| The anaerobic treatment of organic waste fermentation technology to produce biogas is set environmental pollution, reducing carbon emissions and providing renewable energy in one of the biomass energy industry, in an anaerobic fermentation process, accelerate microbial reaction process become a research topic, important means of promoting substrate transfer speed between the liquid and microorganisms will increase the reaction efficiency, to achieve this purpose is stirring. In our country biomass energy industry in support of national industrial policy and environmental protection departments of the achieved rapid development, coupled with the anaerobic fermentation of raw materials and raw materials complex sources of opacity, so the flow field of anaerobic fermentation stirring apparatus were study has very important value.Under normal circumstances, due to the anaerobic fermentation of raw materials opaque, can not get the actual flow distribution, this paper simulated anaerobic fermentation stirred flow field, respectively the use of visualization techniques PIV measurements and numerical simulation of two angles mixed anaerobic fermentation device the study. Stirred tank used in this paper for the second leaf hinge blade paddle, test some applications PIV measurement technique by stirring 9 in the flow field conditions, the three factors: Shaft speed, blade diameter, blade Mounting angle orthogonal test and variance analysis, optimization of the optimum combination of anaerobic fermentation stirring blade is designed to provide ideas, have a certain value. Via CFD simulation technology to simulate the mixing process optimization paddle distribution of the fluid flow field, using Fluent software, using standard k- ε model of turbulence characteristics in the system will be described, and then the results compared with the experimental data to determine the numerical simulation in anaerobic fermentation technology means stirring feasibility study, while not excluding some places there are also differences of local phenomenon. The main work and results of this study include:(1) Simulation test equipment and materials, the application of PIV measurement technique for nine kinds of operating conditions to measure the velocity field, the conditions in 9 velocity profile, vorticity distribution. Flow analysis obtained plane substantially similar and consistent body large circulation direction and speed appear at the blade end of the extreme value.(2) According to the PIV measurements, comparative analysis of three factors: Shaft speed, blade diameter, blade mounting angle, orthogonal test and variance analysis, and optimize the optimum combination blade case 5: stirring shaft speed of 150 r / min, blade diameter of 0.135 m, the blade angle of 60 °. Test indicator shaft power 2.6W, the mixing time is 5s.(3) Optimize the results of Fluent CFD simulation tool based on research using standard k- ε model and equations, Via comparison of experimental research and modeling studies analysis, test the measured velocity distribution and simulation of the flow field velocity distribution of consistency, illustrate the application of CFD simulation technology in the field of anaerobic fermentation stirring feasible. |
