Novel Evaluation Method to Determine the Mixing Time in a Ladle Refining Process

Mixing plays a key role in mass and heat transfer, as well as chemical reactions in various vessels involving agitation. Several studies have confirmed that the mixing time obtained from several monitor locations cannot reflect the mixing time for the whole bath because stirring situation in different locations is variable due to the change of operation schemes. It is proved that some zones with inefficient stirring cannot be monitored by applying a limited amount of probes in physical and mathematical models. This study provides a novel approach to quantify mixing time evaluation considering the tracer variation for the whole bath using a mathematical model. It was found that the mixing time obtained by considering the whole bath is more representative than that of the probe monitor method. Compared with the traditional probe method, about 50 to 70 pct longer mixing times were obtained for different operations by applying the volume track method. In addition, the volume integral of the concerned variable for the whole bath is more representative to determine the developed flow compared to the points monitoring method for a transient simulation.