精馏塔理论塔板数的计算新方法

NEW SHORT-CUT METHOD FOR THE CALCULATION OF THE NUMBER OF THEORETICAL STAGES REQUIRED IN THE DISTILLATION COLUMN

本文考虑馏出液组成x_d和残液组成x_w的变化对精馏操作线斜率的影响,用数学分析的方法,提出了一组计算精馏塔理论塔板数的关联式。该式直接将理论塔板数和操作变量关联,计算简单,其结果与Smoker方程的精确解相符,最大绝对误差仅为0.15块理论板,优于常用的Gilliland关联式,可用于精馏塔的设计计算。

Considering that the changes in composition of distillate and bottom affect the slops of the operating lines, in this paper a new short cut method is developed by means of mathematical analysis. The method correlates the number of theoretical stages with the operating variables directly. The calculation is simple and the results coincide with the exact solutions of Smoker,s equation. The maximum absolute error is 0.15 theoretical stages, it is much smaller than the error of Gilliland,s correlation. The method can be conveniently used in column design.