Mixing characterization in batch reactors using the radiotracer technique

The infusion rate of a slug of tracer into an anchor agitated 100-liter bat ch mixer was characterized by a decay rate constant. This constant was then used to define a dimensionless mixing-rate number which was related to the stirrer Reynolds number. This correlationship allows the calculation of ti me or rotational speed needed to achieve any desired degree of uniformity o f the mixture. Tc-99m was used as radiotracer and the mixing process was fo llowed by a scintillation NaI(Tl) counter situated on the reactor wall near the injection point.