Numerical Simulations of Thermo-Fluid Phenomena in Microwave Heated Packed and Fluidized Beds

Files
diss.pdf (40.74 MB)
Downloads: 12459
TR Number
Date
2003-09-01
Journal Title
Journal ISSN
Volume Title
Publisher
Virginia Tech
Abstract

Microwave heating is implemented in various fields such as drying, material processing, and chemical reactors. Microwaves offer several advantages over conventional heating methods: 1) microwaves deposit heat directly in the material without convection or radiation, 2) microwave heating is easy and efficient to implement, and 3) microwave processes can be controlled.In order to understand how to use microwaves more efficiently, we must understand how they affect the material with which they interact.This requires the ability to predict the temperature distribution that is achieved within the material.In recent years packed and fluidized beds have been used as chemical reactors to achieve various tasks in industry.Recent studies have shown that microwave heating offers the potential to heat the bed particles to a higher temperature than that of the fluid.This results in enhanced reaction rates and improves the overall efficiency of the reactor.T he focus of this work is to determine the temperature distributions within the packed and fluidized beds, and to determine whether the catalyst particles can be heated to a higher temperature than the gas in catalytic reactions. The beds are modeled with multiphase flow equations.The gas velocity profiles along with the solid and gas temperature profiles for packed and fluidized beds are provided. F or the fluidized beds, the hydrodynamics is modeled using FLUENT and the solid velocity profiles are also determined.

Description
Keywords
fluidized beds, packed beds, microwave catalysis
Citation