Process Equipment and Plant Design Questions

• Empirical design correlation: For many refinery distillation columns (relative volatility < 4; μ between 0.07 and 1.4 cP), which correlation reasonably estimates the overall column efficiency η (%) as a function of feed viscosity μ (cP)?
• Packed column practice: In industrial packed columns, small packings are usually dumped, but packings larger than which nominal size are typically stacked individually to control bed porosity and lower gas pressure drop?
• Plant piping color code (utility lines): In chemical process plants, fresh water carrying pipelines are conventionally painted which identifying color?
• Shell-and-tube baffle geometry: A “25 percent cut” segmental baffle in a shell-and-tube heat exchanger means that the baffle plate height equals what fraction of the shell inside diameter (I.D.)?
• Elastic constants (materials science): The ratio of shear stress to shear strain is called what material property?
• Tray selection and performance in distillation: Which statement is WRONG regarding valve trays, sieve trays, and bubble-cap trays used in continuous distillation columns?
• Mechanical design — In strength-based design, the “factor of safety” (FoS) is defined as the ratio of the material's limiting strength to the allowable service (working) stress used for design. Which statement correctly gives this ratio?
• Tray design — For a bubble-cap tray to run stably with even vapour distribution, which of the following statements is incorrect (i.e., the “wrong statement”)?
• Heat exchanger design — When using the LMTD method with correction factor FT (for multi-pass or crossflow arrangements), it is generally not desirable to design for FT below which value?
• Vessel supports — Bracket (lug) supports are most suitable for which type of vessel configuration in process equipment design?
• Mass-transfer equipment — On sieve trays, the perforations (holes) are commonly laid out on a triangular pitch equal to how many times the hole diameter?
• McCabe–Thiele method — Which of the following is not a valid simplifying assumption used for continuous binary distillation when calculating the number of ideal stages by the McCabe–Thiele graphical method?
• Shell-and-tube hydraulics — In a heat exchanger, which design choices can be used to change the shell-side fluid velocity (at fixed flow rate)?
• Random packings — A Lessing ring is created by adding a transverse partition across the centre of a Raschig ring. Approximately how much does this modification increase the available surface area (relative to the original ring)?
• Perforated (sieve) plate towers — Which of the following statements are typically true for design and operation of perforated plate (sieve) columns?
• Riveted joint failure modes in machine design: which of the following is NOT a failure mode of the RIVETS themselves (as opposed to the plate) in a riveted lap/butt joint used on boilers, tanks, or structural connections?
• Valve head-loss basics: the dimensionless loss coefficient K for a FULLY OPEN globe valve is approximately (order of magnitude) _____ under standard fittings data.
• Pressure vessel heads: for a cylindrical vessel closed with heads of equal thickness, which head shape can withstand the HIGHEST internal pressure for the same thickness and diameter?
• Tray internals sizing: for a bubble-cap distillation column with diameter greater than 1.2 m, the typical individual bubble-cap DIAMETER is approximately _____ cm (order of magnitude selection for design).
• Shell-side heat transfer: for the same tube size and shell-side flow conditions, how does the shell-side heat transfer coefficient for a SQUARE tube pitch compare with that for a TRIANGULAR pitch bundle?