DTH Hammer 114
Also known as pneumatic impactor, pneumatic DTH hammer. The power tool at the bottom of the hole, which takes compressed air as the power medium and uses the energy of compressed air to produce continuous impact load, is designed. Compressed air can also be used as pore washing medium. Pneumatic impactor can be divided into high air pressure and low air pressure, valve type and valveless type. Usually, the pneumatic impactor is directly connected with the cemented carbide cylindrical bit to break the rock in the way of impact, and the low-speed rotary drilling is carried out without coring. It is mainly used in hydrological well drilling, coreless geological drilling, geological disaster prevention and control engineering, mine drilling and other fields. It is suitable for application in gravel and hard rock. The bit with special structure can also be used in soft soil. Generally speaking, ROP of mechanical drilling is much higher than that of hydraulic percussion drilling, but it needs to be equipped with air compressor with large capacity, which has large fuel consumption, noise and dust pollution. The drilling depth is greatly affected by groundwater level and quantity.
Also known as hydraulic impact rotary drilling tools, hydraulic DTH hammer. The drilling flushing fluid is used as the power medium, and the energy of high-pressure fluid flow and dynamic water hammer is used to generate continuous impact load. Usually, it is directly connected to the upper part of the coring tool to transmit the continuous impact load to the coring bit while rotary drilling, so that the bit can break the rock by rotary cutting and impact. It is used in geological core drilling, especially in hard, broken rock and medium hardness coarse-grained heterogeneous rock. Hydraulic percussive rotary drilling technology can improve ROP, extend footage and slow down borehole bending. This is an invention in China, and foreign countries are also developing large-scale ones for oil wells and geological drilling.