Study On Gas Extraction Joint Tube System And Method Of Concentration Control

Gas drainage in coal seam is one of the most effective ways in the treatment of damp and prevention of coal and gas outburst, which not only makes safe production needs, but also makes the urgent demands of saving energy and protecting environment. Joint pipe system is a key equipment to ensure the smooth progress of the gas drainage. The gas concentration level is prerequisite of whether the extracted gas is used. At present, the more problems of gas draining joint pipe system in China exist, was largely reflected in the slow joint pipe, cumbersome equipment, high cost, poor corrosion resistance, no reuse, no standard pipe fittings and other associated defects. In the control of gas concentration, there is no specific theoretical guidance and it depends on empirical adjustment, which makes control of gas concentration in poor performance, has a large number of off-hole phenomenon, resulting in enormous waste of resources and leaving a huge risks for coal mine safety production. So, Henan Polytechnic University, on the basis of extensive research, developed a novel type of gas extraction associated pipe control systems,and has done a detailed theoretical analysis aiming at the gas concentration control .In this paper, it makes basic research, and describes the development process of some equipment, including the valve of concentration control , vertical and horizontal joint pipe fittings, as well as a novel orifice flowmeter. At the same time,it conducts laboratory experiments and detection of anti-static flame retardant. Later it is applied to the underground mine for doing industrial installation tests and proves the superiority of the new joint pipe system. Following, the experiment on industrial test of gas concentrating control is got. The result is that low vacuum extraction is not the right method of improving gas drilling concentration of lowconcentration by analyzing the collected datas, as well as drilling with a longer extraction time degreely increases gas flowing and raises gas concentration. On this basis, a novel concentration control method is presented, and the concentration control curve according to the drilling of roadway for the test is drew, can easily be adjusted by the workers. Industrial tests show that the novel joint control system and the gas concentration control method has good application effect.