转炉干法除尘系统粉尘特性实验研究

现场采集了65 t转炉烟气干法除尘系统蒸发冷却器入口、粗灰斗、蒸发冷却器出口(静电除尘器入口)、细灰斗及静电除尘器出口5个不同位置的粉尘,对粉尘的矿物组成、粒度分布及比电阻等特性进行了系统分析。结果表明:转炉粉尘主要成分为金属氧化物,其中含量最高的为Ca O和Fe2O3,各不同部位的粉尘各成分含量有所差别;蒸发冷却器中粗除尘过程除去的粉尘粒径最大,静电除尘器出口粉尘粒径最小,表明粒径小于10μm的细微粉尘不易被静电除尘器收集;温度是影响粉尘比电阻的主要因素之一,在所研究的温度范围内,随着温度升高比电阻先增大后减小,150℃左右比电阻值最大;低温区时,粉尘粒径越大,比电阻也越大,当温度超过140℃后,粉尘粒径越小,比电阻越大,静电除尘粉尘最佳的温度是150~200℃。

Experimental Research on Characteristics of the Dust from Converter Dry Dedusting System

The dust collected from five different sections which were the entrance of the evaporative cooler, crude ash bucket, the exist of the evaporative cooler (the entrance of the electrostatic precipitator), fine ash bucket and the exist of the electrostatic precipitator in the converter dry dedusting system was analyzed in order to study mineral composition, particle size distribution and resistivity of the dust. The results show that the composition of the converter dust was complex and slightly different, but the main component was all metallic oxide such as CaO and Fe2O3. The diameter of the dust which was removed in the evaporative cooler is the largest while the diameter of the dust removed by the electrostatic precipitator is the least and the dust with the diameter less than 10 μm was hard to collect by the electrostatic precipitator. Temperature was one of the main factors influencing the dust resistivity and as the temperature increases the resistivity of the dust increases at first and then decreases, and the largest resistivity appeared around 150 ℃. In the low-temperature region, the larger the particles size the higher the dust resistivity. When the temperature exceeded 140 ℃, the smaller the particles size the higher the specific resistivity. The best temperature scope for the electrostatic precipitator to dedust is 150~200℃.