The Research On Noise Control In Bag-filter System With Numerical Simulation

The continuous improvement of environmental standards,now is promoting the development of dust removal technology.People tend to focus on the dust collection efficiency;emissions of particulate matter concentration of the dust collector,but pay too little attention to noise pollution of dust removal system.And when working,it has caused tremendous negative impact to human beings' environments.So it is of great significance and social value to reduce the noise cost-effectively of dust removal system.The noise of dust removal system is quite complex:such as,centrifugal fan noise, motor noise,plumbing noise,exhaust noise,and so on,and the main aspects is centrifugal fan noise and exhaust noise.In this passage,it is the theoretical support by analyzing various sources of noise of the mechanism,summing up measures on how to control noise.By the theoretical analysis,this paper gives the generation mechanism of centrifugal fan,which means the dipole noise source is the main cause of the aerodynamic noise.The most effective way to control the aerodynamic noise is to install the fan muffler and the exhaust muffler.While the environmental noise standard is higher,the muffler can not control the noise perfectly.So the measure must be considered comprehensively,and the unit acoustic enclosure is the best choice.After preliminary understanding of the noise theory,aerodynamic theory and their numerical analysis method,the numerical simulation analysis is used to study the muffler's performance and regularity.Combined with practical work,and with the help of Fluent,the flow of the muffler is simulated and analyzed to show the generation reasons and mechanism of the regeneration flow.Considering the muffler's acoustic performance,aerodynamic performance and structural performance,the aim and the basic idea of its optimization design are decided.After establishing mathematical model of the optimization,MATLAB is used to optimize the model,and then a better model is obtained.The modal analysis technique is used for the finite element dynamic calculation of muffler shell,for finding the relationship among the natural frequency,vibration type and noise signal,and for improving the muffler's performance.Under the same condition of aerodynamic performance,we can get a better muffler.By the practical work,the design of reducing noise and the treatment result are discussed,and the effects of the noise at boundary of industrial enterprises and some hypersensitive points are tested.It shows that the design of the dedusting system in roaster area has a favourable effect.And it has some reference value in the noise treatment of the same type of dedusting system.This paper designs a new type muffler to follow the mentioned research idea and by the practical work,it validates this method.Using CFD can decrease the cost of production,shorten the period of exploitation and amelioration,and instruct the design of the reducing noise project.