悬臂式掘进机破岩产尘、能耗控制及性能评估

Control of dust make,specific cutting energy and performance evaluation of roadheader

关于掘进工作面的粉尘问题,以往的研究大多集中在粉尘运移规律及治理方法上,对产尘机理及可控指标的研究较少。鉴于此,以截齿破岩机理为基础,分析了截齿破岩产尘机理及影响因素,并把影响因素划分为静态和动态影响因素。静态影响因素包括镐形截齿锥角、截割角以及截割速度等,其特点是在掘进机工作过程中不会改变而影响产尘和能耗;动态影响因素包括截齿磨损和截割厚度等,截割厚度是影响产尘量最重要的可控动态影响因素。研究发现产尘量与比能耗密切相关。文中着重研究了截割厚度对截割破岩产尘及能耗的影响,结果表明:截割厚度产尘量和截割比能耗的影响规律非常相似,随着截割厚度的增大,产尘量和截割比能耗都以幂函数减小。以此为基础,论述了以平均截割厚度9 mm及以上制定掘进机可经济破岩性能指标的合理性,这是控制粉尘和能耗的合理界限,并建立了用岩石抗压强度、截割比能耗表示的掘进机可经济截割岩石硬度指标的计算模型。最后将各模型应用于两个实例,结果表明它们能合理的对掘进机经济破岩能力进行评估,并能用其对掘进机的岩效率进行预测。这些结论对掘进机的设计、选型以及现场应用能提供很好的理论支撑。

The majority of the studies in the past on the dust make in heading face were focused on dust transport law and treatment methods.However,there were few studies focused on the dust make mechanism and controllable indexes.Given this,the dust make mechanism and influencing factors of rock cutting using roadheaders were analyzed in detail based on the rock cutting mechanism using conical picks,and influencing factors were classified into two categories:static factors and dynamic factors.Static factors include the cone angle of picks,the attack angle and cutting speed,etc.Dynamic factors include picks wear and the change of cutting depth.The cutting depth is an important controllable dynamic factor on dust make in the process of rock cutting.It is found that dust make is also closely related with the specific cutting energy.The effects of cutting depth on dust make and specific cutting energy were then studied in detail.The results indicate that the effect laws of cutting depth on dust make and specific cutting energy are extremely similar,namely they all decrease in power function with the increase of cutting depth.Based on this,the rationality of making the rock breaking performance indexes of roadheaders at 9 mm cutting depth was discussed,it is the reasonable boundary to control dust make and energy requirement.The rock hardness indexes to evaluate roadheaders rock breaking ability may be expressed using compressive strength and specific cutting energy of the rock,whose mathematic models were established based on the mean cutting depth of roadheaders.Finally,the models of this study were applied in two engineering examples,and the results indicate that the models could be used to predict the rock breaking ability of roadheaders reasonably,and to predict their production rate satisfactorily.The conclusions of this study can provide theoretical supports for design,model selection and field application of roadheaders.