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Show ) Abstract UNSTEADY PROCESSES IN DROPLET COMBUSTION: APPLICATIONS TO HAZARDOUS WASTE INCINERATION* N. E. Bergan E. K. Flatbush H. A. Dwyer Combustion Research Facility Sandia National Laboratories, Livermore, CA Presented at the AFRC International Symposium on the Incineration of Hazardous, Municipal, and Other Wastes Palm Springs, CA November 2-4, 1987 Using numerical methods, we analyze the unsteady processes governing combustion of droplets under conditions found in a typical waste incinerator. Our primary objectives are to identify and correlate parameters affecting the residence time of chlorinated hydrocarbon droplets in an incinerator. Two different numerical simulations are performed. The first is a one-dimensional solution of the unsteady Navier-Stokes equations for multi-component, spherically symmetric droplet combustion. The second model is a onedimensional Lagrangian model of droplet motion to study the sensitivity of droplet trajectory to combustion parameters. The multicomponent model calculates temperature and concentration profiles to study ignition, burning rates, and extinction of multicomponent droplets. Results from this model agree with experimental trends, but predict burning rates conservatively low, in that actual droplets burn faster than our predictions and thereby achieve a higher destruction efficiency. The trajectory model is used to show the relative importance of burning rates and drag on the droplet penetration distance. Results show that the droplet trajectory is sensitive to Reynolds number definitions used in drag correlations. The burning rate also plays an important role in calculating droplet penetration distances. The paper concludes with recommendations on droplet modeling techniques for hazardous waste incineration, and practical implications of our findings. • This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Engineering and GeosCiences 1 |