S1 Flashcards
Fresh water carrying pipelines in chemical industries are coloured with ________ color.
sea green
Which of the following material is seldom used for pressure vessel construction?
Rimmed still
The ratio of shear stress to shear strain is called
shear modulus
25 per cent cut segmental baffle means that the baffle
height is 75% of the I.D. of the shell.
Liquid/petroleum fuel storage tanks are built underground (as in case of petrol pumps), when the storage capacity is less than __________kilolitres.
45
Le/D for fully open globe value may be around
300
Lug support is
all (a), (b) and (c).
Pick out the wrong statement pertaining to the use of valve tray, seive tray and bubble cap trays in continuous distillation column.
Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features.
With increase in the number of shell passes, the value of FT
increases
Holes of a sieve tray are arranged in triangular pitch of _________ times the hole diameter.
2.5 to 5
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.
5-11
The stress developed in a material without any permanent set is called the
elastic limit
In a shell and tube heat exchanger, the ‘tube pitch’ is defined as the
shortest centre to centre distance between adjacent tubes.
Which of the following is not a valid assumption in continuous binary distillation for calculating the number of equilibrium stages by Mc-Cabe-Thiele’s method?
Reflux is not a saturated liquid.
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 η = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi)
η = 17 - 61.1 log μ
The value of fouling factor depends upon the
all (a), (b) and (c).
In case of bubble cap distillation column of diameter greater than 1.2 metres, the cap diameter is roughly about ________ cms.
10
Tube side pressure drop in a 1-2 heat exchanger (for turbulent flow of fluids through the tubes) is about ________ times, that in a 1-1 heat exchanger having the same size & number of tubes and operated at the same liquid flow rate.
8
To keep the power input constant for a stirred vessel operating under fully developed turbulent flow conditions (constant power number), if the impeller diameter is increased by 20%, the impeller speed should be decreased by a factor of
(1.2)^5/3
Where does the maximum tensile strength occur in a thick cylindrical vessel subjected to internal pressure?
At the inner surface.
It is not desirable to design a heat exchanger for LMTD correction factor, FT, of less than
0.80
A rivetted joint does not fail by __________ of rivets.
none of these
Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger
permits the use of more tubes in a given shell diameter.
Bracket supports are the most suitable for supporting ________ vessels.
thick walled vertical
In a multipass shell and tube heat exchanger, the shell side cross flow area does not depend upon
none of these
Two iron pipes of the same nominal diameter but different schedule numbers will have the same
inside diameter
Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about ________ kcal/hr.m2.°C.
7500
Lessing ring is formed by the addition of a partition across the centre of a raschig ring, which results in an area increase of about ________ percent.
20
In chemical process equipments, the conical bottom heads used, usually has an apex angle of
60°
Smaller sized packings are generally dumped to the packed columns, and the large ones of size greater than __________ mm are stacked individually, which provides better control over bed porosity and offers lower gas pressure drop.
75
Shell side heat transfer co-efficient in case of square pitch as compared to the triangular pitch under similar condition of fluid flow and tube size is
less
Correct use of ‘factor of safety’ is very important in equipment design. It is defined as the ratio of the
ultimate stress to working stress.
The operating velocity in the absorption tower is usually 40-50% of the flooding velocity. Packed absorption towers are normally designed for a pressure drop of about ________ mm of water column per metre height of packing.
20-40
________ tray arrangement is recommended for distillation column having diameter upto 4 ft.
Cross flow
What is the value of ‘q’ for saturated liquid feed to a distillation column?
1
In perforated plate towers, the
all (a), (b) and (c).
The main purpose of providing stepping on the trays is to
facilitate handling of large flow rate of liquid.
The operating pressure drop range in a bag filter is about ________ mm water gauge.
50-150
The ends of a cylinderical vessel can be closed by a head, which can be one of the four shapes. For the same thickness, choose the one which can withstand the highest pressure.
Ellipsoidal
For laminar flow (NRe < 2100) in steel pipe, the optimum inside pipe diameter is given by
Di, opt = 3 Q^0.36 ρ^0.18
Pick out the correct statement.
Packed towers are generally preferred over plate towers, if the liquids have a foaming tendency.
Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is
less
Pick out the wrong statement pertaining to the design of a basket type evaporator.
It is used for high viscosity liquor having large rate of scaling.
Pick out the wrong statement pertaining to the design of the bubble cap tray of a distillation column to give stable operation and even vapour distribution.
none of these.
Speed of the drum of the rotary vacuum filter normally ranges from __________ rpm.
0.1 to 2
A stuffing box is used for
prevention of fluid leakage around moving parts.
Pressure drop (Δp) and the superficial gas mass velocity (G) in case of packed absorption tower operating in the preloading range are related as
Δp = G^2
Pick out the wrong statement.
In an agitated vertical cylinderical reaction vessel, the
dished bottom vessel has very high power consumption.
