Micromixing Efficiency Of Viscous Fluid In Helical Tube Reactor

Some industrial productions with high viscosity, like polymerization and rubber halogenation, involve rapid chemical reaction. Micromixing (i.e. mixing at the molecular scale) of the reactors plays an important role on the molecular structure and weight distribution of the products for these processes. As a result, the study about micromixing in high viscous system has important significance.Because there are no internals and turbulators, helical tube reactors (HTRs) are suitable to improve micromixing efficiency of viscous fluid by means of secondary flow. In this study, the mixing performance of two kinds charging components (including Vertical type and Parallel type) were CFD simulated. Micromixing efficiency of viscous fluid in HTRs were experimentally studied by a parallel competing iodide-iodate reaction system with glycerine adjusting the viscosity. Compared with experimental results, iodide-iodate with viscous system were CFD simulated. Main research contents and results as follows:1. Two kinds of different charging components, parallel type and vertical type were designed, including4kinds of vertical type (2-Φ0.7,4-Φ0.5,10-Φ0.3,24-Φ0.2) to discuss the influence of different initial charging scale. The mixing ability of these charging components were simulated by CFD. The results showed vertical types were better mixing, and the charging hole got smaller, the mixing was better.2. Micromixing efficiency of viscous fluid in these different HTRs was experimentally studied by a parallel competing iodide-iodate reaction system with glycerine adjusting the viscosity, and measured by segregation index Xs. Some results are as follows:(1) The micromixing efficiency increased with the increase of volumetric flow VA. The product segregation index Xs increased significantly with the [H+] increased. And the Xs increased the increase of volumetric flow ratio, when the molar ratio of reagents was fixed.(2) With the increase of either fluid viscosity, micromixing efficiency decreased.(3) During the different vertical charging components, The micromixing efficiency increased with the holes smaller.(4) Micromixing efficiency increased with the diameter of helical tube reactors grow smaller. Compared with straight tube, HTRs had better micromixing performance.3. The iodide-iodate reaction in HTR was simulated by fluent. Effects of the fluid flow rate, volumetric flow ratio, fluid viscosity on the micromixing efficiency were investigated. Compared with the experiment results, the simulation results had error within25%.