Refrigerant recovery system

A device for recovering contaminated refrigerant from a refrigeration system comprising:

• a compressor for compressing refrigerant that is delivered thereto, said compressor having an inlet and an outlet;
• a storage tank for containing contaminated refrigerant;
• a first conduit connected to said refrigeration system and said storage tank;
• a fluid sensor located within said first conduit for sensing the presence of liquid and or gaseous refrigerant as it is being recovered from the refrigeration system, said sensor operable to produce an electrical signal indicative of liquid refrigerant being recovered;
• a second conduit connected to said first conduit and to said compressor;
• a condenser connected to the outlet of said compressor;
• an expansion member located between said condenser and said storage tank;
• a third conduit between said storage tank and said inlet of said compressor;
• a first electrically operated valve located in said third conduit for controlling the flow of refrigerant therein;
• a second electrically operated valve located in said second conduit for controlling the flow of refrigerant therein;
• a third electrically operated valve located between said condenser and said storage tank for controlling the flow of refrigerant therebetween;
• and
• an ambient temperature signal producing member connected to each said valve for controlling the operation of the device.

An automatic refrigerant recovery system having a refrigerant tank volume fill sensor member, said system comprising:

• a recovery compressor powered by an electrical power source;
• a refrigerant storage tank for containing recovered refrigerant;
• a volume fill sensor member including a float switch contained in said refrigerant storage tank, said switch being normally closed and producing a first signal when said tank is less than approximately 80% filled in volume with recovered refrigerant, said switch opening and producing a second signal when said tank is approximately 80% filled in volume with recovered refrigerant;
• an electrical circuit including said float switch and a relay that is normally closed which causes an electrical connection between said recovery compressor and said power source;
• a timer connected to said electrical circuit for delaying the activation of a vapor recovery mode of operation;
• and
• a temperature sensor that produces signals indicative of the ambient temperature, the sensor connected to the timer to control activation of the vapor recovery mode of operation.

A refrigerant recovery system comprising:

• a recovery compressor having a suction side and a discharge side;
• a condenser connected to said compressor;
• an insulated recovery tank for storing recovered refrigerant;
• a liquid vapor control unit producing a first signal for operating said recovery system in a first phase a liquid recovery and for producing a second signal for operating said recovery system in a second phase of vapor recovery;
• an external pressure regulating device located between the recovery tank and the suction side of the compressor for maintaining the discharge pressure of the compressor by restricting the flow of refrigerant to the suction side of the compressor;
• a delay device connected to the liquid vapor control unit for a delay period that is sufficient to ensure that there is insufficient liquid being recovered by the recovery system so as to not damage the compressor;
• and
• a sensor for measuring ambient temperature, the sensor electrically connected to the delay device for operating the recovery system in the first phase for a time period that tis proportional to the ambient temperature.

A refrigerant recovery system comprising:

• a recovery compressor having a suction side and a discharge side;
• a condenser connected to said compressor;
• an insulated recovery tank for storing recovered refrigerant;
• a controller operable to produce a signal indicative of liquid refrigerant being recovered in order to maintain a first phase of liquid recovery;
• a timer device electrically connected to the controller for initiating a second phase of vapor recovery after the controller no longer produces said signal;
• and
• a sensor for measuring ambient temperature, the sensor electrically connected to the timer device for operating the recovery system in the first phase for a time period that is proportional to the ambient temperature.

A device for recovering contaminated refrigerant from a refrigeration system comprising:

• a compressor for compressing refrigerant that is delivered thereto, said compressor having an inlet and an outlet;
• a storage tank for containing contaminated refrigerant;
• a first conduit connected to said refrigeration system and said storage tank;
• a fluid sensor located within said first conduit for sensing the presence of liquid and or gaseous refrigerant as it is being recovered from the refrigeration system;
• a second conduit connected to said first conduit and to said compressor;
• a condenser connected to the outlet of said compressor;
• an expansion member located between said condenser and said storage tank;
• a third conduit between said storage tank and said inlet of said compressor;
• a first electrically operated valve located in said third conduit for controlling the flow of refrigerant therein;
• a second electrically operated valve located in said second conduit for controlling the flow of refrigerant therein;
• a third electrically operated valve located between said condenser and said storage tank for controlling the flow of refrigerant therebetween;
• a timing member for activating said device into a pump-down mode of operation;
• and
• a thermistor that senses ambient temperatures and produces a signal that is indicative of the sensed ambient temperature, said thermistor being electrically connected to said timing member to control said valves.

An automatic refrigerant recovery system having a refrigerant tank volume fill sensor member, said system comprising:

• a recovery compressor powered by an electrical power source;
• a refrigerant storage tank for containing recovered refrigerant;
• a volume fill sensor member including a float switch contained in said refrigerant storage tank, said switch being normally closed and producing a first signal when said tank is less than approximately 80% filled in volume with recovered refrigerant, said switch opening and producing a second signal when said tank is approximately 80% filled in volume with recovered refrigerant;
• an electrical circuit including said float switch and a relay that is normally closed which causes an electrical connection between said recovery compressor and said power source;
• a fluid sensor that is external to the storage tank for sensing the presence of liquid refrigerant recovered by the automatic refrigerant recovery system;
• and
• a temperature sensor located within the electrical circuit, the sensor being operable to produce a third signal indicative of the ambient temperature for controlling the performance of the recovery system.