AVS 47th International Symposium
    Vacuum Technology Thursday Sessions
       Session VT-ThM

Paper VT-ThM7
Design and Operation of Scroll Type Dry Primary Vacuum Pumps

Thursday, October 5, 2000, 10:20 am, Room 201

Session: Pumps and Large Vacuum Systems
Presenter: A. Liepert, Varian Vacuum Technologies
Authors: A. Liepert, Varian Vacuum Technologies
P. Lessard, Varian Vacuum Technologies
Correspondent: Click to Email
Since being rediscovered two decades ago, scroll technology has been successfully adapted to vacuum use. Several innovations have allowed scroll-type pumps to produce vacuums lower than 10 mtorr; the pumps are used in many applications requiring an inexpensive, dry, long-lived pump. In this article, we detail the scroll design procedure, focussing on the tradeoffs between the need for sufficient vacuum and low manufacturing cost. In particular, the bearing and axial seal design are detailed. As an illustrative example, we consider the design requirements for a high helium compression scroll design for use in leak detectors. We also present guidelines for proper pump operation, including the need for gas ballasting, limits on high pressure operation and proper pump isolation schemes.