As to the natural storage materials,the air heating furnace of vertical grinding mill must be configured,unless the materials are dried. It is better to use an air heating furnace to dry the materials so that the  fine powder after grinding will be flew out quickly to improve the capacity. It is decided by the structure of grinding pan. If the wet materials are not dried,the capacity will be reduced, and it also will influence the operating stablity of the vertical grinding mill.

The model of the air heating furnace is decided by the moisture content of the materials. The wet materials need larger power air heating furnace. In contrast,the dry need smaller power.