Experimental Study On The Mechanism Of Air-water Two-phase Atomization For Dust Removal In Confined Space

As one of the world's three major energy sources and China's main energy sources,coal plays an important supporting role for the development of the national economy.As the most important part of coal resources before they are put into use,the washing process of coal is complex,and it will produce a large amount of dust,which will bring adverse effects on employees' health,economic benefits and the environment.There are many dust source points and various dust removal methods in coal preparation plant.The dust removal method combining airtight device and wet dust removal has become an important technical choice in dust removal technology.In airtight device combined with wet dedusting of dust removal method as the research object,through their own research and development design confined Spaces inside air water two phase spray atomization characteristics measuring system and gas water two-phase spray dust control experimental system,using the combination of theoretical and experimental research method,research confined Spaces within the air water two phase jet atomization characteristics and the factors influencing the efficiency of dust.The theoretical basis is provided for the design and development of the sealing device for wet dust removal in coal preparation plant.Firstly,the atomization characteristics of the gas-water two-phase nozzle are studied by using the atomization characteristic measurement system.The pressure sources of the gas-water two-phase nozzle are water supply pressure and gas supply pressure,so the influence of water supply pressure and gas supply pressure on atomization characteristics of the nozzle should be considered respectively.When the gas supply pressure is constant,with the gradual increase of the water supply pressure,the change trend of the atomization Angle of the gas-water two-phase nozzle is firstly increased and then decreased,and the change trend of the particle size of the fog drops is also firstly increased and then decreased.When the water supply pressure is constant,with the gradual increase of the air supply pressure,the change trend of the atomization Angle is firstly increased and then decreased,and the particle size of the fog drops is gradually decreased.It can be seen from the analysis that when the supply pressure is constant and the water supply pressure is small,the atomization of the spray mainly depends on the primary atomization,while when the water supply pressure is large,the atomization of the spray depends on the secondary atomization.The particle size of fog drops at different positions in the space was measured.On the center axis of the nozzle,the particle size of fog drops gradually increased with the distance from the nozzle.Secondly,a self-designed experimental system for dust removal by gas-water two-phase spray in a confined space is used to study the related factors that affect the efficiency of dust removal by gas-water two-phase spray in a confined space.First,the influence of water pressure ratio on dust removal efficiency was experimentally studied.When one of water supply pressure and air supply pressure changed and the other remained constant,the changing trend of dust removal efficiency increased first and then decreased with the gradual increase of variables.At the same time,for the gas-water two-phase nozzle,there is an optimal ratio of water pressure.When the water supply pressure is 0.4 MPa and the air supply pressure is 0.5 MPa,the water pressure of No.First of all,nozzle is the best.At this time,the dust removal efficiency is the highest,the dust removal efficiency of total dust is 92.57%,and that of respirable dust is 84.34%.Then,it is to study the spray time has a greater effect on the efficiency of dust,and set the spray time about 5 s and 10 s two kinds of working conditions,the results show that appropriate increase the spray time can improve the efficiency of dust in the dust,but when the gas pressure is higher,increase the length of the dust efficiency is not obvious,but also can cause the waste of resources.The third is the influence of the closed volume on the dust removal efficiency.The study shows that the dust removal efficiency increases first and then decreases with the increase of the volume.When the dust removal method combining the closed device and spray dust removal is adopted,the appropriate volume should be selected to improve the dust removal efficiency and avoid resource waste.