水平回転円筒による粉体の流動性の測定

抄録

In order to measure the fluidity of powder kept in flowing state, the movement of powder in a rotating horizontal cylinder is first analyzed in analogy of that of fluid. The stationary angle of inclination between the free surface of fluid in a rotating horizontal cylinder and the horizontal plane is measured from the profile of the fluid at one end of the cylinder, and the relations of this angle to the amount, viscosity, density of the fluid and the rate of rotation are theoretically derived, which are verified by measurements on several liquids. By applying this derivation to the case of powder, a quantity which may be called the viscosity of powder is obtained. Though this quantity can reasonably be applied to flowing powder mass as viscosity, observation made on velocity distribution of powder particles proved that the whole mass is not actually flowing, it consists of two parts: the one is actually flowing with velocity gradient between particle layers, the other one which is close to the cylinder walls follows the motion of the cylinder in bulk with no relative movement between particles.