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Home Chemical Engineering Process Equipment and Plant Design Comments

  • Question
  • A forced circulation long tube vertical evaporator as compared to the natural circulation evaporator


  • Options
  • A. is economical in operation.
  • B. employs high velocity, high heat transfer rate and less heating surface requirement.
  • C. employs a centrifugal pump placed between external downtake from vapor drum and inlet to tube bundle.
  • D. both (b) & (c).

  • Correct Answer
  • both (b) & (c). 


  • Process Equipment and Plant Design problems


    Search Results


    • 1. The ratio of down take area to cross-sectional area of the tube, for calendria type evaporator ranges from

    • Options
    • A. 0.5 to 1
    • B. 1 to 1.5
    • C. 1.5 to 2
    • D. 2 to 2.5
    • Discuss
    • 2. What is the slope of the operating line in the stripping section of a distillation column?

    • Options
    • A. 0
    • B. ?
    • C. > 1
    • D. < 1
    • Discuss
    • 3. An increase in the liquid resistance to interphase mass transfer and a resultant reduction in plate efficiency is caused by

    • Options
    • A. an increase in liquid viscosity.
    • B. an increase in relatived volatility for rectification columns.
    • C. decrease in gas solubility for absorbers.
    • D. all (a), (b) and (c).
    • Discuss
    • 4. With increase in temperature drop (in a shell and tube heat exchanger), the LMTD correction factor, FT

    • Options
    • A. decreases very rapidly
    • B. increases very rapidly
    • C. remains constant
    • D. increases linearly
    • Discuss
    • 5. In the agitators, the power required will be changed with the increase of diameter of agitator (D) as

    • Options
    • A. D2
    • B. D5
    • C. D
    • D. D9
    • Discuss
    • 6. In a double pipe concentric heat exchanger, the equivalent diameter of annulus for heat transfer would be (where, D1 and D2 are I.D. of inner and outer pipes)

    • Options
    • A.
    • B. D2 - D1
    • C.
    • D. none of these
    • Discuss
    • 7. Excessive liquid gradient on a tray may result in the

    • Options
    • A. maldistribution of gas.
    • B. back trapping.
    • C. gas blowing beneath cap skit.
    • D. all (a), (b) and (c).
    • Discuss
    • 8. In a cylinderical vessel subjected to internal pressure, the longitudinal stress ?L and the circumferential stress, ?n are related by

    • Options
    • A. ?h = 2 ?L
    • B. ?h = ?L
    • C. ?h = ?L/2
    • D. no relation exists
    • Discuss
    • 9. Rotary driers are most economically designed for the number of heat transfer units (HTU) from

    • Options
    • A. 0.01 to 1
    • B. 1.5 to 2.5
    • C. 5 to 10
    • D. 10 to 20
    • Discuss
    • 10. Heat transfer co-efficient, hG(Kcal/hr.m2 .°C) and mass velocity of air, G (kg/hr.m2 ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to

    • Options
    • A. hG = 1.004G0.37
    • B. 1.004G0.8
    • C. hG = 0.0176G0.37
    • D. 0.0176G1.37
    • Discuss


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