In-situ fume particle size and number density measurements from a synthetic smelt

This paper reports that in Kraft recovery furnaces, significant fuming of sodium and potassium takes place. It is essential to quantify the fume generation rate because fume particles coat heat transfer tubes and plug flue gas passages. To address this problem an ensemble light scattering technique, based on measurement of the polarization ration, was used to measure fume particle size and number density from a synthetic Kraft smelt. This in-situ nonintrusive technique is used because of its application to high density particle-laden flows Measurements were also carried out at different scattering angles in order to determine the imaginary part of the particle complex refractive index. In addition, fume particle size distributions obtained from scanning-electron-microscope images were correlate with the log-normal distribution function. Results indicated that an increase in nitrogen flow rate generated smaller fume particles, while a higher air flow rate produced larger fume particles. In addition increased nitrogen flow rate increased fume mass density, but the air flow rate had a negligible effect