Question

Catalyst pellets of 5 mm diameter are to be fluidized with 45,000 kg/h of air at 1 atm and temp. 30 C in a vertical cylindrical vessel. The density of the catalyst particles is 850 kg/m3; their sphericity is 0.85. The given quantity of air is just sufficient to fluidize the solids. Determine the vessel diameter and terminal velocity. Show pressure drop versus superficial velocity characteristic curve showing both fixed and fluidized bed region. Assume void fraction (under fixed bed state) to be 0.38 and height of vessel is 4 times the diameter of the vessel.

plz write every steps clearly

Answer 1

Given that: - d_p = 5 mm = 5 times 10^-3 m, phi = 0.85: epsilon = 0.38 s_p = 850 kg/m^3 s_y = 1 degree marg/RT = 101.325 times 28.84/8.3148(30 rightarrow 273.15) L = 40 = 1.159 kg/m^3 Delta v viscosity = 1.7 times 10^-5 N.S/m^2 Pressure drop through fixed bed of solids vs: - Deltap/L = 150(1 - epsilon_m/epsilon m^3)^2 mu 40/(phi_s d_p)^2 + 1.75 1 - epsilon/epsilon_m p_y 40^2/phi_s d_p minimum fluidize velocity: - R_em = d_p u_m dy/mu: Delta v = d_p^3 s_y (s_2 - p_y)y/mu^2 R_em = 338.88 mu m Delta v = 4125689.919 phi_s epsilon_mp^3 = 1/14 Rightarrow epsilon rf = 0.438 Delta t fluidization: - Delta v = 1.75/phi_s epsilon_mt^2 Re^2 m + 150(1 - epsilon_mt)/phi_s^2 epsilon_mt^3 R_em 4025689.919 = 10.73 times 338.88^2 um^2 + 1388.568 times 378.88 mu m