John S Purcell

US Patent:

RE363324, Oct 12, 1999

Filed:

Mar 2, 1998

Appl. No.:

9/033946

Inventors:

James G. Pierce - Westerville OH
Charles B. Hood - Naples FL
Sibley C. Burnett - San Diego CA
John R. Purcell - San Diego CA

Assignee:

PHPK Technologies, Inc. - Westerville OH

International Classification:

F17C 502

US Classification:

62 471

Abstract:

A refrigeration system includes a dewar and a refrigerator/liquefier which meets the variable demands of a superconducting magnet within the dewar. The system is sized to meet average loads over a defined duty cycle, and is variably operable to meed demands. In the preferred embodiment, a first supply of fluid circulates through a "condenser" element positioned in a dewar ullage to liquefy a separate supply of fluid in the dewar, and to refrigerate a pulsed cryogenic load therein, such as a superconducting magnet. A portion of the first supply of fluid may be diverted to refrigerate a second pulsed cryogenic load, such as magnet current leads permanently connected to the magnet. The dewar includes a cold gas vapor storage chamber separate from the dewar ullage, and the chamber is preferably located within the inner core of a solenoid superconducting magnet for compact and thermally efficient design. Responsive, independent adjustment of refrigeration to pulsed cryogenic loads is made possible.

US Patent:

54957184, Mar 5, 1996

Filed:

Jan 14, 1994

Appl. No.:

8/182439

Inventors:

James G. Pierce - Columbus OH
Charles B. Hood - Naples FL
Sibley C. Burnett - San Diego CA
John R. Purcell - San Diego CA

International Classification:

F17C 502

US Classification:

62 471

Abstract:

A refrigeration system includes a dewar and a refrigerator/liquefier which meets the variable demands of a superconducting magnet within the dewar. The system is sized to meet average loads over a defined duty cycle, and is variably operable to meed demands. In the preferred embodiment, a first supply of fluid circulates through a "condenser" element positioned in a dewar ullage to liquefy a separate supply of fluid in the dewar, and to refrigerate a pulsed cryogenic load therein, such as a superconducting magnet. A portion of the first supply of fluid may be diverted to refrigerate a second pulsed cryogenic load, such as magnet current leads permanently connected to the magnet. The dewar includes a cold gas vapor storage chamber separate from the dewar ullage, and the chamber is preferably located within the inner core of a solenoid superconducting magnet for compact and thermally efficient design. Responsive, independent adjustment of refrigeration to pulsed cryogenic loads is made possible.

US Patent:

56972202, Dec 16, 1997

Filed:

Mar 4, 1996

Appl. No.:

8/610381

Inventors:

James G. Pierce - Columbus OH
Charles B. Hood - Naples FL
Sibley C. Burnett - San Diego CA
John R. Purcell - San Diego CA

Assignee:

PHPK Technologies, Inc. - Westerville OH

International Classification:

F17C 100

US Classification:

62 451

Abstract:

A refrigeration system includes a dewar and a refrigerator/liquefier which meets the variable demands of a superconducting magnet within the dewar. The system is sized to meet average loads over a defined duty cycle, and is variably operable to meed demands. In the preferred embodiment, a first supply of fluid circulates through a "condenser" element positioned in a dewar ullage to liquefy a separate supply of fluid in the dewar, and to refrigerate a pulsed cryogenic load therein, such as a superconducting magnet. A portion of the first supply of fluid may be diverted to refrigerate a second pulsed cryogenic load, such as magnet current leads permanently connected to the magnet. The dewar includes a cold gas vapor storage chamber separate from the dewar ullage, and the chamber is preferably located within the inner core of a solenoid superconducting magnet for compact and thermally efficient design. Responsive, independent adjustment of refrigeration to pulsed cryogenic loads is made possible.