STABLE OPERATION CONDITIONS FOR GAS SOLID CONTACT REGIMES IN CONICAL SPOUTED BEDS

The operation regimes of spouting and of jet spouting have been delimited in the bed expansion in conical contactors. Both contact regimes, but in particular the original regime of jet spouting, have a characteristic hydrodynamic behavior different from that of the conventional spouted bed, and they combine the characteristics of high velocity of gas and solid, typical of transport beds, with the cyclic movement typical of the spouted bed. Its interest is centered on the handling of particles of large diameter, with adherent solids and with size distribution. The ranges of the geometric factors of the contactor-particle system and of the gas velocity for stable operation in both regimes have been determined by experiments in a pilot plant using different solids. The operative ranges of both regimes in conical contactor are compared with the conventional gas-solid contact regimes. The limitations of the few correlations in the literature for design of conical spouted beds and the nonvalidity of these conventional correlations proposed for cylindrical spouted beds have been proven. Consequently, original hydrodynamic correlations for spouting and jet spouting corresponding to conical contactors have been proposed for the calculation of the minimum velocity in stable operational conditions.