Collect. Czech. Chem. Commun. 1987, 52, 1430-1439

Theoretical and experimental investigation of the function of the wall flow deflecting ring. A mathematical model for the case of a large number of deflecting rings

Krumm Semkova, Nikolai Koleva, Vladimír Staněkb and Pavel Moravecb

a Central Laboratory of Chemical Process Fundamentals, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
b Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol, Czechoslovakia


Solution of the mathematical model has been developed of the distribution of liquid in a random packed bed in the presence of the wall flow deflecting rings. The solution was obtained in the form of a recurrent analytical formula. The formula permits, by repetitive calculation, profiles to be obtained of the densities of irrigation in a bed equipped with an arbitrary number of the wall flow deflecting rings. A comparison of experimental profiles of the density of irrigation with theoretical profiles showed considerable discrepancies between the two profiles. A new optimization of the parameters of the model, taking also the width of the wall flow deflecting ring as an adjustable parameter, showed a good agreement provided that the optimum width of the deflecting ring is about 1·5 times its real physical dimension. This finding can be explained by interaction of the function of the deflecting ring with the packing elements immediately adherring to the ring. This explanation may be partially supported by the visual observation showing the liquid to be deflected by the elements of the packing contacting the deflecting ring instead of the ring alone.