A monolithic refractory ceramic tube sheet for use in all-ceramic
air-to-air indirect heat exchangers, the heat exchanger used in all
temperature and all pressure applications. A method for forming the
monolithic tube sheet includes casting a refractory ceramic in a mold,
where portions of the mold comprise the housing of the heat exchanger.
Precisely formed negatives are used to form through channels and
vacancies within the tube sheet, which are precisely positioned within
the mold allowing uniform and flush formation of openings which receive
the ceramic tubes therein. The same mold is used to provide both tube
sheets of a tube sheet pair allowing accurate alignment of tubes within
the exchanger vessel resulting in ease of assembly and equal loading of
tubes when in use.