(19)

(11)

EP 0 394 236 A1

(12)

(43) Date of publication: 31.10.1990 Bulletin 1990/44 (21) Application number: 88903989.0 (22) Date of filing: 04.05.1988

(51) International Patent Classification (IPC):  B01D 29/ 39( . ) (86) International application number: PCT/SE1988/000228 (87) International publication number: WO 1988/008739 (17.11.1988 Gazette 1988/25)

(84) Designated Contracting States: BE DE FR GB NL (30) Priority: 04.05.1987 SE 19870001820 (71) Applicant: HYDROTECH NILS-AKE PERSSON AB S-211 52 Malmö (SE)	(72) Inventors: PERSSON, Nils-Ake S-211 49 Malmö (SE) RALVERT, Klas S-292 00 Karlshamn (SE) (74) Representative: Rostovanyi, Peter, et al  AWAPATENT AB, Box 5117 S-200 71 Malmö S-200 71 Malmö (SE)