关键词: 多喷嘴射流式分离器, 气固流动特性, 喷嘴造旋, 数值模拟, 分离, 流动

Abstract: Based on Fluent 6.3.26, the gas-solids two-phase flow behavior and details of multi-jet cyclone with swirling based on nozzles, was simulated and analyzed with the Reynolds stress model (RSM) and discrete particle model (DPM). Compared with conventional cyclones, peak value of tangential velocity and average value of free-vortex reached 160 m·s^-1 and 130 m·s^-1 respectively, generating higher flow rotation intensity. Volume rates of downward flow kept declining along the central line, particularly in the stabilization region, inducing more chances for particles being entrained by inner upward flow with lower collection efficiency. Local roof wall-jet and circulating flow nearby the inlet of the hopper were typical secondary flows of multi-jet cyclone. Gross pressure loss of the separator was 27.43 kPa, consisting of outer swirl flow 4.57 kPa (21.8%), inner swirl flow 5.76 kPa (27.6%) in the nozzles region, and outer swirl flow 5.85 kPa (27.6%), inner swirl flow 4.01 kPa (18.9%) in the stabilization region. Particles with diameters larger than 10 μm could be collected completely with cut-diameter 1.6 μm, making it suitable for industrial application. Analyzing with the particle mechanical model in this paper, the critical diameter of particle that can be separated was 1—2 μm and particle concentration for particles large than 3 μm in the vortex finder was less than 0.15 g·m^-3.

Key words: multi-jet cyclone, gas-solid flow characteristics, swirling based on nozzles, numerical simulation, separation, flow