PURPOSE: To enable the control of coating weight over a wide range and to prevent the contact of a steel strip with a nozzle by fluttering.
CONSTITUTION: Gas pressure P and the distance D between the steel strip and the nozzle are used as control elements, and Pmin and Dmin, i.e., the lower limit value of both are previously set. Ordinary, the gas pressure P is fixed to the set lower limit value Pmin, only the distance D is made variable and the distance D is found from the previously decided calculating formula and Pmin, i.e., the lower limit value of the gas pressure P and is regulated. In the case the distance D found by the calculation is less than the lower limit value Dmin, the control is changed, the distance D is fixed to the lower limit value Dmin, only the gas pressure is made variable and, based on the previously decided calculating formula and the lower limit value Dmin of the distance D, the gas pressure P is found and is regulated.
NAKAGAWA TADAAKI
SATO YASUNARI
