Analysis of new blade structure and mixing characteristics of horizontal mixer
The dynamic mixer is the mainstream of today's mixing equipment,and the mixing effect not only affects the production efficiency of the equipment,but also directly determines the performance of the final product.Among them,the structure of the mixing element in the dynamic mixer directly determines its mixing effect on the processed material.Due to the complex structure of the dynamic kneading mixer,the theoretical research on its mixing characteristics is very limited.In this work,the blade structure of the horizontal mixer was optimized and improved,and the structure design of the main and auxiliary blades was adopted to improve the mixing effect of the mixer.By constructing the three-dimensional model and finite element model of the mixer with a new type of blade structure,the mixing characteristics of the mixer were investigated by means of numerical simulation using the computational fluid dynamics software Polyflow,and the influence of blade speed on the mixing performance of the mixer was analyzed.Mixing index,separation scale,average tensile rate,logarithmic tensile rate,and cumulative depolymerization power were used to characterize the dispersion and distribution mixing ability of the mixer,and the accuracy of numerical simulation results was verified by visual experiments.The results of simulation and experiment showed that the simulation results were consistent with the visual experiment results.The material flow type in the mixer with the new blade structure was shear flow,accounting for about 85%.The average tensile rate and average logarithmic tensile rate in the flow field were always positive,indicating that the mixer had good distribution and dispersion mixing ability.The increase of blade speed had little influence on the flow type of materials in the flow field,but can effectively improve the performance of distributed mixing and dispersed mixing of the mixer.When the blade speed increased from 30 r/min to 120 r/min,the average separation scale of the mixer's transverse distribution mixing decreased by 50%,and the average tensile rate increased by 300%.The average cumulative depolymerization work increased by 1500%.