| 摘要 |
PURPOSE:To improve formability, ease of assembly and productivity by a structure wherein multiple heat exchanging fins in one piece are provided on the inside wall of an external sleeve and multiple heat exchanging fins in one piece are provided on an internal sleeve. These two sleeves are assembled together in such a manner as the internal heat exchanging fins and the external heat exchanging fins can be arranged alternately. CONSTITUTION:Multiple radial heat-exchanging fins 2 in one piece are provided on the inside wall of a plastic external sleeve 1, while multiple radial heat- exchanging fins 4 in one piece are provided on a plastic internal sleeve 3. To assemble both the sleeves 1, 3 together, the internal sleeve 3 is inserted into the external sleeve 1 in such a manner as respective heat exchanging fins 2, 4 can be arranged alternately with each heat exchanging fin 2, 4 being fitted in each guide groove 1a, 3a on their companion sleeve. Respective spaces formed by the heat exchanging fins 2,4 are referred to as the primary and secondary passages alternately. Fabrication of such sleeves can easily by accomplished in a way that a flat plate with heat exchaging fins 2 or 4 projecting out is only rolled into a sleeve and welded together so that ease of assembly and productivity can be promoted. |
