Abstract: A mathematical model for describing the start-up period of a plate distillation column operating under total reflux was derived on the basis of the differential-difference equation expressing the material balance on the trays with holdups in the reboiler, trays and condenser, and an analytical solution was presented. The existence of a constant-composition point during the start-up period was proved mathematically. Experimental work on start-up was carried out in a seven-sieve-tray distillation column of 0.17 meter in diameter and operating with a water-acetic acid system. Good agreement was found between experimental data and calculated results. Experiments also showed the evidence of a constant-composition point in the column during start-up.

摘要： 本文从描述塔板上物料衡算的差分-微分方程出发,导出了在全回流封闭操作条件下,当塔顶、塔板和塔底均有存料时开工过程的数学模型并求出其解.根据数学解还证明了板式精馏塔在开工过程中存在着恒浓度点.在一个具有七块塔板,直径为0.17m的筛板塔上对水-乙酸物系进行了开工过程的实验.本文公式的计算值与实验数据较好的吻合并证明了塔内恒浓度点的存在.