针对西北油田大尺寸卡瓦套管悬挂器井口坐挂载荷控制难度较大及卡瓦牙咬入深度与悬挂载荷之间的关系研究少的问题,根据 273 mm WE型卡瓦悬挂器的实际结构,建立了悬挂器坐挂套管的轴对称有限元模型,采用有限元分析与理论计算相结合的方法...针对西北油田大尺寸卡瓦套管悬挂器井口坐挂载荷控制难度较大及卡瓦牙咬入深度与悬挂载荷之间的关系研究少的问题,根据 273 mm WE型卡瓦悬挂器的实际结构,建立了悬挂器坐挂套管的轴对称有限元模型,采用有限元分析与理论计算相结合的方法,对卡瓦牙咬入深度与悬挂载荷之间的关系进行研究。将有限元模拟结果与套管表面实际咬痕进行对比,证明该有限元模型的建立与分析具有一定的准确性。在一定的悬挂载荷作用下,不同卡瓦牙吃入套管的深度不一样,卡瓦牙从下端到上端,吃入深度逐渐减小;随着悬挂载荷增大,卡瓦牙咬入套管的最大深度逐渐加深,套管剩余抗挤强度减小,当套管剩余抗挤强度减小到一定值时,即可求出卡瓦牙在一定咬入深度下对应的最大悬挂载荷。研究结果对于套管坐挂的现场施工具有一定的指导作用。展开更多
Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fin...Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fine rock partic- ulates from drilling could escape from the dust collection system and become airborne under some circumstances causing the roof bolter operators expose to quartz-rich respirable dust. A previous research shows that drilling can be controlled through properly selected penetration and rotational rates to reduce the specific energy of drilling. Less specific energy means less energy is wasted on generating noise, heat and over-breakage of rock. It implies that proper control of drilling has a great potential to generate significantly less fine rock dust during drilling. The drilling experiments have been conducted to study the effect of controlling drilling on reducing respirable dust. The preliminary results show that the size distributions of respirable dust were different when controlling drilling in different bite depths. This paper presents the findings from laboratory experimental studies.展开更多
文摘针对西北油田大尺寸卡瓦套管悬挂器井口坐挂载荷控制难度较大及卡瓦牙咬入深度与悬挂载荷之间的关系研究少的问题,根据 273 mm WE型卡瓦悬挂器的实际结构,建立了悬挂器坐挂套管的轴对称有限元模型,采用有限元分析与理论计算相结合的方法,对卡瓦牙咬入深度与悬挂载荷之间的关系进行研究。将有限元模拟结果与套管表面实际咬痕进行对比,证明该有限元模型的建立与分析具有一定的准确性。在一定的悬挂载荷作用下,不同卡瓦牙吃入套管的深度不一样,卡瓦牙从下端到上端,吃入深度逐渐减小;随着悬挂载荷增大,卡瓦牙咬入套管的最大深度逐渐加深,套管剩余抗挤强度减小,当套管剩余抗挤强度减小到一定值时,即可求出卡瓦牙在一定咬入深度下对应的最大悬挂载荷。研究结果对于套管坐挂的现场施工具有一定的指导作用。
文摘Dust generated from bolt hole drilling in roof bolting operation could have high quartz content. As a dust control measure, vacuum drilling is employed on most of the roof bolters in US underground mines. However, fine rock partic- ulates from drilling could escape from the dust collection system and become airborne under some circumstances causing the roof bolter operators expose to quartz-rich respirable dust. A previous research shows that drilling can be controlled through properly selected penetration and rotational rates to reduce the specific energy of drilling. Less specific energy means less energy is wasted on generating noise, heat and over-breakage of rock. It implies that proper control of drilling has a great potential to generate significantly less fine rock dust during drilling. The drilling experiments have been conducted to study the effect of controlling drilling on reducing respirable dust. The preliminary results show that the size distributions of respirable dust were different when controlling drilling in different bite depths. This paper presents the findings from laboratory experimental studies.
