Velocity distributions of gas flow and the separation efficiency of the semi-spherical cyclone

Abstract

At present it is difficult to elucidate the separation processes of fine solid particles in turbulent rotational air flow in cyclone dust collectors or in centrifugal classifiers. This is because the correlation between the diffusion processes of fine solid particles on the centrifugal effect and the turbulent rotational flow is not clear. Therefore, in this paper, the tangential and axial velocity distributions in the semi-spherical cyclone (SCL cyclone) were measured in detail. Then, based upon the cut-size X c, the mechanical equilibrium particle size X D1, which can be regarded as the mechanically controllable maximum particle size on the two-dimensional flow model at the outer wall ( r = R 1), and the particle size X PBD for the fractional collection efficiency to be η x = 0.99 were estimated. Then the ratio λ/μ, where λ is the transition probability for the diffusion entrainment, and μ is the centrifugal separation for separation processes with fly-ash particles, was discussed by a model of a simple Markov process with the four types of cyclone dust collectors. In general, the ratio λ/μ tends to decrease with the increasing centrifugal effect of V 0 0/ gR 1.