1. A solution is to be concentrated in a single effect evaporator from 20 to 68% solids. The specific heat of the feed, entering at 50F is 0.93. The pressure of the saturated steam to the evaporator is 20 psia and the pressure in the vapor space is 5 in. Hg abs. hhe steam chest has an overall heat transfer coefficient of 200 BTU/hr-ft- F. Water must be evaporated at the rate of 45,000 lb/hr. Neglecting boiling point elevation, what must be the heating surface required? What is the steam economy? 20 pts