微纳米气泡强化喷雾降尘试验研究

An enhanced spray dust suppression method by micro-nano bubbles

为增强雾滴捕获粉尘的性能,提高喷雾降尘效率,提出微纳米气泡强化喷雾降尘的方法。以微纳米气泡水和润湿性差的焦煤粉尘为研究对象,通过实验研究微纳米气泡水的基本特性及其对粉尘的吸附和润湿性能。基于自行设计的喷雾降尘实验平台,对比微纳米气泡水与自来水的喷雾降尘效率。实验结果表明:微米级的气泡能短暂存在于水中,而纳米级的气泡能长期存在于水中;微纳米气泡水比超纯水的Zeta电位高,带电荷的气泡能有效附着粉尘;微纳米气泡水比自来水的表面张力低5.5 mN/m,随着微米级的气泡逐渐破裂,微纳米气泡水的表面张力缓慢增大;微纳米气泡水比自来水对焦煤颗粒的接触角小4.58°,微纳米气泡增强了水润湿焦煤颗粒的性能;随接触时间增加,微纳米气泡水和自来水对焦煤颗粒的接触角均不断减小,且微纳米气泡水减小的速率更大;微纳米气泡水是非稳态体系,比自来水更易蒸发;微纳米气泡水相对于自来水作为喷雾介质,可提高喷雾周围的负氧离子浓度;随着X形旋流压力喷嘴供水压力逐渐增加,微纳米气泡水和自来水喷雾的雾滴粒径均减小;喷嘴供水压力相同,微纳米气泡水喷雾粒径比自来水喷雾粒径小,但雾滴粒径差距不大;随着供水压力增加,喷嘴降尘效率不断增大,且微纳米气泡水比自来水喷雾降尘效率大;微纳米气泡有助于粉尘的润湿和凝聚,更有利于捕获呼吸性粉尘。

To improve the dust capture performance of fog droplets and the spray dust suppression efficiency, a method of utilizing micro-nano bubbles to enhance the spray dust suppression is proposed. Taking micro-nano bubble water and coking coal dust with poor wettability as research objects, the basic characteristics of micro-nano bubble water and its adsorption and wettability to dust are studied through experiments. The spray dust suppression efficiency of micro-nano bubble water and tap water is compared based on the self-designed experimental platform for spray dust suppression. The experimental results show that micro bubbles can exist in water for a short time while nano bubbles can exist in water for a long time. The Zeta potential of the micro-nano bubble water is higher than that of the ultrapure water, and dust can effectively adhere to the charged bubbles. The surface tension of the micro-nano bubble water is 5.5 mN/m lower than that of tap water, and with the gradual rupture of micro bubbles, the surface tension of the micro-nano bubble water increases slowly. The contact angle to coking coal particles of the micro-nano bubble water is 4.58° smaller than that of tap water, and micro-nano bubbles can enhance the wettability of water to coking coal particles. With the increase of contact time, the contact angle of micro-nano bubble water and tap water to coking coal particles decreases continuously, and the reduction rate of micro-nano bubble water is larger. micro-nano bubble water is an unsteady system, and is easier to evaporate than tap water. Compared with tap water, micro-nano bubble water can increase the concentration of negative oxygen ions around the spray. As the water supply pressure of the X-shaped swirl pressure nozzle gradually increases, the spray droplet size of micro-nano bubble water and tap water decreases.At the same nozzle water supply pressure, the spray particle size of micro-nano bubble water is smaller than that of tap water, but not differs significantly. With the increase of water supply pressure, the dust suppression efficiency of nozzle increases continuously, and the micro-nano bubble water shows a higher dust suppression efficiency than that of tap water. Micro-nano bubbles contribute to the wetting and condensation of dust, and are conducive to the capture of respirable dust.