| 摘要 |
Cylindrical castings , suited to thermal insulation applications at high temperatures, are formed by a centrifugal casting process. A mixture of carbon-containing fibers, such as isotropic pitch fibers, and a suitable aqueous binder, such as a sugar solution, is supplied to an apparatus for centrifugal molding including a support frame (12) including a top plate (40) and a bottom plate (20) with a rotating drum (12) supported therebetween. The mixture is supplied via a feed pipe (18) concentrically aligned with a screen (66) of the drum. The fibers and binder collect on a filter cloth (102) supported by an inner surface of the screen (66). Excess binder flows through the filter cloth (102) and passes through adjacent apertures (100) in the screen (66). When a cylindrical preform of sufficient thickness has built up, the drum (12) is disassembled. The preform is dried, to drive off excess water, and heated to a temperature of about 900°C -2000°C to form the casting. |
