A. High pressure drop
B. Low pressure drop
C. Low velocity of the liquid
D. High temperature
Related Mcqs:
- 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 - Flooding in a distillation column is detected by a sharp ___________________?
A. Increase in Murphree plate efficiency
B. Decrease in pressure drop
C. Decrease in liquid hold up in the column
D. Increase in pressure drop - Operating velocity in a packed tower is usually __________________ the flooding velocity ?
A. Half
B. Twice
C. Equal to
D. More than - Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is _______________ the liquid head available in the downcomer?
A. Less than
B. More than
C. Same as
D. Very much less - Under conditions of flooding in packed tower, the gas pressure drop___________________?
A. Decreases rapidly
B. Increases rapidly
C. Remain constant
D. Is maximum - According to the Fenske equation, what will be the minimum number of plates required in a distillation column to separate an equimolar binary mixture of components A and B into an overhead fraction containing 99 mol% A and a bottom fraction containing 98 mol% B ? Assume that relative volatility (αAB = 2) does not change appreciably in the column ?
A. 5
B. 9
C. 12
D. 28 - Packed column distillation is limited to the column _____________ metres?
A. Height < 6
B. Diameter < 0.6
C. Both A. & B.
D. Neither A. nor B. - An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii) ____________________?
A. Less number of trays are required
B. Composition of the residue remains unchanged
C. More number of trays are required but the residue composition remains unchanged
D. More number of trays are required and the residue composition is more dilute in methanol - A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state ?
A. Composition of vapors and that of liquid do not vary throughout the column
B. Reboiler load and condenser load are minimum
C. The top and bottom compositions are unchanged with and without total reflux
D. The top and bottom compositions correspond to the maximum enrichment available - Plate efficiency in a distillation column is reduced due to the ______________________ of liquid?
A. Entrainment
B. Foaming
C. Weeping & dumping
D. All A., B. & C.
