粉尘颗粒亲水性对其雾化离心去除率的影响

Effect of hydrophilicity of dust particles on their removal efficiency in a gas cyclone with atomized water vapor

基于电声换能超声波雾化-旋风除尘器联用技术,研究了亲水性对粉尘颗粒去除率的影响。通过选择若干种亲水性不同的常见工业粉尘,在相同实验条件下研究其亲水性与离心去除率之间的关系。结果表明,在旋风分离前加入雾气,亲水性较好的粉尘颗粒去除率有明显的提升,在通入浓度为4 g·m^(-3)的雾气后,滑石粉颗粒的去除率从无雾气时的76.9%提高到90.1%,增长幅度为13.2%,而亲水性较差的S-zorb脱硫催化剂去除率从72.1%增加到80.1%,增幅仅为8.0%。这一现象尤其体现在粒径在2.5μm附近的细颗粒物上,滑石粉去除率增幅最高点出现在粒径为2μm的颗粒处,从无雾气时的31.5%增长到有雾气时的72.8%,增幅为41.3%,而亲水性较差的S-zorb脱硫催化剂去除率最高增幅只有17.7%,从无雾气时的43.9%增长到有雾气时的61.6%,去除率增幅最高点出现在粒径为2.3μm的颗粒处。实验前后粉尘颗粒形态的SEM扫描电子显微镜图像也证实亲水性对颗粒物团聚、长大有重要影响。研究亲水性对粉尘颗粒去除率的影响,可进一步优化、改进电声换能超声波雾化-旋风除尘器联用除尘技术,使其发挥更大的工业应用潜力,减少PM2.5排放。

In this paper, the effect of hydrophilicity of dust particles on their removal efficiency in a gas cyclone with atomized water vapor was studied by experiments. The water vapor was generated by electro-acoustic transducing ultrasonic atomization technique. Several kinds of industrial dust with different hydrophilicities were injected in the cyclone and their removal efficiencies were measured and compared. The results showed generally the removal efficiency will increase with water vapor added to the cyclone. Such increase will be more significant for more hydrophilic dust particles. The removal efficiency of the talcum powder increased from 76.9% to 90.1% by 13.2%when 4 g·m^-3 vapor was added. However, for the S-zorb desulfurization catalyst with poorer hydrophilicity, the increase was only 8.0% with the same amount of vapor. The effect of hydrophilicity was especially manifested in fine particles with diameter about 2.5 μm. The highest increase of the removal efficiency of the talcum powder appeared at particle size 2 μm, which was from 31.5% to 72.8% with 4 g·m^-3 vapor added,while the highest increase of that of the S-zorb desulfurization catalyst was only from 43.9% to 61.6% at particle size 2.3 μm. Moreover, the dust particles before and after the cyclonewere examined by scanning electron microscopy（SEM） images, and the results confirmed the hydrophilicity has a significant impact on the agglomeration and growth of particles, which should be responsible for the difference in the removal efficiency of different particles. These studies could help optimize and improve the cloud-air-purifying（CAP） technology that combines gas cyclone with atomized water vapor technologies,and extend its versatility to industrial applications for decreasing the emission of PM2.5.