Also known as air conveying, it uses air energy to transport the granular material in the closed pipeline along the direction of air. It is a specific application of fluidization technology. Pneumatic conveying device is simple in structure, easy to operate, it can be set as horizontal, vertical or inclined direction of the transport process. During the process, material can be heated, coolled, dried and so on. Pneumatic conveying is divided into dense phase gas transport, positive pressure thin phase gas transport according to transported air pressure level.