Fail-safe cryopump safety purge delay

Details Fail-safe cryopump safety purge delay Fail-safe cryopump safety purge delay

2005-05-24

2005-05-24

Doerrler, William C. (Department: 3744)

Refrigeration

Low pressure cold trap process and apparatus

Reexamination Certificate

active

06895766

ABSTRACT:
An electronic controller is integral with a cryopump and provides an offline solution for purging a cryopump and an exhaust line during unsafe conditions. The electronic controller is responsible for controlling the opening and closing of purge, exhaust purge and gate valves coupled to the cryopump. The electronic controller can preempt any attempts from other systems to control these valves during unsafe conditions. An unsafe condition can be a power failure in the cryopump, a dangerous temperature in the cryopump or a temperature sensing diode that is not operating properly. When an unsafe condition is determined, the exhaust purge valve is opened and the gate valve closed, while the opening of a purge valve may be delayed for a safe period of time. If the unsafe condition still exists when the safe period of time elapses, the purge valve is allowed to open.A fail-safe purge valve release and time delay mechanism can be used to ensure that the purge valve opens after the period of time elapses. Electrochemical capacitors store an amount of energy to hold a normally open purge valve closed for a safe period of time. When this energy is discharged and the unsafe condition still exists, the purge valve automatically opens.

REFERENCES:
patent: 3254871 (1966-06-01), Limon
patent: 4156432 (1979-05-01), Helwig, Jr.
patent: 4718240 (1988-01-01), Andeen et al.
patent: 4735084 (1988-04-01), Fruzzetti
patent: 4757689 (1988-07-01), Bächler et al.
patent: 4958499 (1990-09-01), Haefner et al.
patent: 5062271 (1991-11-01), Okumura et al.
patent: 5123277 (1992-06-01), Gray et al.
patent: 5305612 (1994-04-01), Higham et al.
patent: 5400604 (1995-03-01), Häfner et al.
patent: 5443368 (1995-08-01), Weeks et al.
patent: 5450316 (1995-09-01), Gaudet et al.
patent: 5513499 (1996-05-01), deRijke
patent: 5517823 (1996-05-01), Andeen et al.
patent: 5684463 (1997-11-01), Diercks et al.
patent: 5893234 (1999-04-01), McKeon
patent: 5906102 (1999-05-01), Bartlett et al.
patent: 6216467 (2001-04-01), O'Neil et al.
patent: 6233948 (2001-05-01), Morishita et al.
patent: 6272400 (2001-08-01), Jankins et al.
patent: 6318093 (2001-11-01), Gaudet et al.
patent: 6327863 (2001-12-01), Yamartino et al.
patent: 6427969 (2002-08-01), Ho et al.
patent: 6510697 (2003-01-01), Buonpane et al.
patent: 0 684 382 (2000-03-01), None
Rao, M.G., et al., “Use of Indigenous Molecular Sieves in Cryosorption Pumping Applications,”VAC News, 12(3): 15-18.
Drzal, L. T., et al., “A high precision volumetric gas adsorption apparatus for surface studies,”Rev. Sci. Instrum., 45(11) 1331-1335 (1974).
deRijke, J.E., “Performance of a cryopump-ion pump system,”J. Vac. Sci. Technol. 15(2) 765-767 (1978).
Longsworth, R.C., et al. “Cryopump regeneration studies,”J. Vac. Sci. Technol. 21(4) 1022-1027 (1982).
Liebert, R.B.., et al., “Safety considerations in cryopumping systems for ion implanters”, Ion Implantation Technology, 94: 548-552 (1995).
Mundinger, H.J., et al., “A New Cryopump with a Very Fast Regeneration System”,Vacuum, 43(5-7):545-549 (1992).

Affiliated with

Also associated with

Rating

Fail-safe cryopump safety purge delay does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fail-safe cryopump safety purge delay, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fail-safe cryopump safety purge delay will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3416842