Gary G Watanuki

US Patent:

55293158, Jun 25, 1996

Filed:

Feb 14, 1994

Appl. No.:

8/195754

Inventors:

Thomas Borrino - Glendale Heights IL
Michaeline G. Kruszynski - LaGrange Park IL
Gary G. Watanuki - Wheeling IL
Daniel N. Kozlowski - Naperville IL

Assignee:

John Crane Inc. - Morton Grove IL

International Classification:

F16J 1538

US Classification:

277 65

Abstract:

A three-part seal comprising an inboard, an intermediate and an outboard seal and defining two chambers, a mixing chamber between the inboard seal and the intermediate seal and a buffer chamber between the intermediate seal and the outboard seal, provides the capability of zero emissions of a process fluid under pressure in a housing. The process fluid may comprise a toxic or otherwise environmentally hazardous process fluid. A radial bore provides fluid communication between the buffer chamber and a buffer fluid reservoir, for example, a source of nitrogen gas, which is maintained at a pressure, preferably about five to eight psi, over the fluid pressure in the mixing chamber. Spiral grooves on at least one ring of the intermediate seal pump the buffer fluid from the buffer chamber into the mixing chamber where it mixes with any leakage of the process fluid and is evacuated through a second radial bore which provides fluid communication between the mixing chamber and a collection pod for collecting and processing the mixed fluid. A method of providing a zero emission seal between a housing and a relatively rotating shaft is also disclosed.