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The axial effective thermal conductivities of packed beds were determined by measuring the axial temperature gradients a t steady state, the heat being conducted in the direction opposite to that of air. The present experiments were carried out with the beds of glass beads, metallic balls, broken pieces of limestone, and Raxhig rings, taken in separate experiments.It was found that the axial effective thermal conductivity increases more with the increose of air flow than i t does in the case of radial conductivity. The axial effective thermal conductivity coincides with the radial conductivity when NE, + 0.

Experiments of heat and mass transfer from the tube wall to the fluids flowing through the packed beds were carried out separately. In heat transfer air was used as the fluid, and several kinds of solid particles with low and high thermal conductivities were investigated to determine effective thermal conductivities and wall heat transfer coefficients. In mass transfer the dissolution rate of the coated material on the inner wall of the packed tube to the water stream was measured, and wall mass transfer coefficients were analyzed. It was found that a close similarity exists between the JH and JD factor for the wall coefficients in the turbulent‐flow region.