| 摘要 |
A pulveriser mill having a rotatable grinding ring and a rotatable port ring around the circumference of the grinding ring co-rotatable therewith, the port ring defining around its 360 degree extent a plurality of openings separated by lands, the openings permitting air to flow from beneath the grinding ring to above the grinding ring, and the lands serving as obstructions to the flow of air from beneath the grinding ring to above the grinding ring, wherein the aspect ratio of the openings is in the range from 1:1 to 3:1. |
