Experimental Study On Atomization Characteristics And Dust-reducing Performance Of Hydrodynamic Ultrasonic Nozzle

Dust is not only explosive,but also the most important cause of pneumoconiosis.At present,China mainly uses spray dust reduction technology to control dust and achieve certain results,but the dust concentration in most workplaces is still quite high.In order to improve the quality of the work environment,reduce the probability of accidents,and ensure the life and health of underground workers,use Malvern spray particle size analyzer,PIV image acquisition and processing equipment,LS 13320 and other orthogonal analysis methods,from macro and micro studies.From the angle,the key factors affecting the atomization effect are analyzed,and the relationship between each influencing factor and the atomization parameters is known.Then comprehensively evaluate and analyze the above research results,select the better combination of working conditions,and finally apply the selected working conditions to the spray dust reduction,explore its relationship with dust reduction efficiency,and carry out the dust reduction effect with the traditional pressure nozzle.A comparative study.Based on the theoretical study of fluid-dynamic ultrasonic nozzles,the atomization and dust reduction experimental platform was utilized and improved.The atomization characteristics experiment was carried out by orthogonal design research method,and the atomization effect index of the nozzle was established.Through the macroscopic characteristics experiments,the relationship between the linear range of the fog field,the atomization angle and the flow rate and pressure,water pressure and aperture are obtained.At constant pressure,as the water pressure increases,the nozzle water flow rate and atomization angle increase continuously,and the gas flow rate and range decrease continuously.Under the same inlet pressure,the atomization angle gradually increases with the increase of the nozzle diameter.When the water pressure is fixed,the nozzle water flow rate and the atomization angle gradually decrease with the increase of the air pressure,and the gas flow rate and the range are gradually increased.Through the experiment of droplet dynamics parameters,the inlet pressure is increased,the droplet diameter is gradually reduced,and the droplet density increases slowly and then increases rapidly;the diameter of the droplet decreases with the increase of water pressure.And the median diameter growth rate is slowing down,and the droplet number density is decreasing.The diameter of the nozzle is gradually increased,and the average diameter of the droplets is generally flat,but the variation of the droplet number density and the median diameter is complicated.The concentration of the droplets increases with the gradual increase of the three factors,and then increases and then decreases.In the horizontal direction,the median diameter describing the droplet diameter and the average diameter of the Souter increase with increasing distance from the nozzle exit;the relationship between the droplet concentration and the horizontal distance is inversely correlated,and the distance is basically increased with the increase of the distance.The above is a linear relationship.The diameter of the droplet at the center point is the smallest,and the concentration of the droplet is the highest.At the same time,the particle size of the droplet on the horizontal line is smaller and the droplet concentration is significantly larger.The inlet pressure is positively correlated with the droplet velocity,the nozzle inlet pressure and its diameter are gradually increased,and the droplet velocity is continuously decreased.The maximum droplet velocity in the mist field is generally concentrated at the nozzle horizontal line position,and in the horizontal direction,the droplet The speed performance is first increased and then decreased.In the vertical section,the droplet velocity above the horizontal line is generally smaller than the symmetrical point position.Compared with the traditional pressure nozzle spray dust reduction effect,the ultrasonic nozzle has obvious advantages in atomization effect,full dust and respiratory dust dust reduction efficiency.Under the same working conditions,the overall performance is the ultrasonic nozzle with a diameter of 1.5 mm,followed by the 1.0 mm nozzle,and the 2.0 mm nozzle is the worst;the three diameter nozzles show the dust reduction effect of dust and respirable dust under various working conditions.The law of increase,then decrease and then increase,the best dust reduction effect when the working condition is(0.4,0.4).Therefore,it is recommended to select the optimum combination of nozzles with a diameter of 1.5 mm and pressure(0.4,0.4)in practical applications.