A. Vs/Dp2
B. Vs2/Dp2
C. Vs2/Dp3
D. Vs/Dp3
Related Mcqs:
- A gas (density = 1.5 kg/m3, viscosity = 2 × 10‒5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5 kg/m3and viscosity of 3 × 10‒5kg/m.s flowing at 3 m/s will be________________?
A. 8400 Pa/m
B. 12600 Pa/m
C. 18900 Pa/m
D. 16800 Pa/m - For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit length of bed depends upon the sphere diameter as_________________?
A. d
B. d2
C. d4
D. d̅ 2 - For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is________________?
A. More
B. Less
C. Equal
D. Independent of porosity - A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun’s equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 103 VOM + 10.94 × 106 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ?
A. 0.2
B. 0.5
C. 0.7
D. 0.8 - Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is________________?
A. 90
B. 60
C. 45
D. 30 - A Newtonian liquid (ρ = density, μ = viscosity) is flowing with velocity „v‟ in a tube of diameter ‘D’. Let Δp be the pressure drop across the length ‘L’. For a laminar flow, Δp is proportional to_________________?
A. Lρv2/D
B. LμV/D2
C. Dρv2/L
D. μV/L - A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun’s equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 × 103 VOM + 10.94 × 106 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is_________________?
A. 12 mm/s
B. 16 mm/s
C. 24 mm/s
D. 28 mm/s - Applying a pressure drop across a capillary results in a volumetric flow rate ‘Q’ under laminar flow conditions. The flow rate for the same pressure drop, in a capillary of the same length but half the radius is____________________?
A. Q/2
B. Q/4
C. Q/8
D. Q/16 - Pressure drop in a packed bed for laminar flow is given by the ______________ equation?
A. Kozeny-Carman
B. Blake-Plummer
C. Leva’s
D. Fanning friction factor - For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) ?
A. μ
B. 1/μ
C. √μ
D. 1/√μ
