The Study Of High Efficiency Tower Technology Application In Production PVA

A study about hydrodynamics and mass transfer for the target to solve stop up the tower or flooding in separate vinyl acetate with polymer , solid froth , foaming substance were complete in the process for production PVA in the tray column and packing tower.To the question that there is a liquid thin in the underlayer, but a liquid thick in the superlayer , which result in it is difficult that forming air bubble drill through "non-activation area" and come into being backmixing and flooding, we design a new tray with some guiding hole in the tray for the liquid achieved steady "piston flow" and where the liquid flow with "nought grads flow" in the tray, base a model mathematics of "nought grads flow" in the distillation tower; and a new corrugation packing which the corrugation line is 300 angle, then 450 angle, the 300 angle and the joint is smooth, base the new type high efficiency packing, X-type and Y-type. And the experiment results showed that when the liquid film flow pass the packing face, the direction of flow of liquid take place change at the corner , and the liquid film appear turbulent flow .Applied the technology about new tray and new packing as before-mentioned in the system of product PVA in Yunnan Yunwei Group Co. Ltd., casus, change bubble cap the into new tray in tower I, and change sieve-plate into new tray in tower II, change float valve into new tray and new packing in tower IV, change float valve into new tray and new packing in tower VI, and change sieve-plate into new tray in polymerization tower III, and change sieve-plate into new tray and new packing in recover tower III, and change sieve-plate into new tray in recover tower VI.The results applied production showed that the total separate efficiency of towers increase 50～70% from 30～50%, and all towersrun placidity, have a high load, and economize energy in evidence. This technology have a economy benefit in the practical application, the yield of VAC increase 2. 8*10~4t/a from 1. 8*10~4t/a, the yield increase 80%, the quality of production advance a grade, the save on 19. 5*10~4t/a of steam and 585*10~4 t/a of cooling water, and reduce 7680t/a of methanol waste liquor , and 1629t/a of acetic acid waste liquor, and 1368t/a of vinlyacetate waste liquor.