US3873281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High energy gas filtration method
Assignee: Johns Manville Corp
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Filing: 1974-01-07
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Granted: 1975-03-25
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Expires: 1994-01-07
Abstract
Abstract A cleanable gas filtration system is described for removal of liquid and solid particulate matter from air or other gas streams. The system operates in the ''''high energy'''' region at gas velocities of 300 to 4,000 feet per minute and pressure drops across the filter medium of 7 to 60 inches of water. The system employs as its filter medium a reticulated elastomeric foam, such as a fully reticulated polyurethane foam, having a void fraction of at least 90%. Submicron and larger size particles can be filtered with high efficiency, and dry solid, liquid and mixed particulate matter can be readily handled.
Inventors
- 👤 Richard Carl Himes
- 👤 Bruce Galvin Craig
- 👤 Walter Field Gulick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:48
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1669; B01D39/1676; B01D46/00; B01D46/18; B01D46/22; B01J; B01J20/00; B01J20/22
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
196 words
IN A PROCESS FOR FILTERING MICRON AND SUBMICRON SIZE LIQUID AND SOLID PARTICULATE MATTER FROM A GAS STREAM BY MEANS OF A FILTER MEDIUM; WHEREIN THE VELOCITY OF SAID GAS STREAM AT THE UPSTREAM FACE OF SAID FILTER MEDIUM IS IN THE RANGE OF FROM 300 TO 4,000 FEET PER MINUTE AND THE PRESSURE DROP ACROSS SAID FILTER MEDIUM IS IN THE RANGE OF FROM 7 TO 60 INCHES OF WATER; AND WHEREIN SAID FILTER MEDIUM IS IN THE FORM OF A MOVABLE, REPLACEABLE, POROUS, GAS-PERVIOUS MAT; A PORTION OF SAID MAT BEING MOVED INTO THE GAS STREAM, LOADED WITH PARTICULATE MATTER,MOVED OUT OF THE GAS STREAM AND A FRESH PORTION OF SAID MAT BEING MOVED INTO SAID GAS STREAM TO REPLACE THE SPENT PORTION, ALL WITHOUT INTERRUPTING THE FILTERING PROCESS; THE IMPROVEMENT WHICH COMPRISES: A. UTILIZING AS SAID FILTER MEDIUM A MAT COMPRISING AT LEAST ONE LAYER OF A FLEXIBLE RETICULATED ELASTOMERIC FOAM HAVING A VOID FRACTION OF AT LEAST 90%; B.PASSING SPENT FILTER MEDIUM INTO CLEANING MEANS AND THEREIN REMOVING TRAPPED PARTICULATE MATTER FROM SAID FILTER MEDIUM;AND C. THEREAFTER RETURNING THE CLEANED FILTER MEDIUM TO A POSITION IN SAID GAS STREAM FOR REUSE THEREIN.
Claim 2
Dependent Claim
196 words
IN A PROCESS FOR FILTERING MICRON AND SUBMICRON SIZE LIQUID AND SOLID PARTICULATE MATTER FROM A GAS STREAM BY MEANS OF A FILTER MEDIUM; WHEREIN THE VELOCITY OF SAID GAS STREAM AT THE UPSTREAM FACE OF SAID FILTER MEDIUM IS IN THE RANGE OF FROM 300 TO 4,000 FEET PER MINUTE AND THE PRESSURE DROP ACROSS SAID FILTER MEDIUM IS IN THE RANGE OF FROM 7 TO 60 INCHES OF WATER; AND WHEREIN SAID FILTER MEDIUM IS IN THE FORM OF A MOVABLE, REPLACEABLE, POROUS, GAS-PERVIOUS MAT; A PORTION OF SAID MAT BEING MOVED INTO THE GAS STREAM, LOADED WITH PARTICULATE MATTER,MOVED OUT OF THE GAS STREAM AND A FRESH PORTION OF SAID MAT BEING MOVED INTO SAID GAS STREAM TO REPLACE THE SPENT PORTION, ALL WITHOUT INTERRUPTING THE FILTERING PROCESS; THE IMPROVEMENT WHICH COMPRISES: A. UTILIZING AS SAID FILTER MEDIUM A MAT COMPRISING AT LEAST ONE LAYER OF A FLEXIBLE RETICULATED ELASTOMERIC FOAM HAVING A VOID FRACTION OF AT LEAST 90%; B.PASSING SPENT FILTER MEDIUM INTO CLEANING MEANS AND THEREIN REMOVING TRAPPED PARTICULATE MATTER FROM SAID FILTER MEDIUM;AND C. THEREAFTER RETURNING THE CLEANED FILTER MEDIUM TO A POSITION IN SAID GAS STREAM FOR REUSE THEREIN.
