Atomization Parameters And Dust Reduction Efficiency Prediction Model Of X-type Swirl Pressure Nozzle

The X-type swirling pressure nozzle is a new internal structure of the swirling pressure nozzle.Due to its unique X-shaped core design,it has good atomization performance.It has been widely used in the field of spray dust reduction in recent years.For a long time,engineers can only rely on cumbersome experiments to obtain parameters such as nozzle atomization characteristics and dust reduction efficiency.However,general engineering sites do not have instruments for measuring atomization characteristics and dust reduction efficiency,for engineering design and spray dust reduction field application.It is a lot inconvenient.Aiming at the above problems,this paper systematically studied the atomization characteristics and dust reduction efficiency of X-type swirling pressure nozzles by theoretical analysis,experimental testing and field application methods,and constructed nozzle atomization parameters and dust reduction efficiency models.The following main conclusions are drawn:(1)The nozzle flow rate increases with the increase of nozzle diameter and water supply pressure.The flow coefficient of the nozzle is obtained by fitting the empirical formula.According to the fitting analysis,the flow coefficient and the nozzle diameter are in a linear relationship.The coefficient increases as the diameter of the nozzle increases,showing a linear relationship.(2)The nozzle atomization angle increases as the nozzle diameter increases,and decreases as the water supply pressure increases.Using the Origin software,the regression analysis method was used to obtain the fitting relationship between the nozzle atomization angle and the nozzle diameter and water supply pressure.The determination coefficient R²is0.981,and the correlation is very high.The calculation formula has certain reference value.(3)The influence of axial distance,water supply pressure and nozzle outlet diameter on the droplet velocity was analyzed by orthogonal test.The droplet velocity increases as the water supply pressure increases,and decreases as the axial distance and nozzle diameter increase.According to the range analysis,the order of the three factors affecting the droplet velocity is:axial distance>nozzle diameter>water supply pressure.The multivariate nonlinear regression mathematical model of droplet velocity was obtained by SPSS software.The predicted value of droplet velocity was basically consistent with the experimental value,and the average relative error was 8.2%.(4)The droplet diameter D₅₀increases as the axial distance and the nozzle diameter increase,and decreases as the water supply pressure increases.According to the D₅₀formula surface map,as the water supply pressure increases,the droplet size decreases.When the water supply pressure changes from 0 to 6 MPa,the droplet size decreases rapidly;the water supply pressure continues to increase,and the droplet size changes slowly.As the axial distance increases,the droplet size gradually increases exponentially.When the water supply pressure and the axial distance are fixed,the small diameter nozzle can obtain a droplet with a smaller particle size.(5)Based on the formula of the droplet size D₅₀derived from the derivation,according to the related theories of fluid mechanics and aerosol,the mathematical model of coal mine downhole dust reduction is established,and the expression of the classification efficiency?is derived.It can be obtained from the classification efficiency formula that the classification efficiency increases with the increase of the water supply pressure,and the increasing trend becomes slower and slower and increases exponentially.The classification efficiency increases as the number of nozzles increases,and the tendency to increase becomes slower and slower.With the increase of dust particle size,the classification efficiency is gradually increased.When the dust particle size reaches 2?m,the classification efficiency is almost unchanged with the increase of dust particle size.