声波与化学团聚协同作用对转炉微细粉尘团聚的影响

Effect of coordination of acoustic wave and chemical agglomeration on fine dust agglomeration in converter

针对转炉烟气中微细粉尘的难处理问题,采用声波与化学团聚协同处理方法,在蒸发冷却器内对转炉烟气粉尘进行预处理,以提高微细粉尘的除尘效率。采用单因素实验和正交实验方法研究了絮凝剂的种类[丙烯酰胺(PAM)、羧甲基纤维素钠(CMC)和黄原胶(XTG)]、絮凝剂浓度、声波频率、声波驻场时间等不同影响因素下的微细粉尘的团聚效果。单因素实验结果表明:三种絮凝剂的团聚效果由大到小依次为PAM>CMC>XTG,絮凝剂浓度为0.1 g/L时团聚效果最好,声波频率为33 KHz时作用效果较为显著,声波驻场停留时间为15 s时效果最佳;声波与化学团聚协同作用效果好于化学团聚和声波团聚单独作用效果。通过正交实验得出,当浓度为0.1 g/L、声波频率33 KHz、声波驻场停留时间15 s的条件下,团聚效果最显著,峰值粒径由原始的3.311μm提升至43.59μm,对应的静电除尘器的除尘效率可达到97%。研究成果可为提高钢铁工业烟气中微细粉尘的去除工艺开发提供可靠的基础数据,为工业烟气中微细粉尘的去除效率提高奠定了基础。

At present,air pollution caused by heavy industrial products such as iron and steel,thermal power generation and cement is still very serious in China.The main reason is the low dust removal effect of PM2.5 and PM10 particles.To solve the problem of difficult treatment of fine dust in converter flue gas,the collaborative treatment method based on acoustic waves and chemical agglomeration was used to pretreat converter flue gas dust in an evaporative cooler to improve the dust removal efficiency of fine dust.Single-factor experiment and orthogonal experiment were used to study the agglomeration effect of fine dust under different factors,such as the type of flocculants[acrylamide(PAM),sodium carboxymethyl cellulose(CMC)and xanthan gum(XTG)],flocculant concentration,acoustic frequency and acoustic field time.The results of the single-factor experiment showed that the agglomeration effect of the three flocculants was PAM>CMC>XTG from large to small,taking the increase of the peak particle size of the fine dust as the evaluation standard.The agglomerating effect was the best when the concentration of agglomerating agent was0.1 g/L,the effect was obvious when the acoustic frequency was 33 kHz,and the effect was the best when the acoustic residence time was 15 s.The synergistic effect of the acoustic wave and chemical agglomeration was better than that of chemical agglomeration and acoustic wave alone.The results of the orthogonal experiment showed that when the concentration was 0.1 g/L,the acoustic frequency was 33 k Hz,and the acoustic residence time was 15 s,the agglomeration effect was the most significant.The peak particle size increased from 3.311μm to 43.59μm,and the dust removal efficiency of the corresponding electrostatic precipitator reached 97%.From the experimental comparison of the coordination mechanism and the single agglomeration mechanism,the synergetic mechanism combined the advantages of a single agglomeration mechanism such as chemistry and acoustic waves,and provided a feasible basis for multi-mechanism dust removal in the industry.The results can provide reliable basic data for improving the removal of fine dust in the flue gas of iron and steel production,and lay a foundation for improving the removal efficiency of fine dust in the industrial flue gas.