A. Reduce the capacity
B. Reduce the economy
C. Increase the economy
D. None of these
Related Mcqs:
- 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 - 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 - 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 - 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 - 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 - In a forward feed multiple effect evaporator, the pressure is ____________________?
A. Highest in last effect
B. Lowest in last effect
C. Same in all effects
D. Dependent on the number of effects - In a forward feed multiple effect evaporator unit__________________?
A. Viscosity of liquid is highest in first effect
B. Transfer from effect to effect is done by pumps
C. No pump is required to withdraw the product from the last effect
D. None of these - Economy of a multiple effect evaporator is not influenced much by the_______________________?
A. Boiling point elevations
B. Temperature of the feed
C. Rate of heat transfer
D. Ratio of the weight of the thin liquor to thick liquor - A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is__________________?
A. 6000
B. 24000
C. 60000
D. 48000 - A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides __________________?
A. Higher economy
B. Lower capacity
C. Both A. & B.
D. Lower economy
