Method of and apparatus for steam preheating endless flexible casting

Abstract

The casting belt is preheated with steam closely ahead of the entrance to the casting zone by providing wrap-around steam feed tubes having nozzles, such tubes being positioned in very deep circumferential grooves in input pulley or nip pulley which moves the casting belt into the input end of the casting zone. These circumferential grooves of the input or nip pulley also house wrap-around liquid coolant feed tubes for cooling the casting belt near the beginning of the casting zone. The wrap-around steam feed tubes also have radial ports positioned to direct steam toward the reverse side of the endless belt, with the port being spaced from the nozzle thereby providing a staged elevation of temperature in the flexible casting belt on the input or nip pulley, while the belt is in contact therewith before the belt reaches the casting zone. Elevating the temperature prior to the endless belt reaching the casting zone and then suddenly cooling the belt when the molten metal is applied thereto improves casting conditions in the operation of such thin, flexible casting belt and enhances and speeds up the casting process. There are several ways for preventing coolant water from cooling the steam header and tubes of the bottom nip pulley in a twin-belt machine.