Comparison of Solid-Liquid Dispersion Performance with Three Types of Impellers in Slurry Polymerization Reactor
1. State Key Laboratory of Polyolefins and Catalysis, Shanghai Research Institute of Chemical Industry Co, Ltd, Shanghai 200062, China;
2. Shanghai Key Laboratory of Catalysis Technology for Polyolefins, Shanghai Research Institute of Chemical Industry Co, Ltd, Shanghai 200062, China;
3. School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Abstract：A solid-liquid dispersion CFD model and cold model experiments of the anchor impeller (AI), double helical ribbon impeller (DHRI) and four pitched blade impeller (FPBI) in a conical reactor were established in order to investigate the influence of blade form and rotating speed of blade on the liquid-solid dispersion performance in the slurry polymerizer. The average error between the simulated torque and the experimental value for the three types of impellers was less than 10%. The simulated concentration field was consistent with the solid holdup distribution obtained from the photography experiment, and the simulated results were reliable. The results showed that the stirring power increases with the increase of agitation speed, and the power consumption relationship of the three impellers was AI > DHRI > FPBI at the same agitation speed, the power number relationship of the three impellers was FPBI > DHRI > AI at the same Reynolds number (Re), and the power consumption relationship for achieving the same concentration variance was AI> DHRI > FPBI. According to the concentration distribution on the characteristic line, the critical speed of full mixing existed for all three impellers. Taking the variance of concentration field as the quantitative index, the optimal solid-liquid dispersion speed existed for all three impellers. Combining the above conclusions, the recommended range of actual operating speed was 120-480 r/min for the anchor impeller, 240-600 r/min for the helical ribbon impeller and 120-600 r/min for the pitched blade impeller.
WANG Xiugang1,2,3 et al. Comparison of Solid-Liquid Dispersion Performance with Three Types of Impellers in Slurry Polymerization Reactor[J]. 化学反应工程与工艺, 2019, 35(4): 358-367.
