The Research And Measurement About Performance Of Novel Extraction Packing

In the first part, the characteristics, classification and technologies of liquid-liquid extraction were introduced briefly. Among them, the development of packed tower used in extraction process, especially its specific packings were discussed. Standard extraction systems and complex extraction theory were consulted. Techniques which developed for measuring the flow and mass transfer characteristics of extraction tower internals were introduced. Some of them were developed for academic analysis, for example, the single droplet experiment; some were developed for measuring the packing performance.In the second part, discussion is mainly laid on a specific structured packing developed for liquid-liquid extraction process which was called Rhombus Mesh Frame Packing(RMFP). The observation and discussion about droplet breakage-coalescence process were given in single–droplet experiments. RMFP, 10mm-ID Pall ring and 25mm-ID QH-1 mini ring as column internals were performed. In the experiment, the relationship between droplet diameter and size of pinhead, the terminal velocity of droplet in void column together with packing and its effects on the breakage ratio and station-time of the droplet, etc were investigated. The flow and break phenomena of the droplet in different column internals were observed. By these observations, some guiding rules for design of extraction column internals, such as Compound Structured Packings(CSP), was developed.The third part is focused on the mass transfer experiment for RMFP. The experiment was carried out in a 50mm in diameter extraction column. Comparative experiment was carried out using a parallel column which packed with 10mm-ID Pall ring. 30%TBP(kerosene)- acetic acid-water was selected as the test system. By considering equilibrium curve and packing void fraction, the apparent Height of mass transfer unit(HTU), holdup of dispersed phase and flooding holdup were measured with different operating parameters such as flow rates of both phases. Experimental results showed that the HTUs of RMFP were lower than Pall ring by 20～30%, the holdups of dispersed phase were higher than Pall ring by 30% and flooding holdup were higher than Pall ring by 14% in average.After laboratory scale experiment, in the fourth part, commercial scale experiment was carried out. The extraction packing column was designed which refered to the water scrubber tower used in industry. The testing system is 98.8% cyclohexene(DMAC)-desalt water. 12mm-ID Pall ring using in real situation was selected as the comparative experiment packing. It was conclued from the experiment that HTUs of RMFP are lower than Pall ring by 26% in average.In the last part, the newly developed novel structured packing, Compound Structured Packing(CSP), specially designed for liquid-liquid extraction process was developed and its mass transfer performance was measured. The experimental results showed that HTUs of CSP were lower than RMFP by 11% and Pall ring 49% in average respectively. From the experiment, it was also observed that CSP could intensify the"breakage- coalescence- breakage again"periodical process dramatically. Finally, the comparison and analysis as to CSP parameters and operation conditions were considered.