Results 11 to 20 of about 265 (205)

Drilling experiment research on bedding directional drilling of soft—fragmentized coal seam of Qinglong Coal Mine

Gong-kuang zidonghua, 2018
For problems of shallow gas drainage hole depth, low control precision of drilling trajectory and poor gas drainage effect in soft—fragmentized coal seam of Qinglong Coal Mine, based on the analysis of mine gas geological conditions and existing pre ...
LI Quanxin, FANG Jun, CHU Zhiwei, LIU Fei   +3 more
doaj   +2 more sources

Research on gas drainage technology and equipment of high-level directional drilling in coal mine [PDF]

E3S Web of Conferences
The gas overrun at the upper corners of the goaf and return air lanes has been restricting the development of China's coal mining industry. To solve the problem of over-limit gas concentration at the upper corners, the fundamental reason is to reduce the
Song Yubo
doaj   +2 more sources

Application of top-board high-positioned directional drilling gas control technology in Wuda mining area [PDF]

Meitan kexue jishu
With the increase of mining depth and mining intensity, the problem of gas emission has become increasingly prominent, which has become a key factor restricting the safe and efficient production of coal mines.
Yong ZHOU, Tengfei XU
doaj   +2 more sources

Development and application of power head for CBM vehicle mounted drilling rig [PDF]

E3S Web of Conferences
In order to meet the construction needs of surface coalbed methane extraction holes, cable holes, and mine surface rescue holes, a multifunctional power head suitable for coalbed methane vehicle mounted drilling rigs has been developed.
Liu Qi
doaj   +2 more sources

Enhancing down-the-hole air hammer capacity in directional drilling

IOP Conference Series: Earth and Environmental Science, 2017
The authors discuss the issue connected with drilling trajectory deviation and present the technique of rotary–percussion drilling with a down-the-hole air hammer. The article describes pilot testing of the air hammer drill PNB76 in Berezovskaya Mine. The ways of improving the air hammer drill are identified, and the basic diagram and R&D test data are
V I Klishin, V V Timonin, D I Kokoulin, S E Alekseev, B Kubanychbek   +4 more
openaire   +2 more sources

Study on determination of development height of mining-induced fissure zone in deep outburst coal seam

Gong-kuang zidonghua, 2022
The use of high-level directional long borehole gas extraction technology instead of high-level extraction roadway to extract mining pressure relief gas can greatly reduce the amount of rock roadway excavation.
GUO Minggong, TAO Yunqi, ZHANG Jianzhao
doaj   +2 more sources

Research on dry-type dust removing device of borehole based on pressure air dust control and ring slot ejecting technology

Meikuang Anquan, 2021
In view of the difficulties in dust control and dust removal in the gas drainage borehole of soft broken coal seam in coal mine, a new technology of dust control by air pressure at orifice and dry dust removal by annular seam injection is proposed.
GONG Xiaobing
doaj   +2 more sources

Pressure–Relief Gas Cooperative Drainage Technology in a Short-Distance Coal Seam Group

Applied Sciences, 2023
The gas in a coal seam is a clean energy source, but it is also the main cause of gas accidents during the mining of mineral resources. There is a large pressure–relief gas influx in the upper and lower adjacent layers of 1211 working face in the Wanfeng
Lianqin Ni, Anying Yuan, Zuxiang Hu
doaj   +2 more sources

Study on gas extraction from parabolic high level drilling during the initial mining period of fully mechanized caving face

Gong-kuang zidonghua, 2021
The gas extraction effect during the initial pressure on the working face by using conventional high-level directional long drilling is poor. In order to solve the above problem, taking the project background of 12309 fully mechanized caving face of ...
LIU Qingbao1, CHEN Long2, GONG Xuanping2, YU Rui3, CHENG Xiaoyu2, DING Jianxun2   +5 more
doaj   +1 more source

Forward multi-stage large-diameter reaming technology for directional high-level borehole in roof

Gong-kuang zidonghua, 2020
Directional high-level borehole in roof is an important means to control mining pressure-release gas in coal mine underground. Due to limitation of drilling device, the borehole diameter is small in once-through drilling, and borehole group arrangement ...
JIA Mingqu
doaj   +1 more source