| From 2010 to 2017,the annual growth rate of sewage discharge in China reached 6%,the problem of sewage treatment has attracted people's attention.oxygen-increasing aeration machine as a typical sewage treatment equipment,the main working principle is to dissolve oxygen into the sewage,improve the oxygen content in the water,to ensure the growth and reproduction of aerobic microorganisms,Promotes oxidation decomposition of hazardous substances in sewage.Therefore,it is necessary to improve the dissolved oxygen efficiency of oxygenation aeration machine.In this paper,mainly research on the structural design and improvement of the aeration aerator water purification equipment,the parameters optimization and simulation for the aeration aerator,and studied the influence of the optimized parameters on the propulsion efficiency,analyze the gas volume fraction distribution and bubble size distribution,and perform modal analysis on the main drive shaft.This article mainly includes the following aspects:1.Focus on the aeration aerators,review the development status and the development trend.The direction and significance on research the aeration aerator,and determine the main research content of this paper.2.Performance parameters and operation mechanism of aeration aerator: Firstly,the working requirements and parameters of the aeration aerator are introduced.The overall structure design and analysis are mainly the design of the polyoxygen magnetization device and the aerobic push device,and finally the analysis of the working process and oxygen transfer.The principle of going to the water.3.Study the influence of the structural parameters of the aerator thrusting device on the water flow propulsion efficiency,and understand the theoretical knowledge related to Fluent single-phase flow simulation.The main influencing factors of propulsion efficiency are analyzed,the blade tip clearance,disk surface ratio and pitch ratio are selected as variables to simulate and analyze.According to the Fluent simulation results,the influence curves of propeller propulsion coefficient,torque coefficient and efficiency are drawn,and the reason of curve change trend is analyzed.The structural parameters lay the foundation for the simulation of two-phase flow in the aeration tank in Chapter 4.4.Two-phase flow simulation: The numerical simulation of gas-liquid two-phase flow of the push-flow device of the aeration machine,such as modify the model,Select turbulence model and multiphase flow model,Set boundary conditions,compare and analysis the simulation results,through the comparison and optimization of liquid phase volume fraction distribution and gas phase volume fraction The percentage and distribution position of air phase are analyzed,and the trend curve of gas phase volume fraction along the axis of vertical rotating axis is plotted.The change of bubble diameter size in water is analyzed by using CFD-PBM model,and finally analyzed in histogram form,and the variation law of Bin-5 bubble size volume fraction at the specified point.5.Firstly,based on the operating environment of aeration water purification equipment,the matching calculation is carried out for the motor of aeration booster device,the underwater motor with the rated output of 3kW and the rated speed is 1430r/min,then the modal analysis of the hollow shaft is carried out in Workbench,and the natural frequency and vibration pattern of the first ten-order modes of the hollow shaft Compared with the excitation load frequency generated by the motor,the hollow shaft will not resonate and its design is reasonable. |
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