Screening machine

A screening machine comprising a plurality of rotors (20) adapted such that in a frame (10) axes of said rotors (20) are arranged parallel to one another from a supply side where objects to be screened (W) including mixed substances different at least in size are supplied from above by a conveying means (C1) to a discharge side where the remainders after screening are discharged, and such that said rotors (20) are rotated in the same direction by a rotating drive means (30) to feed the objects to be screened (W) on said rotors (20) from the supply side to the discharge side and each rotor (20) further comprises a plurality of large diameter sections (25) and a plurality of small diameter sections (28) alternately disposed in the axial direction of each rotor (20) and arranged in a staggered relation in the feeding direction to define screening gaps (G) having desired dimensions between said large and small diameter sections (25-28) and wherein said plurality of rotors (20) are classified into several groups arranged from the supply side to the discharge side, and the peripheral speeds of said rotors (20) of the groups are decreased in order of the classified arrangement from the supply side to the discharge side.

A screening machine comprising a plurality of rotors (20) adapted such that in a frame (10) axes of said rotors (20) are arranged parallel to one another from a supply side where objects to be screened (W) including mixed substances different at least in size are supplied from above by a conveying means (C1) to a discharge side where the remainders after screening are discharged, and such that said rotors (20) are rotated in the same direction by a rotating drive means (30) to feed the objects to be screened (W) on said rotors (20) from the supply side to the discharge side, and each rotor (20) further comprises a plurality of large diameter sections (25) and a plurality of small diameter sections (28) alternately disposed in the axial direction of each rotor (20) and arranged in a staggered relation in the feeding direction to define screening gaps (G) having desired dimensions between said large and small sections (25-28) and wherein said plurality of rotors (20) are classified into several groups from the supply side to the discharge side and the gaps between adjacent large diameter sections of each groups are decreased in the order of the classified arrangement from the supply side to the discharge side.