Abstract: Refrigerants containing HCFC's are replaced with new blends by using R-236fa and R-125, or R-125 with R-245fa, or R-236ea, or R-134a with R-236fa in place of HCFC's. No hardware or oil composition changes are required to maintain temperatures, pressures and capacity substantially unchanged in a refrigeration system.

Abstract: A refrigeration system wherein an ammonia refrigerant fluid in a cascade refrigeration circuit provides auxiliary refrigeration to a multicomponent refrigerant fluid which passes from an autorefrigerator to provide refrigeration to a heat load.

Abstract: Refrigerants containing HCFC's are replaced with new blends by using R-236fa and R-125, or R-125 with R-245fa, or R-236ea, or R-134a with R-236fa in place of HCFC's. No hardware or oil composition changes are required to maintain temperatures, pressures and capacity substantially unchanged in a refrigeration system.

Abstract: A throttle device provides a large number of small flow channels generally in parallel rather than a single flow path. The throttling device, a porous cartridge within a tube, may be porous metal, packed ferrous spheres or other particles, packed fibrous material, a plurality of smaller capillaries joined together in parallel, etc. The number and size of the channels provide proper pressure drop performance of the throttle, and flow is laminar with a Reynolds number less than 2,000. Vibrations are low. With certain refrigerant components, and small openings in the porous throttle device, refrigerant flow resistance increases until all flow ceases below selected and repeatable temperature levels. Thus, a temperature-dependent, variable on to off throttle device is provided without moving parts. This self adjusting throttle device can operate in parallel with a fixed throttle device.

Abstract: An integral combination of expansion valve and evaporator in a cryostat using a single support member. The valve includes two flow orifices, one orifice being used primarily for steady-state operation and the other orifice being used only during cool-down. An actuator having a high coefficient of thermal expansion moves a needle positioned in the cool-down orifice such that a large orifice flow area at the start of cool-down is automatically and continuously reduced as the actuator temperature decreases as refrigerant is throttled through the orifice. Within a range of approximately 30 K from the desired steady-state evaporator temperature, the needle completely blocks the cool-down orifice. Then, refrigerant flows through the steady-state orifice which has a remotely adjustable needle. In the final stage of cool-down, the refrigerant system is entirely controlled by the steady-state orifice and its associated needle.

Abstract: A mixed gas refrigerant for use in the cryogenic range of temperatures between 80.degree. K. and 100.degree. K., with single stage compressor providing high pressures up to 30 Arms. The refrigerant consists of nitrogen between 30 and 50 molar percent, methane less than 20 molar percent, propane, more than 30 molar percent, and ethane the balance.

Abstract: Refrigerants containing HCFC's are replaced with new blends by using R-236fa and R-125, or R-125 with R-245fa, or R-236ea, or R-134a with R-236fa in place of HCFC's. No hardware or oil composition changes are required to maintain temperatures, pressures and capacity substantially unchanged in a refrigeration system.