Refrigerant recovery system

• US 5,511,387 A
• Filed: 01/17/1995
• Issued: 04/30/1996
• Est. Priority Date: 05/03/1993
• Status: Expired due to Fees

• Current Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Original Assignee: Copeland Corporation LLC (Emerson Electric Company)
• Inventors: Tinsler, Theodore E.
• Primary Examiner(s): Sollecito, John M.
• Application Number:
  US08/373,466
• Time in Patent Office: 469 Days
• Field of Search: 62/79, 62/149, 62/292
• US Class Current: 62/292
• CPC Class Codes: B60H 1/00585 Means for monitoring, testing or servicing the air-conditioning
• CPC Class Codes: F25B 2345/002 Collecting refrigerant from a cycle
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant

Abstract

Two preferred embodiments of an improved refrigerant recovery system and method for recovering refrigerant from a separate system are disclosed whereby the first embodiment utilizes a closed-loop refrigeration system employing a portable storage tank to recover refrigerant from a separate system that needs to be serviced. The first embodiment recovers refrigerant from the separate system by placing a storage tank within an evaporator that is cooled by evaporator coils and evacuated by a vacuum pump. The vacuum pump is valved off and recovered refrigerant is directed to the storage tank from the separate system. None of the recovered refrigerant contacts the compressor of the recovery system and vacuum pump. An alternative to the first embodiment provides a booster pump in-line with the storage tank and the separate system for transferring any residual refrigerants into the storage tank. The second preferred embodiment includes a portable storage tank located within an insulation device This system employs two phases whereby during phase 1 primarily liquid refrigerant is directed to the storage tank. Once all of the liquid has been recovered and a predetermined pressure is reached in the storage tank, phase 2 is activated whereby primarily recovered gas is directed through the compressor and eventually dumped into the cooled storage tank. An alternative to this second embodiment provides a fluid sensor which automatically activates phase 2 when all of the liquid refrigerant has been recovered from the separate system and when the storage tank is at a predetermined pressure.

Claims

1. A refrigerant recovery system for recovering contaminated refrigerant from a refrigeration system, said refrigerant recovery system comprising:

storage means for receiving said contaminated refrigerant;

means for cooling the storage means, said means for cooling including an evaporator tank comprising heat exchange coils which substantially surround said storage means;

means for reducing the pressure within the storage means to a predetermined level, said means for reducing pressure including a vacuum pump positioned such that it is not in a direct flow path as defined between said refrigeration system and said storage means; and

valving means for selectively evacuating said storage means either alone or in combination with said direct flow path;

whereby the refrigerant recovery system is operable to receive and contain the recovered refrigerant within said storage means and is further operable to prevent said pump from being directly contaminated by said recovered refrigerant.

2. The system according to claim 1, wherein the means for cooling further includes:

condenser means for condensing refrigerant within the refrigerant recovery system.

3. The system according to claim 1, wherein the means for cooling includes heat exchange coils substantially surrounding said storage means, said means for cooling is operable to receive and cool the storage means to a predetermined low temperature.

4. The system according to claim 1, wherein the means for cooling is operable to cool the storage means to an inside temperature of zero degrees Fahrenheit.

5. The system according to claim 1, wherein the storage means is a pressure vessel portable and insertable within the means for cooling, said storage means further includes valve means for controlling the flow of refrigerant into said storage means.

6. The system according to claim 1, wherein said cooling means includes compressor means for compressing refrigerant contained in a closed-loop system, said compressor being isolated from direct contact with said contaminated refrigerant.

7. A portable closed-looped fluid recovery system for recovering fluid from an independent system, said closed-looped fluid recovery system having a compressor and further comprising:

a transportable storage structure for receiving recovered fluid from the independent system;

a first flowpath extending between the independent system and the storage structure;

means for cooling the storage to a predetermined temperature, said means for cooling comprising an evaporator housing that is connected to a closed-loop refrigeration circuit, said housing having evaporator coils that are operable to receive and surround said transportable storage structure;

a second flowpath connecting the storage structure and a means for reducing pressure, said second flow path defining a means to evacuate said storage structure independent of evacuating said first flow path; and

means for reducing the pressure within the storage structure to a predetermined level, said means for reducing pressure being connected directly to said storage structure and being independent of said means for cooling said storage structure, said means for reducing pressure being connected to a flow path other than said first flow path extending between said independent system and said storage structure;

whereby said closed-looped fluid recovery system is operable to receive and contain the recovered fluid within the storage structure while the recovered fluid avoids contact with said compressor and said means for reducing pressure.

8. The system according to claim 7, wherein the means for cooling the storage structure is an evaporator having heat exchange means surrounding said storage structure, said evaporator being operable to receive and cool the storage structure.

9. The system according to claim 7, wherein the means for reducing pressure is a vacuum pump, said vacuum pump being connected to said storage structure and being operable to reduce the pressure therein.

10. The system according to claim 7, wherein the storage structure is a removable storage tank capable of retaining recovered fluid and capable of being inserted within the means for cooling.

11. The system according to claim 7, further comprising a booster pump positioned to enhance the removal of fluid from the independent system.

12. A closed refrigerant recovery system for recovering refrigerant from a refrigeration unit, said closed refrigerant recovery system comprising:

a storage structure capable of being evacuated and receiving recovered refrigerant from the refrigeration unit;

a cooling device operable to receive the storage structure, and the cooling device further being operable to maintain the storage structure at a predetermined temperature while refrigerant is being recovered;

a condensing device for condensing refrigerant in the closed refrigerant recovery system;

a vacuum pump connected to the storage structure such that the vacuum pump is not in a direct flow path that extends between said refrigeration unit and said storage structure, the pump being operable to reduce the pressure within the storage structure;

an evaporator housing containing said cooling device and said storage structure and connected to said vacuum pump such that said recovered refrigerant does not contact said evaporator or said cooling device;

flow control means operable to control the flow of refrigerant into the storage structure, said flow control means comprising a first valve positioned between said storage structure and said vacuum pump and further comprising a second valve positioned in a line between said refrigeration unit and said storage structure, said first and second valves operable to selectively draw a vacuum on said storage structure and said line; and

a compressor located between the cooling device and condensing device;

whereby the closed refrigerant recovery system is configured to isolate the recovered refrigerant from the compressor and the vacuum pump.

13. The closed refrigerant recovery system according to claim 12, further comprising a portable transporting structure capable of transporting the closed refrigerant recovery system.