基于Mixture模型对浓缩机浓缩沉降过程的数值模拟

Numerical Simulation of Thickener Sedimentation Using the Mixture Model

摘要: 针对煤泥水沉降过程复杂且难以观测的问题，本文以直径6 m中心传动式浓缩机为对象，基于Mixture多相流模型，结合Realizable k-ε湍流模型与群体平衡模型(PBM)，开展了数值模拟研究。结果表明，浓缩机内部存在进口回流区、中部回流区、出口回流区和上部溢流区等典型流动区域，其中中部低速回流区有利于煤泥颗粒与药剂作用。随着时间延长，颗粒逐渐向底部富集，沉降规律清晰可见。在相同工况下，开启PBM模型后颗粒沉降速度明显加快，底部堆积量增加，验证了PBM模型对絮凝过程的适用性。研究结果可为浓缩机运行调控和药剂投加优化提供理论依据。

Abstract: To address the complexity and poor observability of coal slurry sedimentation, this study investigates a 6 m diameter center-driven thickener using numerical simulation. A Mixture multiphase flow model coupled with the Realizable k-ε turbulence model and the population balance model (PBM) was applied. Results show that typical flow regions, including inlet, middle, outlet, and overflow recirculation zones, are formed inside the thickener, with the middle low-velocity zone promoting sufficient interaction between coal particles and flocculants. As time progresses, particles gradually accumulate at the bottom, revealing clear sedimentation patterns. Under identical conditions, simulations with PBM enabled faster particle settling and greater bottom accumulation, confirming its applicability in characterizing flocculation processes. The findings provide theoretical support for the operational regulation of thickeners and the optimization of reagent dosage.