Studies On Improving Acoustic Agglomeration Of Coal-fired Inhalable Particles

In recent years,China's frequent fog and haze,causing a serious harm to human's living environment and health,which is mainly caused by PM_2.5 particles emitted by coal-fired plants.The traditional particle filtering devices have low collect efficiency of PM_2.5 particles.In order to achieve the ideal removal effect,fly ash should be pre-treated before the traditional particle filtering devices.Acoustic agglomeration technology and chemical agglomeration technology are the two most promising pretreatment technology.Acoustic agglomeration technology has the advantages such as obvious effect,rapid agglomeration and easy operation.But also has high energy consumption,large noise pollution defects.Unable to popularize the application of industrial production.In order to improve acoustic agglomeration efficiency and reduce energy consumption.The article introduce the chemical agglomeration system based on the acoustic agglomeration.And the experimental platform of acoustic agglomeration promoting technology was set up.This paper did mechanism and experimental study on agglomeration process of acoustic agglomeration promoting technology.The theoretical analysis shows:The binder droplets,acting as coarse seed particles,raise the agglomeration kernels based on both orthokinetic interaction and hydrodynamic interactions,thus increase the collision frequency of aerosol particles.Liquid bridges and solid bridges between particles are formed in the presence of binder droplets,which are much stronger than van der Waals force to increase the adhesion factors and avoid the breakage of aggregates.The experimental results show:The combination effect of acoustic wave and XTG spray is the best.With addition of XTG spray,the agglomeration efficiency reaches as high as 85%at an acoustic power of 2.5 W.Under the same conditions,it is about 10%higher than water spray,about 15%higher than only XTG spray,about 25%than only water spray,about 30%higher than only acoustic action.It is also found that the agglomeration efficiency becomes much less sensitive to the acoustic frequency change with addition of binders,comparing with the case without the addition of binders.