(19)
(11) EP 0 321 427 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
05.07.1989 Bulletin 1989/27

(43) Date of publication A2:
21.06.1989 Bulletin 1989/25

(21) Application number: 88850409.9

(22) Date of filing: 05.12.1988
(51) International Patent Classification (IPC)4: F27B 5/14, H05B 3/62, F27D 11/02
(84) Designated Contracting States:
DE ES FR GB IT SE

(71) Applicant: Kanthal AB
S-734 01 Hallstahammar (SE)

(72) Inventor:
  • Olsson, Jan-Olof
    S-734 00 Hallstahammar (SE)

(74) Representative: Modin, Jan et al
c/o Axel Ehrners Patentbyra AB Box 10316
100 55 Stockholm
100 55 Stockholm (SE)


(56) References cited: : 
   
       


    (54) Heat radiation tube


    (57) The invention is for heat radiation tubes for furnaces and the like heating devices, mainly for industrial processes.
    Heating can be obtained by electrical heating elements or by combustion for example of gas. The radiation tube is a circular tube having end walls, flanges etc. as required.
    Thereby that a radation tube according to the invention is a seam-less tube made from iron-chromium-aluminium essential advantages are obtained in respect of oxide spalling which is greatly reduced and shape strength at high tempera­tures of use. Preferably the tubes are made by extrusion whereby conditions are chosen to give a rough surface with grooves and ridges which further improves the adhesion of the oxide layer.







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