A. Have low weight per unit volume
B. Have large surface area per unit volume
C. Have large free cross-section
D. Hold up large amount of liquid in the packing
Related Mcqs:
- In a moderately sized packed absorption tower, channelling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter ?
A. > 4 :1
B. < 8 : 1
C. > 8:1
D. < 6:1 - In an absorption column, the flooding velocity for random packing is ___________________ that for stacked/regular packing?
A. Greater than
B. Smaller than
C. Equal to
D. Either A., or B.; depends on the type of packing - Which of the following is an undesirable property in a tower packing ?
A. Large surface per unit volume
B. Large free cross-section
C. Low weight per unit volume
D. Large weight of liquid retained - A natural draft cooling tower is filled with wooden grids, which covers about _________________ percent of the tower height?
A. 10-15
B. 30-40
C. 70-80
D. 90-100 - Pressure drop through plate tower as compared to that through packed tower, for the same duty will be___________________?
A. Less
B. More
C. Equal
D. Either A. or B.; depends on the packing height - At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid _______________ that in dry packed tower ?
A. Is greater than
B. Is lower than
C. Is same as
D. Cannot be predicted as data are insufficient - A packed tower compared to a plate tower for a particular mass transfer operation__________________?
A. Incurs smaller pressure drop
B. Allows installation of cooling coils
C. Is less costly when built in large sizes/diameters
D. Is more suitable, if suspended solids are present in fluid streams - The cooling effect in a cooling tower can be speeded up by _______________________?
A. Increasing the air velocity and area of exposed wet surface
B. Reducing the barometric pressure
C. Reducing the humidity of the air
D. All A., B. and C. - The partial pressure distribution of an ideal gas diffusing through another stagnant ideal gas at steady state follows a/an _________________ law?
A. Exponential
B. Parabolic
C. Linear
D. Cubic - Stacked packing compared to dumped packing_________________?
A. Provides poorer contact between the fluids
B. Gives lower pressure drop
C. Both A. and B.
D. Gives higher pressure drop
