Numerical Simulation Of The Diffusion Characteristics And Control Of Welding Fume In Dense Welding Operations

Dense welding operations has large number of welding stations,the welding workpieces large,Welding fume quantity large,welding fumes diameter small,the multi variability of welding station.so difficult and so welding fume capture,that make capturing welding fume difficult.Welding is an indispensable mechanical technology.Welding fume is the most common occupational hazard factor in welding operation.Welding fumes belongs to "high risk of dust," and they are mostly suspended in the air,so workers for a long time in this environment is likely to suffer from welders pneumoconiosis occupational categories.Therefore,it is necessary to study the diffusion regularity of welding fume and its influence factors,and it is very important to prevent and control the occurrence of occupational diseases.In this paper,numerical simulation studied on the diffusion and concentration distribution of electric welding fume according to the actual situation of welding fume and dust diffusion in a dense welding,using GAMBIT establish geometric model consistent with the actual,electing is unstructured meshing meshing methods,using fluid dynamics software FLUENT based on fluid dynamics establish conservation equations,selecting Realizable k-?model,using pressure-velocity coupling SIMPLEC.The numerical simulation results and experimental data are compared to prove the rationality of the selected model and boundary parameters.Simulation analysis of diffusion of welding fumes obtained the diffusion regularity of welding fumes in the absence of wind conditions and the influence for diffusion of welding fumes of different dust generation sources spacing,different natural ventilation velocity and various collection device location.Research indicates:In the absence of wind conditions,the diffusion of welding fumes in the horizontal direction is to spread evenly around,the scope and concentration diffusion in the vertical direction are larger than the diffusion in the horizontal direction.Concentration with height change trend larger when the height is less than 2m,especially with the increase of height the concentration decreased sharply when the height is less than 1m,the concentration change trend is smaller when the height is higher than 2m.The greater the spacing of the source of dust,the lower the concentration of welding fumes at the same cross-section.The increase of the distance of the dust source will cause theconcentration of the bottom of the workshop to be more than the concentration at the top of the workshop.Merry can reduce the concentration of electric dust in the workshop,near the inlet side of the dust concentration is lower,away from the inlet side of the dust concentration is higher.The the welding fume concentration decreased more in the Z=1m to Z=2.2m cross section with the wind speed changes,the more the concentration decreased the near the cross section of the dust source,the less the concentration decreased the naway the cross section of the dust source.The exhaust device is closer to the dust source,the time of welding dust removal device is short and the operation speed of the welding fume is higher.The ideal position of the exhaust device is about 30 cm from the side of dust source.This study provide some value reference for reasonable distribution welding operations points and merry organizations in the welding workshop.Also provide a reference for put forward reasonable measures to reduce the concentration of welding fumes.