温度对粉尘比电阻的影响_环境工程.rar

摘要:大气污染已成为全世界城市居民生活中一个无法逃避的现实。2009年，全国粉煤灰排放达到3.75亿吨。大气污染控制主要设备之一为电除尘器，除尘效率高、能耗低、能处理温度高烟气量大。而粉尘比电阻是表述粉尘导电性能的基本指标，是电除尘器设计及运行调整的重要参数。粉尘比电阻过大或过小都不利于电除尘器的稳定、正常运行，将对除尘效率产生影响，一般粉尘比电阻在104~5×1010（Ω•cm）范围内最适合电除尘。

本课题采用扫描电子显微镜-X射线能谱仪对粉尘试样的化学成分进行测定，并在DR2-1000型高温比电阻试验仪上对粉尘试样比电阻进行试验分析，重点探索了粉尘在高温下比电阻随化学成分、温度的变化规律。

研究结果表明：

（1）温度在100~900°C范围内，比电阻最大值为1012~1013Ω•cm，最小值为104~107Ω•cm。温度在450°C以上时，粉尘比电阻值随温度升高而下降。

（2）温度从峰值到900°C时，粉尘比电阻和温度满足关系式

（3）粉尘中SiO2含量高，出现比电阻峰值的温度低；铁，铝含量高，出现比电阻峰值的温度高。温度达到900°C时，SiO2含量越高，比电阻值越大。

关键字：粉尘比电阻，温度，化学成分

Abstract:Air pollution is one of the realities that all people around the world can't avoid. In 2009, the amount of coal ash let out is 375 million tons. One of the main equipments that control air pollution is electrical precipitator, which has high efficiency of dust collection, low power, ability to deal with large amount and high temperature dust. The dust resistivity is the basic quota indicates the dust electric conductivity, which is the key parameter to electric precipitator's design and adjustment . The dust resistivity oversized or too small does not favor the electric precipitator stably, and  influence the efficiency to remove dust, generally the dust resistivity, in the scope in 104~5×1010(Ω•cm) most suits the electricity dust removal. 

This study uses the scanning electronic microscope - X-ray spectrometer to test specimen chemical composition, and carries on the experiment on the DR2-1000 high temperature resistivity tester to analyze the dust, emphasis under the high temperature the resistivity changes along with the chemical composition and temperature.

Results:

1..Among 100-900°C, the resistivity maximum values 1012~1013Ω•cm, the minimum values 104~107Ω•cm. When the temperature is above 450°C, the resistivity has an inverse ratio to temperature.

2.Among peak value to 900°C, the dust resistivity and the temperature satisfy the relationship .

3.In the dust, if the SiO2 content is high, the temperature resistivity peak value presents to be low; if the iron, the aluminum content is high, the temperature resistivity peak value presents to be high. When the temperature achieves 900°C, the SiO2 content is higher, the resistivity value is bigger.  

Keyword: Dust resistivity, Chemical composition, Temperature