Thermal Analysis on Triple Effect Falling Film Evaporator

Evaporation is an operation used to remove a liquid from a solution, suspension, or emulsion by boiling off some of the liquid. It is thus a thermal separation, or thermal concentration process. When a single effect evaporator is used to produce a concentrated liquid or crystal the vapour generated is a by-product with a latent heat content that goes to waste. Multiple effect arrangements are designed to utilize this waste heat and reduce steam consumption and heating power. This is done by using the vapour generated in the first stage as the heat source in the second stage and heat source in third stage. In this paper varying the input pressures at inlet from 24 bar to 16 bar mass flow rate of distilled water at three different stages are estimated using mass balance and energy balance equations. Steam generation rates of triple effect forward feed evaporator at different stages are compared with single effect evaporator. Graphs are drawn to predict the variation of enthalpies, heat for evaporation mass flow rate of distilled water for a triple effect forward feed evaporator.