论文部分内容阅读
1 问题的提出目前,我国煤矿开采多以井下开采为主,煤层埋藏较深(一般为200～1000m),并夹带有大量高浓度瓦斯气体,煤矿开采之前必须先进行瓦斯抽放以避免瓦斯突出或爆炸。我国目前抽放瓦斯所使用的钻杆主要有圆形钻杆、螺旋形钻杆等,其使用效果如下。(1)圆形钻杆制造工艺简单,使用较方便。但由于在钻进过程中靠钻杆粉碎和拔动钻渣,因将渣排出孔外的能力有限,即便是送风送水也不能将钻渣有效
1 PROBLEM PROBLEM Presently, most coal mines in our country are dominated by underground mining. The coal seams are buried deep (usually 200-1000m) and a large amount of high-concentration gas is entrained. Before coal mining, gas drainage must be conducted to avoid gas outburst Or explode. At present, the drill pipes used for gas drainage in our country mainly include round drill pipes, spiral drill pipes and the like, and the use effects thereof are as follows. (1) round drill pipe manufacturing process is simple, more convenient to use. However, due to the process of drilling by drilling rod smashing and pulling drilling slag, due to the ability of slag out of the hole is limited, even if the wind and water can not be effective drilling