Effects of Impeller Type on Mixing Performance in Continuous Laminar Flow

Along with the sophistication of required optical performance for glass products, the improvement of molten glass homogeneity has become much more important these days. Under various restrictions, mechanical mixing with impellers plays a significant role in achieving high quality and productivity. However, the mixing in continuous laminar flow such as an industrial glass manufacturing process is less understood. Under this circumstance, an improvement in the mixing technology in glass industries heavily depends on seat-of-the-pants approaches. The purpose of this study is to clarify the effects of impeller type on the mixing performance in continuous laminar flow by a newly defined evaluation index calculated from concentration measurements of injected electrolyte tracer with three types of impeller under various impeller speeds. The calculated mixing performance evaluation index could not be solely dependant on the input power, which showed increasing impeller speed or power input did not always improve mixing in the channel in the case of inappropriate flow patterns. Results in this study showed the importance of flow pattern optimization in the continuous laminar flow to enable an improvement in overall mixing in the channel in a limited residence time of an object substance.