A Digital Computer Model of a Multiple Effect Evaporator

A dynamic mathematical model of a multiple effect evaporator has been developed for a digital computer using the IBM Continuous Systems Modelling Program. The model will be incorporated in an overall simulation of a cane sugar factory. The mathematical model was derived from material and energy balance equations assuming that (i) the liquid phase is perfectly mixed; (ii) the vapour phase is always in equilibrium with its liquid phase. An empirical equation for the heat transfer coefficient was derived from first principles and fitted by non-linear regression to a set of factory data. Other physical parameters were defined by empirical equations derived from data in the literature. Graphs are presented showing the effect of various changes in the feed conditions on exit brix and flowrate.