Researches On The Optimized Design Of New-type Inverted Umbrella Aerator Curved Surfaces Impeller

Nowadays, In response to the current water pollution and scarcity of waterresources, the development and optimization of wastewater treatment processes becomeimportant technical means. However, the oxidation ditch treatment process is the mainsewage treatment technology, and inverted umbrella aerator is the key equipment ofoxidation ditch treatment process. Currently, increasingly high demand come from theoxidation ditch treatment process for aeration equipment, coupled with the increasingshortage energy, the research of new and efficient energy consumption of aerationdevice has become breakthrough which promotes the oxidation ditch processtechnology developing and energy saving. Based on the above background, the paperproposes a kind of blade according to a ruled curved equation, which is to design a newsurface inverted umbrella aerator optimally.Firstly, the paper studies the literature on inverted umbrella aerators at home andabroad, and analyzes the main operating mechanism of the inverted umbrella aeratormixing, plug flow and oxygenation which is due to the rotation of the impeller. With therotation, the water forms water jump and jet that speed up the water body and bundlelots of air parcels during the deceleration, in the same time, the water and airaccomplish mass transfer between gas and liquid. And the water shapes negativepressure air and gradient pressure that act on the stream to accelerate the process ofaeration and mixing. Based on inverted umbrella aerator mechanism, in order toimprove the efficiency of oxidation ditch wastewater treatment and reduce energyconsumption, this research presents curved blades according to equal spiral anglelogarithm spiral equation,and analyses the plug-flow stirred performance of differentboundary conditions of this kind of curved blade in a stable condition by ComputationalFluid Dynamics theory and Fluent software. By comparing the result, the paper selectsan optimal equation. Since in the actual situation,the blade will produce blades bent, thepaper analyses the leaves by the finite element, the results show the stress and strain arein a reasonable range. Based on helix angle logarithmic spiral equation, the studypresents curved blades according to non-equal spiral angle logarithmic spiral equation atlast. As the limit of conditions of study and the requirement of project, the paper uses Froude similar criteria to scale down the corresponding curved blades by the samestandards, and the paper simulates the two kinds of curved blades by ComputationalFluid Dynamics and contrasts their velocity, the results show that non-equal spiralangle logarithm spiral equation has a slightly better stirred plug flow performance. Sothe new style inverted umbrella surface aerator impeller take the non-equal spiral anglelogarithm spiral equation curved blades, while, this paper also designs and selects theother parts of the new inverted umbrella aerators. Before manufacturing, this researchesuse fluid-structure interaction method to verify the reliability of the impeller of theoptimized inverted umbrella aerators, the results of stress and strain show that the newcurved impeller is reliable.In this paper, the new optimal inverted umbrella surface aerator provides atheoretical basis for the designing and analysis of surface aerator,in the meantime,which have a certain role in optimization and innovation of oxidation ditch wastewatertreatment equipment.