Claim 3
Dependent Claim
14 words
The improved process of claim 1 wherein said elastomeric foam is a polychloroprene foam.
Claim 4
Dependent Claim
15 words
The improved process of claim 1 wherein said elastomeric foam is a butadiene-acrylonitrile copolymer foam.
Claim 5
Dependent Claim
15 words
The improved process of claim 1 wherein said elastomeric foam is a glycol-phthalate polyester foam.
Claim 6
Dependent Claim
18 words
The improved process of claim 1 wherein said cleaning means comprises a combination of physical and chemical techniques.
Claim 7
Dependent Claim
17 words
The improved process of claim 1 wherein the cleaning and return of said filter medium is continuous.
Claim 8
Dependent Claim
21 words
The improved process of claim 1 wherein the cleaning and return of said filter medium is conducted in a batch-type operation.
Claim 9
Dependent Claim
22 words
The improved process of claim 1 wherein said elastomeric foam has a pore density of from 5 to 200 pores per inch.
Claim 10
Dependent Claim
22 words
The improved process of claim 8 wherein said elastomeric foam has a pore density of from 20 to 125 pores per inch.
Claim 11
Dependent Claim
21 words
The improved process of claim 1 wherein said elastomeric foam has a void fraction in the range of 90% to 99%.
Claim 12
Dependent Claim
21 words
The improved process of claim 10 wherein said elastomeric foam has a void fraction in the range of 95% to 99%.
Claim 13
Dependent Claim
14 words
The improved process of claim 1 wherein said elastomeric foam is a polyurethane foam.
Claim 14
Dependent Claim
21 words
The improved process of claim 12 wherein said polyurethane foam has a pore density of 5 to 200 pores per inch.
Claim 15
Dependent Claim
21 words
The improved process of claim 13 wherein said polyurethane foam has a pore density of 20 to 125 pores per inch.
Claim 16
Dependent Claim
13 words
The improved process of claim 12 wherein said polyurethane foam is fully reticulated.
Claim 17
Dependent Claim
21 words
The improved process of claim 15 wherein said polyurethane foam has a void fraction in the range of 90% to 99%.
Claim 18
Dependent Claim
21 words
The improved process of claim 16 wherein said polyurethane foam has a void fraction in the range of 95% to 99%.
Claim 19
Dependent Claim
15 words
The improved process of claim 1 wherein said cleaning means comprises a chemical cleaning technique.
Claim 20
Dependent Claim
14 words
The improved process of claim 18 wherein said cleaning means comprises a solvent wash.
Claim 21
Dependent Claim
14 words
The improved process of claim 18 wherein said cleaning means comprises a water wash.
Claim 22
Dependent Claim
16 words
The improved process of claim 20 wherein said water wash also contains a soap or detergent.
Claim 23
Dependent Claim
15 words
The improved process of claim 1 wherein said cleaning means comprises a physical cleaning technique.
Claim 24
Dependent Claim
14 words
The improved process of claim 22 wherein said physical cleaning technique comprises ultrasonic cleaning.
Claim 25
Dependent Claim
17 words
The improved process of claim 23 wherein said ultrasonic cleaning means comprises an ultrasonic bath containing detergent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |