Patent ID: 8359873

Claim:
A method of operating a refrigerant system having a compressor, a condenser, an expansion device, an evaporator and a suction modulation valve, comprising the steps of: operating the system in a normal conventional mode of operation to provide refrigerant flow through the evaporator at a normal rate determined by a thermal demand on the refrigerant system; and periodically, substantially and intermittently increasing the flow of refrigerant through the evaporator such that the flow rate exceeds the normal flow rate to thereby flush out lubricant that has been entrained in the evaporator or suction line wherein said step of increasing the refrigerant flow is accomplished by first throttling one of the expansion device and the suction modulation valve and unthrottling the other of the expansion device and the suction modulation valve to temporarily build up pressure in the condenser and then unthrottling the throttled one of the expansion device and the suction modulation valve to provide a blast of refrigerant through the evaporator.