Abstract: A mill (10) for grinding garbage or like material is disclosed including grinding rotors (48-50) rotatably fixed to and longitudinally adjustable on a shaft (44) rotatable in a grinding chamber (26). Each of the rotors (48-50) include a multiplicity of arms (64) extending radially from a circular disc (54). The arms (64) have replaceable tips (284) including first and second legs (288, 290) forming an L-shaped body portion. First and second bolts (308) extend through apertures (310) in the arm (64) and are threaded into apertures (312) in the first leg (288). A third bolt (314) extends through a counterbore (320) and an aperture (316) in the second leg (290) and is threaded into aperture (318) of the radially outer end of the arm (64). Material anti-wrap provisions (140) in the form of wing plates (240) oriented to extend generally radially from the shaft (44) are provided between the top plate (28) and the first rotor (28) and also between the rotors (48-50).

Abstract: A mill (10) for grinding garbage is disclosed including an octagonal shaped grinding chamber (26). Grinding rotors (48-50) are rotatably fixed to a rotatable shaft (44). An impeller rotor (51) is also rotatably fixed to the shaft (44) below the grinding rotors (48-50). The impeller rotor (51) discharges a stream of air, entrapped material, and projectiles into a projectile deflection device (182) which includes an upwardly sloping bottom plate (202) which deflects the projectiles into an end plate (204) to reduce the kinetic energy thereof. The air stream and entrapped material pass from the projectile deflection device (182) into a plenum (210) which reduces the velocity of the air stream to release much of the entrapped material, with the material release being enhanced by baffles (224) providing a tortuous path for the air stream in the plenum (210) before it enters a cyclonic material separator (216).