Research On The Theory And Application Of Dust-settling Technology By Spray In Fully Mechanized Face

Due to the progress of science and technology, mechanized mining equipment hasbeen widely used in coal mine. But the problem followed it is that dust concentration inthe fully mechanized face is so high that seriously threats the coal mine safety productionand the staff’s physical and mental health. With the gradual attention of occupationalhazard prevention payed by the government, how to control the dust in the fullymechanized face and make the dust concentration lower than the relevant standards, isstill one of the mine safety production problems.By using the method combined theoretical analysis, experimental test, numericalexperiment and engineering application, the theory and application of dust-settling byspray in fully mechanized coal face has been systematically studied, and the knowledgestructure system of this thesis has been formed. During the process finishing this paper,field investigation has been made, and layout in the fully mechanized face as well as theconcentration distribution law of cutting dust has been understood. Qualitative andquantitative analysis of the collected data has been carried out. By using the numericalsimulation method, the distribution law of air-flow field the distribution and migrationlaw of the dust in the fully mechanized face have been analyzed.Through the observation analysis of7141fully mechanized face in Longdong coalmine, combined with dust movement theory, using7141fully mechanized face as thephysical model, based on the physical model of air flow-dust discrete phase and boundarycondition, numerical simulation of dust movement in the air-flow field has been made.By comparison and summary, the law of air flow and dust concentration distribution hasbeen concluded.Because of the high dust concentration in the fully mechanized face andthe easily damaged spray carried by shear, the effect of dust-settling by spray is not ideal.On the basis of former researches, according to the actual characteristics of fullymechanized face, dust control technology has been designed. Aiming at the main dustsource around the shear and the dust diffusion range, a optimized high-speed water jetdust control device has been designed. This device uses air assisted spray nozzle toprovide extremely high velocity water jet mist in low water pressure, forming a waterwall· around the dust source in order to prevent the dust diffusion. At the same time,because of the existence of the negative pressure field, dust can be further controlled andvacuumed, wet and settled in time.