塔板上CaCO_3结垢速率

Fouling Rate of Calcium Carbonate on the Surfaces of Sieve Trays

在100mm塔径的筛板塔内,采用加速结垢的方法研究了Ca(OH)2-H2O-CO2-Air体系内4种不同材质的塔板表面上CaCO3的结垢行为,考察了液相浓度、温度、CO2浓度、F因子、时间及材质对结垢速率的影响.结果表明,塔板上的CaCO3结垢为方解石晶形.结垢过程可大致分为3个阶段:起始阶段、过渡阶段、稳定阶段.各因素对结垢速率影响可拟合成方程u=Ae-E/(RT)ca1cb2qcv,lqdv,gτe,但第三阶段中τ不出现.实验条件下,CaCO3在筛板上结垢的活化能变化范围为8.01～28.4kJ/mol,结垢第三阶段的活化能最大,第一阶段最小,整个过程由扩散控制.

Fouling rate of calcium carbonate formed on the surfaces of 4 sieve trays made of different materials was studied in a 100 mm diameter column.Experiments were carried out in the Ca（OH）2-H2O-CO2-air system with the fast fouling method.The effects of suspension concentration,temperature,CO2 inlet concentration,F factor,time and tray material on the fouling rate were investigated.The instrumental analysis shows that the fouling crystal is calcite.The study indicated that the whole fouling process is mainly consisted of three stages,called as ＂initial stage＂,＂transition stage＂ and ＂steady stage＂,respectively.Based the experiment,factors affecting on the fouling rate in the first two stages can be summarized as：u=Ae-E/（RT）ca1cb2qcv,lqdv,gτe,and τ is not present in the equation.The fouling activation energy on the tray is found in the range from 8.01 to 28.4 kJ/mol.Generally,the fouling activation energy on the 3rd stage is the biggest among the all stages.The activation energy of this fouling process demonstrates that it is controlled by the diffusion.