新型碳化塔重碱结晶动力学及添加剂对结晶影响的研究

以空气－ＮａＨＣＯ３饱和液为介质，在新型碳化塔的模拟塔内，测定了气体流速ｕｇ、液体流速ｕＬ、液相内循环速度ｕｃ、晶浆平均停留时间τ等参数对结晶动力学的影响；重点研究聚丙烯酸钠加入碳化塔后动力学参数的变化规律．按Ｒａｎｄｏｌｐｈ和Ｌａｒｓｏｎ模型计算了结晶成核速率Ｂ０和晶体生长速率Ｇ，并建立了结晶动力学方程．结果表明，添加聚丙烯酸钠，有利于增大结晶颗粒，改善重碱结晶质量．

Study on Crystallization Kinetics of NaHCO_3 in a New Type of Carbonating Column and the Effect of Additive

The crystalliztion kinetics has was studied by using a new type of carbonating column simulator consisting of enclosed trays with guide shell. The experimental studies were carried out in this simulator with air as the gas phase and NaHCO3 saturated solution as the liquid phase. The effects on crystallization kinetics of the operating condihons, e. g.gas velocity, liquid to gas loading ratio, liquid recycle velocity and the average residence time of crystalloid solution were syst ematically measured. The variation of the kinetic parameter for NaHCO3 crystal after the adding of polyacrylic soldium in the column was studies experimentally. The rate of nucleus formation B and the rate of crystal growth G were calculated by Randolph and Larson Model. The crystallization kinetics were obtaind by regrcssion of experimental data. Adding and not adding polyacrylic sodium crystallization operations were compared in terms of kinetic parameters. The experimental results indicate that adding polyacrylic sodium can improve the quality of NaHCO3 crystal and increase the particle size.