Cryogenic pump for small vacuum system - has adjustable screen within housing protecting cooling surface of two-stage cooling head against heat radiation

摘要

The cryogenic pump has a housing (11) with an entry port (22) at right angles to the pump axis and within the housing a two stage cooling head (13). This has at least one cooling surface (17) on the second stage (37) of the head. Around the cooling surface there is a cylindrical screen (15) with an opening (18) on its side and a diaphragm (35) attached to the first stage of the head to protect it against heat radiation. The screen and the housing can be moved with respect to each other so that the opening in the screen can be aligned fully or partially with the entry port. ADVANTAGE - Compact design with high suction capacity.