HORIZONTAL TYPE VACUUM ANNEALING FURNACE FOR METALLIC COIL

摘要

PURPOSE:To maintain the uniform temp. distribution over the entire part of metallic coils mounted into many upper and lower stages in a furnace by providing auxiliary heaters in proximity to the coil array of the intermediate step having a smaller radiation heat receiving area. CONSTITUTION:The metallic coils 10 are mounted to the many upper and lower stages in a cylindrical furnace body 2 of a vacuum annealing furnace by spacing the coils at prescribed distances from each other in such a manner that the axial 11 direction thereof coincides with the transverse direction of the furnace body 2. The respective coils 10 are radiation-heated by heating of heaters 5 provided around the inside wall material 4 of the vacuum annealing furnace 1. Since the coil array of the intermediate step (b) has the smaller radiation heat receiving area, plural pieces of he auxiliary heaters 7 are provided to the inside wall material 4 of the furnace body 2 so as to face both end faces of the coils 10 and to project inward. The coils 10 in the stage (b) are thereby kept at about the same temp. as the temp. of the coils in the stages (a), (c) and the metallic coils 10 having no variance are efficiently produced.