PARTICLE RESIDENCE TIME DISTRIBUTIONS IN 2-PHASE FLOW IN STRAIGHT ROUND CONDUIT

Residence times were studied for single particles (polystyrene spheres 19.1 mm diam) in the straight portion of thc holding section of a continuous flow system. Particle residence times were all less than the mean residence time of fluid; their ranges were within particle-to-fluid residence time ratios of 0.8 to 1.0. The velocities of the fastest moving particles were all about 1.25 times the mean fluid velocity in the turbulent flow regime. Particle density was important in the flow patterns of two-phase flow. The effect of particle-to-fluid density ratios on the particle residence time followed a quadratic function where particles with density ratio of 1.01 had the least residence time.