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ISSN Online: 2377-424X

ISBN Print: 0-89116-909-1

International Heat Transfer Conference 9
August, 19-24, 1990 , Jerusalem, Israel

HEAT TRANSFER AT THE WALL OF PACKED BEDS

Get access (open in a dialog) DOI: 10.1615/IHTC9.3550
pages 255-260

要約

Experimental results on forced convective heat transfer to an air stream flowing through a packed bed are presented. The particle size has been varied from d = 1 to 40 mm, corresponding to a ratio of tube diameter (D) to particle diameter ranging from D/d = 102 to 2.55. Axial temperature profiles along the wall of the electrically heated tube and radial profiles inside the bed have been measured at axial positions from L/D = 1 to 18. By fitting the parameters of a two-dimensional, homogeneous model to the measured profiles, overall heat transfer coefficients αov , as well as radial and axial thermal conductivities of the gas-solid-system Λr , Λax and wall heat transfer coefficients αω have been obtained. The results show, that even for the largest particles with D/d = 2.55 the measured profiles may be interpreted in terms of the homogeneous model. The effects of axial dispersion are found to be neglegible in the range of these experimental conditions. Both radial thermal conductivity and wall heat transfer coefficient have been found to be independent of the axial position (L/D).