2014 Volume 47 Issue 2 Pages 146-150
The high-level performance of a large impeller can be combined with the advantages of an eccentric impeller by using the impeller at an eccentric position. In this study, the power consumption and mixing time for Maxblend, which is a type of large impeller, were investigated. The power consumption P and mixing time θM were measured under various eccentric conditions. The relationships between the power number (Np) and Reynolds number (Re) and between the dimensionless mixing time (nθM) and Re were investigated. It was confirmed that a large amount of energy can be supplied to the mixing liquid in eccentric mixing based on the Np–Re curves. In the laminar state, the value of nθM of eccentric mixing under suitable eccentric conditions was lower than that of concentric mixing with and without baffles. In this region, eccentric mixing was useful in terms of power consumption. On the other hand, the mixing efficiency based on the power consumption at LE=0.04 m was almost the same as that of concentric mixing with baffles in the turbulent state, where Re>2500.