摘要
工业生产过程中排放的含SO2烟气给人们带来了极大的危害,解决SO2污染问题迫在眉睫。传统的脱硫技术都存在难以克服的缺点,如成本高、脱硫产物不能综合利用等。针对这些问题,本文提出了荷电喷雾脱硫技术。
本文首先探讨了荷电喷雾技术及其脱硫机理。研究表明,气液两相射流的感应荷电能获得较大荷电量的雾滴,其荷电破裂主要是由于库仑斥力导致表面张力的降低而引起的。荷电雾滴的脱硫机理主要取决于其物理作用,雾滴表面的净电荷只能间接地通过雾滴对吸收过程起促进作用,其本身并不具有吸收SO2的特性。
实验得出了荷电电压与液气比对雾滴荷质比的影响,实验值与理论表达式具有很好的一致性。
对湿法烟气脱硫系统引入静电效应后产生的脱硫增益作用进行了实验测定。水雾荷电前后的脱硫效率比较实验结果表明,对于较低的SO2浓度,这种效应可使雾滴脱硫效率增加8个百分点左右。实验还讨论了荷电电压、液气比、进口SO2浓度、雾滴距喷嘴的距离对脱硫效率的影响。实验及理论分析指出,荷电对强化烟气脱硫是有益的,雾滴带电后本质上提高了雾滴的表面活性,改善了脱硫通道中雾滴的弥散程度,从而加速了SO2的吸收进程。
Flue gas containing SO2 emitted from the process of the industry production can result in huge damage to human. It’s an emergency to resolve the problem of SO2 pollution. The traditional desulfurization technology has some disadvantages, for example, high investment and poor utilization. Due to these problems, desulfurizing technology with charged spray is proposed.
Charged spray technology and desulfurization mechanism is discussed in this paper. The research shows that high electric charged droplets can be obtained from faradic gas-fluid two-phase jet. The breakup of charged droplets is caused by coulomb repulsion force which leads to decreased surface tension. The desulfurization mechanism of charged droplets depends on physical effect. Net electric charge in the surface of droplets which doesn’t have the quality of SO2 absorption only stimulates the progress of droplets absorption.
The influence of voltage and liquid flux-gas flux ratio to charge-mass ratio is obtained from the experiments. The experimental results is extraordinary consistent with the theoretical results. The enhancement of SO2 absorption efficiencies in a wet flue gas desulfurization system is investigated by introducing electrostatic effect. SO2 absorption efficiencies by water droplets, with and without charges, are compared, and the results indicate that an increment of 8 percent in SO2 removal efficiency can be obtained with a lower initial concentration of SO2. The experiments also discuss the relations that desulfurization efficiency with the voltage, the liquid flux-gas flux ratio, the incoming concentration of SO2 and the distance from droplets to nozzle. The experimental and theoretical analysis shows that net charges on water droplets are beneficial for SO2 capture. The electrostatic effect can improve surface chemical activity and the distributional uniformity of the droplets in the absorption chamber.
引文
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