FURTHER-STUDIES ON FLOWING GAS-SOLIDS SUSPENSIONS IN A TUBE AT HIGH ANGLES OF INCLINATION

The flow of glass (0.571 mm) and canola seed (1.75 mm) particles entrained by air in a 31.8 mm i.d. conduit inclined at 72 degrees or at 90 degrees to the horizontal was studied. With glass particles a transition between a dilute and a dense phase was found at both orientations, but no transition point was found with canola seed particles. Plots of solids volume fraction versus solids flux in the dilute regime were curved, implying interparticle interactions were significant even at very low solids volume fractions. The velocity of canola seed particles in admixture with sand particles (0.186 mm) increased as the proportion of sand in the mixture increased. Finally, it was found that the oily film imparted by the canola seed particles to the sand particles significantly affected the behaviour of the sand particles in the dense regime.