Effect of structural parameters on atomization characteristics and dust reduction performance of internal-mixing air-assisted atomizer nozzle

Abstract

As a air-liquid two-phase flow nozzle, the internal-mixing air-assisted atomizer nozzle has been widely used in the field of spray technology for dust reduction. Structural parameters are important factors to influence the atomization characteristics and dust-reducing performance of the atomizing nozzle. However, the mechanism of the influences of the structural parameters is not clear. In this study, the customized experimental spraying platform for dust control was used to study the atomization characteristics and dust reduction performance of the nozzles under different structural parameters. Based on the experimental results, when the parameters such as water pressure and air pressure were constant, the dust reduction efficiency for both the total dust and the respiratory dust first increased then decreased with the increase of the diameter of the water-injection hole in the liquid cap and the number of air-injections holes. The dust reduction efficiency was optimal when the diameter of the water-injection hole in the liquid cap was 1.5mm and the number of air-injections holes was 4. As the diameter of the air cap outlet increased, the dust reduction efficiency for both the total dust and the respiratory dust was improved; however, the improvement was limited. Based on the comprehensive consideration of the factors including the dust reduction efficiency of the nozzle, the water flow rate, and the air flow rate, the diameter of the air cap outlet should be in the range of 2.0˜3.0mm. When an internal mixing air atomizing nozzle was used for dust reduction in industrial production sites, it is recommended have the diameter of the water-injection hole to be 1.5mm, the number of air-injection holes to be 4, and the diameter of the air cap outlet to be 2.0˜3.0mm. Under these recommended structural parameters, the dust reduction performance of the nozzle is good while the water consumption and air consumption remain relatively low.