(19)

(11)

EP 0 847 300 A1

(12)

(43) Date of publication: 17.06.1998 Bulletin 1998/25 (21) Application number: 96929738.0 (22) Date of filing: 30.08.1996

(51) International Patent Classification (IPC):  B01D 29/ 11( . ) E21B 43/ 08( . ) (86) International application number: PCT/US1996/013723 (87) International publication number: WO 1997/007870 (06.03.1997 Gazette 1997/11)

(84) Designated Contracting States: DE FR GB (30) Priority: 30.08.1995 US 19950002987P 01.02.1996 US 19960011021P (71) Applicant: Pall Corporation East Hills, New York 11548 (US)	(72) Inventor: WHITLOCK, Michael, B. Cortland, NY 13045 (US) (74) Representative: Horner, Martin Grenville, et al  Cruikshank & Fairweather 19 Royal Exchange Square Glasgow G1 3AE Scotland Glasgow G1 3AE Scotland (GB)