Gas Control Technology And Application Of Mechanized Working Area With "U"-Type Ventilation System Of No.15Coal Seam Of Feng Huang Shan Coal Mine

Mine gas is a major risk factor in the process of the coal mine production. Gas accident is one of the most serious natural disasters in coal mine, especially along with the deepening of mining depth, expanding the scope of gob, gas disaster is increasingly prominent, so the gas control is the focus of mine disaster prevention and control.151304working area is the first mining area in the third horizontal plate area in the south flank of Feng huang shan coal mine,in order to minimize the excavation of the mine roadway, ensure the normal order of the mine production, the working area using "U"-type ventilation mode. Compulsory caving and the old top to pressure for the first time all gas overrun at the beginning of the recovery, affected the normal production of working area. Therefore, this article according to the reality of151304"U"-type mechanized mining of Feng huang shan coal mine. First of all to no.15coal seam gas adsorption constant, content, pressure, gas loss based on parameters such as velocity, attenuation coefficient of drilling are measured and discussed, mastered the no.15coal seam of the basic characteristics of gas emission of Feng huang shan; Then according to the basic situation of gas effusing during the primary mining area, analysis of the gas source and quantified emission of the source, and through to the overburden of coal seam mining fissure distribution and goaf gas migration law analysis, concluded that the coal seam roof fracture is a high concentration of gas enrichment area, to provide a theoretical basis for the gas control in gob areas. Early mining face appeared after the gas overrun, successively with increasing working face air, changed the ventilation system and other control measures, are unable to achieve the objective of controlling gas density exceeding limits. And then used the high level borehole gas drainage technology, the layout of a high level drilling field and fan-shaped arrangement of24drilling in the air return way in working face from open-off cut120meters, drilling located at the height of caving zone and fractured zone in the lower part of the top, this not only effectively trapped on the adjacent layer of gas into the mined-out area, but also effectively changed the flow field distribution in the goaf gas, the governance effect is obvious. When recovery from the open-off cut280meters, because the upper layer of No.9coal by the solid coal into goaf, significantly reduced the quantity of gas emission. At the same time, in view of high drilling construction is relatively complex and difficult, then use gas drainage holes along roof strike. In the air-return way of working area, at intervals of60meters to set a roof boreholes drilling field, constructed under the occupation of road, arranged8holes in the each drill fielded. The drainage amount is about103m3/min,the drainage gas density averaged4%and the drainage pure quantity is4.12m3/min.After the implementation of drainage, the upper corner’s and the air-return way’s gas density is below0.8%until the end of mining working area, achieved the good results and made the safety production of mine, it provides a reference for the gas control measures for the similar conditions mine.