On the Discharge from the Bucket of the Bucket Elevator

Abstract

The handling capacity of a vertical bucket grain elevator of centrifugal discharge type, which was deficient owing to the lower discharge efficiency, was considerably improved by changing the shape of the bucket. Further researches on the behavior of grain until the discharge which had caused the improvement were carried out on a model equipment and the following results were obtained. In regard to the discharge efficiency the bottom and top angles of the bucket are essential and those exceeding 25° and 70° respectively seem to be more favourable. If the bottom angle is smaller than 25°, some part falls out before reaching the chute ; if the top angle is smaller than 70°, some quantity is overflowed before the bucket arrives at the top position. Discharge takes place mostly passing closely over the bucket edge in an approximately parabolic motion with a initial velocity nearly equal to the circumferential velocity of the edge.