Coverging/diverging orifice assembly for embodiment in a bowl mill

摘要

A vane wheel arrangement (30) particularly suited for use in a bowl mill (10) of the type that is employed for purposes of effecting therewithin the pulverization of materials such as coal. The subject vane wheel arrangement (30) which is positioned within the bowl mill (10) so as to be located in the path of flow of the air that in flowing through the bowl mill (10) transports therewith the pulverized material, is operative to effect a primary classification of the pulverized material. Encompassed within the subject vane wheel arrangement (30) are vane means (36) supported on the rotatable grinding surface (14) of the bowl mill (10) for rotation therewith, and a converging/diverging orifice means (38) located in spaced relation to the rotatable grinding surface (14). Both the vane means (36) and the exposed surfaces of the converging/diverging orifice means (38) are formed of a material that is noted for its good abrasive resistant qualities.