The Study And Application Of Airflow Distribution In Dust Control Of Loading Vehicle

In many workplaces, such as coking plant, broken mineral aggregates are loaded from silo to train (vehicles). In this process, the serious dust emission causes "industrial dust storm and dust flow", affects the operation process, and contaminates the environment. With the strengthening of national environmental policies, this kind of dust source is urgent to be controlled.One of the important technical means is to set up exhaust hood to control the dust by optimizing airflow distribution. However, at present the design theory of ventilation and dust removal in this kind of vehicle loading conditions is still immature. Control of dust diffusion in vehicle loading parts is always ignored or is designed by experience, and often the expected results cannot be achieved. Hence, how to choose reasonable and effective airflow distribution is of great significance to control dust diffusion and realize energy saving and emission reduction.In this project, taking the train loading of screen coke building in one coking plant as research object, the control effects of different airflow distributions were discussed.In this paper, optimization of airflow distribution was studied by combining the method of CFD and orthogonal test. RNGk-εmodel and Lagrange discrete phase model were used in the turbulence model and the two-phase model, of which the reliability was validated by the experiment. After simulation analysis on the dust diffusion and the control effects of the existing ventilation and dust removal system, this paper put forward side suction hood and around windshield device ventilation method to control the dust diffusion of dust source. Three different types, unilateral air suction, both side suction, and push-pull, were considered. By analyzing the factors which affects capture efficiency and carrying out the orthogonal test, empirical formulas of capture efficiency were obtained. It could be found that the smallest exhaust volume in complete control of dust was given in unilateral suction, in which the system is simpler and of smaller initial investment. Thus, unilateral suction was determined as the best way of airflow distribution.With the method of specific flux and the theory of dimensionless analysis, the function of the limit specific flux about dimensionless parameters was obtained. Through the test data and empirical formula of unilateral suction capture efficiency, using the software of SPSS V13.0 and doing the multiple regression analysis, the relation of the limit specific flux was given. According to the regression expression of the limit specific flux, optimization of the existing dust source control system was carried out, and the expected effects were achieved, which provides basis for airflow distribution design of dust source control in loading vehicle.