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本文研究了聚丙烯中空纤维膜成型的工艺条件与结构性能的关系,并利用聚丙烯中空纤维膜组件进行了氨/水分离和影响分离效果的各种因素的研究.结果表明:在制膜工艺中,聚丙烯分子链在应力场下的结晶过程对后续的轴向拉伸形成微孔结构是非常重要的;伸长率为160%时的聚丙烯中空纤维膜,具有最大的孔隙率、平均孔径和透气率;其组件在/水分离中具有较好的分离效果,脱氨率可达99%以上.进一步对氨/水分离的研究表明:分离过程中的传质系数主要取决于原料液氮一侧,它与原料液流速的三分之一次方成正比,而与吸收酸液浓度、原料液的入口压力和浓度无关.
In this paper, the relationship between the process conditions and the structure properties of polypropylene hollow fiber membranes was studied, and the factors of ammonia / water separation and the effect of separation were investigated by using polypropylene hollow fiber membrane modules.The results showed that in the process of membrane preparation , The crystallization process of polypropylene molecular chains under stress field is very important for the subsequent axial stretching to form microporous structure. The polypropylene hollow fiber membrane with the elongation of 160% has the largest porosity and the average Pore size and gas permeability.The separation of the components in / water has better separation effect, the ammonia removal rate can reach more than 99% .A further study of ammonia / water separation shows that the mass transfer coefficient in the separation process mainly depends on the raw material liquid On the nitrogen side, it is proportional to the third-order power of the flow rate of the feedstock, irrespective of the absorption acid concentration, inlet pressure and concentration of the feedstock.