Abstract: A rigorous computing procedure for multicomponent distillation design has been developed. In each iteration of the procedure, a simplified stage-to-stage calculation is followed by a rigorous operating calculation. The former calculates the equilibrium stages required for each tower section and the suitable feed stage locations, whereas the latter checks whether recoveries of key components are as required. In the stage-to-stage calculation and the operating calculation, the concept of the fractional theoretical stage is used by means of Murphree efficiency, thus the number of equilibrium stages is conceived as a continuous parameter. This treatment has the advantages of making the calculation converge precisely to the required recoveries of key components, reducing the computation work, and locating the suitable feed stages. By using a correlation developed from the Fenske equation, and based on the relevant data from operating calculation, the distribution of each component between distillate and bottomn and also total moles of products are obtained. If the required recoveries are not satisfied, a new iteration is performed together with the newly calculated vapor and liquid flow profiles. This procedure can be applied to conventional multicomponent distillation as well as multifeed complex distillation. It has been used for debutanizer, de-propanizer, acetic acid-formic acid-water tower, acetone-methanol-iso-propanol-water tower and acetone-chloroform-benzene tower. The number of iterations ranges from two to four.

摘要： 本文开发了一个严格的多元精馏设计型计算方法.该法的每一次迭代中,有一个简化的逐板计算和后随一个严格的操作型计算.前者计算各塔段所需之平衡级数以及合适的进料级位置,后者验算关键组分回收率是否符合要求.在逐板计算中,通过Murphree效率使用了分数的理论级的概念,这就可把平衡级数看成一个连续的参数,从而能使计算精确地收敛在规定的关键组分回收率上,可减少计算工作量和得到合适的进料级位置.从Fenske公式推导得到的关系,根据操作型计算所得的有关数据,可获得每个组分在塔顶和塔底的分配,同时也算得产品的总分子数.若要求之回收率未获满足,则连同最近算得的汽、液流率分布,进行一次新的迭代计算.本法可用于常规的多元精馏,也可用于多股进料的复杂精馏.曾对脱丁烷塔、脱丙烷塔、醋酸—甲酸一水塔、丙酮-甲醇-异丙醇-水塔和丙酮-氯仿-苯塔等进行计算,迭代次数为2至4.