Feed at center:
After materials are fed into the hopper, they are, through a central feeding hole, thrown to the impellers, which are rotating at a high speed. Then, the material are accelerated and thrown out of impeller area. These part of materials, first, impact on the other part of materials, which are falling down, and then, they together strike on the material layers or on impact blocks. Due to rebound, they will back to top of crushing cavity and again be shot back to strick on another part of materials which are shot from the impeller flow and form a continuous material curtain. The final products will be discharged from the discharge open at the bottom.