A single effect evaporator is required to concentrate a solution from 10% solids to 30% solids at the rate of 500 kg of feed per hour. If the pressure in the evaporator is 60 kPa absolute, and if steam is available at 200kPa gauge, calculate the quantity of steam required per hour and the area of heat transfer surface if the overall heat transfer coefficient is 2270 J m-2 s -1 C-1 . Assume that the temperature of the feed is 13C and that the boiling point rise of the solution is negligible. Assume, also, that the specific heat of the solution is the same as for water, that is 4.186 x 103 J kg-1 C-1 , and the latent heat of vaporization of the solution is the same as that for water under the same conditions. How would the results be changed if BPR is not negligible? Try BPR is 10, 30 and 50 C.