David F Wilcox

US Patent:

40550753, Oct 25, 1977

Filed:

Apr 8, 1976

Appl. No.:

5/675076

Inventors:

Thomas T. Allan - San Francisco CA
David E. Wilcox - Millbrae CA

Assignee:

Flanders Filters, Inc. - Washington NC

International Classification:

G01M 320

US Classification:

73 407

Abstract:

A method and apparatus for the leak testing of one or more filters, and comprising a housing adapted to sealably mount the filters, means for introducing DOP particles within the housing and immediately upstream of each of the filters, and means for imparting a like electrical charge to the particles such that the particles repel each other and rapidly disperse within the airstream so as to be substantially uniformly dispersed upon reaching the face of each filter. A collecting surface may be disposed downstream of the filters for detecting any of the charged particles to thereby permit a determination as to whether the filters are leaking. Alternatively, a collapsible panel system may be positioned immediately downstream of the filter to condense and impart turbulence to the airstream to thereby permit a sample to be withdrawn for analysis from a point closely adjacent the filter.

US Patent:

40305180, Jun 21, 1977

Filed:

Jul 30, 1976

Appl. No.:

5/710025

Inventors:

David E. Wilcox - Millbrae CA

Assignee:

Flanders Filters, Inc. - Washington NC

International Classification:

F16K 336

US Classification:

137246

Abstract:

A sliding plate air flow control valve adapted for use in a high efficiency air filter system of the type used in clean rooms and the like. The sliding plate valve is preferably positioned on the downstream side of each filter, and includes a highly viscous, non-evaporating fluid positioned between the plates to thereby prevent the air from flowing laterally between the plates, whereby the volume of air flow may be accurately controlled over the full area of the clean room as well as the full area of each filter.