Smaller sized packings are generally dumped to the packed columns, and the large ones of size greater than ______________ mm are stacked individually, which provides better control over bed porosity and offers lower gas pressure drop?

Related Mcqs:

1. In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?

   A. Are easier to clean
   B. Are less prone to fouling
   C. Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less
   D. None of these

2. Liquid redistribution should be done in a packed tower packed with raschig rings every 6 metres or ______________ times the column diameter, whichever is lower?

   A. 2.5-3.0
   B. 5-7.5
   C. 10-12.5
   D. 15-20

3. Commercial packed scrubbers are normally designed for a pressure drop range of ______________ mm water column per metre of packed height?

   A. 4-8
   B. 17-34
   C. 52-68
   D. 88-105

4. Diameter of bubble caps used in high pressure columns is ______________ as compared to that used in identical vacuum columns?

   A. Less
   B. More
   C. Same
   D. Either A. or B.; no generalisation can be made

5. Which of the following factors affect the pressure drop in a co-current gas-liquid absorption packed tower ?

   A. Size, shape, orientation and surface of the packing particles
   B. Density and viscosity of fluids
   C. Fluid flow rates
   D. All A., B. and C.

6. Pressure drop (Δp) and the superficial gas mass velocity (G) in case of packed absorption tower operating in the preloading range are related as_________________?

   A. Δp = G
   B. Δp = G0.5
   C. Δp = G2
   D. Δp = 1/G0.6

7. 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?

   A. 1 to 5
   B. 10 to 20
   C. 30 to 40
   D. 40 to 50

8. Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 – 1.4 cp and relative volatility < 4) (where ε = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi) ?

   A. η = 17 – 61.1 log μ
   B. η = 24.6 (Δp/μ)
   C. η = 1.66 – 0.25 log μ
   D. η = 0.25 log μ – 1.67

9. In packed absorption tower, onset of flooding usually occurs at a pressure drop of about ______________ mm of water column per metre height of packing?

   A. 25-50
   B. 50-75
   C. 200-250
   D. 750-1000

10. The testing pressure of storage tanks and pressure vessels designed as per Indian standard codes should be about ______________ times the design pressure?

    A. 1.5 to 2
    B. 3 to 4
    C. 4 to 5
    D. > 5