The solvent vapor and cracked low-molecular substances generated during the baking process of the enameled wire must be discharged from the furnace in time. The density of the solvent vapor and the humidity in the gas will affect the evaporation and curing during the baking process, and the low-molecular-weight substances have an effect on the smoothness and brightness of the paint film. In addition, the concentration of solvent vapor is related to safety, so waste discharge is very important to product quality, safe production, and heat energy consumption.
Considering product quality and safety production alone, the amount of waste discharged is larger, but a large amount of heat is taken away while discharging waste, so waste discharge should be appropriate. Catalytic combustion hot air circulation furnace usually discharges 20~30% of the hot air volume. The amount of waste discharged depends on the amount of solvent used, the humidity of the air, and the heat of the oven. For every 1kg of solvent used, about 40~50M3 (converted to room temperature) is required to discharge waste. From the heating of the furnace temperature, the scratch resistance of the enameled wire, and the gloss of the enameled wire, the amount of waste discharged can also be judged. If the furnace temperature is turned off for a long time, but the temperature indication value is still high, it means that the heat generated by catalytic combustion is equal to or greater than the heat consumed by the oven, and the oven will be out of control at high temperature, so the waste discharge should be increased appropriately.
If the furnace temperature is heated for a long time, but the temperature indication is not high, it means that the heat consumption is too much, and it is likely that the waste volume is large. After the inspection is confirmed, the waste volume should be appropriately reduced. When the scratch resistance of the enameled wire is poor, it may be that the gas humidity in the furnace is too high, especially in humid weather in summer. The humidity in the air is very high. In addition, the moisture generated after the catalytic combustion of the solvent vapor makes the gas in the furnace The gas humidity is higher, and the amount of waste discharged should be increased at this time. The dew point of the gas in the furnace is not more than 25℃. If the gloss of the enameled wire is poor and not bright, it may also have a small amount of waste. This is because the cracked low-molecular substances are not discharged and attached to the surface of the paint film to make the paint film lose its luster.
Smoke is a common undesirable phenomenon on horizontal enamelled furnaces. According to the ventilation theory, the gas always flows from the point with high pressure to the point with low pressure. After the gas in the furnace is heated, the volume expands sharply and the pressure rises. When a positive pressure appears in the furnace, the furnace mouth will emit smoke, which can increase the exhaust air volume or reduce the air supply volume to restore the negative pressure zone. If there is only one end of the furnace mouth with smoke, it is because the air supply at this end is too large, and the local air pressure is higher than the atmospheric pressure, so that the supplementary air cannot enter the furnace from the furnace mouth, reducing the air supply volume and causing the local positive pressure to disappear.