Power consumption characteristics of an in-line silverson high shear mixer



In-line rotor stator mixers differ from in-tank versions because the flow is often controlled independently of the rotor speed. For in-tank devices the turbulent power can be adequately described by single impeller type power number. For an in-line rotor-stator mixer it is found that the power transmitted by the rotor consists of a power term and a flow term. The constants in this expression are normally obtained from a multilinear regression of a large matrix of experiments. Two simplified methods of obtaining these constants from limited data sets by (1) torque measurement and (2) by heat balance are described herein. These are used to determine the constants for a Silverson 150/250 MS inline mixer with different rotor stator arrangements from the laminar to turbulent regimes. The power and Metzner-Otto constants determined are shown to be in good agreement to data for a larger matrix of experimental data. © 2011 American Institute of Chemical Engineers AIChE J, 58: 1683–1692, 2012