Simulation Study On Flow-field Of The Secondary Negative Pressure Dust Removal System Of Colliery For Parameter Optimization

Dust problems of the working face on fully mechanized caving have affected the safety of the coal mine production seriously. And the dust is harmful to the health of the employees. Therefore, understanding the diffusion rule of producing dust when cylinder cutting coal in the fully mechanized working face, to strengthen the study of spray dust mechanism, improve the efficiency of the purify dust system, reduce the dust concentration, improve the working environment, to provide security for the efficient production of fully mechanized working face has very important significance. The secondary negative pressure dust removal device is one kind of efficient dust removal device through spray high-speed atomization and use water spray piston principle what can form the negative pressure to entrainment and purify dust. In this paper, based on the fluid mechanics theory, the computational fluid dynamics software ANSYS FLUENT was used to simulate the secondary negative pressure dust removal device, it provides a theoretical reference to optimize the structure and working parameters matching.Through observing and analyzing the simulation results of flow field inside the jet tube, we can discover the effect rule of different nozzle injection angle, injection pressure and jet tube structure to the internal flow field of the secondary negative pressure dust removal device, namely when other condition is constant, along with the increase of nozzle angle, the pressure on the face of suction mouth become more and more higher, along with the constant raise of the injection pressure, the negative pressure on the throat area become more and more stronger, namely the relative vacuum also increases gradually; When the diffusion tube length is constant, the negative pressure of the center stronger than the edge of export transformed into the edge stronger than central area with the increase of diffusion angle. The diffusion tube angle become larger, the exit area also increased, the area of negative pressure also get bigger. The lower pressure of the edge is, the more benefit to adsorption and settlement of dust floating near the exit.Through the orthogonal experiment, observing and analyzing the simulation results of flow field outside the jet tube, we can discovered that when other conditions were certain, the change of nozzle diameter, throat length, injection pressure and angle of diffusion tube all have an impact on the flow field of external velocity the jet tube and gas-liquid ratio. Outside the jet tube, the influence of various factors on the distance of flow field of velocity reduce to zero from big to small in turn is the injection pressure, nozzle diameter, angle of diffusion tube and length of throat. The impact on the gas-liquid ratio from big to small in turn is the nozzle diameter, injection pressure, angle of diffusion tube and length of throat. The influence of length of throat on the flow field of external velocity and gas-liquid ratio is very small, so, in the actual installation process, we can properly shortened the length of throat to save installation space to make the device structure more compact according to the size of the installation space.