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coupled through an evaporator and through a solenoid valve to the refrigeration system from which refrigerant is to be withdrawn, and an output coupled through a condenser to a refrigerant storage container.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.

Refrigerant recovery and purification system

A system for recovering, purifying and recharging refrigerant in a refrigeration system comprises a refrigerant compressor having an input connected through an evaporator and a recovery control valve to a refrigeration system from which refrigerant is to be recovered, purified and recharged. A condenser is connected to the output of the compressor in heat exchange relation with the evaporator for liquifying refrigerant from the compressor output. Refrigerant liquified in the condenser is fed to a first port of a refrigerant storage container. During a purification cycle, refrigerant is circulated from a second port of the refrigerant storage container in a closed path through a circulation valve and a filter for removing water and other contaminants, and then returned to the first container port. The refrigeration system from which refrigerant has been recovered is evacuated to atmosphere through a vacuum valve. Following such evacuation, the second port of the refrigerant storage container is connected through a recharging valve to the refrigeration of system for feeding refrigerant from the storage container to the refrigeration system, and thereby recharging the refrigeration system for normal use.

Refrigerant recovery, purification and recharging system

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.

Refrigerant recovery system

A refrigerant recovery and purification system (10) for recovering refrigerant from a heat pump, air conditioner, or other vapor compression refrigerant system into a storage tank while concurrently purifying the recovered refrigerant of impurities and contaminates. The refrigerant recovery and purification system comprises a pair of accumulators (32), (34) connected in line between the compressor (12) and the refrigerant system being evacuated. The output of compressor is then connected to a heat exchanger (42), (46) positioned within each of the accumulators (32), (34). The output of the heat exchangers (42), (46) are then connected to a condenser (50). The accumulators (32), (34) having the heat exchangers (42), (46) positioned therein, function to distill the refrigerant flowing therethrough to separate the oil, together with the impurities and contaminates normally contained in the refrigerant, thereby purifying the refrigerant being evacuated.

Refrigerant recovery and purification system.

A microprocessor provides a diagnostic capability, and includes tables of acceptable values of parameters, such as air discharge temperature, suction pressure, etc., for different automobile makes and air conditioner types; provision is made for adjusting the acceptable ranges of such values due to one or more ambient factors, of which ambient relative humidity may be one. The microprocessor, after determining whether the air conditioning system has a cycling or a non-cyling clutch and providing a valid set of actual system values based on whether the clutch is cycling or non-cycling, compares actual values to acceptable value ranges of the air conditioner operating values, and displays possible causes of air conditioner malfunction on a video screen. Self-testing of both the microprocessor and associated electrical elements, and of mechanical elements such as conduits, valves and a scale is performed. the operator may command the microprocessor to display, in smaller print, a relatively large volume of detailed instrucitonal material dealing with specific checking procedures or repair. An air conditioner charging station withdraws refrigerant from an air conditioner, reclaims it by removing certain materials, and returns the reclaimed refrigerant to the same air conditioner from which it was withdrawn, and also provides new, make-up refrigerant to the air conditoner, in the amount necessary to make a full charge.

System and method for diagnosing the operation of air conditioner systems

A servicing device is shown for recovering and charging refrigerant in a cooling system of the type having a compressor for circulating compressible refrigerant in a closed, pressurized system between a condenser and an evaporator to provide a cooling effect. The servicing device includes a storage container which has a fill port which is adapted to be connected by a fluid conduit to the closed, pressurized system being serviced. Heat exchange coils located within the container are cooled by a heat exchange system to create a low pressure atmosphere within the container and draw refrigerant from the closed, pressurized system into the container. The heat pump system has reversible valves to reverse the flow of auxiliary refrigerant being circulated through the system. When the refrigerant circulation is reversed, the heat exchange coils located within the storage container heats the container to create a relatively higher pressure atmosphere to charge refrigerant from the storage container into the closed, pressurized system.

Gary D. Starnes

Papers

Refrigerant recovery and charging device