Apparatus for maximizing refrigeration capacity

Claim 1

A compression type refrigeration system, comprising: an evaporator, a compressor, a condenser, a refrigerant receiver and conduit means interconnecting the same in a single closed loop for circulating refrigerant therethrough, the conduit means including a first conduit for circulating a flow of refrigerant from the receiver to the evaporator and a second conduit for circulating a return flow of refrigerant gas from the evaporator to the receiver solely through the compressor and the condenser for condensation by the condenser at a first pressure directly related to the head pressure at the compressor; a variable flow expansion valve in the first conduit adjacent the evaporator for expanding the flow of refrigerant into the evaporator; a centrifugal pump in the first conduit adjacent the receiver, the pump being adapted continuously during operation of the compressor to increase the pressure of the condensed refrigerant in the first conduit by a generally constant increment of pressure of at least five pounds per square inch to provide the refrigerant with a second pressure greater than the first pressure by the amount of said increment, the second pressure being sufficient to suppress flash gas and feed a completely condensed liquid refrigerant to the expansion valve, the first conduit circulating the refrigerant solely through the pump; motor means for the pump; and a magnetic pump drive connecting the motor means to the pump to drive the same, whereby the pressure and the temperature of the refrigerant at the outlet of the condenser can be permitted to vary solely in response to ambient conditions at the condenser, and the pressure at the outlet of the condenser is substantially equal to the vapor pressure of the refrigerant.