Sieve with screen rollers to prevent jamming of oversize grain

摘要

Sieve device for sorting screenings into one or more fine grain fractions and one or more oversized grain fractions, the screening device comprising: (a) a frame (2, 3) and (b) a roll screen (1) arranged side by side about a respective roll axis (R) screen rolls (20, 30) supported on the frame (1, 2), each having a roll body (21, 31) and one or more screen structures (22, 32) projecting radially relative to the roll body (21, 31), (c) wherein between the roller bodies (21; 31) of adjacent screen rollers (20; 30) there is in each case a fine grain screen gap through which a fine grain fraction falls, while during rotary drive of the screen rollers (20; 30) an oversize fraction on the roller screen (1) in the roller axial direction (X) characterized in that (d) the roller body (21; 31) of at least one of the screen rollers (20; 30) radially expands in an axial expansion section (25; 35) in the roller axial direction (X) (e) and the width ( W) of the fine-grain sieve gap, which the widening roller body (21; 31) with the roller body (21; 31) of an adjacent screen roller (20; 30), along the Aufweitabschnitts (25; 35) decreases in Walzenachsrichtung (X).