求翻译：粗粉分离器的任务是把磨煤机出来的过粗的煤粉分离出来，送回磨煤机再磨。采用离心式粗粉分离器。对一定容积的分离器，若提高磨煤通风量，磨煤机出来的煤粉分离度增加，而在分离器内停留时间又将缩短，结果煤粉将变粗，因此磨煤机的通风量是一重要参数。是什么意思？

The Classifier task coal mills out of coarse pulverized coal separated and returned to the coal mill regrinding. Centrifugal Classifier. A certain volume of the separator to improve coal grinding ventilation rate, increase in coal mill pulverized coal separation in turn shorten the residence time wi