Q.1

The most common standard size of bubble caps used in industrial operation is

  • 1" dia cap with 0.5" dia riser.
  • 6" dia cap with 4" dia riser.
  • 8" dia cap with 1" dia riser.
  • 4" dia cap with 8" dia riser.
Q.2

Cooling water fouling factors vary in the range of 0.to 0.003

  • (BTU/hr.ft2 . °F)-1
  • (kcal/hr.m2 .°C)-1
  • (W/m2.°K)-1
  • (kcal/hr. m. °C)-1
Q.3

Needle valves are generally not used for

  • very large diameter pipes.
  • high pressure throttling service.
  • very accurate flow control.
  • smaller sizes of pipe.
Q.4

Which of the following types of reactors is the safest from operation point of view ?

  • A vapor phase reactor.
  • Pot type reactor.
  • A liquid phase reactor.
  • A liquid phase catalytic reactor.
Q.5

Value of Peclet number = ∞, is the representative of

  • laminar flow.
  • complete back mixing,
  • plug flow.
  • eddy diffusivity = 0.
Q.6

per cent cut segmental baffle means that the baffle

  • height is 75% of the I.D. of the shell.
  • height is 25% of the I.D. of the shell.
  • spacing is 75% of its height.
  • width is 25% of its height.
Q.7

Saddle supports are used for supporting __________ vessels.

  • horizontal cylinderical
  • tall vertical
  • thick walled vertical
  • thick spherical
Q.8

__________ strain is measured using a 'strain rosetter'.

  • Volumetric
  • Shear
  • Linear
  • none of these
Q.9

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.

  • nozzle or rim
  • flared out
  • fluid in
  • ring plate
Q.10

Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, D = shell diameter )

  • 0.2 D
  • 0.5 D
  • 0.66 D
  • 0.80 D
Q.11

Height equivalent to a theoretical plate (HETP) is the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations like distillation, absorption/stripping and humidification/dehumidification. HETP which is experimentally determined, depends upon the

  • flow rates of each fluid.
  • type and size of packing.
  • concentration of each fluid.
  • all a, b & c.
Q.12

In a bag filter, the pressure drop increases directly as the

  • density of the gas, but is independent of the viscosity of the gas.
  • density of the gas and inversely as viscosity of the gas.
  • viscosity of the gas and inversely as density of the gas.
  • none of these.
Q.13

For a given fluid, as the pipe diameter increases, the pumping cost

  • decreases.
  • increases.
  • remains unaffected.
  • may increase or decreaes depending upon whether the fluid is Newtonian or non-Newtonion.
Q.14

In a shell and tube heat exchanger, triangular pitch arrangement as compared to square pitch arrangement

  • results in higher shell side pressure drop.
  • can accomodate less number of tubes for a given shell diameter.
  • facilitates easier shell side cleaning; hence is more suitable for handling high dirt factor shell side fluid.
  • creates relatively lower turbulence on the shell side resulting in lower shell side heat transfer co-efficient.
Q.15

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

  • 20
  • 30
  • 45
  • 85
Q.16

Low pressure steam (with saturation temperature betweento 120°C) is usually used in the vacuum evaporators, which normally employ a vacuum of about __________ mm Hg (referred to amm mercury barometer).

  • 250
  • 450
  • 650
  • 750
Q.17

The diameter of a propeller agitator used in agitation tank ranges from __________ percent of the tank diameter and its peripherial speed is normallytometres/minute.

  • 5 to 10
  • 15 to 30
  • 40 to 50
  • 55 to 75
Q.18

Thin spherical shells subjected to internal pressure, develop __________ stresses.

  • radial
  • circumferential
  • both (a) & (b)
  • neither (a) nor (b)
Q.19

In case of a continuous distillation column, increase in reflux ratio may result in the

  • lower fixed charges for the column.
  • greater cost for the reboiler heat supply.
  • greater cost for the condenser coolant.
  • all (a), (b) and (c).
Q.20

The maximum liquid gradient over a tray must not exceed

  • 0.5" -1.25".
  • 2"-3.5".
  • 5".
  • half the tray spacing.
Q.21

Pick out the wrong statement.

  • Safety valves are provided in heat exchangers for removal of non-conden-sables.
  • Liquid metals and dowtherm are used for very high temperature heating.
  • In a shell and tube heat exchanger, high pressure fluid is generally routed through the tube.
  • A loop seal or U-seal is provided in a vertical condenser sub-cooler to prevent quick draining of the condensate.
Q.22

The LMTD correction factor (FT) is applied in __________ heat exchangers.

  • 1-1 cocurrent
  • double pipe
  • all multipass
  • all (involving liquid/liquid heat transfer)
Q.23

In most of the shell and tube heat exchangers, the tube pitch is generally __________ the tube diameter.

  • less than
  • 1.25-1.50 times
  • 2.5 times
  • one-fourth of
Q.24

Maximum acceptable total liquid gradient over a tray is about __________ mm.

  • 5.5
  • 12.5
  • 30.5
  • 45.5
Q.25

Pick out the wrong statement about routing of fluids in a shell and tube heat exchanger.

  • The corrosive and fouling fluid should be preferably routed through the tubes.
  • The viscous fluid should be routed through the shell side.
  • Lower flow rate fluid should be routed through the shell side.
  • Higher pressure fluid stream should be routed through the shell side.
Q.26

In most of the shell and tube heat exchangers, the tube pitch is generally __________ the tube diameter.

