What are the factors that affect the fluidity of raw coal particles?

　　(1) Moisture of raw coal. When the surface moisture of coal is greater than 8%, the phenomenon of wall hanging of raw coal will occur.

　　(2) Raw coal particle size. The finer the particle size of the coal, the worse the fluidity of the raw coal under its own weight.

　　(3) Ash characteristics of raw coal. The viscosity of the raw coal increases when the Montmorillonite content in the ash is higher.

　　4) Coal bunker and coal feed channel structure. The wide and steep coal bunker with smooth lining and loosening device is conducive to smooth coal loading. The coal drop pipe should be as vertical as possible, the inner wall should be smooth.

　　5) Position of coal feeding port. The closer the coal feeding port is to the air distribution plate, the higher the internal pressure, and the flue gas will easily flow back.