(19)

(11)

EP 0 868 214 A1

(12)

(43) Date of publication: 07.10.1998 Bulletin 1998/41 (21) Application number: 96941786.0 (22) Date of filing: 13.12.1996

(51) International Patent Classification (IPC):  B01D 39/ 14( . ) B03C 3/ 28( . ) B03C 3/ 155( . ) B03C 3/ 68( . ) (86) International application number: PCT/GB1996/003074 (87) International publication number: WO 1997/023294 (03.07.1997 Gazette 1997/29)

(84) Designated Contracting States: CH DE FR GB IT LI NL (30) Priority: 22.12.1995 GB 19950026489 (71) Applicant: PIFCO LIMITED Manchester M35 OHS (GB)	(72) Inventors: GAY, Geoffrey, Norman, Walter Lancashire WN8 6TY (GB) GRIFFITHS, George Lancashire WN8 6TU (GB) (74) Representative: Lyons, Andrew John, et al  ROYSTONS, Tower Building, Water Street Liverpool L3 1BA, Merseyside Liverpool L3 1BA, Merseyside (GB)