Research On The Characteristics Of Fume Dust From Converter Dry Dedusting Technology

The dust characteristic is an important parameter affecting the dedusting efficiency of the electrostatic precipitator, including the dust composition, particle size distribution, resistivity and pore structure. The effect of dust resistivity affected with the fume temperature, particle size distribution, chemical composition and water content is the most remarkable so only reasonably control all the parameters can guarantee the dust resistivity suitable for the electrostatic precipitator, and ensure the high dust removed efficiency of the electrostatic precipitator.Experiments were carried out to study the mineral composition, particle size distribution, pore structure and the dust resistivity of converter dust in five different positions which were the entrance of the evaporative cooler, crude ash bucket, the entrance of the electrostatic precipitator, fine ash bucket and the exit of the electrostatic precipitator in the converter dry dedusting system. The results show that Ca O and Fe2O3 have different influences on the dust resistivity. The dust resistivity goes up with the Ca O content increase while it goes down with the Fe2O3 content decrease, and the influence of Ca O is stronger than Fe2O3’s.The dust particle with the diameter exceed 100 um is removed in the evaporative cooler while dust particle between 20 um and 100 um is removed in the electrostatic precipitator, and the dust particle under 10 um is hard to collected by the electrostatic precipitator. The dust resistivity decreases after going up while its temperature rise from 20℃ to 220℃,and there is a peak value near 150℃. The resistivity of dust from the entrance of the electrostatic precipitator, fine ash bucket and the exit of the electrostatic precipitator has the rules as follow, before the peak value, the larger the dust diameter the higher the dust resistivity, after the peak value the condition contrary, and the original samples’ resistivity is the least. The smaller of the dust size, the bigger of the specific surface area and total pore volume, so the capacity of adsorbing air and water stronger, as results the surface specific resistance of the dust is lower. The bigger of the specific surface area, the smaller of the bulk density, so the volume conductive ability is weaker as the porosity increasing, leading the volume resistance of the dust higher.Experimental study on the fume dust characteristic was carried out, offer ing the theoretical data for ensuring the dedusting efficiency, and providing the theory reference and data basis for the application and technology optimization of converter producing, evaporative cooler conditioning and electrostatic precipitator dedusting process.