Experimental Study Of Fly Ash Inhalable Particles Agglomeration Based On The Combined Of Acoustic Field And Ultrasonic Atomization

As our country's main fuel, coal plays a very important role in all walks of life. However,coal fly ash generated in the process of coal combustion is the main source of inhalable particles, which is very harmful to the environment and health, especially for the PM2.5.Therefore, how to remove the inhalable particles in fly ash has become the focus of research in our country, and even in the world.Acoustic agglomeration is one of the most advanced pretreatment technologies, which makes the inhalable particles of coal fly ash collide and agglomerate in the sound field, and then removed by the traditional dust removal equipment.Under the support of Shanghai Finance, cooperation with the School of Mechanical Engineering of Shanghai Jiao Tong University, designed and built acoustic agglomeration combined ultrasonic atomization experiment platform, and then compare the agglomeration effect in high frequency and low frequency. The experimental results show that the agglomeration efficiency of the low frequency is better than that of the high frequency,and the optimal frequency is 900Hz. In the best frequency, when we only added the sound field, with the increase of sound intensity, particle concentration and residence time, the agglomeration efficiency can reach 20.67%, 20.22%, and 21.22%, respectively; when we added the atomization and sound field in the same time, the agglomeration efficiency can reach 34.86%, 34.76%, 35.42%, respectively. Compared with only adding sound field, the agglomeration efficiency is increased by about 15%.In the process of the experiment, the samples were collected before and after agglomeration, and then the microstructure of the scanning electron microscope (SEM) images were taken to show the existence of agglomeration.Agglomeration simulation is established based on the orthokinetic and hydrodynamic interaction as main mechanisms. Quadrature method of moments (QMOM) was used to solve the equation. We can get the optimum frequency by the simulation results. Under the condition of the optimal agglomeration, contrast the agglomeration effects of adding different atomized particle size, and it pointed out a new way for the future research.