Separation of paddy and brown rice in a vertical stream.
1990
Kamide J. | Tsuchiya M.
The authors have explored on the possibility of the separation of paddy and brown rice in a vertical air stream. Some experiments were carried out by a batch and a continuous feed system. The pneumatic separation of grains are caused by the difference of these terminal velocity. The separating performance was affected by the ratio of gain to air, and by the behavior of grain in a vertical air column, therefore the separating efficiency increased, as the column height increased and the feed rate decreased. The separating efficiency had a maximum at the air velocity of about 6-5.5m/s, which was the middle value of the both terminal velocity of paddy and brown rice. The collecting percentage of brown rice decreased as air velocity increased, especially over the air velocity for maximum efficiency. The choice of air velocity was critical in attempting to reconcile the conflicting requirements for the both maximum brown rice collection and minimum paddy content in the product. The free air stream velocity distribution cross the column at the height of feeder was determined on 21 points, and the deviation was in the range of 7-8% on each system. In a large scale experiment system, the best performance was 25 kg/h in brown rice collection with the prechamber type, and the power requirement was about 200W in various system.
显示更多 [+] 显示较少 [-]