Research Of Acoustic Agglomeration Process Of Fine Particles In The Standingwave Tube With Abrupt Section

Acoustic agglomeration is considered to be one of the very promising pretreatment method to remove suspension fine particles.According to the existing theory,the sound pressure level of the sound interacting with the fine particles is higher,the better the effect of the acoustic agglomeration.We using air-modulated source to replace the original electronic-acoustic source in this paper,so as to improve the power of the sound source.Further,the multi-orifice plate(uniform porous)is arranged between the air current sound source and the condensing chamber,in order to serve the purpose of separating the sound from the air.The main work of this paper is as follows:(1)Numerical simulation of the sound field in the agglomeration chamber after installing multi-orifice plate show that the resonance frequency change to imparity,and the sound pressure level in the agglomeration chamber decrease.When the total hole area is constant,the hole diameter is smaller,the sound pressure level decreased more in the cabin.And when the hole diameter is constant,the change of the total area of the hole has little effect on the sound pressure level.Therefore,selection of multi-orifice plate in the experiment can change the total area of the hole after determine the appropriate hole diameter to make sure that the air flowed through less and the sound pressure level decreased less.(2)The experimental study of the sound field distribution in the agglomeration chamber driven by two different sound sources is compared.The results showed that the sound pressure level is higher when it is driven by the air-modulated source than it is modulated by the electric-acoustic source obviously,and can reach about 167 dB.(3)The experimental study on the effect of different parameters to the agglomeration efficiency driven by the air-modulated sound source showed that,find several frequencies under which the agglomeration efficiency is higher among 500~1500 Hz,select the appropriate hole diameter and total hole area of the plate,enhance the initial concentration of the fly ash,and then the acoustic agglomeration efficiency will reach maximum of 85%.