(19)

(11)

EP 0 717 818 A1

(12)

(43) Date of publication: 26.06.1996 Bulletin 1996/26 (21) Application number: 94925562.0 (22) Date of filing: 06.09.1994

(51) International Patent Classification (IPC):  B01F 3/ 08( . ) B01F 5/ 06( . ) E21B 43/ 00( . ) E21B 43/ 34( . ) B01F 3/ 04( . ) B01F 5/ 04( . ) B01F 13/ 10( . ) E21B 43/ 12( . ) F04F 5/ 10( . ) (86) International application number: PCT/GB1994/001937 (87) International publication number: WO 1995/007414 (16.03.1995 Gazette 1995/12)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI NL SE (30) Priority: 06.09.1993 GB 19930018419 (71) Applicant: B.H.R. GROUP LIMITED Bedford MK43 0AJ (GB)	(72) Inventor: SARSHAR, Mir, Mahmood Bucks HP9 1JL (GB) (74) Representative: Cline, Roger Ledlie, et al  EDWARD EVANS & CO. Chancery House 53-64 Chancery Lane London WC2A 1SD London WC2A 1SD (GB)