Difference between revisions of "Impact Mills"

[[Category:Particle Size Reduction]]{{Knoppen}}   

[[File:Impact_Mill.jpg |thumb| right |Impact Mill]]  

'''Impact Mills''' are screenless, high-speed beater mills for pulverising  and micro-pulverising. The product to be processed is fed to the mill  centrally via an inlet box at the top and is pre-crushed by primary  beater tools when reaching the top of the rotor. The beaters also  accelerate the product, moving it into the milling zone proper, at the  side of the rotor. There the grinding stock fluidised in the air flow is comminuted by the grinding tools (rotor, stator).  The stator is formed by a cover enclosing the rotor. The inside of this  cover is provided with toothed grooves running vertical, i.e. crosswise  to the sense of rotation of the rotor. The outside of the rotor is  covered by numerous U-shaped sections which form a deep cassette-type  structure. This geometry creates extreme air whirls in the rotor's grinding zone which induce intense secondary comminution  processes due to the particles crashing into each other and due to  friction and shearing forces. The final particle size can be adjusted  over a wide range by changing the grinding rotor clearance, air flow and  rotor speed.