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Title	A Method For Extending Viscosity Prediction Formulas
Creator	Annen, K.; Gruninger, J.; Stewart, G.
Publisher	Digitized by J. Willard Marriott Library, University of Utah
Date	1983
Spatial Coverage	Akron, Ohio
Abstract	Formulas for the prediction of coal slag viscosity and fouling potential are widely used in the boiler industry for the design of boilers and the specification of suitable coals. These formulas are based on the overall composition of the coal ash and are valid for temperatures at which the slag is entirely liquid (i.e., above the liquidus temperature). The extension of viscosity formulas to temperatures below the liquidus temperature can be performed by using a chemical equilibrium code to calculate the composition of the liquid phase to be used in a formula, applying the formula to obtain the viscosity, and then correcting the predicted liquid viscosity for the presence of solids in the liquids. This method has been used to extend the viscosity predictions to temperatures below the liquidus temperature. Results of the extended viscosity method are very encouraging. For slags which are characterized by a pronounced temperature of critical viscosity, the extended formula agrees very well with measured viscosity data. For slags which do not exhibit critical viscosity behavior, the extended formula predicts the qualitative behavior well, but is quantitatively less accurate than the formula prediction based on the initial slag composition. Approaches for improving the quantitative accuracy of the extension methodology include expanding the thermodynamic data base of the ideal solution model and the use of an improved viscosity prediction formula.
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Format	application/pdf
Language	eng
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Conversion Specifications	Original scanned with Canon EOS-1Ds Mark II, 16.7 megapixel digital camera and saved as 400 ppi uncompressed TIFF, 16 bit depth.
Scanning Technician	Cliodhna Davis
ARK	ark:/87278/s61n83n5
Setname	uu_afrc
ID	187
Reference URL	https://collections.lib.utah.edu/ark:/87278/s61n83n5

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Title	Page 10
Format	application/pdf
OCR Text	Show slags. The key feature of the approach is the use of a chemical equilibrium code to calculate changes in the liquid composition of a slag as a function of temperature and gas stream stoichiometry. The method's predictions agreed very well with a slag which exhibited critical viscosity behavior, while they were in fair agreement with a slag that did not exhibit critical viscosity behavior. Refinements in the extended viscosity method may offer improved accuracy for the non-critical viscosity slags In particular. References J.D. Watt and F. Fereday, "The Flow Properties of Slags Formed From the Ashes of British Coals: Part 1. Viscosity of Homogeneous Liquid Slags in Relation to Slag Composition", J. Inst, of Fuel 42, No. 3, 99 (1969). V. Yousefian, M. Weinberg and R. Haimes, "PACKAGE (_Plasraa Analysis, ttremical Kinetics, and Generator _Efficiency): A computer program for the calculation of partial chemical equilibrium/partial chemical rate controlled composition of multiphase mixtures under one dimensional steady flow," Aerodyne Report No. ARI-RR-177 (December 1979). JANAF Thermochemical Tables, NSRDS-NBS 37, June 971 and later revisions. R.A. Robie, B.S. Hemingway and J.R. Fisher, Geological Survey Bulletin 1452 (1979). ^€ o r w o S.^S D-^- J.H. Gruninger, V. Yousefian, J.W. Duff and G.W. Stewart, "Combustion Stream Modeling for Combined Cycle Processes: Implications with Respect to Alkali-Induced Corrosion," Proceedings of DOE Contractors Meeting on Alkali and Particulate Removal, Morgantown, WV (February 1981). H.L. Goldsmith and S.G. Mason, "The Microrheology of Dispersions," in Rheology, Theory and Applications, Vol. 4, F.R. Eirich, ed., Academic Press, New York , p. 208 (1967). A. Sanyal, Private Communication. H.R. Hoy, A.G. Roberts and D.M. Wilkins, Inst. Gas Engrs. Coram. 672, London (November 1964). J. Nolan, P.S. Rogers, A. Sanyal and J. Williamson, "A Laboratory Study of the Thermal Behavior of Coal Minerals", Microstructural Science, 9, 99 (1981). 3-10 1. 2. 5„t> 4. c.V 5. 6. 7. 8. 9.
Setname	uu_afrc
ID	186
Reference URL	https://collections.lib.utah.edu/ark:/87278/s61n83n5/186