Radial heat transport in packed beds at elevated pressures

Values were measured for the effective radial heat conductivity λeff, r and the heat transfer coefficient at the wall αw in a packed bed. This was done for superficial velocities of 5 – 70 cm s−1 and at pressures from 1 – 10 bar. Values for λeff, r and αw were obtained by simultaneous fitting of measured axial and radial temperature profiles. The bed diameter was 5 cm; it was filled with 6.1 mm Raschig rings. Nitrogen gas was used in all cases. Values could be determined with reasonable accuracy. The agreement with correlations presented in the literature is good for λeff, r and less so for αw. The results obtained indicate that λeff, r and αw are a function of the product ‘velocity times pressure’ only. The correlations found can be represented by λeff, r/λg = 21 + 0.23Pe with an average relative error of 4% and Bi = 2.9Pe−0.40 with an average relative error of 5%. The experiments covered the range 25 < PE < 350. These correlations were obtained for one specific gas and one specific set-up