A colloidal solution is to be concentrated from 10 wt% solids to 60 wt% by using a forward feed triple effect evaporator. The solution coming from the heat exchanger at 99C enters the first effect at a rate of 7200 kg/h and saturated steam at 400 kPa is fed into a tube bundle in the 1st effect. The pressure in the evaporation space in the final effect is 60 kPa. Assume that the overall heat transfer coefficients are 2270, 2000 and 1420 W/m2K in the first, second and third effects, respectively.

a) Draw the block diagram of the process.

Calculate b) the heat transfer area in each effect needed to accomplish the desired exit concentration,

c) the steam economy based upon the results of the first estimate.

d) If the area of any effect has 10% deviation from their mean, how will you estimate the new trial? Write only the procedure to find the area in order to reduce the deviation.