Classifier mills for coal grinding and drying

摘要

This report presents a special air classifier mill for coal grinding. Air classifier mills are using the two fundamental process steps grinding and classifying in one machine. An essential advantage is the independent operation of grinding rotor speed and classificer rotor speed. This offers a good control of the produced particle size distribution and a great flexibility in process control. So using an air classifier mill for grinding coal with following direct injection into the firing chamber there is a good control of burn-out. Another advantage is that drying of coal can take place as a parallel step by heating process air passing the classifier mill. In this report an air classifier mill, some typical process data as particle size distributions, possible throughput and an industrial application are shown.