US5090972A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particulate abatement and environmental control system
Assignee: Enviro-Air Control Corp
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Filing: 1991-02-06
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Granted: 1992-02-25
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Expires: 2011-02-06
Abstract
Abstract Improved techniques are provided for improving the environment of hazardous material abatement personnel operating within an enclosed working area while conducting, for example, asbestos removal operations. A negative pressure is established within the working area by a portable air moving unit, which exhausts air from the working area to prevent hazardous material leakage. The exhausted air is filtered, a significant portion of the exhausted air is conditioned by a portable refrigeration, heating and dehumidification system, and the temperature controlled air is returned to the working area. An air diverter is provided for regulating the ratio of the discharged air to the returned and conditioned air in response to the sensed pressure level within the working area. The temperature of the working area is regulated, thereby substantially increasing worker productivity and reducing safety risks. The humidity level within the working area may either be lowered to reduce the curing time for hazardous material final encapsulation operations, or increased to reduce the airborne contaminant level during wet abatement operations. Leakage from the working area is preferably minimized, while the efficiency of the portable conditioning unit is maximized.
Inventors
- 👤 Joe C. Eller
- 👤 James E. Leavens
- 👤 Charles H. Wyatt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:43
CPC Classifications
B; B08; B08B; B08B15/00; B08B15/02; B08B15/026
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
168 words
A method of providing an improved temporary working environment during removal or encapsulation of hazardous particulate material from a working space substantially sealed from space exterior of the working space, the method comprising: powering one or more portable air moving units for exhausting air including hazardous particulate material from the defined working space and maintaining a negative pressure within the working space with respect to the space external of the working space; monitoring the level of negative pressure within the working space; filtering the exhausted air to remove the hazardous particulate material; discharging a first portion of the exhausted air to the space exterior of the working space; powering a portable conditioning unit to condition a second portion of the exhausted air, the second portion of the exhausted air being defined by the exhausted air less the discharged air; returning the conditioned air to the working space; and regulating the amount of the first portion of the exhausted air in response to the monitored level of negative pressure.
Claim 2
Independent Claim
168 words
A method of providing an improved temporary working environment during removal or encapsulation of hazardous particulate material from a working space substantially sealed from space exterior of the working space, the method comprising: powering one or more portable air moving units for exhausting air including hazardous particulate material from the defined working space and maintaining a negative pressure within the working space with respect to the space external of the working space; monitoring the level of negative pressure within the working space; filtering the exhausted air to remove the hazardous particulate material; discharging a first portion of the exhausted air to the space exterior of the working space; powering a portable conditioning unit to condition a second portion of the exhausted air, the second portion of the exhausted air being defined by the exhausted air less the discharged air; returning the conditioned air to the working space; and regulating the amount of the first portion of the exhausted air in response to the monitored level of negative pressure.
Claim 3
Dependent Claim
37 words
The method as defined in claim 1, further comprising: positioning one of the portable air moving units for drawing air from the working space through the portable conditioning unit and discharging conditioned air to the working space.
Claim 4
Dependent Claim
56 words
The method as defined in claim 1, wherein the step of powering the conditioning unit to condition the air comprises: powering a portable air cooling unit to cool the second portion of the exhausted air; and dehumidifying the second portion of the exhausted air to remove water and reduce the humidity level within the working space;
Claim 5
Dependent Claim
55 words
The method as defined in claim 3, further comprising: the step of dehumidifying the second portion of the exhausted air includes cooling the air to a temperature below its dew point to generate condensate from water vapor within the air conditioning unit; and spraying the condensate within the working space against the hazardous particulate material.
Claim 6
Dependent Claim
59 words
The method as defined in claim 3, further comprising: the step of dehumidifying the second portion of the exhausted air includes cooling the air to a temperature below its dew point to generate condensate from water vapor within the air conditioning unit; and spraying the condensate within the conditioned air to increase the humidity levels within the working space.
Claim 7
Dependent Claim
47 words
The method as defined in claim 3, further comprising: monitoring the temperature of air within the working space; monitoring the humidity level of air within the working space; and controlling the operation of the portable air conditioning unit in response to the monitored temperature and humidity levels.
Claim 8
Dependent Claim
74 words
The method as defined in claim 1, wherein the step of regulating the amount of the first portion of the exhausted air comprises: providing a movable air diverter for dividing the exhausted air into a discharged air stream and a conditioned air stream; powering a drive unit for controlling movement at the diverter; and automatically regulating operation of the drive unit in response to the monitored level of negative pressure within the working space.
Claim 9
Dependent Claim
51 words
The method as defined in claim 1, further comprising: automatically and continuously comparing the monitored negative pressure level with a predetermined safety pressure level; and automatically terminating operation of the one or more portable air moving units if the monitored negative pressure level is greater than the predetermined safety pressure level.
