US4530272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling contamination in a clean room
Assignee: International Business Machines Corp
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Filing: 1984-01-13
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Granted: 1985-07-23
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Expires: 2004-01-13
Abstract
Abstract A method is disclosed for controlling the concentration of airborne particulate contaminants in a clean room environment. Air under pressure is continually recirculated through the environment and filtered as it is circulating. Mixing of the filtered air is enhanced by imparting turbulence thereto sufficient to render the filtered air substantially homogenous. The particle count of the filtered air is sensed within the environment and the volume of air that is recirculated is controlled according to the sensed particle count to thereby maintain the particle count substantially at a preselectable concentration.
Inventors
- 👤 Konrad H. Stokes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:40
CPC Classifications
F; F24; F24F; F24F3/00; F24F3/12; F24F3/16; F24F3/167
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
A method for controlling the concentration of particulate contaminants in a clean room environment, said method comprising the steps of: supplying filtered air under pressure to the environment; enhancing mixing of the air after filtering by imparting turbulence thereto sufficient to render the filtered air substantially homogenous; sensing the particle count of the filtered air within the environment; and controlling the volume of air that is recirculated according to the sensed particle count for thereby maintaining the particle count substantially at a preselectable concentration.
Claim 2
Independent Claim
84 words
A method for controlling the concentration of particulate contaminants in a clean room environment, said method comprising the steps of: supplying filtered air under pressure to the environment; enhancing mixing of the air after filtering by imparting turbulence thereto sufficient to render the filtered air substantially homogenous; sensing the particle count of the filtered air within the environment; and controlling the volume of air that is recirculated according to the sensed particle count for thereby maintaining the particle count substantially at a preselectable concentration.
Claim 3
Dependent Claim
17 words
A method according to claim 1, including, during the enhancing step, using oscillating fans to impart turbulence.
Claim 4
Dependent Claim
27 words
A method according to claim 1, including the step of continually recirculating the air through the environment, and filtering the air at least once each recirculation cycle.
Claim 5
Dependent Claim
35 words
A method according to claim 1, including diverting the air under pressure into a selectable one of a plurality of flow paths while significantly restricting flow through the remaining flow paths to further enhance mixing.
Claim 6
Dependent Claim
36 words
A method according to claim 1, including repeatedly diverting the air under pressure, in alternating fashion, into one or the other of two flow paths which generally criss-cross the clean room environment from top to bottom.
Claim 7
Dependent Claim
31 words
A method according to claim 5, wherein as soon as either of the two flow paths is established, the air is diverted to the other flow path to further enhance mixing.
Claim 8
Independent Claim
80 words
A method for controlling the concentration of particulate contaminants in a clean room environment, said method comprising the steps of: providing to the environment air which is filtered and intentionally rendered sufficiently turbulent to thoroughly mix the air and make it substantially homogenous; sensing the particle count of the filtered air within the environment; and controlling the volume of air that is recirculated according to the sensed particle count for thereby maintaining the particle count substantially at a preselectable concentration.
Claim 9
Independent Claim
80 words
A method for controlling the concentration of particulate contaminants in a clean room environment, said method comprising the steps of: providing to the environment air which is filtered and intentionally rendered sufficiently turbulent to thoroughly mix the air and make it substantially homogenous; sensing the particle count of the filtered air within the environment; and controlling the volume of air that is recirculated according to the sensed particle count for thereby maintaining the particle count substantially at a preselectable concentration.
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) | 1988-07-22 | 1989-01-21 | 1989-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-22 | 1993-01-21 | 1993-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-22 | 1997-01-21 | 1997-07-23 | $7700.00 | Window Closed / Lapsed |