7HF - Process Equipment Design - October 1998

Part A (20 x 2 = 40 Marks)
  1. As the operating temperature increases the design stress decreases
  2. When radio graphic tests are conducted for pressure vessels, the joint efficiency is 0.85 for spot radiography and 1.00 for 100% radiography.
  3. For stainless steel materials the corrosion allowance is zero.
  4. For elliptical heads the ratio of major axis to minor axis is 2:1
  5. What losses are taking place in the storage of volatile liquids? Evaporation losses, filling losses, breathing losses.
  6. What is TEMA? Tubular Exchangers Manufacturers Association, USA. Heat Exchanger design and fabrication Code.
  7. Corrosive fluids are passed through tube side of a shell and tube heat exchanger
  8. Baffles are provided in agitated vessels to prevent swirling.
  9. For triple effect evaporators the economy is approximately three.
  10. Heat transfer coefficient has the units of W/(m2.K) in SI.
  11. Plate thickness: hole diameter is between ______:______ for sieve trays
  12. At minimum reflux ratio infinite number of plates are required for distillation.
  13. Define loading
  14. A redistributor is used for every 3D (i.e., 3 times the diameter of height) of the packed section.
  15. In a dryer, number of flights ranges from _____D to _____D where D is in feet.
  16. Define cut size for a cyclone separator. (The minimum diameter of particle that can be collected with 100% efficiency)
  17. Formation of new crystals is termed as __________.
  18. What is an induced draft cooling tower? (Air is sucked by the fans at the top of the tower)
  19. Indicate any two advantages of pressure filter
  20. Define critical speed of centrifuge
  21. Part B (5 x 12 = 60 Marks)

  22. (a) 10,000 kg/hr of a hot fluid is to be cooled from 90oC to 45oC using a cold fluid available at 30oC. The cold fluid leaves the exchanger at 42oC. Both fluids have the properties similar to that of water. Design a suitable shell and tube heat exchanger. The overall heat transfer coefficient is 450 W/m2.K. 2.54 cm dia and 4 m long tubes are used.
    Or

    (b) Draw the sketch of a reboiler and indicate the parts.

  23. (a) A continuous distillation column is used to separate a feed mixture containing 25 mole percent Benzene and remaining toluene into a distillate containing 95% benzene and the bottom product containing 90% toluene. Feed is at its bubble point. A reflux ratio of twice the minimum is used. The overall efficiency is 60%. Design a suitable distillation column after choosing reasonable gas mass velocity. aAB = 2.5
  24. Or

    (b) Draw the sketch of a packed column. Indicate parts such as distributor for liquid, redistributor, packing support, packing materials etc.

  25. (a) Give a stepwise procedure for the design of a rotary dryer
  26. Or

    (b) Draw neat sketch of crystallizer of your choice

  27. (a) Draw the sketch of a reaction vessel. Indicate the parts such as agitators, flanged enclosures, cooling coil etc.
  28. Or

    (b) Draw the sketch of different types of dished heads

  29. (a) Draw the sketch of a rotary drum filter and indicate the parts
    Or

    (b) Draw the sketch of a storage tank for non-volatile liquid