Q.1
Falling film evaporators are a subclass of long tube evaporators.
  • a) True
  • b) False
Q.2
Falling film evaporators can be operated in _______________
  • a) Counter-flow with the vapour
  • b) Co-current flow with vapour
  • c) Both co-current and counter-current
  • d) Separate segments in any direction
Q.3
Falling film evaporators are considered over climbing film evaporators because of which one of the following factor?
  • a) Efficiency
  • b) Product holdup
  • c) Driving force requirement
  • d) Temperature sensitivity
Q.4
The applications of falling film and rising film are more or less same, but if industries have the cost capital, they go for falling film, why?
  • a) It has high temperature gradient and natural convection
  • b) Better efficiency of falling film
  • c) It has less temperature gradient and natural convection
  • d) No need for upward pressure
Q.5
Falling film evaporators are best suited for pharmaceutical industries because
  • a) It has high temperature gradient and natural convection
  • b) Low pressure
  • c) It has less temperature gradient and natural convection
  • d) High headroom available
Q.6
Falling film evaporators can be used with the fluid falling over
  • a) (i)(ii)(iii)
  • b) (i)(ii)
  • c) (i)(iii)(iv)
  • d) (i)(ii)(iii)(iv)
Q.7
Falling film evaporators have __________ product holdup.
  • a) Large
  • b) Very high
  • c) Low
  • d) Zero
Q.8
Which one of the following is not an advantage of falling film evaporator?
  • a) Relatively low cost
  • b) High headroom
  • c) Large surface area for heating available
  • d) Low product holdup
Q.9
Which one of the following cannot be regarded as a demerit of falling film evaporator?
  • a) High headroom requirement
  • b) Corrosive fluids cannot be used
  • c) Large product holdup
  • d) Recirculation needed
Q.10
The fluids in falling tube evaporator usually form a film inside the tubes but there are applications when the fluid forms a film outside the tube and falls subsequently.
  • a) True
  • b) False
Q.11
In order to maintain conservation of mass as this fluid fall proceeds in a falling film evaporator, the downward vapour velocity ___________
  • a) Decreases
  • b) Increases
  • c) Remains Same
  • d) Oscillates
Q.12
Recognize the falling film evaporator.
Questionheat-transfer-operations-questions-answers12.jpg
  • a)
  • b)
  • c)
  • d)
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