Effects of Mill Performance on Unburnt Carbon in Coalfired Boilers
In addition, the primary air flow rate through the mills is above 100 kNm 3 /h, whereas the historical operational values were between 80 to 100 kNm3/h. The higher primary air flow reduces the residence time of coal particles in the mills, reducing the grinding time and thus resulting in coarser coal particle sizes exiting the mill.