Study On Parameters Optimization Of Double Helix Shaft Concrete Mixer

With the development of urban infrastructure and improvement of the quality of modern construction, we have ever-increasing demands of concrete quality and production efficiency. Concrete mixer, as the key device for production, has played a profound impact on mixing quality and production efficiency of concrete. The author choses the advanced double helix axis mixing device for the study to have a parameter optimization which through theoretical analysis and numerical analysis, so as to improve the stirring performance.Firstly, we researched on the effect of the double helix axis mixing device to the concrete mixing consequent, determine the aspect ratio of the mixing tube, screw shaft spiral form, helix angle of the screw shaft and stirring speed as the optimization goal. Then we calculated the geometric parameters of the mixing device and the forces during the mixing process, and ultimately we determined the form of the spiral helix axis and other parameters ranges.Secondly, we applied CFD software for the flow field to have a numerical simulation analysis and established concrete mixing fluid equations which using the simplified model to simplify the flow field, and then determine RNGk-ε numerical model. Compare the speed uniformity and material mixing intensity of the twin screw mixer under different structural parameters and operating parameters, we can determine the optimum parameters match for:mixing tube with wide short, the screw shaft helix angle is 25.7 °and the stirring speed is 1.62 m/s.After that, we compared the optimized twin screw mixer with the blade mixer and ribbon mixer, which were widely used in the market. After determining the optimal parameters of the blade mixer and ribbon mixer, we made a numerical simulation analysis among these three mixers. We concluded that the optimized twin screw mixer have the best velocity distribution uniformity, which mean that the stirring performance of the optimized twin screw mixer is better than the other two models.The research provided a reliable reference data for the development of these mixers and achieved the purpose of improving mixing performance and efficiency. Apart from this, numerical simulation reduced the amount of experimental research, which would save costs and shorten the development cycle, thus the research had a high value and meaning.