(19)

(11)

EP 0 427 804 A1

(12)

(43) Date of publication: 22.05.1991 Bulletin 1991/21 (21) Application number: 90903840.0 (22) Date of filing: 06.03.1990

(51) International Patent Classification (IPC):  B01D 21/ 00( . ) C02F 1/ 52( . ) B01D 21/ 08( . ) C02F 1/ 64( . ) (86) International application number: PCT/FI1990/000059 (87) International publication number: WO 1990/010597 (20.09.1990 Gazette 1990/22)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 06.03.1989 FI 19890001064 (71) Applicant: WISER OY SF-04201 Kerava (FI)	(72) Inventors: JÄRVENPÄÄ, Viljo SF-04230 Kerava (FI) LATVALA, Arto SF-04230 Kerava (FI) (74) Representative: Tiedtke, Harro, Dipl.-Ing.  Patentanwaltsbüro Tiedtke-Bühling-Kinne & Partner Bavariaring 4 D-80336 München D-80336 München (DE)