1. Short drying time, fast dewatering.
2. High thermal efficiency and without overheat.
3. High degree of automation, good quality dry product.
4. Simple structure, little space and cost down.
5. Flexible to choose steam, electricity, blasting furnace, fume furnace or waste heat of boiler as heating source according to users ‘condition and material heat-resistance temperature. The temperature of thermal medium can be chosen from 120℃ to 780℃.
Airflow dryer is also called as hot air tube dryer, which adopts instant drying principle. As hot air moves very fast, wet granula is scattered and driven by high-speed hot air. Thermal efficiency is improved by large contact area between air and material and higher speed of air than material. In this way, unbound water can be nearly removed totally. Moreover, material will not be metamorphic. It saves space and increases efficiency. It is suitable to dry wood powder, sawdust, rice husk, bamboo powder and bran, etc., light and low-density material.
Based on technology of straight pipe air dryer, we develop variable diameter air tube (pulse pipe), in order to increase thermal efficiency. Material goes into small-diameter pipe at first. Meanwhile, air flows at high speed and so it accelerates material. When it comes into bigger-diameter pipe, it stops accelerating. Because of material inertance, its speed is faster than air speed. Therefore, its speed keeps decreasing because of airflow resistance. When material goes to small-diameter pipe, it accelerates again. Material speed increases and decreases again and again, thus heat exchange area and relative velocity are quite big. In this way, it increases thermal efficiency. Dried material will be collected by cyclone dust collector, end gas will be exhausted into atmosphere by induced draft fan.