基于运输扬尘逸散规律的车载喷雾效果探析

Analysis on the Effect of Truck Mounted Spray Based on the Dissipation Law of Dust in Transportation Process

为改善露天铁矿运输环节产生的高浓度扬尘问题,采用理论分析与数值模拟等方法相结合,通过模拟不同车速下扬尘逸散规律并设计车载喷雾降尘系统,探析其雾化效果。研究结果表明:车速为10 km/h时,扬尘会以低风流强度、低运行速度向卡车后上方运动,轮胎与地面摩擦处为运输环节中最大粉尘浓度产尘点,粉尘质量浓度为985 mg/m3;车速增大至30 km/h,扬尘在卡车周身由内向外大范围逸散,逸散范围可达5 m,粉尘质量浓度增加至1400 mg/m^(3),呼吸带粉尘质量浓度最高达224 mg/m^(3),车尾扬尘高度为1.5 m,相较于低车速,车速越高,扬尘逸散的越快;基于运输扬尘逸散规律,对不同喷雾参数的雾化效果进行模拟分析,证实了中压喷嘴在喷雾压力为3 MPa、雾化角为60°、喷嘴直径为1.0 mm时,雾化效果最佳,雾滴粒径为7.42μm,可同时保证全尘和呼吸带粉尘的捕捉。

In order to improve the problem of high-concentration dust generated in the transportation process of open-pit iron mine,theoretical analysis and numerical simulation methods were used to analyze the atomization effect by simulating the dust dissipation law under different vehicle speeds and designing a truck mounted spray dust suppression system.The results show that when the vehicle speed is 1o km/h,the dust will move towards the rear and upper part of the truck at a low airflow intensity and a low operating speed.The maximum concentration position of dust in the transportation process is at the friction point between the tire and the ground,with a dust mass concentration of 985 mg/m^(3).When the vehicle speed increases to 30 km/h,dust will dissipate from the inside to the outside around the truck,with a dissipation range of 5 m.The dust mass concentration increases to 1400 mg/m^(3),and the maximum dust mass concentration in the breathing zone will reach 224 mg/m'.The height of dust at the rear of the truck is 1.5 m.Compared to low vehicle speeds,the higher the vehicle speed,the faster the dust will dissipate.Based on the dissipation law of dust in transportation process,the simulation analysis of the atomization effect of different spray parameters confirmed that the middle pressure nozzle has the best atomization effect when the pressure was 3 MPa,the atomization angle was 60°,and the nozzle diameter was 1.0 mm.The droplet size was 7.42μm,which could simultaneously ensure the capture of total dust and dust in the breathing zone.