Process Equipment

• Fresh water carrying pipelines in chemical industries

  Coloured with sea green
• Material seldom used for pressure vessel construction

  Rimmed steel
• Ratio of shear stress to shear strain

  Shear modulus
• 25% cut segmental baffle

  Baffle height is 75% of the I.D. of the shell
• Liquid/petroleum fuel storage tanks built underground

  When storage capacity is less than 45 kilolitres
• Le/D for fully open globe valve

  Around 300
• Lug support

  • Most suitable for thick vertical vessel
  • Same as bracket support
  • Provided usually for vessels of much smaller height than skirt supported vessels
  • All
• With increase in the number of shell passes, the value of FT increases
• Holes of a sieve tray

  Arranged in triangular pitch of 2.5 to 5 times the hole diameter
• Minimum shell thickness for carbon steel (inclusive of corrosion allowance) in a shell and tube heat exchangerdepending on shell diameter is in the range of 5 to 11 mm
• Stress developed in a material without any permanent set

  Elastic limit
• Tube pitch in a shell and tube heat exchanger

  Shortest centre to centre distance between adjacent tubes
• not valid statement for #ebm stages by McCabe:

  A. Sensible heat changes for vapour & liquid are negligibly small.

  B. Reflux is not a saturated liquid.

  C. Molar latent heat of the two components are equal.

  D. Heat of mixing of normal liquid is assumed to be zero.
• Overall distillation column efficiency for most of the refinery columns

  η = 17 - 61.1 log μ (where η = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi)
• Fouling factor

  • Depends on the characteristic of process fluid,
  • velocity of process fluid containing suspended solids,
  • and suspended solids in the fluid.
  • All
• Cap diameter in a bubble cap distillation column of diameter greater than 1.2 metres

  Roughly about 10 cms
• Tube side pressure drop in a 1-2 heat exchanger (for turbulent flow of fluids through the tubes)

  About 8 times that in a 1-1 heat exchanger having the same size & number of tubes and operated at the same liquid flow rate
• 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)
• Maximum tensile strength in a thick cylindrical vessel subjected to internal pressure

  Occurs 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 tearing, shearing, or tearing of the plate across a row. none
• Bracket supports

  Most suitable for supporting thick walled vertical vessels
• In a multipass shell and tube heat exchanger, the shell side cross flow area does not depend upon baffle spacing, clearance, pitch or none
• 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 7500 kcal/hr.m2.°C
• Lessing ring

  Formed by the addition of a partition across the centre of a raschig ring, which results in an area increase of about 20 percent
• Conical bottom heads used in chemical process equipments

  Usually has an apex angle of 60°
• Smaller sized packings in packed columns

  Generally dumped, while larger ones of size greater than 75 mm are stacked individually
• Shell side heat transfer co-efficient in case of square pitch is less compared to the triangular pitch under similar condition of fluid flow and tube size
• Factor of safety in equipment design

  Defined as the ratio of the ultimate stress to working stress
• Pressure drop in packed absorption towers

  Normally designed for about 20-40 mm of water column per metre height of packing
• Tray arrangement recommended for distillation column having diameter up to 4 ft

  Cross Flow
• Perforated plate towers

  • Hole sizes may be around 1/8" or 3/16"
  • Total hole area may be around 6 to 15% of tower cross-sectional area
  • Pressure drop is less compared to similar bubble cap towers
  • all
• Purpose of providing stepping on the trays

  To facilitate handling of large flow rate of liquid
• Operating pressure drop range in a bag filter

  About 50-150 mm water gauge
• Optimum inside pipe diameter for laminar flow (NRe < 2100) in steel pipe

  Di,opt = 3 Q^0.36 ρ^0.18
• Pick out the correct statement.

  1. Packed towers are generally preferred over plate towers, if the liquids have a foaming tendency
  2. When highly corrosive fluids are to be handled, the plate towers prove to be cheaper and easier to construct than packed tower.
  3. The pressure drop through the packed towers is generally more than th thepressure drop through plate towers designed for same duty.
• Wall thickness of schedule 40 pipe is less compared to that of schedule 80 pipe
• wrong statement: pertaining to the design of a basket type

  evaporator

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

  B. The tube bundle is suspended on bracket.

  C. There is no central downtake.

  D. Downtake is formed by the annular space between the bundle and the shell.
• Speed of the drum of the rotary vacuum filter

  Normally ranges from 0.1 to 2 rpm