A. 1 to3
B. 4 to 8
C. 3 to 12.5
D. 12.5 to 18.5
Related Mcqs:
- 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 - A high vapour velocity is required for high plate efficiency in a sieve plate column. The satisfactory value of operating vapor velocity for design purpose in sieve plate column is about _______________ percent of the flooding velocity?
A. 45
B. 60
C. 80
D. 95 - In a distillation column, bubble caps are located on trays with a pitch of ______________ times the outside diameter of the caps?
A. 1.3 to 2
B. 1.6 to 2
C. 2.5
D. 1.5 to 3 - Holes of a sieve tray are arranged in triangular pitch of _________________ times the hole diameter?
A. 1.5 to 2
B. 2.5 to 5
C. 5 to 10
D. 10 to 15 - Pick out the wrong statement pertaining to the use of valve tray, seive tray and bubble cap trays in continuous distillation column ?
A. Bubble cap trays though most expensive are the best in situations, where low vapour rates is to be handled and a positive liquid seal is essential at all flow rates
B. Murphree efficiency of all the three trays are nearly equal, however the peak efficiency is generally higher for sieve and valve trays than the bubble cap
C. Maintenance cost for valve and sieve trays are comparatively more than bubble cap tray due to their relatively complicated construction features
D. Valve trays have the highest turn down ratio (i.e. the ratio of the highest to the lowest vapour flow rates) and thus provide the maximum flexible operating range - Bubble cap diameter used for the distillation column having diameter ranging from 1.5 to 4.5 metres is about ______________ mm?
A. 10
B. 50
C. 100
D. 200 - The length of straight rectangular weir used on cross-flow trays is generally ________________ the column diameter ?
A. 0.6-0.8 times
B. Equal to
C. Twice
D. 2 ft irrespective of (for column > 3 ft diameter) - 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 - Pick out the wrong statement about the design of sieve plate column and the bubble cap column ?
A. The downcomer design and the residence time in the downcomer is almost same for sieve
plate and bubble cap columns
B. Weir length for a bubble cap plate is the same as that for the sieve plate
C. Weir height for a bubble cap plate column is the same as that for a sieve plate column
D. Weir height in case of a bubble cap plate ranges from 50 to 150 mm and is higher than the
sieve plate - Diameter of the sieve tray column is determined by the_________________?
A. Lower limit of vapour velocity
B. Upper limit of the vapour velocity
C. Hole diameter of the sieve tray
D. Height of the plate spacing
