Velocity distribution in rectangular packed beds and non-ferrous blast furnaces

A theoretical equation for predicting velocity profiles in beds of rectangular geometry packed with equal-sized particles is presented. Use of this equation to predict velocity profiles requires the measurement of only one experimental variable. Predicted and measured velocity profiles in square and rectangular packed beds using a thermistor probe were in good agreement (±5 and ±10 pct respectively). For packings containing a range of sizes it was found that the velocity was greater at the wall and at the center of the bed than it was in the intermediate regions. This behavior, which has not been previously reported, is attributed to porosity variations. Results obtained from a slice model of a copper blast furnace indicate that in these furnaces there are two separate regions of flow. One of these has two components of velocity and the other has only one. In the single component flow region the velocity may be predicted by the theoretical equation presented. The implications of the results of this investigation to nonferrous blast furnaces are also discussed.