The Analysis And Research Of The Fan-shaped Plate Screw Stirrer Flow Field

The superfine powder is a kind of functional materials. It is to show the broadapplication prospects for the research and development of new functional materials.Superfine powder has the chemical reaction faster, most big specific surface–area, highsurface activity, high strength sintered body and fast dissolving. And it is different in themagnetic, the optical properties and the electrical also. So it has been to attention by theindustry widely. But the mechanical crushing method is unique among many methods,because of the characteristics of high yield, low cost, simple process and the like this. Atthe same time, it has a mechanochemical effect in the grinding process and it canimprove the activity of the powder. It has so many advantages. At the same time, themechanical crushing still has some disadvantages, such as the product fineness is notenough, the purity is not high, the appearance is not homogeneous, etc. Therefore, theimprovement of the mechanical crushing effect can’t wait. Stirred mill draws more andmore attention to people in many mechanical crushing equipments, because theadvantages of superfine, energy saving, high efficiency, low pollution, simple operationand superior performance, etc. Stirrer is one of the most important components in stirredmill. Its structural form and movement state directly affects the stirred mill workperformance and product status. But the stirrer’s forms now are not perfect, more or lessthere are defects in structure. This paper based on this point start to improve andresearch stirred mill.The vertical stirred mill is as to the research object in this paper. Firstly, weanalysis the rod type stirrer and the single head screw stirrer on dynamics characteristicsof flow field. Then combined with the characteristics and advantages of the now stirrerworks out the improved the fan-shape plate screw stirrer, to improve productionefficiency, reduce the loss of purpose. This paper applied Pro/E software for three kinds of stirrer3-d model, and applied Gambit software to divided grid the fluid computationaldomain of the stirrer grinding chamber. Finally，use the method of CFD for grindingchamber flow field dynamics analysis.The conclusion in this paper: Firstly, the stirred bar of the fan-shape plate screwstirrer is fan-shape plate bar, and it is into a spiral arrangement. So, it not only increasedthe number of the bar, but also changed the bar of the rod type stirrer now. So it canmake the flow velocity difference bigger, the shear stress more uniform, the crushingeffect better.Secondly, the bar of the fan-shape plate screw stirrer is discontinuous. Comparedwith the original sing-head screw stirrer, the new is effective volume bigger. And thanstress no uniformity is improved effectively. At the same time, it makes the wear andtear down at the top of the stirrer.