Industrial furnace or oven has inner lining surrounded by additional vacuum insulation, avoiding local temperatures which could cause thermal deformation

摘要

An additional layer of thermal insulation is implemented as a unitary, hollow, hermetic vacuum casing. It surrounds the refractory lining (1) externally. Its inner wall is located no more closely to the furnace interior (2) than the layer in which the casing material critical thermal deformation temperature is reached. Internal air pressure in the additional thermal insulation layer is no greater than 0.001 atmospheres. It partially or entirely encloses the lining material. Casings for furnaces of larger dimensions are made from individual vacuum segments or ring sections, fastened gaplessly together.