不同变质程度煤体表面液滴铺展特性实验研究  

Experimental study on the spreading characteristics of liquid droplets on coal surfaces with different degrees of metamorphism

作　　者：谢彪 郁静静 杨天艺 张兴华 李柏辰 胡嘉奇 XIE Biao;YU Jingjing;YANG Tianyi;ZHANG Xinghua;LI Baichen;HU Jiaqi(College of Safety and Emergency Management Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学安全与应急管理工程学院,山西太原030024

出　　处：《实验技术与管理》2024年第7期22-29,共8页Experimental Technology and Management

基　　金：山西省基础研究计划项目(202103021223108);山西省回国留学人员科研教研资助项目(2023-076)。

摘　　要：为研究不同变质程度煤体表面液滴铺展特性,采用实验与数值计算相结合的方法,通过观察纯水液滴撞击煤体的动态铺展过程,探讨撞击高度对不同变质程度煤表面接触角及液滴铺展系数的影响,揭示不同变质程度煤体的润湿机理。测量4种不同煤质的静态接触角,实验结果表明:褐煤的润湿性最强,肥煤次之,无烟煤和焦煤的润湿性最差;观察纯水液滴碰撞不同煤样的动态变化发现,撞击高度与纯水液滴的铺展系数之间存在正相关关系;在相同高度下,纯水液滴铺展系数的变化均表现为先增大后降低再增大,最终趋于一个稳定状态。该研究结果可为矿井湿式除尘技术提供一定的理论参考。[Objective]This study investigates the influence of droplet impact height on the spreading characteristics of liquid droplets on coal surfaces with different degrees of metamorphism.The study also explores the surface reaction mechanism and adsorption behavior of coal when subjected to droplet impact.The dynamic interactions between water droplets and coal surfaces are crucial for enhancing the effectiveness of spray dust reduction in coal mines.This research reveals the characteristics of coals with different degrees of metamorphism when exposed to water mist,providing a theoretical basis for improving the working environment of coal miners,reducing coal dust pollution,and mitigating explosion risks.[Methods]The dynamic spreading process of pure water droplets impacting different coal samples from different heights was examined using high-speed video cameras,contact angle measurement instruments,and piezometers.Experiments and numerical calculations were used to explore the effects of impact height on the contact angle and spreading coefficient of pure water droplets on coal surfaces with varying degrees of metamorphism.The wetting mechanism of coal bodies with different degrees of metamorphism and the changing pattern of the impact of the pure water droplets on coal bodies with different degrees of metamorphism was analyzed from both macro and microscopic perspectives.[Results]The experimental results show that upon impacting four coal samples with different degrees of metamorphism,water droplets initially spread rapidly from the collision center to the periphery.After reaching the maximum contact area with the coal surface,the droplets began to retract toward the center,achieving the maximum retraction height before settling into a steady state following continuous oscillation and eventually lying flat on the surface of the coal sample.The effect of deterioration on the coal-water contact angle was observed at consistent impact heights.The contact angle between coal and pure water first increased and then decr

关 键 词：撞击高度 煤变质程度 接触角 铺展系数 润湿机理 

分 类 号：TD936[矿业工程—选矿]