(19)
(11) EP 0 854 342 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
17.03.1999 Bulletin 1999/11

(43) Date of publication A2:
22.07.1998 Bulletin 1998/30

(21) Application number: 98100817.0

(22) Date of filing: 19.01.1998
(51) International Patent Classification (IPC)6: F28D 1/03, F28F 3/04
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 20.01.1997 JP 8026/97

(71) Applicant: ZEXEL CORPORATION
Tokyo 150 (JP)

(72) Inventor:
  • Kato, Soichi, c/o Zexel Corporation
    Osato-gun, Saitama (JP)

(74) Representative: Füchsle, Klaus, Dipl.-Ing. et al
Hoffmann Eitle, Patent- und Rechtsanwälte, Arabellastrasse 4
81925 München
81925 München (DE)

   


(54) Tubes for heat exchanger


(57) To provide tubes for a heat exchanger having a higher corrosion resistance and capable of contributing to a longer life of the heat exchanger, the tubes having recesses resulting from beads or grooves formed on the upper and lower tube walls. Tubes for the heat exchanger, each tube being formed by bending a sheet of plate or by joining two sheets of plates, wherein the tube 2 is formed with a plurality of beads 11A, 11B, the top of each bead being joined with the surface of the opposite tube wall to form a plurality of divided passages in the tube. Of the beads 11A and 11B, at least one bead located on the most upstream side of the air flow projects upwardly from the lower tube wall.






Search report