Residence time distribution (RTD) measurements were carried out in a packed bed column designed for exchange of hydrogen isotopes. The main objective of the study was to characterize the liquid phase mixing under various processes and operating conditions. The packed bed was composed of a mixture of two different types of catalytic packing materials, i.e., a hydrophobic material and a hydrophilic material. Technitium-99m (^99mTc) as sodium pertechnetate was used as a radiotracer for RTD measurements. From the measured RTD curves, mean residence times (MRTs), liquid holdup and degree of mixing of liquid phase were evaluated. An axial dispersion model exchange with stagnant zones was used to simulate the measured RTD curves. The results of model simulation showed that volume fraction of hydrophobic to hydrophilic packing and gas/liquid superficial velocities affect the liquid holdup, bed pressure drop and liquid phase dispersion/mixing characteristics. The results of the present study will help to screen packing, optimize the volume of the packing fractions, design and construct the catalyst and optimize the operating conditions for scale up of the isotope exchange process.

停留时间分布 (RTD) 测量在设计用于交换氢同位素的填充床柱中进行。该研究的主要目的是表征各种工艺和操作条件下的液相混合。填充床由两种不同类型的催化填充材料，即疏水材料和亲水材料的混合物组成。Technitium-99m ( ^99mTc) 作为高锝酸钠用作 RTD 测量的放射性示踪剂。根据测得的 RTD 曲线，对平均停留时间 (MRT)、持液率和液相混合程度进行了评估。使用带有停滞区的轴向扩散模型交换来模拟测得的 RTD 曲线。模型模拟结果表明，疏水填料与亲水填料的体积分数和气/液表观速度会影响持液率、床压降和液相分散/混合特性。本研究的结果将有助于筛选填料、优化填料馏分的体积、设计和构建催化剂以及优化同位素交换过程放大的操作条件。