Abstract: A circuit for recovering refrigerant from a disabled refrigeration unit combines a vacuum pump, vapor pump or compressor in series with a compressor for drawing gaseous refrigerant from the disabled unit. The series arrangement of the vacuum source and the compressor provides approximately -29 inches of mercury at the suction side of the vacuum source. A condensor in series with the compressor converts the gaseous refrigerant into a liquid refrigerant and a storage tank in series with the condenser receives liquid refrigerant from the condenser. In one preferred arrangement a valve system connected in series between the condenser and the storage tank allows the storage tank to be disconnected from the circuit without release of refrigerant from the tank to the atmosphere. The circuit may also include a coil in parallel with the condenser and the compressor and helically disposed around the storage tank for cooling the storage tank.

Abstract: An improved centrifugal refrigeration system having an elongated rotatably supported shaft with means to rotate the shaft, a condenser unit affixed to and rotated with the shaft, the condenser unit having a tubular member coiled about the shaft in a path beginning at a condenser unit inlet point at a first radius from the shaft and increasing as it is coiled about the shaft to an outlet point at a greater radius, an evaporator unit affixed to and rotated by the shaft and being spaced from the condenser unit, the evaporator unit having a tubular member coiled about the shaft in a path beginning with an inlet point adjacent the shaft and an outlet point at a second radius from the shaft, the second radius of the evaporator unit outlet point being less than or at least not substantially greater than the first radius of the condenser inlet point, a refrigeration return line connecting the evaporator outlet point to the condenser outlet point, a refrigerant delivery tube connecting the condenser outlet point to th