ヘリウム冷凍・液化機用新型ねじ圧縮機

抄録

In order to meet the recent demand for large scale helium compressors, we have undertaken the development of a scerw compressor of the oil injection type. As a first step in this project, a screw compressor with a capacity of appox. 120Nm³/hr has been constructed and tested. The compressor consists of a compression unit and an oil separation unit. The construction is characterized by a tandem type design, two stages of which are connected hermetically on both sides of the motor. By injection of a considerable amount of oil in the compression process, the following performance characteristics are obtained; a high compression ratio as a single stage and the lowering of discharge gas temperature in contrast to oil free type compressors.
Since our screw compressor is of the oil injection type, the reliability of the refrigerator/liquefier system strongly depends on the removal of the oil from the discharge gas. This problem has been solved by the development a special oil separation unit.
In a 100hr operational period of the compressor combined with a refrigerator/liquefier, no reduction in the liquefaction rate has been recognized. Results confirm the feasibility of this type of compressor and suggest a direction for further development of large scale screw compressors of the oil injection type.