PE 7

• Cylindrical storage tanks used for the storage of volatile liquids (e.g., naphtha)

  Have floating roofs
• Larger depth of liquid on the trays of a distillation column

  A. leads to high tray efficiency.

  B. results in higher pressure drop per tray.

  C. both (a) & (b).

  D. neither (a) or (b).

  ANSWER: both (a) & (b).
• Minimum recommended residence time in the downcomer of a distillation column

  5 seconds
• Condensing film coefficient in case of a horizontal condenser

  Almost thrice the value expected in case of vertical condenser
• Relationship between rivet hole diameter (d, mm) and plate thickness (t, mm)

  d = 1.6 √t
• Binary liquid azeotropic mixture

  Has boiling point lower than either of the components when it shows positive deviation from Raoult's Law
• Evaporator where steam is fed inside the tube while the liquor is outside the tube

  Horizontal tube evaporator
• Purpose of baffles on the shell side of a multipass shell and tube heat exchanger

  Creating turbulence
• Impeller diameter for a turbine agitator

  0.3 to 0.5 d
• Pressure drop per unit length in tube side when a single tube pass heat exchanger is converted to two passes

  Increases by 21.6 times
• The most common type of baffle used in industrial shell and tube heat exchanger is 25% cut segmental baffle
• Minimum recommended ligament for square pitch arrangement in case of heat exchangers

  6.5 mm
• Purpose of safety valves in chemical equipment

  To guard against excessive pressure/pressure fluctuation
• Equivalent diameter for pressure drop


  Smaller than that for heat transfer
• Cylindrical shape of most storage vessels/tanks

  • Greater structural strength
  • Easy to fabricate
• Distance between the top of the slots and the liquid surface when the static liquid is just ready to flow over the overflow weir

  Static submergence
• Cause of liquid gradient over the tray in a distillation column

  Resistance offered to flow of liquids by caps & risers and the flow of gas
• The function of baffles in a shell and tube heat exchanger is to increase the tube side heat transfer co-efficient by inducing turbulence
• Satisfactory value of operating vapor velocity for design purpose in a sieve plate column

  About 80 percent of the flooding velocity
• Approximate liquid depth in an agitation tank

  Equal to the tank diameter
• Baffle width in an agitation tank

  0.1-0.12 times the tank diameter
• Thickness of a cylindrical pressure vessel of volume 6 πm3 to withstand a maximum internal pressure of 10 atm, with allowable design stress of 125N/mm2 and corrosion allowance of 2 mm, for a length/diameter ratio of 3

  10 mm
• Packing material that provides for maximum mass transfer

  Cross-partition rings
• Property of water that makes it a widely used coolant in heat exchangers

  High specific heat
• Equivalent diameter for fluid flow through a channel of constant non-circular cross section

  4 A/P
• Condition when fouling factor must be included in the calculation of overall design heat transfer coefficient

  When the liquid containing suspended solids flows at low velocity
• Purpose of lug support


  For supporting small vessels
• Basis of overall mass transfer co-efficient in case of absorption of NH3 in water

  Gas film (phase) controlling
• Tube arrangement in a heat exchanger that would facilitate highest heat transfer rate

  Triangular pitch
• Pressure drop per tray in the atmospheric distillation column

  0.07 - 0.12 psi
• Thickness of segmental baffles (25 -35% cut truncated plates usually)

  Twice the tube wall thickness
• Safe height (h) to diameter (d) ratio (i.e., h/d) for liquid/petro fuel storage tank of capacity more than 45 kilolitres


  Less than 1
• Increase in the maximum number of tubes that can be accommodated in a shell of tripled inside diameter, for given number of passes, pitch & tube diameter

  Considerably more than 9 times
• The ratio of linear stress to linear strain

  Modulus of elasticity
• Bubble cap plate column

  A finite stage contactor
• Hole pitch in sieve plate column

  2.5 to 4.0 times the hole diameter
• The joint made by overlapping of one plate over the other, and then riveting the two plates together with two rows of rivets is not called 'double riveted butt joint'
• Bubble cap diameter used for the distillation column having diameter ranging from 1.5 to 4.5 metres


  About 100 mm
• Film heat transfer coefficient for air in a single pass air heater connected to a two pass unit
Varies in the ratio of $2^{0.8}$