HEAT TRANSFER THROUGH A BED OF GRANULAR MATERIAL FROM A HOT SURFACE OF A TUBE CONCENTRICALLY MOUNTED IN A ROTARY APPARATUS TO THE WALL OF THE LATTER

摘要

Heat transfer rate through a granular bed in a rotary unit has been investigated. The results are expressed in the form of the effective thermal conductivity. A very characteristic relation between this quantity and the number of revolutions of the unit, as well as the degree of filling of the apparatus with the granular material has been found.nThe critical numbers of revolutions a for which the maximum values of the thermal conductivity have been obtained are different for each degree of filling of the apparatus;the lower theφ the lower n k. A dependence of the effective thermal conductivity on the grain size has been also found.