Q.1
Large process vessels operating under extreme temperature and pressure conditions are normally clad/ lined with materials like stainless steel, aluminium, nickel & its alloys, copper & its alloys and titanium. The cladding thickness is generally about __________ percent of the total thickness.
Q.2
Heat transfer co-efficient, hG(Kcal/hr.m² .°C) and mass velocity of air, G (kg/hr.m² ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to
Q.3
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.
Q.4
Normally, the ratio of the total riser area to the tower cross sectional area (for bubble cap towers of diameter more than 3 ft) is around
Q.5
For given number of passes, pitch & tube diameter, the maximum number of tubes that can be accommodated in a shell of tripled inside diameter will be __________ times.
Q.6
The necessary wall thickness for a metallic storage vessel is a function of the
Q.7
Friction factor for turbulent flow in a new pipe is given by
Q.8
For a given fluid, as the pipe diameter increases, the pumping cost
Q.9
Cylinderical shell thickness of rotary drier is generally __________ mm.
Q.10
High pressure fluid in a shell and tube heat exchanger should preferably be routed through the
Q.11
Ratio of tube length to shell diameter for a shell and tube heat exchanger is
Q.12
Which tube arrangement in a heat exchanger would facilitate highest heat transfer rate?
Q.13
In inclined long tube vertical evaporators, the tubes are inclined at an angle of
Q.14
Which of the following packing materials provides for maximum mass transfer?
Q.15
A cylinderical pressure vessel of volume 6 πm³ has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm² and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to
Q.16
The distance between the top of the slots and the liquid surface when the static liquid is just ready to flow over the overflow weir is called
Q.17
Liquid gradient over the tray results due to the
Q.18
Which of the following factors determine the amount of entrainment in a distillation column?
Q.19
A 'rupture disc' is provided in chemical equipments as an accessory meant for
Q.20
Corrosion allowance in the design of pressure vessel/chemical equipment is not necessary, if
Q.21
In the downcomer of a distillation column, the minimum recommended residence time is about __________ seconds.
Q.22
In which of the following evaporators, steam is fed inside the tube while the liquor is outside the tube?
Q.23
__________ of water makes it a widely used coolant in heat exchangers.
Q.24
Poisson's ratio of a material is the ratio of unit lateral strain to the unit axial elongation within its elastic limit. The value of Poisson's ratio for structural and pressure vessel steel may be taken as
Q.25
Of the pressure vessels, with same thickness but different diameters, which one withstands higher pressure?
Q.26
In a multipass shell and tube heat exchanger, the problem of differential expansion between the shell and tube passes is taken care of by using a
Q.27
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.
Q.28
The ratio for the rate of washing to the final rate of filtration in a washing type of plate and frame filter is
Q.29
Maximum plate efficiency is achieved in case of __________ flow.
Q.30
Pick out the wrong statement.
Q.31
In a shell and tube heat exchanger, triangular pitch arrangement as compared to square pitch arrangement
Q.32
Steam is preferred to be used as a heating medium in heat exchangers, because of its
Q.33
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 to 18 with the numbers 14 and 16 being more commonly used. Outside diameter of tubes varies from about 15 to 50 mm; however a tube of less than __________ mm outside diameter is generally not recommended for fouling fluids.
Q.34
What is the value of 'q' for saturated liquid feed to a distillation column?
Q.35
The wall thickness for a large high pressure pipeline is determined by the consideration of the
Q.36

A shell may by termed as thin if its thickness to diameter ratio is less than 0.The factor which can be neglected in the calculation of membrane stresses is

  • bending
  • deformation
  • shear
  • elongation
Q.37

Pick out the wrong statement.

  • If sufficient residence time (around 8 seconds) is not proivided to the downcoming liquid in the downcomer, it may entrain some vapour.
  • The liquid head in the downcomer should not be greater than one half the plate spacing to avoid flooding.
  • The dischare end of the downcomer must project far enough into the tray liquid so that no gas bubbles can enter the open end and by pass the bubble caps.
  • none of these.
Q.38

Steam economy is defined as the amount of evaporation per unit amount of steam used, while the capacity is the total evaporation obtained per hour. Use of multiple effect in evaporation

  • increases capacity.
  • increases economy.
  • does not affect the capacity.
  • both 'b' & 'c'.
Q.39

Cylinderical shell thickness of rotary drier is generally __________ mm.

  • 2-3
  • 18-22
  • 6-8
  • 12-15
Q.40

Scale up problem in design based on the similarity concept takes into account __________ similarity.

  • geometrical
  • kinematic
  • dynamic
  • all (a), (b) and (c)
Q.41

__________ heat exchanger is also known as 'hair pin type' exchanger,

  • Double pipe
  • Finned
  • Plate type
  • Regenerative
Q.42

What is the value of 'q' for saturated vapor feed to a distillation column ?(where q = fraction of the feed stream that is liquid.)

  • 0
  • 1
  • <0
  • > 1
Q.43

Pick out the wrong statement pertaining to shell and tube heat exchanger.

  • Clearance between shell & baffles and between tube & baffles should be minimum to avoid by-passing of the fluid, but it should be enough to permit the removal of tube bundle.
  • Baffles are supported independently of the tubes by tie rods and positioned by spacers.
  • Tie rods are fixed at one end in the tube sheet by making blind holes and the minimum number of tie rods is 4 with at least 10 mm diameter.
  • Bracket supports are used for horizontal shell, while saddle support is used for vertical shell.
Q.44

Log mean temperature difference in case of multi-pass shell and tube heat exchanger is always

  • less than arithmetic mean value.
  • more than arithmetic mean value.
  • more than geometric mean value.
  • both(b) & (c).
Q.45

The ratio of lateral strain to linear strain is termed as the

  • Poisson's ratio
  • bulk modulus
  • modulus of elasticity
  • shear modulus
Q.46

The distance between the centre of a rivet hole to the nearest edge of the plate is called

  • pitch
  • margin
  • back pitch
  • none of these
Q.47

A 'rupture disc' is provided in chemical equipments as an accessory meant for

  • relieving excess pressure.
  • creating turbulence.
  • enhancing mixing rate.
  • avoiding vortex formation.
Q.48

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 ?

  • Segmental baffle
  • Flat plate extending across the wall
  • Disk type baffle
  • Helical type baffle
Q.49

The average velocity in the tubes of a 1-4 heat exchanger is __________ times that in 1-1 heat exchanger having the same size & number of tubes and operated at same liquid flow rate.

  • 2
  • 1/2
  • 4
  • 1/4
Q.50

Pick out the wrong statement about the design of a sieve plate column.

  • An increased weir height improves the tray efficiency at the cost of high plate pressure drop; optimum wear height being 40-90 mm for column pressure above atmospheric and 6-12 mm for vacuum columns.
  • For segmental downcomers, the chord length is 60-80% of the column diameter. An initial value of downcomer area of 12% is taken in the design.
  • Width of the calming section provided at the inlet and outlet sides of the plate is 75 mm for column diameter below 1.5 metres and 100 mm for larger diameter columns.
  • Minimum recommended downcomer residence time for the disengagement of entrained vapour is the same for both foaming and non-foaming liquids, which is about 20 seconds.
0 h : 0 m : 1 s