Dynamic Characteristics And Mathematical Simulation Of Pulsed Extraction Column For Co-decontamination And Separation Cycle

The spent fuel reprocessing PUREX process is the main reprocessing process in various countries,in which the uranium and plutonium co-decontamination and separation process is one of the key links in the whole chemical separation process.Compared with other extraction equipment,pulsed extraction column has been widely used in the co-decontamination and separation cycle due to its excellent performance.Because of the complex fluid characteristics in the extraction column and the difficulty in measuring the output variables online,it is of great significance to explore the dynamic behavior characteristics in the extractor for safe and stable operation and production.In this paper,the dynamic characteristics and simulation of pulsed extraction column extraction and reverse extraction in the co-deconfouling separation cycle were studied with uranium-plutonic acid as the research system.In this study,the axial diffusion model was used to simulate the mass transfer process of the pulsed extraction column.Combined with mass transfer,interphase mass transfer and REDOX,the basic model of mass transfer of the pulsed extraction column was established.According to the actual process conditions of the co-decontamination separation cycle,the mathematical model of the co-decontamination separation cycle extraction and reverse extraction was established.And use Matlab to build and solve the model.The main contents and conclusions of this paper are as follows:The mass transfer model of the co-decontamination separation cycle extraction and reverse extraction process was established,and the two mass transfer partial differential equations were obtained.The calculation results of the model were analyzed and compared with the experimental data in literature and the calculation results of the Pulco program.In order to solve the problem that the results of the dispersed phase calculated by the axial diffusion model are not good,the step coefficient is proposed based on the basic model,and the optimization results of the diffusion model are good.The precision and efficiency of the extraction column were slightly lower than that of the optimized model.The effects of the two-phase rate,pulse intensity,reaction temperature and feed concentration on the two-phase concentration in the pulsed extraction column were investigated.The calculated results of the model accord with the changes of the actual process and are expected to be used to simulate the actual process.