(19)

(11)

EP 1 397 631 A1

(12)

(43) Date of publication: 17.03.2004 Bulletin 2004/12 (21) Application number: 02738976.6 (22) Date of filing: 31.05.2002

(51) International Patent Classification (IPC)7: F27B 13/02, F27B 13/06 (86) International application number: PCT/NO2002/000193 (87) International publication number: WO 2002/097350 (05.12.2002 Gazette 2002/49)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 01.06.2001 NO 20012740 (71) Applicant: NORSK HYDRO ASA 0240 Oslo (NO)	(72) Inventors: NERLAND, Kjell, Anne N-6885 Ardalstangen (NO) RUUD, Anders N-6885 Ardalstangen (NO) HOLDEN, Inge N-6885 Ovre Ardal (NO) LINGA, Hogne N-6885 Ardalstangen (NO) NATERSTAD, Tormod N-1386 Asker (NO) (74) Representative: Bleukx, Luc  Norsk Hydro Technology B.V.,Avenue Marcel Thiry 83 1200 Brussels 1200 Brussels (BE)