高温袋式除尘器金属滤袋脉冲喷吹清灰性能分析

Performance analysis of high-temperature metal filter bag by pulse injection

为解决高温袋式除尘器在应用中因压缩空气温度偏低导致金属滤袋糊袋,以及因清灰参数选取不当导致滤袋残余阻力上升和除尘器运行阻力升高的问题,使用滤料微观模型分析过滤状态下颗粒在清洁金属和有机纤维层的穿透过程;并结合物理模型与数值模拟正交实验研究不同因素对不锈钢金属滤袋脉冲喷吹清灰过程的影响;以传统有机滤袋做对照,通过数值模拟实验研究在高温状况下脉冲喷吹清灰气流对金属滤袋袋口区域结露的影响。结果表明,在相同的颗粒粒径条件下,清洁金属滤料纤维的颗粒穿透量和穿透距离更大,拦截效应低于有机纤维滤料。滤袋清灰效果整体呈现上部>底部>中部的趋势,且金属滤袋清灰评价指标测试值整体低于传统有机滤袋;显著影响滤袋清灰的因素均为喷吹压力和喷吹孔径,金属滤袋最佳喷吹距离为200 mm,喷吹时间为100 ms。当脉冲喷吹气流温度为0℃时,滤袋袋口0.5~2 m处有结露风险,升高至50℃可有效防止工业窑炉烟气滤袋袋口区域结露现象的产生。该研究结果可为高温袋式除尘器金属滤袋的喷吹参数设计和结构优化提供参考。

During the application of high-temperature bag filter,there may be bag sticking phenomenon of metal filter bag due to the low temperature of compressed air.In order to solve the problem of residual resistance of filter bag increasing and the operating resistance of bag filter rising due to the improper selection of cleaning parameters,the penetration process of particles in the clean metal and organic fiber layers under filtration status was analyzed through the micro-model of filter material.On this basis,316L stainless steel metal filter bag was selected,and the impact law of different factors on the pulse jet cleaning process of filter bag was studied by orthogonal experiment combining physical model and numerical simulation.Compared with traditional organic filter bag,the influence of pulse jet cleaning airflow on bag mouth condensation of filter bag under high temperature was finally studied by numerical simulation test.Results showed that under the same particle size conditions,the intercepting effect of clean metal filter material fiber was lower than that of organic fiber filter material,the particle penetration amount and distance were larger.The overall trend of filter bag cleaning ability was upper>lower>middle,and the test value of metal filter bag cleaning evaluation index was lower than that of traditional organic filter bag.In the orthogonal experiment,the significant influencing factors on filter bag cleaning were blowing pressure and blowing orifice size,and the optimal blowing distance and blowing time of metal filter bag were 200 mm and 100ms,respectively.When the pulse jet cleaning airflow temperature was 0℃,there was condensation risk in the range of 0.5 m to 2 m of filter bag.Raising the temperature to 50℃can effectively prevent the occurrence of bag mouth condensation in industrial kiln flue gas filter bag.This study can provide a reference for the optimization of injection parameters and structure of metal filter bags.