水喷淋法控制煤尘的研究

STUDY ON COAL DUST SUPPRESSIONBY WATER SPRAY

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.