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Title:
HEAT TRANSFER PIPE FOR FLOW-DOWN LIQUID FILM TYPE EVAPORATOR
Document Type and Number:
Japanese Patent JP11257888
Kind Code:
A
Abstract:

To provide a heat transfer pipe for a flow-down liquid film type evaporator that has a high evaporation performance of the liquid film of a refrigerant and has improved evaporation heat transfer performance.

A heat transfer pipe 1 is provided with a rib 5 that is formed in a projection shape on the inner surface of the pipe and is extended spirally with an appropriate interval, a recessed part 2 that is formed on the outer surface of the pipe and is extended spirally with an appropriate interval, and a plurality of independent projections 6 that are formed on the outer surface of the pipe and are arranged spirally. With the projections 6, the upper surface is recessed so that a part 7 that matches the rib 5 on the inner surface of the pipe is lower than a part 8 that matches the region between ribs. Also, the recessed part 2 on the outer surface of the pipe and the rib 5 on the inner surface of the pipe are formed at mutually matching positions. The projections 6 are in a quadrangular pyramid shape with a height ranging from 0.20 to 0.40 mm and an area ratio A between upper and lower surfaces is 0.25≤A≤0.40. Also, a pitch P of a recessed part 8 on the upper surface of the projections 6 is 5.75≤P≤6.75 mm when viewed from a pipe axis orthogonal section and an angle θ formed by the pipe axis direction of the rib 5 is 40°θ≤44°.


Inventors:
Takahashi, Hiroyuki
Saeki, Chikara
Furukawa, Masahiro
Irakai, Kazutaka
Application Number:
JP1998000063771
Publication Date:
September 24, 1999
Filing Date:
March 13, 1998
Export Citation:
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Assignee:
KOBE STEEL LTD
SANYO ELECTRIC CO LTD
International Classes:
F28F1/42; F25B39/02; F28D3/02; F28F1/12; F28F1/40; F25B39/02; F28D3/00; F28F1/10; F28F1/12; (IPC1-7): F28F1/42; F25B39/02; F28D3/02; F28F1/12; F28F1/40