Refrigeration machine

Abstract

A refrigeration machine, in particular a cryopump for generating a vacuum, having a compressor for compressing a refrigerant substantially comprising helium and oil. Together with the compressor, an oil separator is arranged downstream in the delivery direction of the coolant. Furthermore, a cooling device in which the refrigeration medium expands. In order to adsorb harmful gases, an adsorption device is arranged upstream of the cooling device in the delivery direction.

Description

BACKGROUND1. Field of the Disclosure[0001]The disclosure relates to a refrigeration machine, in particular to a cryopump for generating a vacuum.2. Discussion of the Background Art[0002]With the use of refrigeration machines, which find application, among others, in cryopumps, it is possible to obtain very low temperatures of less than 10 K. Thereby, it is possible e.g. to generate a very high vacuum of up to 10−10 mbar in a closed vacuum chamber. Refrigeration systems comprise a compressor pump, such as e.g. a scroll pump, with which a refrigerant is compressed. Helium is used as the refrigerant. The same generally comprises a certain proportion of oil to prevent excessive heating of the helium during compression. A heat exchanger is arranged first downstream of the compressor, seen in the delivery direction of the refrigerant, so as to allow for a cooling of the medium. Thereafter, the oil present in the helium is separated. This is effected, for example, by providing a plurality ...

AI Technical Summary

Benefits of technology

The patent text describes the placement of a gas adsorption device in a refrigeration system. The device is placed downstream of an oil separator to prevent contamination by oil. The technical effect of this arrangement is that it ensures the gas adsorption device operates efficiently without being contaminated by oil.

Problems solved by technology

Occasionally, problems occur in refrigeration machines already after relatively short operating periods.

Sometimes, it is no longer possible already after short operating periods to cool down the cooling device, such as the cold head, to the lowest temperature.

This entails high costs.

Studies have shown that the present hypotheses on why a cryopump can no longer cool down to the desired low temperatures are not entirely correct.

Studies have now shown that the impairment of the cooling device is particularly due to the presence of nitrogen and oxygen.

Other gases such as neon, argon, carbon dioxide or the like may also have adverse effects if they occur.

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