DRYING OF CHROMATE-TREATED STEEL SHEET

PURPOSE:To make it possible to manufacture a chromate-treated steel sheet with excellent corrosion inhibitive properties and the long life of an organic solvent paint by recycling a high-temperature exhaust air originating from dryer equipment for an organic paint coated steel sheet for a chromate-coated film drier, and controlling the temperature of the chromate-coated steel sheet to a specified range. CONSTITUTION:When a dryer 9 is newly installed following the provision of a new chromate film coating coater, a high-temperature exhaust air originating from an existing dryer 1 for an organic paint-coated steel sheet through an deodorizing furnace 4, is allowed to branch off by an air feed blower 10 before a flue for the existing dryer 1, and then is blown out to a steel sheet using the newly installed dryer 9. In addition, an air is mixed into the hot blast with the help of an exhaust air thermometer 11 and an air damper 12 in order to ensure a temperature control of the exhaust air for blowoff. Further, the temperature of the chromate-coated steel sheet is controlled by the hot blast from the existing dryer 1 so that said temperature stands at 60 to 100 deg.C. After that, a exhaust air blower 13 for exhausting an air from the newly installed dryer 9 and a flue 14 are provided to allow the exhaust air into the atmosphere.