GATE 2020 CH – Question 56

Fluid Mechanics and Mechanical Operations · Settling, centrifuges, cyclones, thickening, filtration, agitation and mixing · 2 marks · Numerical answer

A vertical packed bed is 1 m high with void fraction 0.1 at no flow. Minimum fluidization is induced by fluid of density 1 kg/m³; solid density is 3000 kg/m³. With g = 9.81 m/s², find pressure drop at incipient fluidization in Pa, rounded to the nearest integer.

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 26450 to 26500

Explanation

At minimum fluidization, pressure force balances the buoyant weight of the bed solids. Per unit area, $\Delta P=(\rho_p-\rho_f)(1-\epsilon)gL$. Substitute $(3000-1)(1-0.1)(9.81)(1)=26478.171$ Pa. Rounded pressure drop is 26478 Pa. The fluid’s buoyancy and the solids volume fraction are both included.

More Settling, centrifuges, cyclones, thickening, filtration, agitation and mixing questions

GATE 2026 CH Q49 – Laboratory filtration is conducted at constant pressure drop of 200 kPa on a slurry of…
GATE 2025 CH Q49 – A leaf filter is operated at 1 atm (gauge). The volume of filtrate collected (V in m3) is…
GATE 2024 CH Q58 – A metallic spherical particle of density 7001 kg m-3 and diameter 1 mm is settling…
GATE 2023 CH Q20 – For a packed-bed comprising of uniform-sized spherical particles of diameter D p, the…
GATE 2023 CH Q53 – A large tank is filled with water (density = 1 g cm-3) upto a height of 5 m. A 100 µm…
GATE 2022 CH Q53 – In a constant-rate cake filtration operation, the collected filtrate volumes are 120 m3…

All Settling, centrifuges, cyclones, thickening, filtration, agitation and mixing questions →