Beater wheel mill

Application

 

Beater wheel mill is high speed (750-1500rpm) coal mill, which is widely used for direct firing lignite pulverizing system in thermal power plant with capacity 200MW or higher. It plays multi-purposes: drying, pulverizing, classifying, conveying. As a leading supplier for beater wheel mill in China, we ever had N, S and MB model for different applications. S type is used for bituminous coal and aged lignite, whose moisture content is lower than 40%, while N type is used for xyloid lignite with moisture content 40-70%.

 

Working principle

 

Beater wheel mill has a fast rotating beater wheel, which is armed with beater plates at radial direction. Its volute casing is covered with wearing resistant steel lining plates. Coal is sent to center beater wheel through chute. Under the impact of beater plates, coal is crushed. Crushed coal will hit on the surface of lining plates and get crashed into powders. Fine particles will be taken away to boiler burner by hot flue gas, oversize particles will be separated by classifier and sent back to beater wheel mill. Impurities like iron blocks are collected in sump on the bottom of casing.

 

Benefits

 

1. Adjustable airflow. On top of classifier, there is adjustment device for overall airflow and inner loop. Regulation ability could 0-30% of rated airflow. It could effective adjust the ratio of air and coal to match with boiler load variation.
2. Higher pressure head up to 2000Pa for pulverized coal conveying.
3. Good adaptability for lignite coal with moisture content 30-50%.
4. Adjustable pulverized coal temperature at outlet. Between coal mill and classifier, there is an inner loop, which has baffle plates to adjust pulverized coal temperature.
5. Beater plates made of high strength, wearing & heat & impact resistant materials.
6. Adjustable and uniform coal particle size.