Method of fabricating a heat exchanger for Stirling engine

Claim 1

A method for fabricating a ceramic heater head for use in a Stirling engine, comprising: (a) forming a ceramic slurry comprised of a binder and silicon filler powder, said binder consisting essentially of a mixture of a selected parafinic oil and a tri-block polymer with polystyrene end blocks, said oil being selected to prevent destruction of the cross links formed by the thermal plastic domains of said polymer and a boiling point range of 200°-400° F., (b) mixing said slurry at a temperature of 200°-300° F. to obtain a uniform mixture, (c) forming said slurry into tubes having an internal diameter which is 5-6 times the tube wall thickness and into a dominant cylindrical chamber effective to operate as a hot chamber for said Stirling engine, (d) heating said formed sheets in a carburizing atmosphere in steps: 200°-240° F. for four hours, 250°-275° F. for four hours, 350°-450° F. for four hours, 800° F. for four hours, (e) perforating openings in the wall of said cylindrical chamber having a size effected to mate with outside diameter of said tubes, (f) assembling said formed tubes to extend in parallel arrangement across the interior of said chamber having the ends of said tubes supported in said perforate openings of said walls, (g) heating said assembly rapidly in a carburizing atmosphere, to 2000°, at a rate of 600°-800° F. per hour, and then to 2200° F.-2500° F. at a rate of 100° F. per hour.

Claim 2

A method for fabricating a ceramic heater head for use in a Stirling engine, comprising: (a) forming a ceramic slurry comprised of a binder and silicon filler powder, said binder consisting essentially of a mixture of a selected parafinic oil and a tri-block polymer with polystyrene end blocks, said oil being selected to prevent destruction of the cross links formed by the thermal plastic domains of said polymer and a boiling point range of 200°-400° F., (b) mixing said slurry at a temperature of 200°-300° F. to obtain a uniform mixture, (c) forming said slurry into tubes having an internal diameter which is 5-6 times the tube wall thickness and into a dominant cylindrical chamber effective to operate as a hot chamber for said Stirling engine, (d) heating said formed sheets in a carburizing atmosphere in steps: 200°-240° F. for four hours, 250°-275° F. for four hours, 350°-450° F. for four hours, 800° F. for four hours, (e) perforating openings in the wall of said cylindrical chamber having a size effected to mate with outside diameter of said tubes, (f) assembling said formed tubes to extend in parallel arrangement across the interior of said chamber having the ends of said tubes supported in said perforate openings of said walls, (g) heating said assembly rapidly in a carburizing atmosphere, to 2000°, at a rate of 600°-800° F. per hour, and then to 2200° F.-2500° F. at a rate of 100° F. per hour.