The effect of burner orientation on the convective heat transfer rate in around furnace

Top-charged round furnaces are advantageously used for remelting aluminium scrap of various size and shape. There are no detailed data available about the effect of the number and orientation of burners on the heat transfer b etween flame and charge. It has been generally assumed that a rotational fl ow pattern improves the uniformity of residence time and intensifies heat t ransfer. The effect of burner orientation on the how pattern and residence time was analyzed earlier in several cold how studies. The so-called heated skin technique was also developed to determine the convective heal transfe r coefficients. This paper presents the results of an analysis aimed at det ermining the influence of changing the tangential velocity component in the furnace systematically. The average heat transfer coefficients along the h orizontal surface of the molten metal bath are presented in dimensionless f orm. The burner angle settings varied from the radial-centerward pattern (0 degree) to 15 degrees. The average Nusselt number data are correlated with the flow pattern observations and velocity profile measurements. (C) 1998 Canadian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved.