After the liquid paint is applied on the color coated plate production line, the solvent is heated and evaporated by the heat in the curing furnace, and the strip is heated to a predetermined temperature to solidify the coating. This process consumes a lot of energy. At present, in order to meet the environmental protection standard, the domestic color coated plate production line usually exhausts the exhaust gas from the furnaceThe waste gas is heated to the temperature of cracking point (733 ° C) for pyrolysis and incineration, and then discharged into the atmosphere through flue, exhaust fan and chimney to achieve standard emission. At this time, a large amount of heat energy and greenhouse gas are generated in the atmosphere, which not only pollutes the environment, but also can not make full use of energy. Therefore, some enterprises are located in the high temperature zone above the pyrolysis point Most of the solvents containing toxic gases in the waste gas are cracked, burned and cracked, which releases a large amount of heat energy and consumes most of the oxygen in the waste gas, resulting in high temperature inert (control the excess oxygen content to about 5-8%, relatively inert) flue gas, forming high-temperature and low oxygen flue gas, passing through the heat exchanger Heat the fresh air and send the heated air into the curing furnace through the blower to solidify and dry the painted steel strip. For example, the application date is June 6, 2008, and the publication date is Io month 8, "waste heat utilization of concentrated incineration of harmful gases in color coating line". According to the explosion-proof theory, the conditions required for explosion in the curing furnace are determined There are three main points, namely temperature, solvent concentration and oxygen content. In this scheme, the hot air supplied in the curing furnace is hot air, and the oxygen content is 21%. Therefore, in order to prevent the gas explosion in the curing furnace, the concentration of solvent in the furnace should be controlled. High power fan should be used to extract the gas in the solvent rich furnace to a large extent, In this way, the fan power is large and the energy consumption is large. After heat exchange, the air is supplied to the curing furnace and other places in the production line that need heat source. The emission of incineration tail gas will take away a large amount of heat, which needs to be fixed in the The heat supply tuyere of chemical furnace and other positions of production line need heat source to increase the shortage of hot air temperature after supplementary heat exchange of combustion engine, which not only increases the combustion engine, but also needs to consume a lot of gas.