掘进机外喷雾负压二次降尘装置的研制与应用

为了有效喷雾沉降综掘工作面掘进机截割产尘,数值模拟确定了喷雾负压二次吸风装置吸风及内部风流场的运移规律,研制了可形成完全覆盖截割产尘的水雾幕及对截割臂周围粉尘有效吸入净化的新型掘进机外喷雾负压二次降尘装置,并对其性能进行了测定实验,结果表明:喷雾压力由2 MPa增大至8 MPa过程中,选用喷嘴在4 MPa压力时,喷雾场雾化角及距喷口1.5 m处雾滴群的索特平均直径D32分别为87.6°及56.295μm,综合雾化性能最优,新型装置的气液比先增大后减小,4 MPa时达到最大值1.269,因此,选定4 MPa为最佳喷雾压力;新型装置的现场试验结果表明:相对于原有方式,对全尘和呼尘的平均降尘率分别提高了19.4%和20.1%,其中,负压二次降尘分别提高了6.0%和6.5%。

Research and application on external spray secondary dust falling device with negative pressure of roadheader

In order to effectively produce spray and settle the roadheader cutting dust，the law of suction and internal wind flow field migration of the external spray secondary suction device with negative pressure was investigated through the method of numerical simulation.Furthermore，a new type of external spray secondary dust suppression device with negative pressure was successfully developed which can produce a water spray curtain that completely covers the cutting dust，which can also effectively absorb and purify the dust around the cutting arm.Performance measurement experiment of the device was conducted，and the results show that when the nozzle pressure is 4 MPa，the atomization performance is optimal during the process of the pressure change from 2 MPa to 8 MPa and the atomization angle and Sauter average diameter of the droplet group at 1.5 m away from nozzle is 87.6° and 56.295 μm respectively.Gas liquid ratio initially increased，then decreased and reached a maximum value 1.269 when the pressure was 4 MPa.Therefore 4 MPa was selected as the best spray pressure.The new device’s field test results show that the dust suppression rate to total coal dust and respirable dust increased by 19.4 and 20.1 percentage points respectively compared with the previous method.Among them，the negative pressure secondary dust suppression increased by 6.0 and 6.5 percentage points respectively.