摘要
过滤除尘器采用的脉冲喷吹式清灰造成清灰影响阶段粉尘排放浓度的大幅升高,制约除尘器的过滤捕捉性能。为了探索脉冲喷吹工况对清灰影响阶段粉尘排放的影响规律,为工业除尘器清灰设计提供技术参考,构建了脉喷清灰滤筒除尘器试验系统,测试滤筒内壁的压力分布,考察TSP（总粉尘）、PM_（10）、PM_（2.5）分级排放质量浓度变化,并研究了气包压力、过滤风速、最大允许过滤阻力对粉尘排放的影响。结果表明,在脉喷清灰影响阶段,TSP、PM_（10）、PM_（2.5）具有类似的变化趋势,排放质量浓度均先快速升高而后缓慢降低,持续时长30~60 s;排放量总体上随气包压力、最大允许过滤阻力增加而升高,其中气包压力达到临界值0.4 MPa时,排放质量浓度峰值和排放量增加显著;而粉尘排放随过滤风速增加先增后减。研究表明,通过调整脉喷工况可降低清灰影响阶段粉尘排放。
dust emission characteristic features under the impact of the pulse-jet operation condition under the theoretical and technological support for the dust cleaning design of such collectors. For the said purpose, we have built up a pulse-jet cleaning cartridge filter testing system so as to examine and identify the pressure distribution on the top-surface, the middle and the bottom of the filter cartridge interior wall in the process of the pulse-jet formation by using a high frequency dyfiamic pressure sensor. At the same time, we have also made an exploration of the various features of the TSP （the total suspended particulates）, PM10 and PM2.5 fractional emission with a muhi-channeling laser dust concentration on-line detector so as to make an investigation of the effects of the pulse pressure, the filtration velocity and the maximally allowable pressure drop on the TSP, PM10 and PM2.5 emission. The results we have gained prove that the static pressure distribution rate at the inner surface of the filter cartridge tends to increase withthe increase of the tank pressure in the stage of impact. The maximum static pressure distributing on the cartridge bottom, the minimum pressure scattering on the top, as well as the average pressure should be equal to 1. 066 kPa according to the tank pressure. However, in the stable operation stage, the average emission concentrations of TSP, Phi10 and PM2.5 should be equal to 0. 923 mg/m3, 0. 856 mg/m3 and 0. 683 mg/m3, correspondingly, whereas the content rate of PM2.5 has to be the dominant part accounting for 74% of the TSP. On the other hand, the variation tendencies of TSP, PM10 and PM2.5 of the dust emission prove to be similar during the pulse-jet cleaning affected stage, that is, tend to first increase fast and then come to decrease slowly in a brief duration of about 30 s to 60 s. Besides, the dust emission rate has also been found increasing with the increase of the pulse pressure whereas the maximum allowable pressure drop of the total dust emission peak concentration rate turns to increase evidently on the condition when the pulse pressure comes to 0.4 MPa. Furthermore, the dust emission also tends to increase first and then decrease with the increase of the filtration velocity of the maximum dust emission Concentration at the filtratiorl speed of 0. 63 m/min. Thus, it can be seen that our research indicates that the dust emission rate during the cleaning affected stage can be restrained or confined by regulating the pulse-jet operation condition.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2018年第1期315-319,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(51704166)
中国博士后科学基金项目
江西省博士后研究人员科研项目(2017KY13)
关键词
环境工程学
脉冲喷吹
清灰影响阶段
粉尘排放
分级除尘效率
environmental engineering
pulse-jet
cleaning affected stage
dust emission
dedusting classificationefficiency
