Abstract:

Considering the difficulty of tilted falling of wet particles due to their poor flowability, a visualized tilt-fall experimental setup with mechanical vibration coupled with auxiliary fluidized gas was established, the effects of liquid saturation S, surface tension σ and tilt angle δ on the mass flow rate of three types of wet Geldart-D particles (plastic beads, glass beads and zirconia beads) were investigated, and three auxiliary dropping methods including individual mechanical vibration, individual auxiliary fluidized gas and vibration coupled with auxiliary fluidized gas were compared and evaluated. The research results show that, affected by the liquid bridge force, the mass flow rate q_m of the wet granule blanking process was reduced by more than 60% compared with that of the dry granule. The mass flow rate q_m of wet particles during tilt-fall increased with an increase of vibration intensity Γ and auxiliary fluidized gas velocity u_f. The effect of vibration intensity Γ on heavy particles such as glass beads and zirconia beads was comparatively considerable, and the influence of the auxiliary fluidized gas velocity u_f on the light particles, e.g., the plastic beads was more obvious. The auxiliary drop method of vibration coupled with auxiliary gas brings about higher wet particle drop mass flow rate under the same energy consumption, which is considered as the more energy-efficient method compared with other methods.

Key words: particle, flow, tilt-fall, agglomeration, vibration intensity, fluidized gas

摘要：

针对湿颗粒流动性较差、倾斜落料困难的问题，建立了机械振动耦合辅助流化风的可视化倾斜落料实验装置，研究了液体饱和度S、表面张力σ和倾斜角度δ对三种Geldart-D类湿颗粒(塑料珠、玻璃珠、氧化锆珠)倾斜落料量的影响，并对机械振动、辅助流化风和振动耦合辅助流化风三种助流落料方法进行了实验比较。研究结果表明，受液桥力影响，湿颗粒落料过程的质量流量q_m较干颗粒降低60%以上。随振动强度Γ和辅助流化风气速u_f的增加，湿颗粒质量流量q_m增加，其中振动强度Γ对重质类颗粒(玻璃珠、氧化锆珠)的强化效果较佳，辅助流化风气速u_f对轻质类颗粒(塑料珠)的强化效果较佳。相同能耗条件下，振动耦合辅助流化风具有更高的质量流量q_m，是相对节能的助流落料方法。

关键词: 粒子, 流动, 倾斜落料, 团聚, 振动强度, 流化风