The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 1997
Filed:
Mar. 14, 1996
Ralph C Longsworth, Allentown, PA (US);
Francis T Lotz, Whitehall, PA (US);
APD Cryogenics, Inc., Allentown, PA (US);
Abstract
A Group I gas cryopumping system includes a compressor throttle cycle refrigerator using mixed refrigerants. Cold refrigerant flows through a cryopumping surface located in a vacuum chamber, whereon vapor freezes. The refrigerant then passes through a heat exchanger in cross flow with refrigerant from the compressor. Refrigerant flow entering and leaving the heat exchanger is in uninsulated lines at substantially room temperature. All exposed cold lines are eliminated. The throttle device and cold cryopumping surface are an integral unit that connects directly to the flow paths of the heat exchanger without intermediate lines. The compressor/aftercooler unit may be located at any convenient distance from the heat exchanger and cryopumping surface, and the heat exchanger is located immediately adjacent to the pumping surface in a separate housing outside the vacuum chamber. The heat exchanger housing may share or be isolated from the vacuum of the vacuum chamber. Selected mixed refrigerants provide a wide range of cooling capacity over narrow, selectable temperature ranges. Thus, in a selected temperature range, gases are selectively collected to the exclusion of other gases. A tray collects liquid water from the cryopump surfaces during defrost.