Effect of Turbulence on the Performance of a Gas Cyclone

Particle dispersion in turbulent flow is ubiquitous in many applications. This paper investigates the effect of turbulent flow on the performance of a gas cyclone involving gas-particle flow by using computational fluid dynamics. The turbulence of gas was simulated with the Reynolds stress model, while particles were simulated by the Lagrangian particle tracking model, in which the stochastic tracking (random walk) approach was used to predict the particle dispersion due to turbulence. It is shown that gas turbulence can deteriorate the collection efficiency by increasing the possibility of particles to disperse into the inner vortex. The turbulence plays a critical role at the bottom of the vortex finder where the turbulence intensity is the highest. The negative effect is more significant when the ratio of the radial drag force to the centrifugal force on particles is close to 1, which can be one of the reasons for the poor collection of PM2.5 in cyclones.