Analytical study of ultrasound influence on the molten metals atomization

This paper focuses on the study of influence of ultrasound on liquid atomization using ejection nozzles. Two principles of influence of ultrasound on the atomization process such as a change of conditions on gas-liquid boundary during the generation of ultrasound oscillation in the gas and liquid jet (film) disintegration under the action of capillary forces in cases of generation of ultrasound oscillation in the liquid are considered. The optimal values of the ultrasound oscillation frequencies are calculated. Two constructions of the nozzles patented are proposed

Sedimentation of a Fine Aerosol in the Acoustic Field and with the Electrostatic Charge of Particles

Finding an efficient way to eliminate fine dust (particle diameter of 1-15 µm) from a room can be a challenging problem. Acoustic radiation emitters are widely used to accelerate particle coagulation and sedimentation. In this study, we propose one more method for depositing harmful particles – dispersion of electrostatically charged particles. These particles attract uncharged particles from the air and accelerate coagulation. The paper is devoted to a comparison of methods for the acoustic and electrostatic sedimentation of aerosols. The mathematical model for the coagulation of aerosols on the basis of Smoluchowski’s equation is proposed in the options corresponding to acoustic and electrostatic coagulation. A number of conclusions about the most effective conditions of sedimentation were made on the basis of the analysis of a kernel type of Smoluchowski’s integral equation. The results of the experiments on acoustic and electrostatic sedimentation of the model aerosol media (coal dust) are given. The results of the calculations according to the mathematical model of coagulation taking into account the proposed mechanisms for the sedimentation of aerosols in the acoustic field and electrostatic charging of particles are given

Mechanisms of Aerosol Sedimentation by Acoustic Field

Acoustic radiation sources are successfully applied to cleaning rooms from dust of fairly large particle sizes (ten micrometers and larger). The sedimentation of fine aerosols (particle diameter of 1–10 microns) is a more complicated challenge. The paper is devoted to the substantiation of the acoustic sedimentation method for such aerosols. On the basis of the mathematical model analysis for aerosol sedimentation by the acoustic field the mechanisms of this process have been determined and include the particle coagulation acceleration and radiation pressure effect. The experimental results of the acoustic sedimentation of a model aerosol (NaCl) are shown. The calculation results according to the mathematical model for coagulation and sedimentation, on the basis of the Smolukhovsky’s equation taking into account various mechanisms of aerosol sedimentation by sound depending on the particle sizes and sound intensity, are given. The necessity to use intensive sources of high-frequency sound has been confirmed, suggesting that these sources must be located above dust clouds

Analytical study of ultrasound influence on the molten metals atomization

This paper focuses on the study of influence of ultrasound on liquid atomization using ejection nozzles. Two principles of influence of ultrasound on the atomization process such as a change of conditions on gas-liquid boundary during the generation of ultrasound oscillation in the gas and liquid jet (film) disintegration under the action of capillary forces in cases of generation of ultrasound oscillation in the liquid are considered. The optimal values of the ultrasound oscillation frequencies are calculated. Two constructions of the nozzles patented are proposed

Propagation of viral bioaerosols indoors.

Here we look into the spread of aerosols indoors that may potentially carry viruses. Many viruses, including the novel SARS-CoV-2, are known to spread via airborne and air-dust pathways. From the literature data and our research on the propagation of fine aerosols, we simulate herein the carryover of viral aerosols in indoor air. We demonstrate that a lot of fine droplets released from an infected person's coughing, sneezing, or talking propagate very fast and for large distances indoors, as well as bend around obstacles, lift up and down over staircases, and so on. This study suggests equations to evaluate the concentration of those droplets, depending on time and distance from the source of infection. Estimates are given for the safe distance to the source of infection, and available methods for neutralizing viral aerosols indoors are considered