摘要 |
<p>The invention provides a method of improving an existing pulveriser mill by provision of an improved port ring (124) located around the circumference of a grinding ring of the mill for common rotation therewith. The conventional port ring has openings separated by thin vanes. The improved port ring (124) has wider openings (142) now separated by lands (144). The wider openings can pass more unground materials back through the port ring as rejected material but the overall air mass flow can be kept unchanged.</p> |