Abstract: A refrigerant recovery system that includes a refrigerant accumulator having an inlet port for connection to the liquid port of equipment from which refrigerant is to be recovered, a vapor outlet port connected to the inlet of a refrigerant compressor, and a liquid outlet port. A valve connects the liquid outlet port of the accumulator to the inlet of a liquid refrigerant pump, which has an outlet for connection to a refrigerant storage container. A liquid refrigerant sensor is coupled to the accumulator and responsive to presence of liquid refrigerant within the accumulator for operating the valve and thereby connecting the accumulator liquid outlet port to the liquid pump. A second valve is responsive to the liquid refrigerant sensor for connecting the compressor outlet to the vapor port of refrigeration equipment under service.

Abstract: A refrigerant recovery system includes a compressor and an evaporator connected to the compressor inlet for evaporating refrigerant passing therethrough to the compressor inlet from refrigerant equipment under service. A sensor is coupled to the system input for detecting presence of liquid phase refrigerant. A valve is connected to the compressor inlet in parallel with the evaporator for bypassing refrigerant from the evaporator to the compressor inlet when the sensor indicates that liquid refrigerant is absent at the system input. The liquid refrigerant sensor takes the form of an open canister between the system input and the evaporator, and a liquid level sensor coupled to the canister for sensing level of liquid refrigerant collected within the canister. A solenoid valve is connected in parallel with the evaporator, and is responsive to the liquid level sensor for opening the valve and bypassing the evaporator in the absence of liquid refrigerant within the canister.

Abstract: A refrigerant recovery system that includes a refrigerant accumulator having an inlet port for connection to the liquid port of equipment from which refrigerant is to be recovered, a vapor outlet port and a liquid outlet port. The liquid outlet port of the accumulator is connected to the inlet of a liquid refrigerant pump, which has an outlet for connection to a refrigerant storage container. A valve is responsive to pressure differential between the liquid refrigerant pump and the accumulator for operatively connecting the accumulator vapor outlet port to the inlet of a compressor. Thus, operation of the compressor functions to draw refrigerant from the equipment under service into the accumulator by reducing pressure within the accumulator, while the liquid pump operates to pump liquid refrigerant collected with the accumulator directly to the refrigerant storage container bypassing the compressor. The valve limits pressure differential across the liquid pump.

Abstract: A refrigerant handling system that includes a liquid refrigerant storage container and a pump for feeding refrigerant in liquid phase to the container so that any air in the container or carried by the circulating refrigerant is captured within the container over the refrigerant. A bulb containing a reference refrigerant (R12) is positioned in heat transfer relation with refrigerant fed to the container. A pressure gauge is coupled to the bulb and calibrated to indicate saturation temperature of the reference refrigerant, and thereby reflect actual temperature of refrigerant in the container. A differential pressure gauge has separate scales for multiple refrigerant types (R22, R134a, R500, R502) to indicate apparent refrigerant temperature as a function of any bulb/container pressure differential. A valve is coupled to the container for venting air therefrom when apparent refrigerant temperature exceeds actual refrigerant temperature for the specific refrigerant type under service.

Abstract: In a combined recovery, purification and recharging system, a refrigerant compressor has an inlet coupled to a recovery control valve for connection to a refrigeration system under service from which refrigerant is to be recovered, purified and recharged into the system. The compressor outlet is connected to a first port of a refrigerant storage container. A filter for removing contaminants from refrigerant is coupled to a circulation control valve for selectively circulating refrigerant in a closed path during a purification cycle from a second port of the container through the filter back to the first port of the container. A vacuum pump is coupled to a vacuum control valve for selective connection to the refrigeration system under service during a vacuum cycle for evacuating the system under service to atmosphere. A pressure sensor is connected to the vacuum pump for automatically terminating vacuum pump operation when pressure in the system under service is below a preselected low-pressure threshold.

Abstract: Apparatus for identifying and distinguishing between at least two different types of refrigerant includes a sample container having a fixed internal volume. Refrigerant to be tested is selectively admitted into the container in vapor phase, vapor pressure of refrigerant within the container is measured, and admission of refrigerant into the container is terminated when the vapor pressure of refrigerant contained therein reaches a preselected level. A sensor and associated electronics are coupled to the container for determining type of refrigerant vapor in the container as a function of one or more selected properties of the refrigerant, and indicating such refrigerant type to the operator.

Abstract: A refrigerant handling system that includes a compressor and a plurality of refrigerant system components connected in series between a refrigerant source, such as a system under service, and a refrigerant storage container. To clear a selected system component of refrigerant, such as a refrigerant filter or a refrigerant condenser, a valve is connected between the selected component and the compressor. The valve has multiple ports and valve positions, in one of which refrigerant is fed through the selected component to the storage container in normal operation, and in another of which the selected component is isolated from the storage container and connected to the pump inlet for drawing refrigerant from the component and feeding such refrigerant directly to the container. A check valve cooperates with the multi-port valve to isolate the selected component from the storage container during the clearing mode of operation.

