Study On Theory Of Dust Control Based On Gas-Solid Two-Phase Flow And Its Application In Coal Preparation Plant

With the rapid development of society, dust pollution has been attracting much attention from people. Today, dust control theory is becoming a research hotspot, in which dust particles movement law and dust control mechanism have already become an emphasis and difficulty.Firstly, through gas-solid two-phase flow theory combining with the properties of dust particles, two-fluid model is constructed with3D that can simulate dust concentration diffusion. Besides that, particle-trajectory model is constructed with3D by DEM method that can simulate movement trajectory of dust particles.And then, dust control mechanisms of negative pressure and micro fog are studied by numerical simulation, theoretical analysis and application in coal preparation plant. Movement trajectories of various graded dust particles after airflow change and droplets capturing are simulated respectively. Dust control efficiencies about the two methods are verified by numerical simulations and field measurement.Based on movement law of dust particles in material-receiving point of belt, dust control closed-loop method is proposed innovatively. and it is discussed by numerical simulation of3D through gas-solid two-phase flow theory and particle collision theory. The results show that movement trajectory of dust particles is controlled effectively and kinetic energy of particles is reduced obviously by the closed-loop dust control. Therefore, the method of closed-loop dust control has a broad prospect for practical application.Dust control methods of "resistance outside and suppression inside" and "absorption inside and suppression outside" are tested respectively through put two theories into practice in crushing station and coal drop tower. By theoretical analysis, numerical simulation and field measurement, effectiveness of theirs dust control methods are tested and verified.The results show that theoretical analysis,3D numerical simulation and practical application of the dust control mechanism have significantly increase dust removal efficiency.