Research On The Structure And Characteristics Of Antifreeze Spray Nozzles For Coal Trains

During the production and processing of coal,it will accumulate a certain amount of moisture,and in the cold winter when transporting coal,it is easy to freeze the coal together with the inner surface of the carriage,which brings great difficulties to the loading and unloading of coal on the train.Spraying antifreeze on the inner surface of the carriage is a widely used and effective solution at present.As the executive component of the antifreeze spraying system,the nozzle undertakes the important task of spraying antifreeze evenly.Therefore,the antifreeze nozzle plays a key role in the spraying device.Because the height of the spray rack and the distance between the nozzles are directly related to the spray angle,and the speed of the train is related to the spray flow and the injection speed.Therefore,in order to achieve uniform coverage of the inner surface of the railway carriage,the spray characteristics of the antifreeze nozzle need to be well understood.However,due to the defects of small spraying angle and uneven spraying of the fan nozzles currently configured,these defects bring a series of problems to the spraying system,such as the waste of antifreeze fluid,the complexity of mechanical structure and control system caused by excessivesprinkler layout,etc.Therefore,it is necessary to conduct in-depth study and analysis of the internal and external flow field of the nozzle,and to optimize the structural parameters and related position parameters of the fan nozzle.The main contents and conclusions of this paper are as follows:(1)Firstly,the influence of the key structural parameters of the nozzle on the spraying characteristics was studied.Through single factor simulation analysis,the variation of flow rate,spraying angle,water content of cut-off line and jet velocity with hemispheric diameter,offset and groove angle were revealed,and the appropriate parameters range was selected for orthogonal experiment simulation.(2)According to range analysis and variance analysis of spraying characteristics of antifreeze nozzle,offset was the most important factor affecting the spraying characteristics of fan nozzle,hemispheric diameter and grooving angle were the secondary factors,and the influence of each spraying characteristic index from large to small was: offset,hemispheric diameter,grooving angle;(3)The influence of pressure on spraying characteristics was investigated,and the relationship between pressure and jet shape,nozzle flow rate and jet velocity was judged.(4)The influence of nozzle position parameters on spraying characteristics was studied.It was found that when the nozzle rotates at a certain angle,the interference between the two nozzles flow fields can be reduced and thedistribution of water content was more uniform.However,with the increase of the rotation angle,vortices would occur in the interference area of the two flow fields,which would affect the spraying effect.The numerical simulation results showed that the flow field distribution of the nozzle was the best when the nozzle rotates at 25 degrees.The water content distribution in the cross section was the most uniform.(5)Spraying experiments were carried out on some nozzles to verify the effects of pressure,nozzle offset,groove angle and other parameters on spraying characteristics.The experimental results are basically consistent with the numerical simulation results,that is,the pressure has little effect on spraying angle,the greater the pressure,the faster the jet velocity and the more the atomization effect of liquid;the larger the offset of the nozzle,the smaller the spraying angle;the larger the grooving angle of the nozzle,the smaller the spraying angle.