| Sintering process is the biggest source of dust emission in iron and steel industry,accounting for 41%to its total dust emission.Performance requirements for the dust collector are also getting higher and higher because the particulate emission standards become more stringent.The dedusting system with stability reliability at sintering machine head part was studied and designed based on the 600 m2 sintering machine head dedusting modification project for one ironworks of Baosteel Corporation.Sintering process,dust characteristics and three main dust collectors were described and analized.The result showed that ESP has obvious economic advantages under the same dedusting performance compared to bag filter and electrostatic-fabric integrated precipitator,both of which will lead to pasting bag.So ESP was chosen as the dust control equipment for the sintering machine head part.From the aspect of stability and reliability of the electrostatic precipitator,a highly-combined type test,vibration acceleration test,and numerical simulation test of the airflow distribution of the electrostatic precipitator of the sintering head were carried out.According to experimental results and analyses,RSB1 and 480C were used for the first and second electric field while RS-1 and 480C for the third and forth electric field.The weight of the collecting electrode rapping hammer was 5.7 kg and its diameter was about 90 mm while the weight of the discharge electrode rapping hammer was 8.0 kg and its diameter was about 120 mm.The appropriate flue deflector and inlet hood orifice plate structure were used to ensure that the relative error between the practical and ideal gas flow of each inlet hood was less than 5%and the relative root mean square error??r?of gas distribution at the inlet section of the electric field was less than 0.25.According to the accumulated engineering design experience,based on the experimental research results,the electrostatic precipitator design study was focused on stability and reliability.The electric field gas velocity was decided 0.9 m/s1.0 m/s under which the effective cross-sectional area of each ESP was 500 m2556 m2 with 2ESPs.The compole distance was decided 450 mm while the specific collection area was decided 75 m2/(m3·s-1)80 m2/(m3·s-1)so the calculated particle migration velocity was5.25 cm/s5.60 cm/s.The electric field number was decided 4.The effective length,width and height of each ESP were 16 m,36 m and 15 m,respectively.Accordingly,the effective cross-sectional area,the gas velocity and the specific collection area were calculated 2×540 m2,0.93 m/s and 76.8 m2/(m3·s-1),respectively.The high frequency power supply was adopted whose current capacity was 1.8 A and voltage rating was 85kV.The outlet particle concentration,pressure drop and air leak percentage of ESP are required less than or equal to 50 mg/m3,250 Pa and 3%,respectively.6 field tests were carried out on the project during which the average outlet particle concentration,pressure drop and air leak percentage of#1 ESP were 42.2 mg/m3,240 Pa and 2.2%,respectively.The average outlet particle concentration,pressure drop and air leak percentage of#2 ESP were 41.3 mg/m3,242 Pa and 2.3%,respectively.The outlet particle concentration,pressure drop and air leak percentage of ESPs could all met design requirements.In addition,from the point of view of equipment operation in recent years,the equipment has been in a good state of operation and has been overhauled from no downtime.Compared with before,the inspection and maintenance load has also dropped significantly,indicating that the equipment stability and reliability have reached the expected level. |
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