AVS 46th International Symposium
    Vacuum Technology Division Wednesday Sessions
       Session VT-WeM

Paper VT-WeM2
A Highly Simplified and Reliable Means of Regenerating Closed-Loop Gaseous Helium Cryopumps

Wednesday, October 27, 1999, 8:40 am, Room 610

Session: Vacuum Pumping Systems
Presenter: K.M. Welch, Consultant
Authors: D.W. Crone, Ebara Technologies Inc.
J. Brady, Ebara Technologies Inc.
M.O. Foreman, Ebara Technologies Inc.
K.M. Welch, Consultant
Correspondent: Click to Email
A unique means of regenerating closed-loop, gaseous helium refrigerator cryopumps is reported. If one reverses the rotation of the expander motor of a Gifford-McMahon refrigerator, the thermodynamic cycle is reversed and heat rather than refrigeration is produced at the expander cooling stations. The heat input stemming from reversing the thermodynamic cycle may be used in a controlled manner to achieve a simple, safe and effective regeneration cycle of the cryopump. This reverse cycle regeneration process, and its effectiveness and reliability will be described.