Energy Management in Multiple –Effect Evaporator System: A Heat Balance Analysis Approach

With the increase in awareness to cost curtailment of energy consumption coupled with the increase in the consumption of the concentrated and dehydrated food products, energy management has become indispensable in food industries. One such process of obtaining these food products is by employing evaporation in food industries. The process of evaporation is employed in the food industry primarily as a means of bulk and weight reduction for fluids. Therefore, evaporation is one of the most large scale operations in food industry. Energy is the most important running cost item in evaporation. High energy consumption is known to have direct or indirect impact on climate change. The operating cost of an evaporator system is mostly determined by the energy that is required to achieve certain evaporation rate. Under steady state condition there must be a balance between the energy entering and leaving the system. Energy can be saved by re-using vapour formed from the boiling product. One of the few ways of accomplishing such is by multiple-effect evaporation. This paper is attempted to explain how total cost of evaporation can be reduced by using multi-effect evaporator thereby achieving an economically optimal number of effects. This can be proved through application of heat-balance analysis.