Air classifier system for the separation of particles

An air classifier device for particulate material comprising:

• a horizontally disposed classification chamber having an upstream end, a downstream end, an upper part and a lower part, said upstream end and said downstream end allowing air flow therethrough;
• air suction means located adjacent said downstream end of said chamber for drawing air through said chamber from said upstream end to create a chamber air stream;
• a feed stream input in said upper part proximate said upstream end of said chamber for feeding particulate material into said chamber for entrainment in said chamber air stream, a vibrating screen feeder juxtaposed to said feed stream input having an amplitude of less than about 5 mm and a frequency of above about 3 cycles per second with openings at least about three times larger than the largest particle in the particulate material;
• a screen section adjacent and upstream of said upstream end of said chamber and said feed stream input, said screen section comprising from two to three, 1-20 mesh, wire screens having a fraction of open area of between about 55 and 60 percent with succeeding screens placed from about 30 to 100 wire diameters apart;
• a honeycomb adjacent to said screen section;
• and
• a plurality of receiver sections, serially disposed in an upstream to downstream arrangement in said lower part of said chamber, for collecting particles falling out of said chamber air stream, and an air inlet in at least one of the receiver sections for providing an upwardly directed air stream through said receiver section of a volumetric air flow less than about one-third of the volumetric air flow of said chamber air stream.

An air classifier for particulate material comprising:

• a substantially horizontally disposed classification chamber with an upstream end and a downstream end allowing air flow therethrough, an upper part and a lower part;
• a feed stream input in the upper part proximate the upstream end of the chamber for feeding particulate matter from a source of such material into the chamber;
• a screen section adjacent and upstream of said upstream end of said chamber and said feed stream input;
• a honeycomb adjacent to said screen section;
• an air suction device located proximate the downstream end of the chamber for creating a chamber air stream between the upstream and downstream ends thereof, said chamber air stream receiving and entraining particulate matter fed into the chamber through the feed stream input;
• and
• a plurality of receiver sections, serially disposed in an upstream to downstream arrangement in the lower part downstream of the feed stream input in the chamber, for collecting particles falling out of said chamber air stream, at least one of said receiver sections having an air inlet thereto that provides an upwardly directed air stream through said receiver section to keep fines entrained in said chamber air stream and moving toward the downstream end, and a receiver section screen for moderating said upwardly directed air stream.