What are the characteristics of the cylinder steel ball mill and the medium speed coal mill, and under what circumstances are they suitable for use


Release time:

2021-06-09

The low-speed coal mill is mainly a drum type steel ball mill, generally referred to as a steel ball mill or ball mill. It is a rotating cylindrical or tapered drum with steel balls inside. The speed of the drum is 15~25 rpm.

The low-speed coal mill is mainly a drum type steel ball mill, generally referred to as a steel ball mill or ball mill. It is a rotating cylindrical or tapered drum with steel balls inside. The speed of the drum is 15~25 rpm. During work, the steel balls in the cylinder continuously hit and squeeze the coal block to grind the coal block into pulverized coal. Then the coal is dried by the hot air passing into the drum and the pulverized coal is sent out, and after being separated by the separator, the pulverized coal of a certain particle size is sent to the pulverized coal silo or directly sent to the pulverized coal burner. The steel ball mill is bulky, high power consumption and high noise; However, it has a wide range of adaptability to coal types and reliable operation, which is especially suitable for grinding hard anthracite. 
  
Medium speed coal mill The speed is 50~300 rpm, and there are many types. Common are flat disc mills, bowl mills, E-mills and roller mills. Their common feature is that the milling part consists of two sets of grinding bodies moving relative to each other. The coal block is crushed by extrusion, milling and crushing between the surfaces of these two groups of milling bodies. At the same time, the hot air passing into the coal mill dries the coal and sends the pulverized coal to the separator in the upper part of the milling area. After separation, the pulverized coal of a certain particle size is brought out of the mill with the air flow, and the coarse pulverized coal is returned to the milling area for regrinding. The medium-speed coal mill has compact structure, less metal consumption, small footprint, and less initial investment; The power consumption during operation is small (about 50~75% of the steel ball mill), especially when the unit grinding coal power consumption is not increased much at low load; Low noise; When equipped with rotary semolina separator, the uniformity of pulverized coal is very good. However, the structure and manufacturing are more complicated, the maintenance cost is large, and it is not suitable for grinding harder coal. In large-capacity coal-fired boilers and blast furnace coal injection, bowl type medium-speed milling is more used.