Sieve chute for feed of bulk grains has full-width curtains preventing entrapment of fine grains in coarse grains such as sand and gravel

摘要

A feed of bulk grains (1) e.g. sand or gravel is sieved and graded as it descends down a plane inclined at an angle alpha, which is also a flat sieve (2). The in-fed of bulk grains has to pass one or more throttle gaps (10) which are formed by semi-rigid curtains (4) spanning the sieve (3) width and transverse to the direction of flow. The size of the vertical gap (10) is adjustable.