标题： 水平管道中静止条件下颗粒悬浮液的沉降 显示英文标题

标题： Sedimentation of particulate suspensions under stagnant conditions in horizontal pipes

摘要： 水平管道中的颗粒悬浮液沉降会导致固体状床层的形成、增长和压实，这可能会严重阻碍管道性能。 在工业过程中，静止流动条件经常出现，关键的操作问题包括：(i) 沉降以何种速率和程度进行，以及 (ii) 沉降动力学是否可以通过常规悬浮液表征方法预测？ 我们通过批量沉降试验表征了水基高岭土悬浮液的沉降特性，并将一维沉降理论的预测结果与水平圆柱管道实验进行了比较。 我们证明，颗粒沉降可以被准确预测，表明估算的沉降性质是具有代表性的材料属性，并且瞬态效应（如重力流）并不显著。 相反，我们发现一维理论无法很好地预测沉降的压实情况，这表明应力状态并非一维，可能涉及管道壁的影响。 这些静止圆柱管道的结果为预测更一般条件（层流和湍流）下的管道沉降提供了基础。 显示英文摘要

摘要： Sedimentation of particulate suspensions in horizontal pipes can lead to formation, growth and consolidation of a solid-like bed which can severely retard pipeline performance. As stagnant flow conditions frequently arise during industrial processes, critical operational questions are: (i) at what rate and extent does sedimentation proceed, and (ii) can the sedimentation dynamics be predicted from conventional suspension characterisation methods? We address these questions by characterising the sedimentation properties of an aqueous Kaolin suspension via batch settling tests and comparing predictions from 1D sedimentation theory with experiments in a horizontally oriented cylindrical pipe. We show that particulate sedimentation can be accurately predicted, indicating that the estimated sedimentation properties are representative material properties, and that transient effects such as gravity currents are not significant. Conversely, we find that the consolidation of the sediment is not well predicted by 1D theory, suggesting that the stress state is not 1D and likely involves contributions from the pipe walls. These stagnant cylindrical pipe results provide a basis for the development of methods to predict pipeline sedimentation under more general (laminar and turbulent) flow conditions.