US4938031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigerant recovery and purification system
Assignee: SPX Technologies Inc
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Filing: 1989-03-03
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Granted: 1990-07-03
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Expires: 2009-03-03
Abstract
Abstract A refrigerant recovery system which includes a compressor having an input coupled through an evaporator and through a solenoid valve to the refrigeration system from which refrigerant is to be withdrawn, and an output coupled through a condenser to a refrigerant storage container. The evaporator and condenser are contained within a closed cylindrical canister for heat exchange and oil separation, the canister having an oil drain valve in the bottom. The refrigerant storage container is carried by a scale having a limit switch coupled to control electronics to prevent or terminate further refrigerant recovery when the container is full. The entire system, including the control electronics, is mounted on a two-wheel hand truck to facilitate transport to a job site such as a building air conditioning or heat pump system. Apparatus for purifying recovered refrigerant includes a replaceable core filter/dryer, and a liquid pump for circulating refrigerant from the liquid port of the storage container through the core and then to the container vapor port. A differential pressure gauge is connected across the filter/dryer to indicate need for core replacement. A moisture indicator displays water concentration in the refrigerant. The purification apparatus may be either separate from or combined with the recovery system.
Inventors
- 👤 Kenneth W. Manz
- 👤 Roger D. Shirley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:00
CPC Classifications
F; F25; F25B; F25B45/00; F25B2345/00; F25B2345/002; F25B2345/005; F25B2345/0052; F25B2345/007; Y; Y02; Y02B; Y02B30/00; Y02B30/52
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
217 words
A self-contained portable refrigerant recovery system comprising a support; a refrigerant compressor mounted on said support and having an inlet and an outlet; refrigerant evaporator means for adding heat to and evaporating refrigerant passing therethrough; refrigerant condenser means for extracting heat from and condensing refrigerant passing therethrough; means including a first pressure sensor for connecting said compressor inlet through said evaporator means to a refrigeration system from which refrigerant is to be recovered, said first pressure sensor providing an electrical signal as a function of pressure of refrigerant to said evaporator means; means including said condenser means for connecting said compressor outlet to a refrigerant storage container; means responsive to content of said container for sensing impending overfill of said container; and automatic refrigerant recovery control means mounted on said support and comprising a solenoid control means mounted on said support and comprising a solenoid valve for selectively admitting refrigerant to said evaporator means, means responsive to operator actuation for selectively applying electrical power to said solenoid valve and said compressor, means responsive to said first pressure sensor for removing power from said solenoid valve and said compressor, and means responsive to said content-responsive means for inhibiting application of electrical power to said solenoid valve and said compressor when said container is in an impending overfill condition.
Claim 2
Dependent Claim
217 words
A self-contained portable refrigerant recovery system comprising a support; a refrigerant compressor mounted on said support and having an inlet and an outlet; refrigerant evaporator means for adding heat to and evaporating refrigerant passing therethrough; refrigerant condenser means for extracting heat from and condensing refrigerant passing therethrough; means including a first pressure sensor for connecting said compressor inlet through said evaporator means to a refrigeration system from which refrigerant is to be recovered, said first pressure sensor providing an electrical signal as a function of pressure of refrigerant to said evaporator means; means including said condenser means for connecting said compressor outlet to a refrigerant storage container; means responsive to content of said container for sensing impending overfill of said container; and automatic refrigerant recovery control means mounted on said support and comprising a solenoid control means mounted on said support and comprising a solenoid valve for selectively admitting refrigerant to said evaporator means, means responsive to operator actuation for selectively applying electrical power to said solenoid valve and said compressor, means responsive to said first pressure sensor for removing power from said solenoid valve and said compressor, and means responsive to said content-responsive means for inhibiting application of electrical power to said solenoid valve and said compressor when said container is in an impending overfill condition.
Claim 3
Dependent Claim
22 words
The system set forth in claim 1 wherein said content-responsive means includes a scale mounted on said support and supporting said container.
Claim 4
Dependent Claim
53 words
The system set forth in claim 2 wherein said scale comprises a platform movably carried by said support, means resiliently bearing weight of said container and platform with respect to said support, and a limit switch for sensing predetermined motion of said resiliently-bearing means corresponding to a full condition at said refrigerant container.
Claim 5
Dependent Claim
27 words
The system set forth in claim 1 wherein said content-responsive means further comprises a second pressure sensor for sensing vapor pressure of refrigerant stored in said container.
Claim 6
Dependent Claim
91 words
The system set forth in claim 1 wherein said first pressure sensor and said content-responsive means comprise respective electrical switch means; and wherein said control means comprises start switch means responsive to operator actuation, control relay means connected in series with said start switch means, said first pressure sensor switch means and said content-responsive switch means across a source of electrical power, first relay switch means connected across said start switch means, and second relay switch means for connecting said source of electrical power to said compressor and said solenoid valve.
