摘要
为了进一步提高综采工作面空气幕隔尘效率,提出采用新型旋转风幕进行隔尘。根据冲击射流相关理论,推导出了垂帘合理安装位置及垂吊高度。利用旋风分离理论,导出了旋转风幕所能控制的最大粉尘粒径和隔尘效率表达式。借助模型试验,对旋转风幕隔尘下的综采工作面粉尘质量浓度分布及旋转风幕的隔尘效率进行了分析。结果表明:采用旋转风幕隔尘时,空气幕气流在煤壁侧形成一旋转风幕,采煤机滚筒割煤所产生的粉尘在该旋转风幕的卷吸作用下,被控制在煤壁侧,并被工作面风流带走;由于垂帘的阻隔作用,空气幕气流冲击顶板后只能往煤壁方向运动,阻止了空气幕将卷吸进来的粉尘带到采煤司机的工作区,提高了空气幕的隔尘效率;旋转风幕隔尘时,司机侧的粉尘质量浓度较普通空气幕隔尘时进一步降低,其粉尘质量浓度由78 mg/m^3降低至69 mg/m^3,粉尘隔尘效率由81.8%提高至84.2%,提升了2.4%;旋转风幕对呼吸性粉尘的隔尘优势更为明显,司机侧呼吸性粉尘质量浓度由14 mg/m^3降至8 mg/m^3,呼吸性粉尘隔尘效率高达92.6%,较普通空气幕提高了6.5%;旋转风幕对不同粒径粉尘的隔尘效率有差异,随粉尘粒径增加,旋转风幕的隔尘效率不断下降。
In order to improve the dust isolation efficiency of air blind at fully-mechanized working face,the paper intends to propose a new kind of rotating air blind to prevent the dust diffusion and reduce the dust pollution for the miners.For the research goal,we have worked out the theoretical impact of the jet flow,the rational position of the blind installation,as well as the height of the falling blind.In addition,we have also derived the expression for the maximum particle size and the dust isolation efficiency via the cyclone separation theory.What is more,we have also made a careful exploration of the dust distribution and the isolation efficiency under the condition of the air blind rotation through a model experiment.The results of our theoretical and experimental studies indicate that the airflow of the aforementioned air blind is in a position to result in a rotating air blind at the coal-mining wall sphere when the rotating air blind is working on.Under the action of the rotating air blind,it is possible to control the dust produced by the shearer on the coal-wall sides or drain the dust off by the airflow of the working face.Besides,since the restriction of the falling blind can only influence the air flow movement on the two coal wall sides,the entrainment dust of the air blind can be carried into the driver side,the dust isolation can be effectively improved by the air blind.Furthermore,the total dust concentration of the driver side can also be reduced under the action of the rotating air blind up to 69 mg/m3 from 78 mg/m3,in addition to the dust isolation efficiency rise of the total dust to 84.2%from 81.8%,that is,the additional reduction of 2.4%.The advantage of the rotating air blind can be made more outstanding in respirable dust,whose dust concentration of the driver side can be reduced to 8 mg/m from 14 mg/m.Thus,it can be seen that it would be possible to promote the dust isolation efficiency up to 92.6%,which is 6.5%higher than the generally used air blind for the time being.As to the different dust particle sizes,there remains difference with the dust isolation efficiency,which can be made to drop down continually with the increase of the dust particle size.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2015年第6期68-72,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(51574123)
关键词
安全工程
综采工作面
旋转风幕
粉尘
隔尘效率
safe engineering
fully-mechanized work face
rotating air blind
dust
dust isolation efficiency
