New Type Of The Inverted Umbrella Surface Aerator Push Flow Oxygen Filling Principle And Its Experimental Study

Oxidation ditch technology is ditch treatment by activated sludge process, and very economical and effective in waste water treatment.The surface aerator is a key equipment to ensure the efficiency of the oxidation ditch process.Surface aerator in the process of aerated flow, mixing, and oxygen filling effect, has the advantages of simple structure, convenient maintenance, is widely used in sewage treatment process.But at present, the independent development of aerator is few, the core of the sewage treatment technology and equipment, relying on expensive imports.Domestic equipment smaller power and oxygen filling effect of poor performance, pushing flow were some shortcomings, it is hard to meet the development requirements of the environmental protection sewage treatment.In this paper, based on the research of the existing surface aerator, this paper proposes a curve equation based on some rule changes of impeller blades,optimization design a new type of surface of impeller impeller inverted umbrella aerator. This article targeted research blade geometry and operating parameters, to find a close correlation between these two parameters and flow characteristics between the oxidation ditch, and ultimately determine the shape of a bend surface exposed by the new non-equiangular logarithmic spiral Surface Constraint gas turbine blades. Through simulation analysis, the blade fluid performance, high oxygenation efficiency and blade running, you can load with the size and speed by dynamically adjusting the curvature of the blade pitch angle is changed, we can change the amount of water to control the oxygen supply load amount, which can ensure that the mixing of the oxidation ditch circulation and mixing equipment performance, dynamic control surface aerators is always in the best situation. New aerators can reduce the energy consumption of aeration system to meet the appropriate aeration oxidation ditch process required to ensure the deposition of sludge aeration tanks does not occur,the system meets the minimum flow rate requirements.First of all, through reading literature both at home and abroad, we learned that the inverted umbrella the working principle of the aerator is with the rotation of the impeller, liquid present water curtain from the edge of the impeller blade, wrapped in a large number of air at the same time, constantly updated by mixing liquid level at the same time, thus accomplishes the oxygen aeration equipment, mixing and flow process.Then, this paper proposes a spiral Angle, such as logarithmic spiral lineequation of curved blade.By using computational fluid dynamics theory analysis of the curved blade under stable conditions of mixing flow performance.At the same time, the bending deformation may be produced at the time of the actual work, blade finite element analysis, in order to ensure that stress and strain within the reasonable fan blades.In the end, we put forward a kind of based on the spiral Angle, such as logarithmic spiral line equation of the curved blade. Then, based on froude similarity criterion, we closed geometric design and production of the new curved blade surface aerator.And under the condition of test of tap water, total oxygen transfer coefficient,the theory of aerator oxygen filling ability, the theory of dynamic efficiency, water velocity of flow, were tested.Test by testing the dynamic efficiency value of aerator,to study the new aerator oxygen filling performance as the surface of the impeller speed and impeller submersion depth changes.The results show that the impeller speed is 37.5 RPM and impeller submersion depth is 41.25 mm, oxygen transfer performance is superior, the new aeration equipment of dynamic efficiency to achieve the best value.At the same time, when we determine the equipment run efficiently,should control the impeller speed and impeller submersion depth range.Finally, through summarizing the new curved blade surface aerator blade structure, flow characteristics and mechanism of dissolved oxygen and so on various aspects factor, we can determine the work mechanism of the new aerator completely accords with the mass transfer of gas-liquid two phase interface theory, conform to the open channel vorticity equations of fluid mechanics theory.In this paper, optimal design of new type inverted umbrella aerator for aeration equipment research and development design provides a theoretical basis, at the same time of city sewage plant upgrades and oxidation ditch sewage treatment equipment performance improvement has important significance.