【作者】 梁栋；

【导师】 景山；

【作者基本信息】 清华大学 ， 化学工程与技术， 2005， 硕士

【摘要】 针对高放废液全分离流程中采用亚铁氰化钛钾无机离子交换剂的除铯系统,本论文首先研究了工业上可用于从高放溶液中去除铯离子的Ф280mm密实移动床离子交换柱的颗粒输送能力以及其影响因素。实验结果表明:密实移动床的进液量u_F1、提升液表观操作流速u_F2和密实移动床中的交换剂高度是影响固体颗粒提升速率u_s的因素,并从压力平衡的角度对实验现象进行了解释。根据实验结果,对这些影响因素进行了无因次关联,针对亚铁氰化钛钾建立了密实移动床离子交换系统的流体力学经验模型。在本实验中,斜管内串液量V_leakage保持恒定,串液的方向是由提升管流进离子交换柱底部,这说明细长斜管可以有效的减小串液量。其次,本论文还针对此流程的除铯系统中亚铁氰化钛钾离子交换剂的干燥动力学进行实验研究。实验结果表明:在干燥阶段,为了保证无（CN）₂分解产生,应选择温度小于120℃,并且干燥过程是吸热过程,需要对干燥器进行外供热;本论文选用固定床干燥器并采用以气体通过来带走水分的干燥方式。干燥过程可以分为三个不同的阶段:调整阶段,恒速干燥阶段和两段降速干燥阶段;亚铁氰化钛钾无机离子交换剂的临界含水量X_c随着干燥操作气速的增大而线性减小,同时,决定了第二降速干燥阶段的临界含水量X_D;根据实验结果,给出了在本实验所使用的干燥系统中,亚铁氰化钛钾离子交换剂干燥过程的动力学经验方程,为该除铯系统在核工业后处理过程中应用提供依据。更多还原

【Abstract】 For the cesium-removing process using potassium titanium hexacyanoferrate（KTiFC） as ion exchanger in the Chinese total partitioning process for highlevel liquid waste, the particles transport velocity and influencing factors forФ280 moving-bed column, which is possibly used in industry for removing¹³⁷Cs ions from the highly radioactive solution, are investigated firstly in thisthesis. Experimental results show that the feeding rate of liquid into themoving-bed column, the liquid rising velocity of the riser and the height ofparticles in the moving-bed column have dominant influence on the particlestransport velocity, and the reason has been analyzed by the pressure balanceof system. Based on these results, the dimensionless correlation for theparticles transport velocity and an empirical hydrodynamic model for the ionexchange system are presented. Experimental results also show that theleakage rate of liquid through the solid-return pipe remains constant and itsdirection of the liquid leakage is from the riser to the downer due to therestively thin and long solid-return pipe.Secondly, the drying process of the ion exchanger which came from themoving-bed has also been investigated. The real ion exchanger was used inthe experiment and the appropriate temperature range, the velocity of drynessand the factors which can effect the velocity have been investigated at thesame time. Experimental results show that the appropriate temperature of thereactor should be under 120℃ so that the ion exchanger will not decomposeto discharge （CN）₂, and the process need be heated. The drying processincludes three phases: the adjustment phase, the constant rate phase and thetwo types of underspeed phase. If the other experimental conditions areunchanged, the critical moisture content X_C of the ion exchanger reduceswhen the gas velocity increases and another critical moisture content X_Dbetween the two types of underspeed phase, linearly depends on the values ofXC. Finally, Based on the data, an empirical dynamical correlation for thedrying process is presented. These results will be applied in the disposal ofnuclear industry.更多还原