Pulse Jet Mixing of a Non-Newtonian Waste Slurry Simulant

The mixing of radioactive waste slurries by Pulse Jet Mixers (PJM) was simulated by using non-Newtonian clay suspensions. A quarter scale mockup of a 6 PJM cluster configuration was tested with different nozzle sizes of 25.4 mm, 31.8 mm, and 38.1 mm I.D., nozzle velocities of 8–18 m/sec, and yield stresses from 11 to 35 Pa. Mixing was measured by dye and ultrasonic velocity probe methods. Under PJM only operation, a well mixed region or cavern is developed which is distinct from the stagnant region. The data of cavern heights to tank diameter ratio are well correlated as a function of the product of the Yield Reynolds number to the square root power and the ratio of nozzle to tank diameter. A fully mixed tank was obtained for a nozzle diameter of 38.1 mm, nozzle velocity of 18 m/sec and yield stress of 21 Pa. An alternate mixing configuration consisting of 25.4 mm nozzles and 5 spargers at 3 scfm each, 18 m/s nozzle velocity and yield stress of 30 Pa was found also to be fully mixed using glass bead tracers which also simulated large solids.