Heat transport in a wall heated tubular packed bed reactor at elevated pressures and temperatures

At different flow rates, pressures and temperature levels heat transfer parameters according to both one- and two-dimensional pseudo-homogeneous model without axial dispersion were determined from steady state temperature measurements in a wall heated tube packed with an industrial ring shaped catalyst. For the effective radial conductivity the following correlation was obtained [Coefficient]. The wall heat transfer coefficient was correlated as [Coefficient]. Both Re and Nu are based on particle size. The temperature dependence of the parameters investigated with wall temperatures between 100 to 250°C, is well characterised in these correlations by the temperature influence on the kinematic viscosity in Re and the gas conductivity in Nu. A temperature dependence of limit of the Bodenstein number p_guC_pd_p/ϵλ_eff,r at high Reynolds number, was observed experimentally.

The overall heat transfer coefficient U was at constant gas flow rate found to increase with temperature. The usual lump relation in combination with the experimentally obtained correlations for λeff,r, and αw under predicts this temperature dependence of U. None of the parameters showed any dependence on pressure in the investigated range between 0·3 and 0·9 Mpa

The influence of effective axial conductivity was found to be negligible for our experimental conditions. Inclusion of effective axial heat conductivity is not required for heat transfer experiments when appropriate boundary conditions are chosen in the heat transfer model.