Claim 10
Dependent Claim
38 words
The method as defined in claim 1, wherein the step of powering the conditioning unit to condition the air comprises: heating the second portion of the exhausted air prior to returning the conditioned air to the working space.
Claim 11
Dependent Claim
73 words
The method as defined in claim 1, wherein the step of defining the working space comprises: defining the working space within a portion of a building; and sealing the working space from other space within the building such that less than 1% of the volume of the working space per minute leaks into the working space from the space external of the working space while negative pressure is maintained within the working space.
Claim 12
Dependent Claim
47 words
The method as defined in claim 10, further comprising: filtering the exhausted air at a position upstream from the portable air moving unit, such that both the discharged air and the conditioned air are filtered; and discharging the first portion of the exhausted air outside the building.
Claim 13
Independent Claim
179 words
An apparatus for improving the working environment of a working space substantially sealed from space external of the working space during hazardous particulate material abatement operations, the apparatus comprising: a portable air moving unit for exhausting air including hazardous particulate material from the working space and maintaining a negative pressure within the working space with respect to the space external of the working space; pressure sensing means for monitoring the level of negative pressure within the working space; a filter unit for filtering the exhausted air to remove the hazardous particulate material; a discharge duct for discharging a first portion of the filtered exhausted air to the space exterior of the working space; a portable conditioning unit for conditioning a second portion of the exhausted air, the second portion of the exhausted air being defined by the exhausted air less the discharged air; a return duct for returning the conditioned air to the working space; and air discharge control means for regulating the amount of the first portion of the exhausted air in response to the pressure sensing means.
Claim 14
Independent Claim
179 words
An apparatus for improving the working environment of a working space substantially sealed from space external of the working space during hazardous particulate material abatement operations, the apparatus comprising: a portable air moving unit for exhausting air including hazardous particulate material from the working space and maintaining a negative pressure within the working space with respect to the space external of the working space; pressure sensing means for monitoring the level of negative pressure within the working space; a filter unit for filtering the exhausted air to remove the hazardous particulate material; a discharge duct for discharging a first portion of the filtered exhausted air to the space exterior of the working space; a portable conditioning unit for conditioning a second portion of the exhausted air, the second portion of the exhausted air being defined by the exhausted air less the discharged air; a return duct for returning the conditioned air to the working space; and air discharge control means for regulating the amount of the first portion of the exhausted air in response to the pressure sensing means.
Claim 15
Dependent Claim
37 words
The method as defined in claim 12, further comprising: another portable air moving unit downstream of the portable air conditioning unit for pulling air through the air conditioning unit and discharging conditioned air into the working space.
Claim 16
Dependent Claim
50 words
The method as defined in claim 12, wherein the portable air conditioning unit comprises: a refrigeration unit including a refrigerant compressor, and expansion chamber, and an evaporation coil; and a refrigerant dehumidification unit for lowering the air temperature to below its dew point to generate condensate from the exhausted air.
Claim 17
Dependent Claim
25 words
The method as defined in claim 14, further comprising: spraying means for spraying the condensate within the working space and against the hazardous particulate material.
Claim 18
Dependent Claim
63 words
The method as defined in claim 12, further comprising: a temperature sensing unit for monitoring the temperature of air within the working space; a humidity sensing unit for monitoring the humidity level of air within the working space; and a control unit for controlling operation for the portable air conditioning unit in response to the temperature sensing unit and the humidity sensing unit.
Claim 19
Dependent Claim
42 words
The method as defined in claim 12, further comprising: a drive unit for controlling operation of the air discharge control means; and a drive control unit for automatically regulating the operation of the drive unit in response to the pressure sensing means.
Claim 20
Dependent Claim
72 words
The method as defined in claim 12, further comprising: a worker decontamination area external of and adjoining the working area, the decontamination area including wall means for substantially sealing the decontamination area from the environment external of the decontamination area, a shower area, a changing area, an entry door for worker access into the worker decontamination area, and an exit door for worker access from the decontamination area into the working area.
Claim 21
Dependent Claim
59 words
The method as defined in claim 12, further comprising: the working space in part being defined by permanent walls of a building; one or more permanent air ventilation ducts within the building for normally circulating air within the working space; and sealing means for preventing air movement between the one or more air ventilation ducts and the working space.
Claim 22
Dependent Claim
22 words
The method as defined in claim 12, wherein the portable conditioning unit further comprises: a heating unit for heating the conditioned air.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-24 | 1995-08-26 | 1996-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-24 | 1999-08-26 | 2000-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-24 | 2003-08-26 | 2004-02-25 | $7700.00 | Window Closed / Lapsed |