PURPOSE: To facilitate working and assembling of the title heater, and enhance the efficiency of heat generation.
CONSTITUTION: A metal-made flat oval pipe is wound up and joined in cylindrical shape, thereby forming a pipeline 7. Heating coils 8 and 9, which are shaped up by winding up spirally along each curved surface, are mounted on an inner peripheral surface 7a and an outer peripheral surface 7b of rows of pipelines wherein a plurality of pipelines 7 are installed side by side. Since the pipelines 7 are formed with the flat oval pipes which are joined and wound up in cylindrical shape, keeping its longitudinal cross section in parallel with its axial direction, the pipelines 7 are arranged to minimize their bending resistance and bent in the same curvature, which makes it possible to bend the pipes easily. Both the inner and outer peripheral surfaces of the pipelines 7 are flatly formed substantially in a similar manner except for adjacent contact areas, which increases the amount of penetration of alternating flux at the welded parts of the heating coils 8 and 9.
MATSUNAGA TETSUO
SAWADA MUNEHARU
HASEGAWA HIROAKI
FUJI ELECTRIC CO LTD
HOKURIKU ELECTRIC MFG
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