENSIONS OF THE GRANULAR MATERIAL.
Claim 3
Dependent Claim
70 words
A method in accordance with claim 1 wherein said backwashing step includes introducing at least two pulses of pressurized air, spacing the pulses so that the second pulse reaches the filter bed before the fluidized bed has completely collapsed from the first pulse, and said step of fluidizing said bed including using air having a velocity substantially greater than the velocity needed to fluidize the bed and transport collected particulates.
Claim 4
Dependent Claim
22 words
A method in accordance with claim 2 wherein the pulses are timed so as to be approximately 0.10 to 0.15 seconds apart.
Claim 5
Dependent Claim
28 words
A method in accordance with claim 1 wherein the volume of the high pressure backwash air is substantially less than the volume of air in the outlet chamber.
Claim 6
Dependent Claim
25 words
A method in accordance with claim 1 wherein the volume of the primary backwash air is substantially less than the volume of induced backwash air.
Claim 7
Dependent Claim
37 words
A method in accordance with claim 2 including lifting up the bed after each fluidization of the bed so as to have a void between the bottom of the bed and a support screen below the bed.
Claim 8
Dependent Claim
19 words
A method in accordance with claim 1 wherein said backwashing step includes detaching particulate adhered to the granular material.
Claim 9
Dependent Claim
32 words
A method in accordance with claim 1 including using inlet screens having openings in the form of elongated slots whose transverse dimensions are less than the transverse dimensions of the granular material.
References Cited (Backward Citations)
US2804168A
Cited
US2951551A
Cited
US3166382A
Cited
GB984844A
Cited
US3410056A
Cited
US3410055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |