【摘要】 建立了新的半经验半微分传质传热模型,以苯/N-甲酰吗啉(NFM)水溶液体系为代表,研究了真空膜蒸馏分离去除苯的传质传热过程.并通过数学模拟和实验考察了操作参数对苯的传质通量、去除效率、分离因子以及水传质通量的影响.结果表明,新模型能较好地描述真空膜蒸馏的传质传热过程,能直观地解释实验结果,模拟值与实验值吻合.另外进料浓度、流量、温度及真空度的提高有利于提高苯的传质通量,但不利于提高分离效果.浓度、流量对传质的影响表现为对液相扩散传质能力的增强.温度及真空度对传质的影响表现为对气液界面分压的影响.以上因素的影响最终体现为对扩散组份跨膜分压差的影响.更多还原

【Abstract】 A differential and experiential mathematical model was developed for the transport of benzene through hollow fiber membrane in the presence of an aqueous N-Formylmorpholine(NFM) solution in an vacuum membrane distillation process.The model was based on "non-wetted mode" and the laminar parabolic velocity profile was used for the liquid flow in the tube side,whereas,the vacuum was applied in the shell side.The effects of various factors such as liquid benzene concentration,liquid flow rates,liquid temperature and degree of vacuumon mass transfer were studied by means of experiments and mathematical simulating.Moreover,the simulation results were validated with the experimental data.It was found that the increase of liquid inlet concentration,liquid flow rate,liquid temperature and degree of vacuum have positive effect on benzene and water mass transfer process,but have the negative effect on benzene separation factor.更多还原