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Show due to the freezing of certain molten or softened species, the reduction in vapor phase alkalis, etc .. A comprehensive model for deposition (4] is currently being used and modified to identify these phenomena and suggests that a change in the mechanism of deposition occurs between these different reaction temperatures. Summary For practical purposes, the results presented here identify a significant link between deposition behavior and the combustion temperature (reactor temperature). The effectiveness of surface cooling to control deposition has been demonstrated, but the results are strongly dependent on the combustion history of the coal and ash. It appears that a combination of high reactor temperature and low surface temperature is needed to reduce the sticking coefficient. A low reactor temperature produced a surprisingly large sticking coefficient independent of the surface temperatures studied. References 1. France, J. E., Grimm, U., Anderson, R. J., Kovach, J. J., "Deposition and Corrosion in Gas Turbines Utilizing Coal or Coal Derived Fuels," OOE/METC/84- 17 (DE84009290), 1984. 2. Rosner, D. E., Nagarajan, R. "Toward a Mechanistic Theory of Net Deposit Growth from Ash-Laden Flowing Combustion Gases: Self-Regulated Sticking of Impacting Particlers and Deposit Erosion in the Presence of Vapor Deposited - or Submicron Mist - 'Glue'," AiChE Symposium Series, Heat Transfer -Pittsburgh 1987, No. 257, Vol. 83. 3. Ross, J. S., Anderson, R. J., Nagaraj an , R., "Effect of Sodium on Deposition in a Simulated Gas Turbine Environment," J. Energy & Fuels, 1988 ~, 282. 4. Nagaraj an , R., Anderson, R. J., "Effect of Coal Constituents on the LiquidAssisted Capture of Impacting Ash Particles in Direct Coal-Fired Gas Turbines," ASME Paper 88-GT-192, 1988. |