摘要 |
A method and apparatus for the dry grinding of solids, comprises initial coarse grinding of the solids in a controlled vortexing of a fluidized bed and directing the solid fine particles generally upwardly into a vortex grinding zone and grinding the upwardly directed solid particles in the vortex grinding zone by passing a portion of the particles through the vortex grinding zone. The vortex grinding zone comprises at least one successively vertically disposed grinding stage comprising passing particles upwardly through at least one horizontal vortex zone of an annular gap, defined by a stationary plate with a circular aperture, hereafter cleaning up the upward moving product mix by eliminating coarser particles by gravity separation with a centrifugal expelling fan and subjecting the remaining part of the upwardly particles to the vertical vortexing of a rotating semipermeable means, defined by a rotating assembly containing a broad mesh screen therein.
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