A. Forward
B. Backward
C. Parallel
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 - A multiple effect evaporator as compared to a single effect evaporator of the same capacity has _________________?
A. Lower heat transfer area
B. Lower steam economy
C. Higher steam economy
D. Higher solute concentration in the product - For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in_____________________?
A. Increased economy
B. Decreased economy
C. Lower capacity
D. No effect on economy - 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 - Evaporation of 1kg of water from a solution in a single effect evaporator requires about ________________ kg of steam?
A. 0.4 – 0.6
B. 1-1.3
C. 1.8-2
D. 2 – 2.4 - For the same heat transfer area and the terminal conditions, the ratio of the capacities of a single effect evaporator to a triple effect evaporator is_________________?
A. 3
B. 0.33
C. 1
D. 1.33 - In a multiple effect evaporator, the effect of boiling point elevation is to______________________?
A. Reduce the capacity
B. Reduce the economy
C. Increase the economy
D. None of these - For hot feed, forward feeding as compared to backward feeding results in ______________ economy?
A. Increased
B. Decreased
C. No effect on
D. None of these - 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 - Multiple effect evaporation accounts for___________________?
A. Steam economy
B. Lower operating costs
C. Investment economy
D. None of these
