The drying room is generally equipped with a circulating fan and an exhaust fan. The circulating fan draws air from the drying room, and then sends it back to the drying room after being heated by the heating device (heater or heat exchanger). The exhaust fan removes the solvent vapor and oil fume generated during the drying process from the drying room.
hot air circulation system, the hot air drying oven relies on the convective heat transfer of the circulating air, the heating rate of the to-be-dried material and the uniformity of the drying temperature distribution depend on the design of the hot air circulation system. Therefore, the hot air circulation is the key to the design of the drying room. It is composed of a fan, a circulating fan, a blowing port, and a circulating air heating device.
The coated object should be at the same temperature in the drying room. This is very important. It is necessary to keep the air speed of the drying room uniform, and the design adopts an adjustable damper to adjust the air speed of the air outlet. When the shape of the object to be coated is flat, etc., high-speed blowing can greatly shorten the heating time.
The methods for blowing air include down blowing, measuring blowing, up blowing, etc., depending on the shape of the object to be dried, the way of conveying and hoisting. There are also two combinations, down blowing and side blowing, and up blowing and side blowing.
Lower blowing is generally suitable for hanging conveying; side blowing is suitable for conveying plate-shaped and rod-shaped objects, and upper blowing is suitable for ground conveying.
The drying quality (such as appearance and decoration) is required to be high, and indirect heating is adopted, that is, the combustion gas (flue gas) passes through the heat exchanger to heat the circulating air in the drying chamber, and the burner participates in the hot air circulation. Use direct heating and indirect heating for low-quality products, and then increase by 20-30%.