精馏塔压力热旁路控制系统中热旁路气体流量的计算

Vapor Flowrate Calculation of Distillation Column Pressure Hot Vapor Bypass Control System

精馏塔压力热旁路控制系统已被广泛用于石油化工装置中。热旁路气体的流量是热旁路控制系统的一个重要参数,是保证该系统正常操作的关键因素。本文介绍了两种用于计算热旁路气体流量的经验方法,即回流罐内气、液介质混合后全部变为饱和液体的方法和维持回流罐内气、液界面＂液膜＂温度恒定的方法。以某MTBE装置催化蒸馏塔热旁路控制系统为具体实例,分别计算出热旁路气体的流量并与工艺包数据作比较。结果表明用前一种方法计算的数据与工艺包数据相贴近。实际设计过程中热旁路气体流量可按塔顶气体总量的15%~25%取值。

Distillation column pressure hot bypass control system has been widely used in petrochemical plants.Hot vapor bypass flow rate is an important parameter of hot bypass control system,and is a key factor to ensure the normal operation of the system.This paper describes two empirical methods for calculating hot bypass vapor flow,namely one method of all the vapor and liquid medium inside reflux tank changed into saturated liquid after mixing,and the other method of maintaining a constant temperature of ' liquid film' of the vapor and liquid interface inside reflux tank.Taking the specific example of the catalytic distillation column hot bypass control system of a MTBE unit,the flow of hot vapor bypass is respectively calculated for the comparison with the data of process package.The results indicate that the data calculated with the former method is close to the data of process package.During the actual design process,the hot bypass vapor flow can take the value of 15%25%of the total overhead vapor flow.