Download or read book Investigation of Mineral Transformation and Ash Deposition During Staged Combustion. Final Report, October 1, 1993--September 30, 1997 written by and published by . This book was released on 1997 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is to document a recently completed four-year study to examine the impact of low-NOx firing technologies on ash formation and deposition while firing pulverized coal. Low-NOx burners and staged combustion inhibit NOx formation by restricting the amount of oxygen available to form a fuel-rich zone in which nitrogen compounds are reduced to molecular nitrogen (N2) rather than oxidized. Additional oxygen is provided downstream for complete combustion. Consequently, coal and mineral particles encounter different temperatures and oxygen concentrations when they are burned under low-NOx firing conditions than they do in conventionally-fired units. Two coals with distinctly different inorganic contents and ash characteristics were fired in a pilot-scale laboratory combustor under both conventional and staged combustion conditions. Ash and deposit samples were collected at various locations in the reactor and analyzed in order to assess the influence of staged combustion. This report is organized as follows. First, a background section provides the foundation needed in order to understand the motivation for and the results of the experimental program. The next section presents a description of the experimental apparatus and procedures, including the development the analytical methods critical to the study. Results of the analyses of coal, ash and deposit samples are then presented and discussed for each of the two coals. Finally, the report ends with a short summary and statement of conclusions.