Evaporation of Tomato Juice Under Vacuum. Tomato juice having a concentration of 12 wt% solids is being concentrated to 25% solids in a film-type evaporator. The maximum allowable temperature for the tomato juice is 135°F,which will be the temperature of the product. The feed enters at 100°F.Saturated steam at 25 psia is used for heating. The overall heat-transfer coefficient U is 600 btu/h*f?.°F and the area A is 50 ft. The heat capacity of the feed c, is estimated as 0.95 btu/lbm°F. Neglect any boiling-point rise if present. Calculate the feed rate of tomato juice to the evaporator.