Portable, refrigerant recovery unit with a condenser bypass mode

Abstract

A portable, refrigerant recovery unit to transfer refrigerant from a refrigerant system to a storage tank. The recovery unit includes a condenser bypass mode controlled by a valving arrangement that can be employed when the cooling and phase change functions of the condenser are not needed such as commonly exist during the initial stages of the overall recovery process when the refrigerant from the system may already be in liquid phase. In such cases, the bypass mode avoids having the flow run through the tubing and other plumbing of the condenser which otherwise would add significant length (e.g., 2-3 feet or more) and resistance to the flow through the recovery unit for a faster overall recovery process. The valving arrangement of the recovery unit has a single control knob and can be positioned in a plurality of modes including off, condenser bypass, recovery, and condenser purge.

We claim: 
     
         1 . A portable, refrigerant recovery unit for transferring refrigerant from a refrigerant system to a storage tank, said recovery unit having an inlet line selectively connectable in fluid communication to said system and an outlet line selectively connectable in fluid communication to said storage tank,
 said recovery unit further including at least a compressor and a condenser and a valving arrangement to selectively establish at least first and second flow paths through the recovery unit from the inlet line thereof to the outlet line thereof with (a) said first flow path running from said inlet line to and through the compressor and to and through the condenser to said outlet line and (b) said second flow path bypassing said condenser and running from said inlet line to and through the compressor to said outlet line without running through the condenser.   
     
     
         2 . The recovery unit of  claim 1  wherein said first flow path runs in series from the inlet line to and through the compressor and the condenser in a first direction to said outlet line. 
     
     
         3 . The recovery unit of  claim 2  wherein said valving arrangement further selectively establishes a third flow path blocked from fluid communication with the inlet line and running within said recovery unit to and through the condenser in a second direction opposite to said first direction and to and through the compressor in said first direction to the outlet line to purge the condenser. 
     
     
         4 . The recovery unit of  claim 3  wherein said valving arrangement further selectively establishes an off position blocking flow between the inlet line and outlet line of the recovery unit. 
     
     
         5 . The recovery unit of  claim 1  wherein said first and second flow paths selectively run through at least one common valve having at least one inlet port and two outlet ports, said common valve being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through one of the outlet ports of the common valve and (b) the second position forming a portion of the second flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through the second of the outlet ports of the common valve. 
     
     
         6 . The recovery unit of  claim 5  wherein the two outlet ports of the common valve are in fluid communication with the inlet port and each other. 
     
     
         7 . The recovery unit of  claim 5  wherein said common valve is a ball valve having passages therethrough forming a T-shape having a stem and two arms with the inlet port at the stem of the T-shape and the outlet ports at the respective ends of the arms of the T-shape. 
     
     
         8 . The recovery unit of  claim 5  wherein said first and second flow paths selectively run through at least a second common valve having at least two inlet ports and one outlet port, said second common valve being positioned upstream of the compressor in both said first and second flow paths and being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing one of the inlet ports in fluid communication with the outlet line of the recovery unit through the outlet port of the second common valve and (b) the second position forming a portion of the second flow path and placing the second of the inlet ports in fluid communication with the outlet line of the recovery unit through the outlet port of the second common valve. 
     
     
         9 . The recovery unit of  claim 8  wherein the two inlet ports of the second common valve are in fluid communication with the outlet port and each other. 
     
     
         10 . The recovery unit of  claim 8  wherein said second common valve is a ball valve having passages therethrough intersecting orthogonally and respectively forming the two inlet ports and one outlet port. 
     
     
         11 . The recovery unit of  claim 8  wherein said second common valve is upstream of the first mentioned common valve in both said first and second flow paths and said first and second flow paths each run through the second common valve and the first mentioned common valve in the same direction. 
     
     
         12 . The recovery unit of  claim 1  wherein the first and second flow paths respectively run through the compressor in the same direction. 
     
     
         13 . A portable, refrigerant recovery unit for selectively transferring refrigerant from a refrigerant system to a storage tank in a recovery mode and a push/pull mode, said recovery unit having an inlet line and an outlet line, said storage tank having a vapor port and a liquid port with said inlet line being selectively connectable in fluid communication to said system and said outlet line being selectively connectable in fluid communication to the liquid port of said storage tank in said recovery mode and said inlet line being selectively connectable in fluid communication to the vapor port of said storage tank and said outlet line being selectively connectable in fluid communication to said system in said push/pull mode,
 said recovery unit further including at least a compressor and a condenser and a valving arrangement to selectively establish (i) at least a first flow path through the recovery unit from the inlet line thereof to the outlet line thereof in said recovery mode and (ii) a second flow path through the recovery unit from the inlet line thereof to the outlet line thereof in said push/pull mode with (a) said first flow path running from said inlet line to and through the compressor and to and through the condenser to said outlet line and (b) said second flow path bypassing said condenser and running from said inlet line to and through the compressor to said outlet line without running through the condenser.   
     
     
         14 . The recovery unit of  claim 13  wherein said first flow path runs in series from the inlet line to and through the compressor and the condenser in a first direction to said outlet line. 
     
     
         15 . The recovery unit of  claim 13  wherein the first and second flow paths respectively run in the same direction through the compressor. 
     
     
         16 . The recovery unit of  claim 13  wherein said valving arrangement further selectively establishes an off position blocking flow between the inlet line and outlet line of the recovery unit in said recovery and push/pull modes. 
     
     
         17 . The recovery unit of  claim 13  wherein said first and second flow paths selectively run through at least one common valve having at least one inlet port and two outlet ports, said common valve being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through one of the outlet ports of the common valve and (b) the second position forming a portion of the second flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through the second of the outlet ports of the common valve. 
     
     
         18 . The recovery unit of  claim 17  wherein said first and second flow paths selectively run through at least a second common valve having at least two inlet ports and one outlet port, said second common valve being positioned upstream of the compressor in both said first and second flow paths and being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing one of the inlet ports in fluid communication with the outlet line of the recover/unit through the outlet port of the second common valve and (b) the second position forming a portion of the second flow path and placing the second of the inlet ports in fluid communication with the outlet line of the recovery unit through the outlet port of the second common valve 
     
     
         19 . The recovery unit of  claim 17  wherein said second common valve is upstream of the first mentioned common valve in both the first and second flow paths and said first and second flow paths each run through the second common valve and the first mentioned common valve in the same direction