Economy of a multiple effect evaporator depends upon the _____________________?

Related Mcqs:

1. 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

2. 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

3. 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

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

5. 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

6. In a single evaporator system, the steam economy ________________ by creating vacuum in the evaporator?

   A. Increases
   B. Decreases
   C. Remain constant
   D. May increase or decrease, depends on the vacuum

7. Steam consumption in kg/hr in case of an evaporator is given by (where, C & E are capacity the economy of the evaporator respectively) ?

   A. C/E
   B. E/C
   C. CE
   D. 1/CE

8. 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

9. In a backward feed multiple effect evaporator ___________________ ?

   A. Feed is introduced in the first effect
   B. Feed flows from low pressure to high pressure
   C. No pumps are required between successive effects
   D. None of these

10. 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