Motion characteristics and residence time of particles in the new cross structure under constant-pulse condition

Abstract

The residence time of particles in the flow field is highly sensitive to the fluid’s flow characteristics and the particles’ motion. We proposed a dynamic entry mode with the constant-pulse (CP) condition in response to the conditions of symmetric impinging streams and asymmetric impinging streams. Single-particle motion behaviors and particle residence time in a novel cross-type structure reactor we designed were studied and discussed in this article. This was done by looking at how these variables changed depending on the impulse inlet velocity conditions, the reactor geometry, and the particle properties. The results demonstrate that when particle relaxation time is short, those particles without oscillatory motions were directly accelerated to leave the active area. When its relaxation time is reasonably set, even a single particle can hugely elevate the oscillatory motions. With the structure of the novel cross type, the particle merely exhibits three oscillatory under the condition of the symmetric pulse inlet flow and asymmetric pulse inlet flow, notwithstanding, CP contains at least three oscillatory motions. The t tot is the duration that an individual particle spends in the working region. The t tot and active area were affected by inlet velocity, parameters of particles and the shape of the reactor parameters of particles and the shape of the reactor. The t tot raised with τ* increased in a certain range. T is the inlet velocity variation period. The particle resides time at T = T b reaches a maximum in the CP. The maximum residence times T b was affected by particle relaxation time, under CP with a diameter ratio of 5 and inlet velocity difference of 0.8. The particle retention time in the novel cross-type structure reactor was heightened by 7 times. The CP and the novel cross-type structure reactor can improve the retention time of particles in the flow field.