Optimization of a multiple Effect Evaporator System

Abstract

A septuple effect flat falling film evaporator system for the concentration of black liquor is studied and a generalized cascade algorithm is developed for the different operating strategies. The amount of live steam consumption in the system is evaluated for the given base case parameters. Then the amount of auxiliary vapour produced due to the use of one feed flash tank and seven condensate flash tanks was determined. It was found that the presence of flash tanks helps in recovering heat from the used vapour and thereby reduces the overall live steam consumption of the system and improves the overall steam economy of the system. Thus it helps in making the system more economical.