除尘器袋室结构改进及内部气固两相流动特征分析

Characteristics of Gas-Solid Two-Phase Flow for Filter Dust Collector with Low Entry

为了解决某显像管厂DMC180型袋式除尘器尾部滤袋工作寿命过短的问题 ,提出了扩大进风管直径和在下箱体中布置钝体两项结构改造措施 ,力图通过改善袋室内部气固两相流场 ,延长滤袋寿命 .使用FLUENT5 0计算流体动力学软件 ,对原型和改进型袋式除尘器内部气固两相流动进行了数值模拟 .结果表明 :原型中的旋涡回流流动加速了尾部滤袋的磨损和破坏 ;改造后 ,袋室内部形成了由钝体导引的 3股主流流动 ,压力场比较均匀 ,各滤袋组过滤速度偏差可控制在 - 10 %～2 0 %以内 ;上箱体中形成了比较均匀的纵掠滤袋流动 ,绝大部分区域的滤袋间隙速度小于最大允许值 ;袋室阻力降低了约 6 0 % .

A computational fluid dynamics(CFD) commercial software (FLUENT5.0) is applied to optimize the bag house design for a prototype filter dust collector by application of the k ε model and a two way coupling Lagrangian scheme. By using a larger inlet pipe and four blunts in the lower part of the bag house, the recirculation flow with vortex in the original structure is changed to a three streams pattern directed by the blunts. The pressure field is quite uniform and the filtration velocity variation is within-10%～20%.Parallel flow within the filter groups is formed. In most area of the upper part, the can velocity is less than the threshold. The total pressure loss through the bag house is reduced by about 60%.