低压脉冲袋式除尘器清灰结构的优化研究

发布时间：2018-03-27 09:44

本文选题：低压脉冲袋式除尘器　切入点：清灰结构　出处：《安徽工业大学》2013年硕士论文

【摘要】：脉冲喷吹袋式除尘器作为一种重要的除尘设备，因其具有过滤效率高、处理气量大、清灰效果好等优点，目前在冶金、电力、化工、环保等领域得到了广泛的应用。袋式除尘器的运行实践表明，适宜的滤料、袋室内流场的均匀性以及优良的清灰系统是确保袋式除尘器成功运行的三项关键因素。优良的清灰系统取决于清灰系统设计的科学性，而清灰系统设计的科学性则要求对清灰结构进行深入的优化设计。本文首先对脉冲清灰机理进行归纳总结，确定以压力峰值作为衡量清灰性能好坏的评价指标；搭建脉冲清灰实验台，并对文丘里管结构对袋式除尘器清灰性能的影响进行了测试。然后在模型实验研究的基础上，建立起单条滤袋的清灰数值计算模型，并对数值计算模型进行了验证；同时利用数值计算方法研究了工业袋式除尘器在不同操作参数和不同清灰结构时的清灰流场。最后，本文基于响应曲面法并使用统计软件Minitab V15研究了喷嘴直径、喷吹高度、文丘里管喉管直径、文丘里管及布袋长度对袋式除尘器清灰性能的影响，并得出了这5个影响因子的二次多项式预测模型，，结果表明：（1）在本文模型实验研究范围内，没有文丘里管时袋式除尘器清灰性能较好，并且文丘里管喉径对脉冲清灰性能影响较小，而文丘里管长度对脉冲清灰性能的影响较明显；对工业中两种不同文丘里管结构清灰流场的数值模拟发现，文丘里管结构对清灰性能具有重要的影响，选择合适的文丘里管可以优化清灰系统。（2）通过数值计算结果与文献实验结果和模型实验结果的对比，数值计算结果和文献实验测试结果吻合较好，误差在10％左右，说明本文采用的数值计算模型可以用于计算袋式除尘器清灰结构的清灰性能。（3）袋式除尘器的清灰性能随着喷吹压力的增加而得到提高，但是喷吹压力并不是越大越好，过大的喷吹压力会造成耗能的增加，从而导致设备运行费用的增加；在一定的时间范围内，延长喷吹时间可以改善清灰性能，当喷吹时间超过一定值后再延长喷吹时间，只是增加了压缩空气消耗量，并不能提高滤袋侧壁的压力峰值。（4）工业脉冲袋式除尘器的清灰性能随着喷嘴直径的增加而提高，并且在滤袋中下部其压力峰值基本上已趋于稳定；喷吹系统存在着理想的喷吹高度，喷吹高度过低会导致滤袋侧壁的压力峰值分布不均匀，喷吹高度过高会削弱滤袋下部的清灰强度；随着滤袋长度的增加，滤袋中下部压力峰值迅速降低，滤袋过长会导致其中下部清灰不利。（5）基于响应曲面法并通过方差分析和回归方程系数显著性检验可知，喷嘴直径（d/D）、文丘里管喉管直径（de/D）和布袋长度（L/D）是影响清灰性能的显著性因素；其中清灰性能随着喷嘴直径和文丘里管喉管直径的增大而提高，随着布袋长度的增大先提高后降低。在本文所研究的尺寸范围内，当d/D=0.125，即d=20mm、de/D=0.375，即de=60mm、L/D=21，即L=3360mm时，清灰效果分别达到最优。
[Abstract]:As an important dust - removing equipment , the pulse - blowing bag - type dust collector is widely used in the fields of metallurgy , electric power , chemical industry and environmental protection . The operation practice of bag - type dust collector shows that the proper filter material , the uniformity of the flow field in the bag chamber and the excellent ash cleaning system are the three key factors to ensure the successful operation of the bag - type dust collector . The excellent ash - cleaning system depends on the scientific nature of the design of the ash cleaning system , and the scientific nature of the design of the ash cleaning system requires an in - depth optimization design for the ash cleaning structure .

Firstly , the principle of pulse ash cleaning is summarized , and the pressure peak value is used as the evaluation index to measure the performance of ash cleaning .
The effect of the structure of Venturi tube on the ash removal performance of bag - type dust collector is tested . Based on the experimental study of the model , a numerical model for calculating the ash content of single filter bag is established , and the numerical calculation model is verified .
The effects of nozzle diameter , blowing height , venturi throat diameter , venturi tube and bag length on the ash removal performance of bag - type dust collector are studied by using numerical calculation method . Finally , the quadratic polynomial prediction model of these five influencing factors is obtained . The results show that :

( 1 ) In the range of the experimental research of this paper , the dust - removing property of bag - type dust collector is better when there is no Venturi tube , and the throat diameter of the Venturi tube has little influence on the pulse cleaning performance , and the influence of the length of the venturi tube on the pulse ash cleaning performance is obvious ;
The numerical simulation of ash flow field in two different Venturi tube structures in industry shows that the Venturi tube structure has important influence on the ash removal performance , and the suitable Venturi tube can be selected to optimize the ash cleaning system .

( 2 ) By comparing the numerical results with the experimental results of the literature and the experimental results of the model , the numerical results agree well with the experimental results of the literature , and the error is about 10 % . The numerical calculation model used in this paper can be used to calculate the ash - cleaning performance of the dust - removing structure of the bag - type dust collector .

( 3 ) The ash - removing performance of bag - type dust collector is improved with the increase of blowing pressure , but the higher the blowing pressure is , the better the blowing pressure is , the excessive blowing pressure can increase the energy consumption , which can lead to the increase of equipment operation cost ;
In a certain time range , prolonging the blowing time can improve the ash cleaning performance , and when the blowing time exceeds a certain value , the blowing time is prolonged , only the consumption of compressed air is increased , and the pressure peak value of the side wall of the filter bag cannot be improved .

( 4 ) the ash removal performance of the industrial pulse bag filter increases with the increase of the diameter of the nozzle , and the pressure peak in the lower part of the filter bag is basically stabilized ;
An ideal blowing height is found in the blowing system , which leads to uneven distribution of pressure peaks in the side wall of the filter bag , which can weaken the ash removal strength at the lower part of the filter bag .
As the length of the filter bag increases , the peak value of the lower pressure in the filter bag is rapidly decreased , and the filter bag is too long to cause the lower part to clear ash .

( 5 ) Based on the response surface method and the difference analysis and the regression equation coefficient significance test , it can be seen that the nozzle diameter ( d / D ) , the diameter of the venturi throat ( de / D ) and the length of the bag ( L / D ) are significant factors that affect the ash cleaning performance ;
In this paper , when d / D = 0.125 , that is , d = 20 mm , de / D = 0 . 375 , that is , de = 60mm , L / D = 21 , that is , L = 3360mm , the ash cleaning effect is optimal .

【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU834.64

【参考文献】