Experimental Study On Air Jet Characteristics Of Flat Diverticulum Stope

With the increasing development of the times and people's living standards,the safety production is more and more valued by people,The government made great efforts to improve the overall safety level,to curb the production safety accidents,made positive progress in the prevention of occupation disease harm and other targets.Underground mining of mineral resources is also facing the situation,the new challenges.With the increasing demand for resources,mining technology,mining chamber space scale is greatly increased,air chamber stope structure changes,resulting in difficult ventilation;improvement of modern blasting technology,the increase of the quantity of dust after blasting;the use of large machinery operating equipment,made the toxic and harmful gases by mechanical equipment emissions increased.Therefore,occupational disease prevention and treatment of workers is facing great challenges.As one of the most important underground mine ventilation and dust removal methods,air jet has a very high frequency of use in the underground mine because of its simple ventilation and good ventilation effect.However,the size and structure of the flat chamber are special,especially the width of the chamber is too wide,which makes it become a major difficulty in ventilation.In this paper,I take a non coal mine underground flat chamber in Yunnan as a prototype,based on the theoretical study and experimental phase.According to the aerodynamics,ventilation theory,similarity criterion,security theory,statistics theory,using the ratio of 1:20 to construct three dimensional flat chamber experimental model,determine the feasibility the measuring instrument,measuring method,study the reliability of the model and investigate the reliability of the model and the feasibility of the experimental scheme by means of the pre experiment.The experiment mainly carries on the research of two kinds of subjects:"variable wind speed" and "variable size".The conclusion of the study includes:? The distribution law of the flow field of the flat chamber model with different wind speeds and different sizes,including the law of the movement of the air flow,and the velocity profile in the chamber model;? The time averaged characteristics of the air jet in a flat chamber,including the velocity distribution of the cross section of the jet,the envelope of the jet,the variation of the flow velocity along the axis of the jet,the maximum jet width and position,etc.;? The turbulent characteristics of the air flow in the flat chamber,such as the fluctuating velocity,the turbulent intensity distribution of the jet section,the turbulent intensity along the axis of the jet,and the skewness of the velocity distribution.Through the experimental study,it provides data reference and theoretical support for the ventilation of the flat chamber,which is of great significance for the prevention and control of occupational hazards in the flat chamber.