俄罗斯科学院采矿研究所机械实验室,现已研制出一种风动环形冲击锤,冲击锤的轴线通道与双钻杆的内管路相通,形成了一条笔直光滑具有等截面的排泥浆通道。采用这种设计,钻井作业就能有效和连续地排除泥浆,同时,能有效和可靠地进行矿物勘探l的测试工作。然而在永冻的层理岩层中,钻具和泥浆回收管不久就会被堵塞,以致钻速 The Russian Academy of Sciences Institute of Mining Machinery Laboratory, has developed a pneumatic ring impact hammer, hammer axis channel and double drill pipe connected to the inner pipe to form a smooth straight with equal cross-section of the mud channel. With this design, drilling operations can effectively and continuously remove slurries and, at the same time, effectively and reliably conduct tests of mineral exploration. However, in permafrost stratigraphic formations, the tool and mud recovery pipe will soon be plugged so that the rate of penetration