不規則形状粒子群の干渉終速度
管路における堆積層を伴うスラリ-の流動に関する研究
1988 年 104 巻 1206 号 p. 505-512
詳細
1988 年 104 巻 1206 号 p. 505-512
The type of slurry flow behavior attained in a given pipe diameter is largely determined by the settling velocity of solid particles in a fluid. However, it varies as a function of slurry concentration C, particle diameter, and particle shape. Since the slurry are composed of irregular shaped materials in most slurry pipeline application, design requires an accurate knowledge of the effect of a shape factor used for evaluating the particle shape on terminal settling velocity Vt and on hindered settling velocity Vε
The object of this paper is to find the method of estimating Vε of irregular shaped particles in a fluid bounded by rigid wall. It is well known that a sedimenting suspension and a fluidized bed are similar hydrodynamically, therefore experimentswith a variety of materials were carried out in batch fluidized systems, covering the particle Reynolds number range 180 to 1400.
Based on the experimental results we discussed the modified Richardson's equation which could be describedby: Vε/Vt=Ko (1-C) n
The index n is a function of the particle Reynolds number and of the dimensionless number depending upon the configulationof suspended particles, while the factor Ko represents the wall effect and increases with area index of particles. Experimental data were analysed taking into account the particle segeregation and the types of behavior of fluidized systems. Moreover, the generalized equation of Vε was derived, and then the quantity ψ(ε) representing the mutual interferenceof particles was determined by experiments.
