S1 Flashcards

1
Q

Fresh water carrying pipelines in chemical industries are coloured with ________ color.

A

sea green

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2
Q

Which of the following material is seldom used for pressure vessel construction?

A

Rimmed still

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3
Q

The ratio of shear stress to shear strain is called

A

shear modulus

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4
Q

25 per cent cut segmental baffle means that the baffle

A

height is 75% of the I.D. of the shell.

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5
Q

Liquid/petroleum fuel storage tanks are built underground (as in case of petrol pumps), when the storage capacity is less than __________kilolitres.

A

45

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6
Q

Le/D for fully open globe value may be around

A

300

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7
Q

Lug support is

A

all (a), (b) and (c).

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8
Q

Pick out the wrong statement pertaining to the use of valve tray, seive tray and bubble cap trays in continuous distillation column.

A

Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features.

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9
Q

With increase in the number of shell passes, the value of FT

A

increases

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10
Q

Holes of a sieve tray are arranged in triangular pitch of _________ times the hole diameter.

A

2.5 to 5

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11
Q

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

5-11

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12
Q

The stress developed in a material without any permanent set is called the

A

elastic limit

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13
Q

In a shell and tube heat exchanger, the ‘tube pitch’ is defined as the

A

shortest centre to centre distance between adjacent tubes.

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14
Q

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?

A

Reflux is not a saturated liquid.

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15
Q

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)

A

η = 17 - 61.1 log μ

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16
Q

The value of fouling factor depends upon the

A

all (a), (b) and (c).

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17
Q

In case of bubble cap distillation column of diameter greater than 1.2 metres, the cap diameter is roughly about ________ cms.

A

10

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18
Q

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.

A

8

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19
Q

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

A

(1.2)^5/3

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20
Q

Where does the maximum tensile strength occur in a thick cylindrical vessel subjected to internal pressure?

A

At the inner surface.

21
Q

It is not desirable to design a heat exchanger for LMTD correction factor, FT, of less than

A

0.80

22
Q

A rivetted joint does not fail by __________ of rivets.

A

none of these

23
Q

Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger

A

permits the use of more tubes in a given shell diameter.

24
Q

Bracket supports are the most suitable for supporting ________ vessels.

A

thick walled vertical

25
Q

In a multipass shell and tube heat exchanger, the shell side cross flow area does not depend upon

A

none of these

26
Q

Two iron pipes of the same nominal diameter but different schedule numbers will have the same

A

inside diameter

27
Q

Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about ________ kcal/hr.m2.°C.

A

7500

28
Q

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.

A

20

29
Q

In chemical process equipments, the conical bottom heads used, usually has an apex angle of

A

60°

30
Q

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.

A

75

31
Q

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

A

less

32
Q

Correct use of ‘factor of safety’ is very important in equipment design. It is defined as the ratio of the

A

ultimate stress to working stress.

33
Q

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.

A

20-40

34
Q

________ tray arrangement is recommended for distillation column having diameter upto 4 ft.

A

Cross flow

35
Q

What is the value of ‘q’ for saturated liquid feed to a distillation column?

A

1

36
Q

In perforated plate towers, the

A

all (a), (b) and (c).

37
Q

The main purpose of providing stepping on the trays is to

A

facilitate handling of large flow rate of liquid.

38
Q

The operating pressure drop range in a bag filter is about ________ mm water gauge.

A

50-150

39
Q

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.

A

Ellipsoidal

40
Q

For laminar flow (NRe < 2100) in steel pipe, the optimum inside pipe diameter is given by

A

Di, opt = 3 Q^0.36 ρ^0.18

41
Q

Pick out the correct statement.

A

Packed towers are generally preferred over plate towers, if the liquids have a foaming tendency.

42
Q

Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is

A

less

43
Q

Pick out the wrong statement pertaining to the design of a basket type evaporator.

A

It is used for high viscosity liquor having large rate of scaling.

44
Q

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.

A

none of these.

45
Q

Speed of the drum of the rotary vacuum filter normally ranges from __________ rpm.

A

0.1 to 2

46
Q

A stuffing box is used for

A

prevention of fluid leakage around moving parts.

47
Q

Pressure drop (Δp) and the superficial gas mass velocity (G) in case of packed absorption tower operating in the preloading range are related as

A

Δp = G^2

48
Q

Pick out the wrong statement.
In an agitated vertical cylinderical reaction vessel, the

A

dished bottom vessel has very high power consumption.