Albert R Vaia

US Patent:

49216627, May 1, 1990

Filed:

Apr 19, 1988

Appl. No.:

7/183874

Inventors:

Richard D. Franklin - Jeannette PA
Gregg D. Auld - Trafford PA
David E. Murray - Greensburg PA
John J. Lescisin - Pittsburgh PA
Albert R. Vaia - Export PA
Thomas E. Dunn - Pittsburgh PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

F22B 3748

US Classification:

376316

Abstract:

A method for loosening and removing sludge and debris from the vessel of a heat exchanger, such as the secondary side of a nuclear steam generator, is disclosed herein. The method generally comprises the steps of providing a sufficient volume of a liquid, such as water, into the steam generator so that the lower portion which includes the tubesheet is submerged, and then generating a succession of pressure pulses within the water from one or more pressure pulse generators wherein each pressure pulse creates shock waves that exert momentary forces throughout the submerged portion of the generator of a magnitude sufficient to loosen the sludge and debris, but safely below the yield and fatigue limits of the heat exchanger tubes and other components within the generator. The pressure pulses commence as soon as a sufficient amount of water is introduced into the steam generator to submerge the tubesheet, and continue all the way through the draining of the steam generator.

US Patent:

50063049, Apr 9, 1991

Filed:

Oct 20, 1989

Appl. No.:

7/424879

Inventors:

Richard D. Franklin - Jeannette PA
Gregg D. Auld - Trafford PA
David E. Murray - Greensburg PA
John J. Lescisin - Pittsburgh PA
Albert R. Vaia - Export PA
Thomas E. Dunn - Pittsburgh PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

F22B 3748

US Classification:

376316

Abstract:

A method for loosening and removing sludge and debris from the vessel of a heat exchanger, such as the secondary side of a nuclear steam generator, is disclosed herein. The method generally comprises the steps of providing a sufficient volume of a liquid, such as water, into the steam generator so that the lower portion which includes the tubesheet is submerged, and then generating a succession of pressure pulses within the water from one or more pressure pulse generators wherein each pressure pulse creates shock waves that exert momentary forces throughout the submerged portion of the generator of a magnitude sufficient to loosen the sludge and debris, but safely below the yield and fatigue limits of the heat exchanger tubes and other components within the generator. The pressure pulses commence as soon as a sufficient amount of water is introduced into the steam generator to submerge the tubesheet, and continue all the way through the draining of the steam generator.