Abstract:
To effectively address the severe dust pollution issue in fully-mechanized excavation faces of coal mines, this study takes a fully-mechanized excavation face at Hulusu Coal Mine as the research background, conducts a coupled solution of the airflow field-dust field of the fully-mechanized excavation face under the action of a long-pressure short-exhaust air extraction dust removal system, and finally determines the steady-state distribution characteristics of key parameters such as dust trajectory, dust particle size, and dust concentration in the fully-mechanized excavation face, while exploring the influence laws of relevant factors on air extraction dust removal effectiveness. The research results show that: after dust is generated from the dust source, the vast majority enters the dust removal fan through the dust hood for purification, while the remaining part diffuses toward the rear of the roadway under the action of return air in the overlapping section. During this process, the dust mass median diameter continuously decreases, and the dust mass flow rate also gradually reduces; the dust concentration in the dust removal action zone first rapidly rises to a maximum value, then quickly decreases to a smaller value, and finally gradually and slowly reduces in the natural sedimentation zone; the order of dust concentration in the dust removal action zone is central > sidewalk > machine way, while in the natural sedimentation zone it is sidewalk > central > machine way; dust source type, dust source location, cutting speed, dust removal air volume, exhaust air ratio, and dust removal measures are the main factors affecting dust removal effectiveness. The air extraction dust removal effectiveness is better when the dust source type is the first conveyor belt, the dust source location is upper left, the cutting speed is 27 r/min, the dust removal air volume is 360 m
3/min, the exhaust air ratio is 3∶1, and the dust removal measure is wall-attached air duct dust removal.