Refrigerant recovery, purification and recharging system and method

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. The purification cycle may be initiated either automatically upon initiation of a vacuum cycle, or by an operator independently of the vacuum cycle. A recharging control valve is coupled to the second port of the refrigerant storage container for selectively feeding fresh refrigerant from the storage container to the refrigeration system under service during a recharging cycle.