METHOD FOR CONTROLLING NOZZLE SLIT GAP OF BLOWING AND WIPING-OFF APPARATUS USED IN MOLTEN METAL PLATING DEVICE

摘要

PURPOSE:To constantly control the gap of a nozzle slit during molten plating operation, by a method wherein the temp. of an upper and a lower lip members forming a nozzle slit is measured and the temp. of injected compresed gas is regulated on the basis of the measured values. CONSTITUTION:In molten zinc plating, the temps. of the leading end parts of an upper and a lower lip members forming a nozzle slit wiping off the molten metal adhered to a strip body is measured. On the basis of the temp. difference of the upper and the lower lip members, the changing state of the gap dimension of the nozzle slit with respect to the dimension at the time of setting during operation is grasped. Because corelation is present between the changing situation of the nozzle slit and the temp. of injected compressed gas, the temp. of the injected compressed gas from the nozzle of a blow wipe-off apparatus is regulated on the basis of the temp. difference of the upper and the lower slip members. By this method, the gap of the nozzle slit can be accurately and easily controlled corresponding to the situation of plating operation.