Practice Test: Question Set - 15
1. In the agitators, the power required will be changed with the increase of diameter of agitator (D) as
- (A) D2
- (B) D5
- (C) D
- (D) D9
2. Which of the following packing materials provides for maximum mass transfer?
- (A) Raschig rings
- (B) Raschig rings
- (C) Cross-partition rings
- (D) All give the same value
3. Pick out the wrong statement.
- (A) Safety valves are provided in heat exchangers for removal of
non-condensable
- (B) Liquid metals and Dowtherm are used for very high temperature
heating
- (C) In a shell and tube heat exchanger, high pressure fluid is generally
routed through the tube
- (D) A loop seal or U-seal is provided in a vertical
condenser sub-cooler to prevent quick draining of the condensate
4. The absorption factor is defined as (where, S1 = slope of the equilibrium curve, S2 = slope of the operating line)
- (A) S1/S2
- (B) S1.S2
- (C) S2/S1
- (D) 1/S1.S2
5. Pressure drop per tray in the atmospheric distillation column is about _________ psi.
- (A) 0.01 - 0.5
- (B) 0.07 - 0.12
- (C) 0.5 - 1.0
- (D) 1 - 3
6. In a shell and tube heat exchanger, tube side _________ of the mass velocity.
- (A) Heat transfer co-efficient is proportional to 0.8th power
- (B) Pressure drop is proportional to the square
- (C) Both 'a' & 'b'
- (D) Neither 'a' nor 'b'
7. In a thin cylindrical shell, the hoop stress is _________ stress.
- (A) Radial
- (B) Circumferential tensile
- (C) Compressive
- (D) Longitudinal
8. In sieve plate column, holes are drilled or punched in sizes ranging from 2.5 to 12 mm (5 mm being widely used). The hole pitch is normally _________ times the hole diameter to give the required hole area.
- (A) 0.5 to 1.5
- (B) 2.5 to 4.0
- (C) 5 to 10
- (D) 10 to 15
9. The maximum liquid gradient over a tray must not exceed
- (A) 0.5" -1.25"
- (B) 2"-3.5"
- (C) 5"
- (D) Half the tray spacing
10. "A claming section" before the liquid flows into the downcomer is provided to
- (A) Permit release of entrained vapor in the liquid
- (B) Reduce the discharge fluctuation
- (C) Ensure better vapor-liquid contact
- (D) Cool the liquid before it flows down
11. In the downcomer of a distillation column, the minimum recommended residence time is about _________ seconds.
- (A) 2.5
- (B) 5
- (C) 12.5
- (D) 17.5
12. With increase in pressure drop (for a given particle size), the dust collection efficiency of a cyclone separator will
- (A) Increase
- (B) Decrease
- (C) Remain unaffected
- (D) Increase or decrease depending on the nature of the dust
13. Flanges are connected to pipes by
- (A) Screwing
- (B) Welding
- (C) Brazing
- (D) All (a), (b) and (c)
14. Most of the storage vessels/tanks are made cylindrical, because of the fact that a cylinder
- (A) Has greater structural strength
- (B) Is easy to fabricate
- (C) Both (a) and (b)
- (D) Neither (a) nor (b)
15. Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower.
- (A) Plate tower is preferred, if interstage cooling
is required to remove heats of reaction or solution
- (B) Plate tower is preferred over packed tower, if the operation
involves liquids containing dispersed solids
- (C) The total weight of a dry plate tower is usually
much more than that of a dry packed tower designed for the same duty
- (D) In operations involving large temperature
changes. (e.g. distillation), plate towers are preferred over packed towers as
the packing may be crushed due to large temperature changes
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