竪型リボン混合機の所要動力の解析

抄録

Power requirement for agitating a powders bed in a vertical ribbon mixer has been analyzed by introducing a simplified model, which regards the motion of the helical ribbon blade as that of a flat plate.
The total force exerted on the blade by the powders bed is assumed to be the sum of; (i) the pressure force by the powders bed in the passive Rankine state, (ii) the shear force acting on the circumscribed cylindrical surfaces about the ribbon blade, and (iii) the inertia force for accelerating the powders mass surrounded by the cylindrical surfaces. Among these forces, the shear force has been dominant.
This assumption leads to the equation
N_P=K₀N_M^-1+K₃
The ratio of the total force to the inertia force, N_P and the ratio of the inertia force to the shear force, N_M are calculated and N_P is plotted against N_M^-1.
The coefficients, K₀ and K₃, were determined experimentally as; K₀=1.08 and K₃=0.025. An agreement within an accuracy of ±20% was obtained between the measured power and the one predicted by this equation.