Method for heating a hot air circulating-type of furnace for baking and drying coatings on articles

摘要

A method of heating a drying furnace for use in hot air-circulating type coating drying in which a hot air is supplied, under circulation, to the inside of the furnace thereby heating and drying coated articles, wherein heating for the furnace is conducted through a direct heating type hot air-circulating path in which the air inside of the furnace sucked from a return duct is heated directly by a combustion gas from a burner and supplied under circulation from a supply duct again to the inside of the furnace while conducting a step of increasing the temperature by pre-heating the inside of the furnace, whereas heating for the furnace is conducted through an indirect heating type hot air circulating path in which the air inside of the furnace sucked from the return duct is heated in a heat exchanger and then supplied, under circulation, through the supply duct again to the inside of the furnace while conducting a coating drying step when the temperature inside of the furnace reaches a predetermined temperature.