Title page for ETD etd-081412-151228

Document Type dissertation

Author Name Rockwell, Scott

Email Address srockwel at wpi.edu

URN etd-081412-151228

Title Influence of Coal Dust on Premixed Turbulent Methane-Air Flames

Degree PhD

Department Fire Protection Engineering

Advisors
Ali S. Rangwala, Advisor
Kathy A. Notarianni, Committee Member
Simon W. Evans, Committee Member
Sanjeeva Balasuriya, Committee Member
Alfonso F. Ibarreta, Committee Member
Forman A. Williams, Committee Member

Keywords
experimental technique
turbulent burning velocity
coal

Date of Presentation/Defense 2012-08-14

Availability unrestricted

Abstract
The hazard associated with dust deflagrations has increased over the last decade industries that manufacture, transport, process, or use combustible dusts. Identification of the controlling parameters of dust deflagration mechanisms is crucial to our understanding of the problem. The objective of this study is to develop an experimental platform, called the Hybrid Flame Analyzer (HFA), capable of measuring the laminar and turbulent burning velocity of gas, dust, and hybrid (gas and dust) air premixed flames as a function of properties specific to the reactants such as dust-particle size and concentration.
In this work the HFA is used to analyze a particle-gas-air premixed system composed of coal dust particles (75-90 µm and 106-120 µm) in a premixed CH4-air ( = 0.8, 1.0 and 1.2) flame. This work ultimately aims to improve the knowledge on fundamental aspects of dust flames which is essential for the development of mathematical models. This study is the first of its kind where multiple different parameters that govern flame propagation (initial particle radius, particle concentration, gas phase equivalence ratio, turbulent intensity, and integral length scale) are systematically analyzed in a spatially uniform cloud of volatile particles forming a stationary flame.
The experiments show that the turbulent burning velocity is more than two-times larger than the laminar counter-part for each and every case studied. It is observed that smaller particles and larger concentrations (> 50 g/m3) tend to enhance the turbulent burning velocity significantly compared to larger particle sizes and lower concentration ranges. The experimental data is used to develop a correlation similar to turbulent gas flames to facilitate modeling of the complex behavior.

Files
Rockwell_thesis_with_App_v06.pdf

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Document Type	dissertation
Author Name	Rockwell, Scott
Email Address	srockwel at wpi.edu
URN	etd-081412-151228
Title	Influence of Coal Dust on Premixed Turbulent Methane-Air Flames
Degree	PhD
Department	Fire Protection Engineering
Advisors	Ali S. Rangwala, Advisor Kathy A. Notarianni, Committee Member Simon W. Evans, Committee Member Sanjeeva Balasuriya, Committee Member Alfonso F. Ibarreta, Committee Member Forman A. Williams, Committee Member
Keywords	experimental technique turbulent burning velocity coal
Date of Presentation/Defense	2012-08-14
Availability	unrestricted
Abstract The hazard associated with dust deflagrations has increased over the last decade industries that manufacture, transport, process, or use combustible dusts. Identification of the controlling parameters of dust deflagration mechanisms is crucial to our understanding of the problem. The objective of this study is to develop an experimental platform, called the Hybrid Flame Analyzer (HFA), capable of measuring the laminar and turbulent burning velocity of gas, dust, and hybrid (gas and dust) air premixed flames as a function of properties specific to the reactants such as dust-particle size and concentration. In this work the HFA is used to analyze a particle-gas-air premixed system composed of coal dust particles (75-90 µm and 106-120 µm) in a premixed CH4-air ( = 0.8, 1.0 and 1.2) flame. This work ultimately aims to improve the knowledge on fundamental aspects of dust flames which is essential for the development of mathematical models. This study is the first of its kind where multiple different parameters that govern flame propagation (initial particle radius, particle concentration, gas phase equivalence ratio, turbulent intensity, and integral length scale) are systematically analyzed in a spatially uniform cloud of volatile particles forming a stationary flame. The experiments show that the turbulent burning velocity is more than two-times larger than the laminar counter-part for each and every case studied. It is observed that smaller particles and larger concentrations (> 50 g/m3) tend to enhance the turbulent burning velocity significantly compared to larger particle sizes and lower concentration ranges. The experimental data is used to develop a correlation similar to turbulent gas flames to facilitate modeling of the complex behavior.
Files	Rockwell_thesis_with_App_v06.pdf