Search

The existing in-mold electromagnetic stirrers (M-EMS) that are widely applied in the steel industries have experienced low efficiencies due to the high operational temperatures and open system structures. Based on simple mechanical attachments and verified by detailed 3-D electromagnetic field analyses, this paper will propose a guided field path arrangement that can enhance the overall performance of an M-EMS system by a factor of 28% in the designated stirring directions while maintaining the same energy inputs. Such evident improvements will certainly provide a valuable design and adjustment guidance for the related metal industries. Index Terms--Continuous casting process, finite-element analysis (FEA), in-mold electromagnetic stirrer, molten steel.

Static mixers are increasingly being used to perform a variety of mixing tasks in industries, ranging from simple blending to complex multiphase reaction systems. Use of static mixers to process non-Newtonian fluids is quite common. Data on the pressure drop of non-Newtonian fluids in static mixers and the degree of mixing of materials through the mixer are very useful in the design and engineering application of these tools. This paper extends a previous study by the authors on an industrial helical static mixer and illustrates how static mixing processes of single-phase viscous liquids can be simulated numerically. A further aim is to provide an improved understanding of the flow pattern of pseudoplastic liquids through the mixer. A three-dimensional finite volume simulation is used to study the performance of the mixer The flow velocities, pressure drops, etc., are calculated for various flow rates, using the Carreau and the power law models for non-Newtonian fluids. The numerical predictions by these two models are compared to existing experimental data. Also, a comparison of the mixer performance for both Newtonian and pseudoplastic fluids is presented. The effects of the Reynolds number of the flow and also properties of pseudoplastic fluids on the static mixer performance have been studied. It is shown that for the materials studied here, the fluid type is not effective on the degree of mixing. It is also shown that the fluid type has a major impact on the pressure drop across the mixer. [DOI: 10.1115/1.2174058] Keywords: static mixer, non-Newtonian fluid, Carreau law, power law, particles distribution uniformity

A model for flow in a Farrel Continuous Mixer based upon cylindrical coordinate hydrodynamic lubrication theory is presented. Pressure and flux fields over the rotor surface are calculated. The pumping characteristics of the various sections of the machine rotors were calculated. Generally Farrel Continuous Mixers are operated under starved conditions. Calculations are presented for continuous mixers operating under starved conditions. Pressure and fill factor profiles are determined. Fill factors are predicted to be increased by increasing throughput, increasing exit gate pressure and reducing screw speed., INTRODUCTION Continuous mixers are processing machines in which the rotor designs of batch mixers are combined with pumping elements such as screws to produce a continuous mixing device. This type [...]