A feedforward triple-effect evaporator evaporates
a sugar solution with negligible boiling point rise and 5% solids by weight to 25% solids .
Saturated steam at 205 kPa is used for heating. The third
effect is 13.65 kPa in vapor pressures. The feed rate is 22 680 kg/h and the temperature
is 299.9 K. Liquid heat capacity cp = 4.19 – 2.35x where cp kJ/kg K and x are weight
fraction types. The heat transfer coefficients are U1 = 3123, U2 = 1987 and U3 = 1136
W/m2K.
Calculate the superficial portion of each effect and the amount of steam required if each has an area of effect . Calculate steam economy