Claim 7
Dependent Claim
22 words
The system set forth in claim 5 further comprising a lamp connected across said content-responsive switch means for indicating conductive condition thereof.
Claim 8
Dependent Claim
28 words
The system set forth in claim 4 wherein said wheeled support comprises a two-wheel hand truck having a frame on which the remainder of said system is mounted.
Claim 9
Dependent Claim
20 words
The system set forth in claim 4 further comprising a check valve connected between said condenser means and said container.
Claim 10
Dependent Claim
106 words
The system set forth in claim 1 for a refrigerant storage container having separate first and second ports, said compressor outlet being operatively connected to said first port; and wherein said system further comprises filter/dryer means for removing water from refrigerant passing therethrough, pump means, means for connecting said filter-dryer means and said pump means to said ports to circulate liquid refrigerant in a closed path from said second port through said filter/dryer means and said pump means to said first port, means for indicating water concentration in refrigerant in said path, and means for operating said pump means independently of said automatic recovery control means.
Claim 11
Dependent Claim
28 words
The system set forth in claim 1 wherein said wheeled support comprises a two-wheel hand truck having a frame on which the remainder of said system in mounted.
Claim 12
Dependent Claim
27 words
The system set forth in claim 9 wherein said support comprises a two-wheel hand truck having a frame on which the remainder of said system in mounted.
Claim 13
Dependent Claim
26 words
The system set forth in claim 1 wherein said container has an open internal volume, said condenser means connecting said compressor outlet to said internal volume.
Claim 14
Dependent Claim
211 words
A self-contained portable refrigerant recovery system comprising a support; a refrigerant compressor mounted on said support and having an inlet and an outlet; refrigerant evaporator means for adding heat to and evaporating refrigerant passing therethrough; means including a first pressure sensor for connecting said compressor inlet through said evaporator means to a refrigeration system from which refrigerant is to be recovered, said first pressure sensor providing an electrical signal as a function of pressure of refrigerant to said evaporator means; a refrigerant storage container having an open internal volume; means including refrigerant condenser means for extracting heat from and condensing refrigerant passing therethrough connecting said compressor outlet to said internal volume; means responsive to content of said container for sensing impending overfill of said container; and automatic refrigerant recovery control means mounted on said support and comprising a solenoid valve for selectively admitting refrigerant to said evaporator means, means responsive to operator actuation for selectively applying electrical power to said solenoid valve and said compressor, means responsive to said first pressure sensor for removing power from said solenoid valve and said compressor, and means responsive to said content-responsive means for inhibiting application of electrical power to said solenoid valve and said compressor when said container is in an impending overfill condition.
Claim 15
Dependent Claim
211 words
A self-contained portable refrigerant recovery system comprising a support; a refrigerant compressor mounted on said support and having an inlet and an outlet; refrigerant evaporator means for adding heat to and evaporating refrigerant passing therethrough; means including a first pressure sensor for connecting said compressor inlet through said evaporator means to a refrigeration system from which refrigerant is to be recovered, said first pressure sensor providing an electrical signal as a function of pressure of refrigerant to said evaporator means; a refrigerant storage container having an open internal volume; means including refrigerant condenser means for extracting heat from and condensing refrigerant passing therethrough connecting said compressor outlet to said internal volume; means responsive to content of said container for sensing impending overfill of said container; and automatic refrigerant recovery control means mounted on said support and comprising a solenoid valve for selectively admitting refrigerant to said evaporator means, means responsive to operator actuation for selectively applying electrical power to said solenoid valve and said compressor, means responsive to said first pressure sensor for removing power from said solenoid valve and said compressor, and means responsive to said content-responsive means for inhibiting application of electrical power to said solenoid valve and said compressor when said container is in an impending overfill condition.
Claim 16
Dependent Claim
73 words
The system set forth in claim 13 further comprising filter/dryer means for removing water from refrigerant passing therethrough, pump means, means for connecting said filter/dryer means and said pump means to said container to circulate refrigerant in a closed path through said filter/dryer means from and to said container, means for indicating water concentration in refrigerant in said path, and means for operating said pump means independently of said automatic recovery control means.
Claim 17
Dependent Claim
22 words
The system set forth in claim 14 wherein said content-responsive means includes a scale mounted on said support and supporting said container.
Claim 18
Dependent Claim
28 words
The system set forth in claim 15 wherein said wheeled support comprises a two-wheel hand truck having a frame on which the remainder of said system in mounted.
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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) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |