下进风袋式除尘器内部气固两相流动数值模拟

Numerical Simulation of Gas-Solid Two-Phase Flow in a Filter Dust Collector with a Low Entry

为了研究袋式除尘器滤袋失效机理 ,进一步指导除尘器的设计、运行和改进 ,通过简化滤袋结构和应用结构化 /非结构化混合网格技术 ,对DMC180型下进风袋式除尘器实际运行条件下的内部气固两相流动进行了数值模拟。计算结果表明 ,袋室内形成了旋涡回流和不均匀压力场 ,袋室后端滤袋组过滤速度和滤袋间隙速度大大超过最大允许值 ,是后端滤袋易于磨损失效的主要原因。通过计算还得到了不同处理风量和过滤介质表观渗透率条件下 ,各滤袋组过滤速度和颗粒沉积量分布规律。

Numerical simulation was carried out to predict the gas solid two phase flow in a filter dust collector with a low entry.Gas phase flow was simulated by using the k ε model,while particle trajectories were computed in a Lagrangian frame of reference.Two way coupling was used to incorporate the effect of the discrete phase trajectories on the continuum.It shows that a recirculation pattern with vortex is formed within the bag house and the pressure field is nonuniform.The filtration velocity and the can velocity exceed the threshold greatly at the rear end.The filtration velocity and the quantity of particle accumulated on each bag group are also disclosed under different filter media permeabilities and inlet flow rates.It is proposed that some optimizing means should be used to direct the gas streams parallel with the bags and form uniform pressure field.