The GATE Grind

GATE 2024 CH – Question 24

Mass Transfer · Stage-wise and continuous contacting, stage efficiency, HTU and NTU · 1 mark · Multiple choice

Which one of the given statements is correct with reference to gas-liquid contactors for mass transfer applications?

  1. A tray tower is more suitable for foaming systems than a packed tower.
  2. Tray towers are preferred over packed towers for systems requiring frequent cleaning.
  3. For a given liquid flow rate, the gas flow rate in the loading region is greater than that in the flooding region.
  4. Flooding can never occur for counter-current contact.

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Show answer and explanation

Correct answer: (B) Tray towers are preferred over packed towers for systems requiring frequent cleaning.

Explanation

Tray towers have manholes and are easy to clean, so they suit fouling systems. Packed towers suit foaming liquids (A is false). Loading begins at a lower gas rate than flooding (C is false), and flooding is a limit of counter-current contact (D is false).