| People start to pay more attention to the air quality for the haze weather is becoming increasingly serious. It is necessary to take effective measures to reduce the harm of dust particles in the air for it has been a great threat to human health. In mis thesis, the technology of high-pressure spray dust-settling of air-assisted is used to reduce the dust particles in the air effectively.The main content of the thesis is the analysis of some vital factors influencing the effect of atomization in the spray system, also including design and optimization structure of key parts. First of all, the thesis elaborates two kinds of mechanisms of aqueous solution been broken into the atomizing particle as well as the mechanism of the settlement of atomizing particle to dust particles. The key factors that influence the effect of dust fall can be obtained through the research of the former mechanisms. Thus, it could offer a theoretical basis for the selection of the system scheme and its corresponding framework. Secondly, the working principle of various kinds of wet dedusting technologies would be introduced in detail, and also the characteristics and applications of every kind of technical equipment The application of the air-assisted high pressure dust suppression by spraying system can be sure through the comparison of different dedusting technologies and also the analysis of the distributions of dust particles. Thirdly, the design on the spray device as well as air-assisted device can be done. The design and calculation of nozzle and the selection of the high-pressure pump would be included in the spray system, while structural design of the spray-duct as well as the type selection and design of the fan in the air-assisted system. The relations of the reasonable matching and interaction among various vital parameters of the whole system could be obtained through the analysis. Lastly, the FLUENT software could be used to optimize the structure size of the air-duct. The optimal structural size of the air-duct could be obtained through numerous numerical simulations in orthogonal experiment with the aim of optimum velocity in the air outlet of the air-duct.Through the study on the mechanism of dustfall, the thesis emphatically analyze the rational matching relations between some vital factors influencing the effect of atomization, including the relationship between the spray pressure, the outlet diameter of nozzle and droplet size, as well as the relationship between tapered section size of air-duct, outlet velocity and spray width. Then from above conclusion, the power element use horizontal plunger pump; the outlet diameter of swirl pressure nozzle is Φ1.5mm; parameters of axial flow fan could be calculated; structure of spray-duct is gradual contraction type. Specific size of air-duct could be obtained in orthogonal experiment after optimization:the length of cylindrical segment is 725 mm, the corresponding inlet diameter is Χ700 mm; the length of tapered segment is 655 mm, the corresponding outlet diameter is Φ550 mm. The length of semi-major axis about semi ellipsoidal flow guider in air-duct is 600 mm, which the semi-minor axis length is 135 mm. The structure size of the wind turbine is as follows:the diameter of wheel hub is Φ270 mm; the diameter of blade is Φ340 mm; the installation angle is 30°; the number of blades is 12. The thesis has accomplished the rational matching relations between those parameters through determining the structure size of the air- duct to to achieve the design goals about atomizing particle diameter and spray width as well as gain better dust-controlling effect. |
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