Abstract: A system for servicing refrigeration equipment having at least one service fitting of first predetermined configuration includes devices for recovering, purifying and/or recharging refrigerant within such equipment. A manifold includes a first refrigerant hose or conduit having an end coupling for releasable connection to the service fitting of the equipment under service and a second refrigerant hose or conduit having an end coupling for selective releasable connection to service fittings on each of the refrigerant service devices. Each of the first and second couplings includes facility for automatically sealing the associated conduit upon disconnection from the fittings, and thereby sealingly retaining refrigerant within the conduits.

Abstract: A refrigerant handling system in accordance with the present invention includes a closed liquid refrigerant storage container and a pump for feeding refrigerant in liquid phase to the container so that any air carried by the circulating refrigerant is captured in the container over the refrigerant. A differential pressure gauge has a first input that receives a fluid pressure signal which varies as a function of saturation pressure of refrigerant in liquid phase fed to the container, and a second input that receives an associated fluid pressure signal as a function of air pressure within the closed container volume. An indicator dial on the gauge displays pressure differential between the refrigerant saturation pressure and the container vapor pressure at the first and second gauge inputs for observation by an operator. A valve is coupled to the container for venting air from the container when such pressure differential exceeds a preselected threshold.

Abstract: A refrigerant handling system that includes a compressor having an inlet and an outlet, a condenser for withdrawing heat from and at least partially condensing refrigerant passing therethrough, and a compressor oil separator connected between the compressor outlet and the condenser for separating oil from refrigerant passing to the condenser. The compressor oil separator takes the form of a closed canister having an open internal volume, a vapor inlet and a vapor outlet at an upper portion of the canister, and an oil drain at a lower portion of the canister. A refrigerant coil is mounted externally of the canister in heat exchange relationship with the canister sidewall. The vapor inlet, vapor outlet and refrigerant coil are connected in series between the compressor outlet and the condenser coil such that heat of refrigerant passing through the coil heats the canister internal volume to prevent condensation of refrigerant therein.

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 refrigeant 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.

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.

Abstract: A system for purification of refrigerant within a storage container includes a filter/dryer for removing contaminants' from refrigerant passing therethrough, and a refrigerant pump connected to the storage container to circulate refrigerant in a closed path from the container through the filter/dryer and return the refrigerant to the container. The system configuration is such that the refrigerant is in liquid phase in at least a portion of the closed path. A pressure-differential valve has an inlet coupled to a purge port on the container for receiving air captured within the container. Container air pressure at the valve inlet is fed to one side of a flexible diaphragm. Circulating liquid refrigerant is passed in heat transfer contact with a sealed enclosure containing liquid refrigerant, so that the refrigerant within the enclosure is at saturation pressure and acts on the opposing side of the diaphragm in conjunction with a valve spring.

Abstract: A system for servicing refrigeration equipment having at least one service fitting of first predetermine configuration includes devices for recovering, purifying and/or recharging refrigerant within such equipment. A manifold includes a first refrigerant hose or conduit having an end coupling for releasable connection to the service fitting of the equipment under service and a second refrigerant hose or conduit having an end coupling for selective releasable connection to service fittings on each of the refrigerant service devices. Each of the first and second couplings includes facility for automatically sealing the associated conduit upon disconnection from the fittings, and thereby sealingly retaining refrigerant within the conduits.

Abstract: A refrigerant recovery system that includes a compressor having a inlet connected to a refrigeration system from which refrigerant is to be recovered, and an outlet connected through a condenser to a refrigerant storage container. The condenser includes multiple condenser sections, preferably in an integral assembly having parallel independant refrigerant flow paths. Valves alternately and selectively connect the compressor outlet through the several condenser sections to corresponding storage containers, such that differing refrigerants are fed to associated containers through correponding condenser sections without substantial intermixing or contamination.

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.

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.

Abstract: 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.

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.

Abstract: Apparatus for service and recharge of refrigeration equipment, with particular application to automotive air conditioning equipment. A vacuum pump, and oil and refrigerant charge containers are housed within a portable enclosure and configured for selective connection by electrically operated solenoid valves to refrigeration equipment under service. The refrigerant and oil containers are carried by a scale which provides electrical outputs signals as a function of weight of refrigerant and oil remaining in the containers. A microprocessor-based controller receives the scale signals and control signals from an operator panel for automatically cycling through vacuum, oil charge and refrigerant charge stages in a programmed mode of operation. The microprocessor-based controller includes facility for operator programming of the vacuum time and oil and refrigerant charge quantities, and for self- or operator-implemented diagnostics. Operating conditions and stages are displayed at all times to the operator.