Saturation carrying capacity at high archimedes number of vertical concurrent gas–particle flow

Abstract

The existing literature data on the saturation carrying capacity G s * for vertical concurrent gas–particle flow are limited to Archimedes numbers Ar below 1000. By experimental measurement and dimensionless analysis the present article extended Ar to 2500 to demonstrate how G s * varies with gas velocity under these high Ar values. The obtained result revealed that G s * is subject to the same kind of correlation with gas velocity irrespective of Ar. The degree that G s * depends on gas velocity, however, generally decreases with raising Ar and it tends to be a constant when Ar becomes higher than 530. This shows in fact that the flows with heavy/large particles or dense/viscous gas possess a low increase in particle-carrying capability with increasing gas velocity until a steady specific capability per m/s is reached at Ar of 530. The article also reanalyzed the influence of column diameter on G s * , demonstrating that the column diameter influence exists only in small columns and for flows with heavy/large particles. The influence is negligible in commercial conveying columns and differs according to Ar in those small columns employed in laboratory studies. All of these findings resulted in an upgraded correlation for G s * , which manifested not only wide applicability to flows in differently sized columns and with Ar of up to 2500 but also better accuracy in the mentioned flow conditions when comparing with several other literature correlations.