Dynamic Analysis of Evaporators

Abstract

Dynamic analysis of natural and forced circulation evaporators is presented in this paper.
Basic differential equations are given which describe the dynamic properties of evaporators by taking into consideration the mass and energy balances of solution, the material balance of solute, etc.. These equations are linearized and Laplace transformed and matrix transfer function is obtained to show dynamic behavior between several inputs and outputs.
As a numerical example, step responses of density, temperature, drum pressure and solution level for condenser flow rate and feed rate variations, etc. are compared in an evaporator of caustic soda.