The Working Principle Of A Drum Dryer For Wood Chips

1. Heating process

The heating process of the wood chip dryer is to heat the air through the heater, send the hot air into the inside of the drum, and conduct heat exchange with the moist material so that the moisture in the material is evaporated and taken away. Heaters usually use fuel, natural gas, steam, and other energy sources to convert energy into heat. The thermal power and energy consumption of the heater are important factors affecting the thermal efficiency of the tumble dryer. During the heating process, the temperature of the material gradually increases, and the water begins to evaporate, forming steam with a certain humidity, which is the prerequisite for entering the next process.

2. Heat transfer process

During the heating process, hot air exchanges heat with the material to achieve the purpose of heat transfer. There are three ways of heat transfer: convection heat transfer, radiation heat transfer, and conduction heat transfer. The drum dryer mainly dries materials through convective heat transfer. The hot air forms convection inside the drum, transferring heat energy to the surface of the material, causing the surface temperature of the material to gradually increase, causing the water on the surface of the material to evaporate. The efficiency of convective heat transfer is affected by many factors, such as wind speed, humidity, temperature, etc.

3. Mass transfer process

Mass transfer refers to the transfer process of matter through diffusion, convection, or conduction of matter. In a drum dryer, mass transfer is the process of diffusing the moisture in the material from the surface of the material into the air. The rate of mass transfer depends on factors such as the humidity of the material surface and the humidity and temperature of the air. The efficiency of the mass transfer process is one of the important factors affecting the drying of materials.

The working principle of the drum dryer for wood chips is to dry materials through three processes: heating, heat transfer, and mass transfer. During the heating process, the heater heats the air to a certain temperature and then sends the hot air into the inside of the drum to exchange heat with the material. During the heat transfer process, hot air forms convection inside the drum, transferring heat energy to the surface of the material, causing the surface temperature of the material to gradually increase, causing the water on the surface of the material to evaporate. During the mass transfer process, the moisture in the material diffuses from the surface of the material into the air. The working principle of the drum dryer is the basic principle in the material drying process. Mastering its working principle will help improve the drying efficiency of the equipment and ensure the quality of material drying.