| Converter steelmaking is an important process in iron and steel industry,which will produce a lot of dust.At present,the concentration of dust emitted from the tail of wet dedusting system is generally 30?50 mg/m3,which is difficult to achieve the goal of ultra clean emission of converter fine particles.In this paper,the ultra clean dust removal technology of phase change coagulation converter is proposed.The supersaturated water vapor environment is constructed by using the waste heat steam generated by the converter to promote the growth of fine particles in the converter.Combined with the membrane high-efficiency demisting technology,the ultra clean emission of flue gas particles from the actual industrial transfer furnace is realized.The experimental study includes the demisting characteristics,resistance characteristics and the effect of steam phase transformation on the growth and removal of Fe3O4fine particles under supersaturation condition;the variation of demisting efficiency with mesh porosity and droplet size is studied by ANSYS platform,and the influence of the number and angle of swirling device on the flow field velocity distribution and resistance loss of demisting tower is studied The impact of the.Under the guidance of similarity criterion theory,the main body of demisting tower was designed and built according to the proportion of 1:10.The experimental platform of integrated demisting and dedusting system was established.The resistance loss characteristics,demisting characteristics and steam phase change condensation dedusting experiments were carried out.The numerical model of demisting tower and demisting device was established.In order to verify that adding steam can promote the efficiency of dedusting The industrial test of fine particulate matter emission was carried out in the super clean emission reconstruction project of 50t/h#1 converter in a steel plant.The research includes three main aspects:pressure resistance loss characteristics;demisting efficiency;dust removal efficiency.The experimental results show that the influence factors of pressure drop and demisting efficiency include air velocity,mesh thickness,mesh porosity,mesh type and so on.Among them,the influence of air velocity on pressure drop and demisting efficiency is the most obvious.By using the control variable method to control the single factor change,it can be concluded that:with the increase of screen thickness,the system pressure drop increases,and the demisting efficiency improves;with the increase of mesh number,the system pressure drop increases,and the demisting efficiency improves;the position of screen and screen material have no obvious effect on the system pressure drop and demisting efficiency;for the air velocity,the pressure drop becomes a quadratic function curve with the air velocity The results show that with the increase of gas velocity,the flooding gas velocity is in the range of 3?3.5 m/s,and the demisting effect is the best under this gas velocity.The secondary entrainment is caused by the excessive gas velocity,and the demisting efficiency decreases;the resistance loss of the empty tower obtained by simulation is not different from the experimental results,s<10%.The influencing factors of dust removal efficiency include:steam addition,air velocity,flue gas inlet temperature and dust particle size.The test results of industrial experiment show that the addition of steam combined with membrane dehydrator can effectively reduce the emission concentration of fine particles.The addition of steam at 20mg/m3can effectively promote the growth and removal of fine particles,and achieve the goal of ultra clean emission with emission concentration less than 10mg/m3. |
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