Study The Air Volume Ratio And Air Monitoring Technology For The Fully Mechanized Workface Long Press Short Smoke Ventilation Dust

Fully mechanized workface is an important dust producing point in coal mine.If no measure is adopted to remove dust,dust concentration will be tens or hundreds of times over the maximum allowable concentration which is stipulated in coal mine safety regulation.Practice and research shows that long press short smoke ventilation dust removal is the most effective dust control measure,but the efficiency of this measure largely depends on suction pressure air volume ratio.The dust control efficiency rises up with the increase of suction pressure air volume ratio,Because of the existence of gas,suction pressure air volume ratio cannot be too high.So that the research of the best suction pressure air volume ratio and how to maintain the best suction pressure air volume ratio are the technological means of adopting long press short smoke ventilation dust removal to achieve the best dust control efficiency.According to the reality of fully mechanized workface in coal mining,theoretical analysis and experiments are combined to study the air volume ratio and air monitoring technology of the fully mechanized workface.Main research results are as follows:(1)Measuring device is developed and can be used to measure the cross section pressure wind air volume in excavation roadway,based on the principle of Bernoulli equation and speed measuring tube.Measurement error of this device is less than 5%,and it can be used to monitor the press-in air volume automatically and in real time.(2)Precise measuring method used to measure the pull-out air volume in excavation roadway is studied according to fan performance curve and power curve.Measurement error of pull-out air volume is less than 5%,and it can be used to monitor the pull-out air volume automatically and in real time.Using the power and the frequency of fan to calculate air volume makes it no need to measure the straight pipe.If the fan is controlled by frequency converter,no more equipment or sensors are needed,and the volume of the device is small.(3)Monitoring device used to monitor suction pressure air volume ratio is developed,and it lays foundation for the safety operation of long press short smoke ventilation dust removal system and to reach the best dust control efficiency.(4)Based on computational fluid dynamics and experimental methods,the long-short pumping pressure ventilation and dust removal system flow field,the movement of dust,the value range of the roadway pumping pressure ratio and pressed into the influence of air flow efficiency for dust control is given in the roadway.For this article studied the roadway,pumping pressure ratio in the range of 0.8-1.0 values,the position of the driver and the efficiency of roadheader dust control positions are 5 m will be more than 96%;pumping pressure ratio is constant,the pressure into the air volume is increased to improve the efficiency of dust control excavation face..