The flooding velocity curves for two different structured packings (P and Q) are shown. The ratio of mass velocities of liquid (Gx) to gas (Gy) is 1.27; liquid density 1200 kg m⁻³, gas density 1.2 kg m⁻³. For both packings, the allowable superficial vapor velocity is 60% of flooding velocity. The ratio of allowable mass velocity of vapor in packing P to that in packing Q is _____________ (rounded off to one decimal place).

Question

Accepted Answer

The correct answer is 1.4 to 1.6. GATE 2026 official key: 1.4 to 1.6. Reading u0,F off each curve at the given abscissa and taking 60% of flooding velocity for both packings, the ratio of allowable Gy (since ρy is common to both) works out to about 1.5.