傾斜といにおける粒体の流量

抄録

Effects of the length of channel and the kind of granular masses on the flow rate have been investigated. Samples are seashore sands sieved by Japanese Industrial Standard sieves. The hopper by which the sample is supplied is provided with a curved tube of rectangular cross section. By adjusting a stopping plate which can be raised or lowered at will, the outlet area is varied.
The obtained results are as follows. If the channel is not connected with the hopper, the relation between the flow rate W from the hopper alone and the raised height of the stopping plate x can be shown as
W=Kxⁿ
where the constant n is between 1.5 and 1.6. The larger the granule, the larger the constant.
When the channel is connected with the hopper, a quite different state is observed. If the length of the channel is long enough, the flow rate W increases with x at first, but when W reaches a certain value it remains constant. The saturation flow rate depends on the inclination and the kind of granules, but is independent of the length of the channel. For granules with small saturation flow rates, the angle of friction against the channel bottom is small but the angle of repose is large. It seems that the internal friction of the mass of granules is at least one important cause of the flow rate becoming saturated.