Cryogen spraying

摘要

The apparatus has a flow network equipped with a pair of legs (30,32) for dividing the flow of cryogenic refrigerant into a major stream and a subsidiary stream. A vaporizer (34) is positioned in the second leg for vapourizing the subsidiary steam. A mixing device (36) produces a two phase cryogenic refrigerant by combining the mainstream and the subsidiary stream. The two phase cryogenic refrigerant is fed to several spray nozzles (16) via a proportional valve (44). The spray nozzles spray the cryogenic refrigerant on the articles (12) positioned within a spray zone (20). A heat conductive element (22) positioned beneath the spray zone catches and vaporizes the cryogenic refrigerant oversprayed in the spray zone.