A. Keep a check on the liquid gradient over the plate by direct visual observation
B. Give access to the individual trays for cleaning, maintenance and installation
C. Guard against foaming & entrainment by dumping antifoaming agent through it
D. All A., B. and C.
Related Mcqs:
- Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 – 1.4 cp and relative volatility < 4) (where ε = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi) ?
A. η = 17 – 61.1 log μ
B. η = 24.6 (Δp/μ)
C. η = 1.66 – 0.25 log μ
D. η = 0.25 log μ – 1.67 - An adequate clearance between the tray and the shell wall of a distillation column is provided to_____________________?
A. Drain the liquid from the tray when the unit is not in operation
B. Allow for thermal expansion and facilitate installation
C. Avoid back-trapping
D. None of these - In case of a shell and tube heat exchanger, the minimum shell thickness for carbon steel (inclusive of corrosion allowance) depends on shell diameter and is in the range of ________________ mm?
A. 3-5
B. 5-11
C. 8-15
D. 12-18 - Compensation against openings in process vessels for giving inlet and outlet connections, for providing sight glasses and manholes etc. is provided for strength and rigidity. The most efficient type of compensation is of _______________ type?
A. Nozzle or rim
B. Flared out
C. Fluid in
D. Ring plate - Baffles are provided in a shell and tube heat exchanger to increase the turbulence and velocity of the shell side fluid. Which of the following shaped baffles does not fall in the category of transverse baffle ?
A. Segmental baffle
B. Flat plate extending across the wall
C. Disk type baffle
D. Helical type baffle - In a multipass shell and tube heat exchanger, the baffles on shell side is primarily provided for______________?
A. Reducing scale deposition
B. Increasing pressure drop
C. Fixing the tubes
D. Creating turbulence - The centre to centre distance between two consecutive baffles in a shell and tube heat exchanger is called the baffle pitch or baffle spacing, which is more than 1/5th the I.D. of the shell. Which of the following is not a function of the baffles ?
A. To increase the residence time of shell side fluid
B. To provide support to the tube bundle
C. To reduce the induced vibration in the tubes
D. To increase the tube side heat transfer co-efficient by inducing turbulence - Weep holes provided in the plates of a distillation column ____________________?
A. Facilitate draining out liquid from a tray when the unit is not in operation
B. Are normally located near the overflow weir so that any delivery of liquid during operation
follows approximately the same path as the overflow fluid
C. Must be large enough (usually 1/4″ to 5/8″ dia) to prevent plugging but should not deliver
excessive amount of fluid during operation
D. All A., B. and C. - In packed towers provided with pall rings liquid redistributors are positioned at heights of every 6 metres or 5-10 times the column diameter, whichever is less. Maximum size of the pall rings should not exceed _______________________ of the column diameter?
A. 1/10-1/15th
B. 1/5-1/10th
C. 1/20-1/30th
D. 1/2 to 1/4th - In a multipass shell and tube heat exchanger, the shell side cross flow area does not depend upon______________________?
A. Baffle spacing
B. Clearance
C. Pitch
D. None of these
