Classifying apparatus for particulate materials

Apparatus, for classifying particulate material, comprising in combination:

• i. a housing having a cylindrical wall and having at its top end a discharge opening for fine particulate material and at its bottom end a discharge opening for coarser particulate material
• ii. means adjacent the bottom end of said housing for admitting a flow of fluid tangentially into said housing, thereby to create an upward whirling flow of fluid in said housing towards said top end discharge opening
• iii. means disposed intermediate said top end and said bottom end of said housing for admitting mixed fine and coarser particulate material into said upward whirling flow of fluid
• iv. rotary vanes disposed in said housing adjacent the top end thereof for separating coarser particles from fine particles, such that said fine particles may be discharged through said top end discharge opening
• v. a rotary disc disposed in said housing above said flow admitting means and below said rotary vanes, said disc including a plurality of radial nozzles,
• vi. blower means connected to said nozzles for blowing fluid through said nozzles to project said fluid from said blower means as jet streams against the wall of said housing
• vii. a plurality of guide plates disposed in said housing adjacent to said flow admitting means for smoothly guiding coarser particles falling down along the wall of said housing such that said falling particles are not disturbed by the whirling flow of fluid admitted through said flow admitting means, and
• viii. a rotary dispersion plate disposed in said housing between said rotary disc and said material admitting means to receive thereon material admitted by said material admitting means, said plate being of less diameter than said rotary disc and being perforated to permit a portion of said admitted material to fall into a space between said plate and said rotary disc.