Question

Question 10,000 kg of sand with a mesh size of 0.2 mm are fluidized at 300°C and 10 atm pressure, in a cylindrical column of 1 m diameter. Given that the minimal porosity for fluidization is 0.5, and R = 0.082 atm.m²/kmol.K, calculate: (a) The minimal height of fluidized bed, if the density of the particles is 3000 kg/m². (b) Pressure drop experienced by air when passing through the sand bed. (c) Minimal fluidization velocity, if the viscosity of the air is 0.018 mPa's. (d) The nature of the air flow.

Answer 1

D = I'm 7 Chemical Engtreening (1) Given that Mass of Sond = 10,ooo lng (olp) mesh size = 0.2 x 103 m 573.15 K P. 10 atm Coloum dia cd) : Im Porosity (Em) R = 0.082 atm.m3 molik denisty of Particle Pp) = 3ot ly/ (a) Minimum height we know that at minimum fluidization The gravity due to land a mg = I ALCI- Em) g 3000 x yg: 1 x (1)² x L x C1-015) *g 0.5 air L = 8.48m Minimum height (b) At Minimum fluidization AP = ( Sp - Sf) (I-E)g If = Ard density - P.m If RT 10x dg 010821 x 573115 - 6.16 kg/m3 - (3000 - 6.16) x (1-0.5x9 8.48 I DP = 124.526 kPa

(6) Using the Burke plemer Equation Os Op g (Sp- Sf) 1.75 SA for Sphercial particle (as) = 1 Vm: 0.2810 349.81 x (3000-6164) 1.75X6164 Vm= 0.73755 m/s (d) Reynold Number of Pratiche CNRep) = Dp Sp Vm up given up = -0.018mPa.s = 1.8x10 pais Noep 0.2 X10-3 x 3000X 0.73755 1.8 xlors Neep 24585 so, The Nature of the air flow is Turbulent.