During the production of raw material vertical roller mill, we sometimes encounter the failure of rotary feeder. One company has shared with us the solution to the material deposit and shutdown of roatry feeder, as follows:
This company's chaeng raw material vertical roller mill system was completed and put into operation in March 2008. During the operation, under the influence of the rainy season, low silica and iron raw material moisture, the air-locking type rotary feeder shut down 85 times because of serious material deposit from 2013 to 2014 in January.

1.Solutions
In February 2014, this company took use of the maintenance time of rotary kiln to increase the Φ209 hot air duct pipes (including manual butterfly valve) at the both end of rotary feeder. The inlet port of the pipe was connected with the hot air inlet port of the vertical roller mill, and air outlet port was connected to the outlet pipeline of separator (see Figure 1). Increase the grid at the outlet valve of the pipe to prevent the small particles from entering the separator of the vertical roller mill.

2.Effect
The technical transformation time was February 2014. After the implementation, the shutdown frequency of vertical roller mill caused by the material deposit in rotary feeder was greatly reduced. Until 2014 December, it happened only once, and the result was very satisfactory.