A single effect evaporator is to be designed to concentrate 8000 kg/hr of a chemical solution from 10% to 20% by weight, feed enters at 25oC, saturated steam at 110oC (latent heat 532 Kcal /kg) is available, condensate leaves at saturation temperature, the solution boils at 45oC (latent heat is 570 Kcal/kg), specific heat of all the solution may be taken as 1 Kcal/kg and overall heat transfer co-efficient is 1800 Kcal/hr.m2 . oC . Find (a) Steam economy (b) Heat transfer area.