氯碱电解槽阳极室内液相返混的研究

发布时间：2018-03-20 23:05

本文选题：液相返混　切入点：氯碱电解槽　出处：《沈阳化工大学》2017年硕士论文　论文类型：学位论文

【摘要】：在离子膜电解槽运行过程中,液相返混程度直接关系到槽内电解液的浓度分布、温度分布以及反应速率和反应产物分布,从而影响电解过程的经济性和电解槽的使用寿命。鉴于离子膜对电解液有低浓度差、低温度差等要求,适当的增大液相返混对电解过程是有利的。因此,本文提出以液相返混程度作为电解槽性能优劣的评价指标。本文采用冷模实验和数值模拟两种方法对离子膜电解槽阳极内液相返混的影响进行了研究。利用多釜串联模型,定量考察了气体流量和液体流量对液相返混程度的影响。对本文所研究的六种不同结构的电解槽内的液相返混进行了比较。研究结果表明,当电流密度为5 kA·m~(-2)时,电解槽的多釜串联模型参数为2.782。仅增大液体流量,模型参数随之增大,返混程度变小;仅增大气体流量,液相返混程度呈现先变增大后减小的趋势,说明液体流量一定时,电解槽存在最佳操作气速(或最佳操作电流密度);当电流密度增大时(气液相流量同时增大),液相返混程度逐渐减小。液体流量是影响液相返混的主要因素。本文所研究的六种电解槽内的液相返混程度由大到小依次为:前后开口鼓泡板、前开口加圆管、前后开口、原始槽型、后开口和后开口槽板倾斜。本文研究表明,液相返混程度可以作为电解槽结构优劣的评价指标。返混程度越大,槽内温度和浓度分布越均匀。
[Abstract]:During the operation of ionic membrane electrolyzer, the liquid phase backmixing degree is directly related to the electrolyte concentration distribution, temperature distribution, reaction rate and reaction product distribution. Therefore, the economy of electrolysis process and the service life of electrolytic cell are affected. In view of the low concentration difference and low temperature difference of ionic membrane, it is advantageous to increase the liquid phase backmixing properly. In this paper, the degree of liquid phase backmixing is proposed as the evaluation index for the performance of electrolytic cells. The effects of cold model experiment and numerical simulation on the liquid phase backmixing in the anode of ionic membrane electrolyzer are studied in this paper, and the multivessel series model is used. The effects of gas flow rate and liquid flow rate on the degree of liquid phase backmixing are quantitatively investigated. The liquid phase backmixing in six kinds of electrolytic cells with different structures studied in this paper is compared. The results show that when the current density is 5 Ka 路m ~ (-1), The model parameters of the multi-vessel series model of the electrolyzer are 2.782.The model parameters increase with increasing the flow rate of liquid, and the degree of backmixing becomes smaller, and the degree of backmixing increases first and then decreases when the flow rate of gas is increased, which shows that when the flow rate of liquid is fixed, The optimum operating gas velocity (or optimal operating current density) exists in the electrolytic cell; when the current density increases (the gas-liquid flow rate increases at the same time, the liquid phase backmixing degree decreases gradually. The liquid flow rate is the main factor affecting the liquid phase backmixing. The degree of liquid phase backmixing in the six kinds of electrolytic cells studied in this paper is as follows: front and rear opening bubbling plate, In this paper, it is shown that the liquid phase backmixing degree can be used as the evaluation index of the structure of the electrolytic cell, and the greater the backmixing degree, the greater the backmixing degree. The distribution of temperature and concentration in the tank is more uniform.
【学位授予单位】：沈阳化工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ114.262

【参考文献】