Multi-dimensional hydrodynamic and erosion modeling of fluidized beds
The objective of this investigation was to further the understanding of hydrodynamics controlling solids and gas motion around in-bed components. These are the main parameters influencing wear. Hence, detailed knowledge of solids circulation and bubble motion is essential to the understanding of metal wear in fluidized bed combustors units. The experimental and computed solids motion in a bubbling fluidized bed with a simulated tube banks and uniform air superficial velocity has been studied in detail for the first time to the author's knowledge. Generally good agreements between predicted and experimental solids flow patterns and solids axial velocities was obtained. A methodology to compute bubble parameters in a fluidized bed operated in the hostile environment of industrial reactors as well as a variety of research applications was developed. The industrial results compared reasonably well with our predictions. Well-defined fluidized bed experiments were conducted to provide data such as instantaneous porosity oscillations, pressure, fluctuations, bubble frequencies and velocities. Two fluidized beds containing five and nine tubes were investigated and used to predict wear patterns. Time-averaged transient erosion rates were calculated using a monolayer energy dissipation model. The experimental and computed erosion rates were compared. They show a reasonable agreement. A unique test of the ability of our hydrodynamic model to predict solid discharge rates was developed. The predicted solids velocity profiles agreed well with experimental data. A well-posed three dimension al model for bed dynamics was developed starting from a previous ill-posed model.
- Research Organization:
- Illinois Inst. of Tech., Chicago, IL (United States)
- OSTI ID:
- 5102852
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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