x=10000 kg/h

It is desired to concentrate Xkg/h of a solution at 40C and 10% solids to a product that contains 50% solids. Steam is available at 2 bar absolute and the last effect of a triple effect evaporator with nearly equal heat transfer surface in each effect will be assumed to operate at a vacuum of 100mm vacuum. Assume negligible BPE. Assume difference in pressure between effects to be equal. Calculate (i) steam consumption (ii)heating surface required for each effect. Data: Overall heat transfer coefficient I effect =3400W/m2K; II effect =1420W/m2K; III effect =710W/m2K; Cp=4187J/kgK