  • less than
  • 1.25-1.50 times
  • 2.5 times
  • one-fourth of
Q.27

Which of the following is the best tube material from thermal conductivity point of view alone?

  • Aluminium
  • Stainless steel
  • Copper
  • Carbon steel
Q.28

In packed towers provided with saddle packing, liquid redistributors are positioned at every __________ times column diameter or 6 metres whichever is less.

  • 2-3
  • 5-8
  • 10-15
  • 20-25
Q.29

With increase in the reflux ratio for a fixed production from a continuous binary distillation column, the __________ decreases.

  • fixed charges initially
  • running cost of cooling water for condenser
  • vapour & liquid load both
  • running cost of steam for reboiler
Q.30

In a distillation column, the minimum residence time for liquid in the downspout is about __________ seconds.

  • 1
  • 8
  • 80
  • 180
Q.31

An underdesigned steam trap will

  • waste steam.
  • destroy itself of acceleration wear due to rapid recycling.
  • back up condensate and cause water hammer in steam line.
  • none of these.
Q.32

With increase in gas flow rate to fabric surface area ratio (Nm3/hr/m2 fabric surface area), the size & the cost of a bag filter

  • increases
  • decreases
  • remain unaffected
  • none of these
Q.33

Accidents in chemical plants are mostly due to

  • inadequate equipment design.
  • faulty operating procedures.
  • improper layout of the equipments.
  • failure of equipments.
Q.34

Movement of pipeline caused by thermal expansion is taken care by providing

  • expansion joint.
  • changes in its direction.
  • change in the shape of pipeline.
  • all (a), (b) and (c).
Q.35

Pick out the wrong statement pertaining to the design of a horizontal tube evaporator.

  • It is unsuitable for concentrating those liquids, which form a scale or deposit salt.
  • It is suitable for process, in which the final product is a liquor instead of solid.
  • Its usual dimensions are: tube dia = 2-3 cms; evaporator body dia = 1-4 metres and evaporator height = 2.5-4 metres.
  • Liquor flows inside the tube, while the steam is outside submerging the tube.
Q.36

In a distillation column, bubble caps are located on trays with a pitch of __________ times the outside diameter of the caps.

  • 1.3 to 2
  • 1.6 to 2
  • 2.5
  • 1.5 to 3
Q.37

In case of a 'thin' pressure vessel, the ratio of its diameter to wall thickness is

  • < 10
  • > 10
  • > 20
  • 30
Q.38

The necessary wall thickness for a metallic storage vessel is a function of the

  • ultimate tensile strength (or yield point) of the material and operating temperature.
  • operating pressure and welding/joint efficiency.
  • diameter of the vessel.
  • all (a); (b) and (c).
Q.39

Normal screwed fittings are used for pipes upto a diameter of __________ inches.

  • 1.5
  • 3
  • 5
  • 7
Q.40

Optimum reflux ratio in a continuous distillation column is determined by the

  • maximum permissible vapour velocity.
  • flooding limit of the column.
  • total cost consideration (fixed cost of the column plus the cooling water & steam cost).
  • none of these.
Q.41

The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is

  • 0
  • 1
  • minimum
Q.42

The slope of the feed line in distillation opeartion is given by (where, q = fraction of the feed stream that is liquid.)

  • -q
  • -q/(1-q)
  • -q/(q-1)
  • none of these
Q.43

A head comprises of straight flange section, corner torus, section and central dished section. Crown radius and knuckle radius in a head is related respectively to the

  • central dished section and corner torus section.
  • corner torus section and central dished section.
  • central dished section and straight flange section.
  • straight flange section and corner torus section.
Q.44

The design stress, which is more than the damaging stress, is the least unit stress that will render a member unfit for service before the end of its normal life. The design stress factor or factor of safety indicates the margin between design stress and the __________ stress.

  • working
  • damaging
  • allowable
  • none of these
Q.45

Flanges are connected to pipes by

  • screwing
  • welding
  • brazing
  • all (a), (b) and (c)
Q.46

For identical operating conditions, the pressure drop over __________ tray is the highest out of the following.

  • sieve
  • valve
  • counterflow
  • bubble cap
Q.47

For a cylindrical shell, (subject to the thickness of uppermost course being more than the minimum for diaofthe tank in question), the thickness of the courses of shell

  • decreases upwards.
  • increases upwards.
  • remains same throughout.
  • may decrease or increase upwards depending upon whether vacuum or positive pressure would be maintained inside the shell.
Q.48

Weep holes provided in the plates of a distillation column

  • facilitate draining out liquid from a tray when the unit is not in operation.
  • are normally located near the overflow weir so that any delivery of liquid during operation follows approximately the same path as the overflow fluid.
  • must be large enough (usually 1/4" to 5/8" dia) to prevent plugging but should not deliver excessive amount of fluid during operation.
  • all (a), (b) and (c).
Q.49

In actual operation of distillation column, the vapour is not distributed uniformly among the bubble caps, primarily because of the

  • liquid gradient on the tray.
  • lower skirt clearance.
  • lower static submergence.
  • small downcomer liquid seal.
Q.50

Tube wall thickness depends on the cor-rosiveness of the fluids and their operating pressure & temperature and is specified by Birmingham wire gauge (B.W.G)-a number which varies from 8 towith the numbersandbeing more commonly used. Outside diameter of tubes varies from abouttomm; however a tube of less than __________ mm outside diameter is generally not recommended for fouling fluids.

  • 16
  • 19
  • 28
  • 38
0 h : 0 m : 1 s