Method and apparatus for comminuting solid particles

A device for comminuting solid particles to produce microparticles and drying said particles comprising:

• a cylindrical vessel having outlets near the upper end thereof;
• means for feeding said particles into said vessel;
• a drive shaft rotatably mounted in said vessel;
• means for rotatably driving said drive shaft;
• a plurality of screens connected to said drive shaft for rotation therewith, said screens being spaced from each other in opposing relationship;
• a compressor fan connected to said shaft for rotation therewith, said compressor fan being positioned in said vessel to drive the particles upwardly through said screens;
• first and second discs connected to said shaft for rotation therewith, said discs being spaced from each other along said shaft and positioned between said screens and said outlets;
• first and second plates fixedly attached to said chamber in positions opposite said first and second discs respectively, said plates having circular apertures formed therein in which the discs are located, a circular space being formed between each of said plates and its associated disc, a vortex zone being formed in said circular space when said discs are rotated by said shaft;
• cyclonic classifier means for separating microparticles from gas in which they are carried;
• first and second centrifugal fans connected to said shaft for rotation therewith, said first fan being positioned between said first and second discs and opposite a first one of the outlets of said vessel to drive the comminuted particles and gas carrying said particles through said first one of said outlets to said cyclonic classifier means, said second fan being positioned between both of said discs and the other end of said chamber and opposite a second one of the outlets of the chamber to drive microparticles and gas through said second one of said outlets to said cyclonic classifier means;
• and
• means for recycling gas from said cyclonic classifier means back to said vessel, said recycling means including means for removing moisture from said gas.

A method for comminuting solid particles comprising the steps of:

• feeding said particles in a gas stream into a vessel;
• driving said particles and said gas stream upwardly so that they are suspended in said vessel;
• comminuting said particles in a vortex zone formed in said vessel;
• feeding the comminuted particles to a cyclone to separate said particles from said gas stream;
• recycling the gas stream from said cyclone back to said vessel;
• and
• removing moisture from said gas stream during said recycling.