Fluent臭氧分解流化床反应器模拟.ppt

Company Confidential Copyright 2001 Fluent Inc. All rights reserved. New Initiatives at Fluent Inc. Ozone decomposition mechanism Ozone decomposition is catalyzed by sand impregnated with iron oxide in fluidized bed O3?(g) ? 1.5 O2 (g) The decomposition rate is expressed as k = 1.57 ? [O3] where ? is the volume fraction of catalysts Ozone decomposition modeling Physical models Eulerian-granular model Syamlal and O’Brian drag law Species transport in multiphase Ozone decomposition modeling Operating conditions the fluidized bed is 0.229 m of diameter and 2 m of height; the bed height is 0.115 m catalyst particles are of 117 ?m diameter; their density is 2650 kg/m3 superficial gas velocities vary from 2 to 14 cm/s Numerical methods higher order discretization scheme is used grid size is 110 x 70 VOF of Gas Conversion Rate and Gas Holdup Conversion Rate and Gas Holdup Gas phase reaction takes place in bed region only Cout/Cin of ozone (1 – conversion) (pink) vs. gas velocity compares well with data (blue) Saturation in gas holdup occurs when bed can no longer hold more gas, even at higher velocities Summary FLUENT captures complex physics in a single simulation for this important industrial application * UGM 2001 Ozone Decomposition in Fluidized Bed Reactors Bin Yang Jayanta Sanyal UGM 2001 t = 0.5 sec t = 1.0 sec * *