A. Open pan evaporation
B. Long tube vertical evaporator
C. Agitated film evaporator
D. None of these
Related Mcqs:
- It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is____________________?
A. 3.06 × 105
B. 6.12 × 105
C. 7.24 × 105
D. 9.08 × 105 - Boiling point elevation for a strong and concentrated solution is found by Duhring’s rule, which states that at the same pressure, the boiling point of a solution is a linear function of the _______________ of pure water?
A. Boiling point
B. Dynamic viscosity
C. Kinematic viscosity
D. Density - Open pan evaporators are preferred to be used, when the solution to be concentrated is_________________?
A. Scaling
B. Highly viscous
C. Corrosive
D. Salty - A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because__________________?
A. Total heat transfer area of all the effects is -less than that in a single effect evaporator system
B. Total amount of vapor produced per Kg of feed steam in a multiple effect system is much
higher than in a single effect
C. Boiling point elevation in a single effect system is much higher than that in any effect in a
multi-effect system
D. Heat transfer co-efficient in a single effect is much lower than that in any effect in a multieffect
system - For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a _______________ evaporator?
A. High pressure
B. Vacuum
C. Backward feed
D. None of these - In case of a super-cooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is ________________?
A. More
B. Less
C. Same
D. More or less; depends on the nature of solution - Heat sensitive materials can be concentrated in an evaporator employing_______________?
A. Vacuum
B. High pressure
C. High residence time
D. None of these - Fruit juice (a heat sensitive material) can be concentrated in a ____________ evaporator?
A. Long tube
B. Falling film
C. High pressure
D. None of these - Viscous & heat sensitive liquids are concentrated in _____________ evaporators?
A. Open pan
B. Long tube
C. Agitated film
D. None of these - Black liquor generated during paper manufacture is concentrated in a___________________?
A. Single effect evaporator
B. Single effect evaporator followed by a crystalliser
C. Multiple effect evaporator
D. Multiple effect evaporators followed by a crystalliser
