VERTICAL PULL-THROUGH FURNACE FOR DECARBONIZING ANNEALING Russian patent published in 1998 - IPC

FIELD: vertical pull-through (tower-type) furnaces for thermochemical treatment of steel strip. SUBSTANCE: the last third section of holding chamber of tower-type furnace has additional branch pipes in the system of supply of working medium at two and more levels over the height of both side longitudinal walls facing each other and perpendicular to the plane of motion of strip, and headers located in furnace working space above each lower roller. Opposite branch pipes at each level are displaced relative to each other and located in those passages where there are no lower conveying rollers. The first and last branch pipes supply working medium between the third and fourth passages of strip considering from end face walls to provided for satisfactory opening of jets of working medium supplied from branch pipes located in end face walls of section. Lower headers ensure supply of medium to interstrip space uniformly in width of passage with the help of holes facing furnace roof and oncoming and outgoing branches of strip. To intensify the process of heat-mass-transfer installed in all sections of holding chamber above lower conveying rollers in working space are headers with holes facing the furnace roof and oncoming and outgoing strip branches ensuring supply of working medium to interstrip space over the strip width. EFFECT: higher efficiency. 6 dwg