(19)

(11)

EP 0 539 459 A1

(12)

(43) Date of publication: 05.05.1993 Bulletin 1993/18 (21) Application number: 91913304.0 (22) Date of filing: 27.06.1991

(51) International Patent Classification (IPC):  B01D 47/ 00( . ) B01D 53/ 72( . ) C02F 3/ 00( . ) C02F 3/ 06( . ) C02F 9/ 00( . ) B01D 47/ 04( . ) B01D 53/ 77( . ) C02F 3/ 02( . ) C02F 3/ 12( . ) (86) International application number: PCT/SE1991/000465 (87) International publication number: WO 1992/000792 (23.01.1992 Gazette 1992/03)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI NL SE (30) Priority: 13.07.1990 SE 19900002429 (71) Applicant: ABB FLÄKT AKTIEBOLAG S-120 86 Stockholm (SE)	(72) Inventor: LARSSON, Ola S-352 45 Växjö (SE) (74) Representative: Siebmanns, Hubertus  Gotapatent AB, Box 154 S-561 22 Huskvarna S-561 22 Huskvarna (SE)