Optimization Research On Structure Improvement Of Mixing Equipment For Preparation Of Aluminum Alloy-Glass Particulate Composites Based On Numerical Simulation

Glass/aluminum metal matrix composites has been manufactured with waste glass and waste aluminum. The effect of various parameters on glass/aluminum matrix composite including glass particles act as reinforced phase was investigated by using stirring casting technique. Glass particles has been mixed into the molten aluminum by the action of an agitator in the agitated tank. The composite material is a low-cost,light and resistant material, profiting from high hardness of glass particles and good toughness of aluminum matrix. Due to the lower density of glass than aluminum, glass particles will be floated on the top of the molten aluminum during operation. It is important how to make glass particles into molten aluminum evenly. In order to improve the efficiency of present mixing equipment, the structure of agitator must be optimized. To disperse glass particles into molten aluminum more evenly is the major objective, while there are more purpose that is to reduce the mixing time, mixing speed, mixing power, to reduce fault in material and increase the mixed quantity of glass particles in the aluminum matrix.As a kind of efficient, economical and reliable method, Computational Fluid Dynamics (CFD) method has been used extensively in the field of chemical industry and metallurgy. The application of CFD have been very focused mainly on mixing equipment design and optimization. With the help of FLUENT 6.3, the impeller has been improvement and optimization, and verified by experiment.Two phase flow system comprised by glass particles and molten aluminum, can be simulated by constructing Euler multi-phase model in FLUENT. The mixing process of glass particles and molten aluminum can be computed accurately. Flow field distribution of the current impeller has been investigated by building a numerical model and numerical calculation with computer. There are two main reasons about the low mixed efficiency. The first, glass particle can not be effectively transported from fluid surface to the bottom of the tank. The second, the power provided by agitator is not used effectively. To solve these problems, the helical screw ribbon impeller is used to replace the current impeller, and its flow field distribution is obtained by the method of numerical simulation. According to the twice simulation results, mixing time of the helical screw ribbon impeller has been reduced by 30% relative to the current impeller, and the improved impeller mixing power is to be equivalent to the original that of 44%.Finally, the effect of the improved mixing agitator has been verified by the verification experiment. The experimental results demonstrate that the dispersiveness of glass particles in glass/aluminum matrix composites has been obviously improved by using the improved impeller. Compared with the current impeller, material defect, abradability of the mixing equipment and mixing time have been reduced partly in the verification experiment. Especially, energy consumption of the improved impeller is only a third of the original. These conclusions of numerical simulation are basically consistent with these of the verification experiment.