Simulation Experimental Study And Application On Airflow Uniformity In The Bag Filter With Dust Bucket Inlet

Dust bucket inlet is one of the common ways of the air into the bag filter. It’s becomes easily secondary anti-mixing and is not conducive to the deposition and cleaning of the dust in the baghouse with dust bucket inlet.However, as the reaction vessel with the absorption of harmful gases, it can improve degree of mixed reaction of the adsorbent dust and harmful gases. That’s because it determines the adsorption effect of harmful gases that evenness of dust concentration in filter bags space and dust layer on the filter bag surface. It’s easy to make the air flow and dust concentrate to the back of the dust collector, which result in the uneven distribution of airflow in the dust collector box and the adsorbent dust and harmful gases reacting inadequately.This article focuses the bag filter with function of adsorbing HF as the research object. Through the uniformity of airflow is improved in the bag filter, evenness of dust concentration in filter bags space and dust layer on the filter bag surface is improved indirectly according to the relationship between dust and air movement, and thus enhance the adsorption efficiency of HF.Aim at the problem of the airflow uniformity in the bag filter, a research is done into situation of airflow uniform distribution in both directions, one is the direction that airflow enters into dust hopper and goes backward, one is the direction that airflow is distributed form bottom to top of bags. The bag filter physical model is established, which is simulated by CFD. The standard κ-ε model is used as turbulence model, and the porous jump media model is used as bag model. The validity of the model is verified experimentally. The flow field uniformity is analyzed in the bag filter to make effective research and improved methods.Aim at the problem of the airflow uniformity in the bag filter with dust bucket inlet, the or-thogonal experiment method is used to design simulation experiment and establish the baghouse physical models with different guiding device structures and boundary conditions.(1) Firstly, the existing structure of diversion device in the dust bucket is researched and the relative root mean square a, is used as evaluation index of distribution uniformity degree of airflow under the bags. The three parameters of wing panel at the end of baffle is selected, including the length L, the gra-dient increment AL among wing panels, the angle0of wing panel, to analyze the relationship that they affect the airflow uniformity under the bags in the same filtration velocity v. It’s reached that the three parameters affect the uniformity insignificantly, which determines the presence of wing panel isn’t available to airflow uniformity,so that they can be canceled to simplify the structure.(b) It’s a way to design the intake uniform board to improve the uniform effect of battle. It’s re-searched in the different filtration velocity v that the relationship between distribution uniformity degree of airflow σ2and the number of boards n, board length L, the angle0the increasing length from the bottom of baffle AL, the height from the lop of the board to bottom of the board AH,which deduces their functional relation and the order that they affect distribution uniformity degree of airflow, that is, L>0> n>△H>△L.(e) It is simulated to get the airflow distribution of dust bucket. Airflow uniform distribution methods is proposed according to the law of conserva-tion of incompressible gas. The specific design size of intake uniform board is determined by the use of discrete method and the intra-variance method. The effect of the different amount of intake uniform boards is compared to determine the most reasonable amount.Aim at the problem of the airflow uniformity along the filter bags from the bottom up, the orthogonal experiment method is used to design simulation experiment and establish the baghouse physical models with different bag structure parameters and distribution and boundary conditions. The relationship is researched between bag structure parameters and the airflow uniformity.The relative root mean square σ2is used as evaluation index of distribution uniformity degree of air-flow along the height direction of bags. Through orthogonal test method, The relationship between σ2and filtration velocity v, bag length H, bag diameter Φ, bags distance L, permeability α is re-searched to obtain their function relation and the order that they affect distribution uniformity de-gree of airflow along the height direction of bags, that is, α> H> Φ>v> L.Finally, combined with the engineering practice and project source, it’s improved and de-signed that the original structure and size of the filter bags and intake uniform board in the bag filter with function of adsorbing hydrogen fluoride. The improved effect can be predicted by CFD to provide reference to the future design.