摘要
水喷淋法是连续采煤过程中广泛应用的一种有效的除尘方法。由于煤是憎水性物质,使水喷淋的除尘效率受到一定的限制。本研究表明,粉尘的粒径影响极大,粒径越小的煤尘,界面张力对它的影响相对就越大,其捕集效率就越低,使用表面活性剂的效力也就越明显。当尘粒极微小时,其斯托克数亦很小,使动能小于穿透功(Ek<W),惯性碰撞不再是支配性的捕集作用机理,尘粒与水滴之间的界面作用要受到许多其他参数的控制。在不同的操作条件下,许多作用力互相竞争,起着各种各样的协同作用。喷淋水中含有电解质会降低煤尘捕集效率,含盐量的多少是一个不可忽视的因素。阳离子表面活性剂可以提高憎水性煤尘的捕集效率,但是,喷淋水中的电解质会干扰离子型表面活性剂的效力。
As an effective dust-controlling method ,water spray has long been widely used in con-tinuous mining, but the collection efficiency is limited because of the hydrophobic nature ofcoal. This study reveals that the smaller the particall size ,the bigger relative inflence of interfa-cial tension and the larger increment of efficiency by using the surfactant. In the case of fineparticals with small Stoke s number and Ek<W, inertia impaction is no longer the dominantmechanism ,many parameters combining together to ptay a synergetic role in interfacial condi-tions which is very important for the capture of particles. Electrolyte in droplets decreases thecollection efficiency and sait concentration is a non-negligible factor. Cationic surfactant canenhance the capture ability for hydrophobic coal dust ,but in the presence of common ions inwater ,electrolytes disturb the function of this amphipathic agent.
关键词
水喷淋法
除尘
煤矿开采
water spray method
dust control method
coal dust , water quality