Simulation And Optimization Of Micromixer And Application In Olefin Sulfonation

The continuous development of scientific and mathematical theories makes the field of engineering technology begin to optimize and innovate constantly,and miniaturization and integration have become the mainstream trend of the development of the whole modern industry.The development of fluid products is greatly limited due to its large volume and low integration,so the miniaturization of fluid control has become one of the important directions of industrial miniaturization.However,since the fluid flow in the microchannel is laminar flow,mixing is poor.For the rapid reaction,mixing becomes the main factor affecting the efficiency.The sulfonation reaction is a rapid reaction.Designing a micromixer with high mixing efficiency for sulfonation reaction is of great significance for improving the reaction efficiency.The main research work of this paper is as follows:(1)The mixing performance of micromixer at low Reynolds number was studied numerically.The influences of three structural parameters,channel width to height ratio,maximum width at divergence and dislocation height at collision,on pressure drop,mixing index and mixing efficiency of micromixer were analyzed.Through simulation analysis,the mixing effect is the best when the dislocation height at the fluid collision is 0.4mm,the channel divergence width is 0.6mm,and the channel aspect ratio is 1:1,and it is found that the dislocation height has the most obvious influence on the mixing performance,while the change of the channel divergence width has no obvious influence on the mixing efficiency.The optimized micromixer(MST)was optimized,and the optimized micromixer(MTT)was compared with MST and ordinary T-type micromixer(MT).The mixing performance of MTT and MST was better than that of T-type micromixer.The MTT micromixer shows the greatest mixing capacity.(2)The performance of MTT micromixer is analyzed,and the MTT micromixer is compared with published micromixers,which reflects the advantages of MTT micromixers.The mixing performance of MTT micromixer and T-type micromixer with the same channel length was analyzed at different Reynolds numbers.Compared with T-type micromixers with the same channel length,misaligned micromixers basically have higher mixing index at all Reynolds numbers.Moreover,under the same channel length,the pressure of misaligned micromixers is lower than that of T-type micromixers.This is because there is no direct fluid collision at the collision point of misaligned micromixers,resulting in smaller pressure drop.The mixing analysis of MTT micromixers with different sizes shows that when hydraulic diameter ≤1mm,the influence of size on mixing efficiency of MTT micromixers is not obvious,but the pressure drop increases obviously with the decrease of size.(3)the MTT micromixer was used in the olefin sulfonation reaction,and the experimental results were compared with the simulation results.The mixing degree of the materials was an important factor affecting the content of the active substances,the better the mixing degree was,the higher the content of active substances,the lower the degree of mixing,the lower the content of active substances.By analyzing the color of products under different flow rate,it is found that the by-product content is affected by the inlet flow rate.The higher the inlet flow rate,the higher the mixing degree and the lower the by-product content,however,when the mixing efficiency is increased to a certain extent,the increase of one-side inlet flow will result in the reduction of material residence time,which is not conducive to the improvement of sulfonation yield,instead,it increases the by-product content of the product.