粉煤灰预处理浆液槽流场分析与搅拌参数优化

Flow Field Analysis and Stirring Parameters Optimization of Fly Ash Pretreatment Slurry Tank

粉煤灰预处理浆液槽在混合的同时实现预反应,并对颗粒细化,为后续预脱硅反应奠定基础.其浆液调配的准确度与料浆混合的均匀度将直接影响粉煤灰预脱硅效率,继而影响高铝粉煤灰制备氧化铝的产品质量及能耗.结合某单位生产现场的物料细化实验数据,采用实验室搅拌实验验证的数值模拟方法对该单位浆液槽内的流场进行分析,在此基础上对其操作参数进行优化.研究发现优化转速与物料粒径呈正相关关系,搅拌功率随颗粒粒径、初始固相体积分数及搅拌转速的增加而增大,其中搅拌转速对功率的影响最大,优化后搅拌能耗可降低30%,左右.

The fly ash pretreatment slurry tank provides a foundation for the pre-desilication process in the preparation of aluminum oxide from high-alumina fly ash as it can offer place for the pre-reaction of materials,blend the fluid and particle well and pulverize the particles at the same time.So the accuracy of the blending process and the uniformity of mixture in it will directly influence the pre-desilication efficiency and then the quality of products and total energy consumption.Based on the refining particle experimental data from the industry and the stirring experimental data in laboratory, a numerical computation method was adopted to simulate the flow field in the slurry tank and then optimize the operating parameters on the basis of the calculation results. The study indicates that the optimized stirring speed is positively correlated with the particle size of material,and the stirring power increases with the increase of particle size,initial solid volume fraction and stirring speed,among which the stirring speed has the most significant impact on the stirring power.Calculation shows that the energy consumption can be reduced by nearly 30% after employing the optimized operating parameters