Heater for hot isostatic pressing apparatus

Claim 1

A heater assembly unit for use in HIP apparatus for treating at least one work item in a high temperature and high pressure gas atmosphere by isostatic application of pressure, said heater assembly unit comprising: (a) two axially vertically disposed sinuous graphite heating elements each of which is composed of a plurality of longitudinal segments disposed in an array which is a portion of a cylinder in shape, each of said longitudinal segments extending the axial length of said heating element, being connected to the adjacent longitudinal segment on one side at the top of said heating element and to the adjacent longitudinal segment on the other side at the bottom of said heating element by a circumferential segment of the graphite heating element, and being spaced from both adjacent longitudinal segments along the axial length thereof, whereby each of said heating elements is one continuous piece of graphite in grid-like form having axial slits therein which are open alternately at their upper and lower ends and which are closed at their opposite ends by one of said circumferential segments; (b) a plurality of terminal end portions extending radially outwardly from the upper end of each of said graphite heating elements and being part of a circumferentially extending radial projection, each of said terminal end portions having a vertically disposed mounting hole therethrough; (c) a pair of metallic retaining members having fins thereon for shielding radiation heat and holes therein for suppressing heat conduction; (d) a vertically oriented support column fixedly erected on each of said metallic retaining members, each of said vertically oriented support columns having an upwardly disposed abutment surface which abuts the underside of one of said terminal end portions and a male screw portion at its upper end which protrudes through the mounting hole in said one of said terminal end portions, said support column serving as means for supplying electric power to said heating elements; and (e) securing means threaded onto the male screw portions of said support columns so as to abuttingly engage the upper surfaces of said terminal end portions.