Dynamic filtration method and apparatus for separating nano powders

A multiple-stage powder separator apparatus for separating nanometer-sized particles of a powder, said apparatus comprising:

• (a) powder feeder means;
• (b) at least a first stage filter device in flow communication with said powder feeder means to receive powder particles therefrom;
• said filter device comprising casing means;
• at least a flexible filtering mesh inside said casing means with mesh openings at least two times larger than the average size of said particles to be separated;
• said filtering mesh and said casing means forming a first outer cell therebetween and a first inner cell inside said filtering mesh, said first inner cell in flow communication with said powder feeder means;
• rotor equipped with a plurality of powder classifying vanes being inside said inner cell and swirling around an axis of said rotor, said rotor being driven by a first motor means;
• said swirling vanes driving fine particles smaller than a first desired size to permeate through said mesh openings to enter said first outer cell, leaving behind coarser particles inside said first inner cell;
• vibration means in shaking relation to said flexible filtering mesh to form dynamic mesh holes;
• control means in control relation to said vibration means;
• first powder collector in flow communication with said first inner cell to receive said coarser powder particles therefrom;
• particle size sensor means in electronic communication with said control means to measure the sizes of said coarser particles and feed the acquired size signals to said control means;
• and
• (c) dust collector means in flow communication with said at least first stage filter device to receive said fine particles therefrom, said dust collector means comprising a dust filter to filter out finest particles of desired sizes and a collector container to collect said finest particles, permitting the residual gas to exhaust through said dust filter.