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 entra ined 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 transiti on 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 c urved, implying interparticle interactions were significant even at ve ry low solids volume fractions. The velocity of canola seed particles in admixture with sand particles (0.186 mm) increased as the proportio n of sand in the mixture increased. Finally, it was found that the oil y film imparted by the canola seed particles to the sand particles sig nificantly affected the behaviour of the sand particles in the dense r egime.