旋风-颗粒床过滤器两级除尘的分析与优化

Analysis and optimization on two-stage dust removal of cyclone separator-granular bed filter

为解决粉煤热解工艺中焦油气除尘问题,采用单因素和正交试验法研究了滤料粒径、滤料厚度和氮气流量对旋风-颗粒床过滤器两级除尘性能的影响。结果表明:在实验参数范围内旋风分离器平均除尘效率为98.43%。相比石英砂滤料,以半焦为过滤介质的颗粒床过滤器具有较高的过滤性能。滤料粒径由1.25—2.5 mm减小到0.38—0.83 mm时,颗粒床过滤器平均除尘效率由93.88%增大到97.18%,而最大床层压降也随之增加了59.99%。滤料厚度由100 mm增加到200 mm时,颗粒床过滤器平均除尘效率由90.99%增大到95.91%。随氮气流量的增大,颗粒床过滤器除尘效率降低,而两级除尘系统总效率略有降低。正交试验结果表明:滤料厚度是影响两级除尘效率的主要因素,其次是滤料粒径,氮气流量对系统总除尘效率影响最小。

To solve the problem of separating coal dust from tar gas in the process of pulverized coal pyrolysis by using the two-stage dust removal apparatus consisting of cyclone separator and fixed granular bed filter,the effects of filter size,filter thickness and nitrogen flows on the dust removal performance were investigated by single factor and orthogonal experiments at room temperature.The results show that,in the range of experimental parameters,the average dust removal efficiency of the cyclone separator is 98.43%.Compared with quartz sand filter,granular bed filter has higher filtration quality when semi-coke is used as filter medium.When the filter size of filter material decreases from 1.25-2.5 mm to 0.38-0.83 mm,the average dust removal efficiency of granular bed filter increases from 93.88%to 97.18%,and the maximum bed pressure drop increases by 59.99%.When the filter thickness increases from 100 mm to 200 mm,the average dust removal efficiency of the granular bed filter increases from 90.99%to 95.91%.With the increase of nitrogen flow,the dust removal efficiency of the granular bed filters decreases,while the total efficiency of the two-stage dust removal system decreases slightly.The results of the orthogonal experiment show that the filter thickness is the main factor affecting the dust removal efficiency of the granular bed filter,followed by the filter size and the nitrogen flow has the least influence on the two-stage dust removal efficiency.