Study of the entrainment motion of oily fine particles (PM2.5) in a standing wave acoustic field under the influence of cohesion

Oily fine particles (PM2.5) are considered important pollutants in the industrial environment, and long-term exposure to such oil mist pollutants can bring serious harm to the health of production personnel and the quality of processed products. Acoustic agglomeration is a mechanism of particle agglomeration in which the acoustic wave enhances the entrainment effect of the flow field on fine particles, promotes the collision polymerisation of fine particles and then reduces the suspended concentration of fine particles in the factory environment. However, the existing theory of acoustic agglomeration does not consider the effect of the cohesive force of adjacent oily fine particles on entrainment motion. In this paper, an entrainment model of oily fine particles is established, and a gas wave model of standing wave acoustic field is used to deduce the entrainment coefficient of the sound wave’s ability to carry oily fine particles. The results reveal that the less dense oily fine particles are more easily carried by sound waves. There is a frequency range where the entrainment coefficient changes most significantly. Practical Application The study on acoustic agglomeration of oily fine particles provides a foundation for developing advanced air purification systems in buildings. Architects and engineers can utilize these findings to design HVAC systems that effectively reduce indoor pollutants, enhancing air quality and aligning with sustainable design principles. This technology supports the creation of healthier, more efficient spaces, particularly in industrial or manufacturing settings where airborne particles are a concern.