A fruit juice at 30°C with 5% total solids is being concentrated in a single-effect evaporator. The evaporator is being operated at a sufficient vacuum to allow the product moisture to evaporate at 80°C, and steam with 85% quality is being supplied at 169.06 kPa. The desired concentration of the final product is 40% total solids. The concentrated product exits the evaporator at a rate of 2500kg/h. Calculate the (a) steam requirements and (b) steam economy for the process, when condensate is released at 90°C. The specific heat of liquid feed is 4.05kJ/(kg°C), and of concentrated product is 3.175kJ/(kg°C).

A fruit juice at 30°C with 5% total solids is being concentrated in a single-effect evaporator. The evaporator is being operated at a sufficient vacuum to allow the product moisture to evaporate at 80°C, and steam with 85% quality is being supplied at 169.06 kPa. The desired concentration of the final product is 40% total solids. The concentrated product exits the evaporator at a rate of 2500kg/h. Calculate the (a) steam requirements and (b) steam economy for the process, when condensate is released at 90°C. The specific heat of liquid feed is 4.05kJ/(kg°C), and of concentrated product is 3.175kJ/(kg°C).