Annular grinding mill
AssigneeMicroprocess Ltd.
InventorsFrank A. Matter, Hans E. Brunner
Life of this patent
Estimating the term…
Abstract
A wet mill for producing very finely ground end products with particles in the low micron range from feed particles sized up to about 300 microns has a cylindrical rotor closely inserted within a cylindrical vessel with a pumping space between the bottom of the rotor and the vessel and a narrow annular gap between the side walls of the rotor and vessel. The particles to be ground are introduced into the pumping space from which they are forcefully discharged by rotating vanes on the bottom of the rotor to pass upwardly through the grinding medium in the annular gap. The grinding medium is retained in the annular gap by the force of the pumping action and if thrown up may be caught on a screen over the outlet while the finer ground particles are discharged.
Claims12
A grinding mill for reducing the size of particles of material in a fluidized suspension form by forceful interaction with a particulate grinding medium, comprising a cylindrical vessel having smooth internal side walls, a cylindrical rotor having a smooth external side wall, the cylindrical rotor being closely inserted in the cylindrical vessel whereby a narrow annular gap is disposed between the side walls of the rotor and vessel, the rotor and vessel having circular bottoms, rotary means mounting the rotor concentrically with the cylindrical vessel with a pumping space disposed between the bottom of the rotor and the bottom of the vessel, drive means connected to the rotor for rotating it within the vessel, impeller means disposed within the pumping space, the impeller means being constructed and arranged for generating a positive forceful flow of slurry from the pumping space up through the annular gap whereby the grinding medium and particles being ground are substantially prevented from dropping downwardly from the gap into the pumping space and the ground particles are carried upwardly through the gap, and the impeller means comprises a circular array of pumping vanes on the bottom of the rotor disposed within the pumping space.
Dependencies are inferred from the claim text.