Answer to Question #171229 in Chemical Engineering for zainab

Question

Determine minimum fluidization velocity of sand particle using water at 20 oC. The sand particles are mono-sized with surface volume spherical equivalent diameter dsv= 162 micron, a sphericity of 0.9

and density 2600 kg/m3

Answer 1

{(150$\mu$u_mf) / ($\phi$_s²d_p²)} x {(1 - ε_mf) / ε_mf³)} + {(1.75$\rho$u_mf²) / ($\phi$_sd_p)} x {1 / ε_mf³)}

= g(ρ_h - $\rho$)

d_p = the diameter for spherical particles or the nominal diameter for irregular-shaped particles; ρ = the density of the fluid; ρ_h = the hudraulic density of the solid; g = the gravity acceleration constant, 9.81 m²/cm; μ = the dynamic viscosity of the fluid; ε_mf = the minimum fluidization voidage; u_mf = the minimum superficial fluidization velocity; and

ϕs = the sphericity of the particle.

d_p = 162 micron = 162 x 10^-6 m

$\rho$(water) = 998 kg/m³

$\rho$_h(sand) = 2600 kg/m³

g = 9.81 m²/cm

μ = 1.002 x 10^-3 Pa•s

ε_mf = (0.071 / ϕ_s)^1/3 = (0.071 / 0.9)^1/3 = 0.429.

{(150 x1.002 x u_mf) / (0.9²(162 x 10^-6)²} x {(1 - 0.429) / (0.429)³)} + {(1.7 x 998 x u_mf²) / (0.9 x 162 x 10^-6)} x {1 / (0.429)³)}

= 9.81(2600 - 998)