Separation Principles. This is Multi stage Evaporation 3 kg/s of a salt solution is concentrated from 10%

Separation Principles. This is Multi stage Evaporation

Transcribed Image Text:

3 kg/s of a salt solution is concentrated from 10% to 55% solid in a backward feed double effect evaporator using steam at 393 K. the effects are operated under vacuum such that the bubble point in the second effect is 325 K. The feed is initially at 297 K and each effect is identical. Additional information: a. C, is taken to be 4.18 kJ/kg K b. Boiling point rise can be neglected c. The overall heat transfer coefficients are as follows: First effect= 2.5 kW/m? K Second effect= 2.0 kW/m? K d. Since the feed enters as a cold stream, the first effect requires more heat than the second effect. AT1 must be increased and AT2 must be decreased proportionately. In this case, assume AT, is increased by 2 degrees K and AT2 is decreased by 2 degrees K. 2.1. Draw the flowsheet for this process and define the applicable operating conditions for each effect. (2) 2.2. Calculate the steam consumption required? (19) 3 kg/s of a salt solution is concentrated from 10% to 55% solid in a backward feed double effect evaporator using steam at 393 K. the effects are operated under vacuum such that the bubble point in the second effect is 325 K. The feed is initially at 297 K and each effect is identical. Additional information: a. C, is taken to be 4.18 kJ/kg K b. Boiling point rise can be neglected c. The overall heat transfer coefficients are as follows: First effect= 2.5 kW/m? K Second effect= 2.0 kW/m? K d. Since the feed enters as a cold stream, the first effect requires more heat than the second effect. AT1 must be increased and AT2 must be decreased proportionately. In this case, assume AT, is increased by 2 degrees K and AT2 is decreased by 2 degrees K. 2.1. Draw the flowsheet for this process and define the applicable operating conditions for each effect. (2) 2.2. Calculate the steam consumption required? (19)

Answer rating: 100% (QA)

F3ugs ploy0X55Y05 Hui TF Me Ts mis 2 Cp Tz F loy 0 ... View the full answer