Vertical roller mill are widely used in thermal power plants with the advantages of low investment, simple operation, low power consumption, and compact structure.
Trouble phenomenon:

The coal quality changes greatly, and the raw coal has a large moisture;

Improper adjustment of air and coal volume, out-of-balance of air-to-coal ratio, and too small primary air volume;

The inlet air temperature of the vertical roller mill is too low;

The entrance of the stone coal hopper is blocked or the slag is not discharged in time;

The coal feeder control device is malfunctioning.

Solution:

1. Reduce the amount of coal fed, increase the primary air flow, and increase the outlet temperature of the mill; take precautions during processing to prevent a large amount of coal powder accumulated in the mill from suddenly blowing into the furnace, causing a sudden increase in boiler load and steam pressure;

2. Increase the number of discharges of pebble coal;