ONE-FACE CHEMICAL CONVERSION TREATMENT OF STEEL PLATE BY GALVANIZING DEVICE

PURPOSE:To carry out one-face chemical conversion treatment completely and easily by appropriately providing an air spray nozzle and a curtain to prevent the oozing out of a processing soln. onto the upper surface of a steel sheet when one-face chemical conversion treatment is applied to the lower surface of the thin steel sheet. CONSTITUTION:In a both-faces chemical conversion treatment apparatus for a thin steel sheet 1, only the lower line of nozzles tubes 7 is used, a processing soln. is spouted from the nozzles and one-face chemical conversion treatment is carried out. At this time, the processing soln. oozing out from the lower face to the upper face along both ends of the thin steel sheet 1 is blown off by blowing compressed air from a nozzle 12 of an edge air curtain spray header 10. The blown processing soln. is collected by a curtain 11 (thin nonwoven fabric, etc.) for preventing the splash of the processing soln. and dropped onto the bottom part of a treating vessel 5. Besides, the processing soln. pressed out by the lower roll of a wringer roll 6 is blown off by the compressed air injected from a nozzle 14 of a wringer roll meniscus spray header 3 so that the processing soln. is not oozed out onto the upper face of the thin steel sheet 1. Moreover, the orientation, distance and angle of respective nozzles 12 and 14 are appropriately regulated to carry out effective treatment.