Multi-Species Slurry Pipeline Transportation

管道系统广泛应用于交通运输行业。例如，煤炭、铁矿石、矿物精矿、尾矿、污水污泥和核废料的运输。在许多这样的应用中，运输的泥浆是复杂的多组分混合物。在过去，大多数的理论和实验研究只涉及单一组分的浆体，如沙或煤水混合物；对多组分浆体的了解很少。基于单组分泥浆研究的管道系统设计在安全性和效率方面存在很大的局限性。因此，有必要对多组分泥浆输送进行研究，为今后更好的管道系统设计提供科学依据。建议使用商用求解器和开发新的计算机程序，在实验室规模的流动回路中进行多组分泥浆输送的实验和数值研究。研究中将使用双组分和三组分的泥浆，重点研究泥浆组分密度对输送特性的影响。玻璃颗粒、沙子、氧化铝和氧化镍等材料将包括浆料成分，以研究较重与较轻材料的密度比在1.2至5.0的范围内。将测试50m至500m范围内不同粒度的浆料组分，以及不同浆液组分的相对浓度。此外，我们还将研究每种浆料配方中5%至40%体积分数的固体浓度。将建造一个用于泥浆输送实验的流动回路。流量回路及其仪表将通过在清水中进行实验进行校准。接下来，将进行流动回路中的浆料输送实验。重要的工程参数，如临界沉积速度和压降与流速的关系将是有意义的。采用粒子图像测速仪(PIV)等流动可视化技术研究与不同流型相关的流型。雷诺数的范围从500到100000将被认为涵盖层流、过渡流和湍流区。临界沉积速度将通过目测颗粒沉降和从压降-平均流速曲线上的转折点确定。将对正在调查的泥浆进行流变学研究。建立合理的多组分泥浆流动数值模型。实验数据将被用来改进数值模型。改进后的模型将被用于参数研究，以获得关于固体密度、颗粒大小和固体浓度对泥浆传输特性的影响的详细信息。此外，我们还将研究再暂停现象，以探讨管道重启的可行性和特点。泥浆在环路中完全沉降，然后平均泥浆速度逐渐增加，直到沉降层完全消失。本研究得到的关联式和数值模型将有助于设计下一代多组分泥浆输送管道系统。这项研究还将有助于改善对与多相流相关的物理现象的基本理解。该奖项是由工程探索研究运输业(ETI)计划征集颁发的。

Pipeline systems are widely used in transportation industries. Examples are transportation of coal, iron ore, mineral concentrates, ore tailings, sewage sludge, and nuclear waste. In many of these applications, transported slurries are complex multi-species mixtures. In the past, most of the theoretical and experimental studies dealt with only single-component slurries such as sand- or coal-water mixtures; little is known about multi-species slurries. The design of pipeline systems based on the studies of single-component slurries causes substantial limitation of safety and efficiency. Thus, there is a significant need to study multi-species slurry transportation in order to build a scientific basis for better pipeline system design in the future. It is proposed to study multi-species slurry transportation both experimentally in the lab-scale flow loop and numerically, using commercially available solvers as well as developing new computer codes. Both two- and three-component slurries will be used in the study to focus research on the effects of slurry component density on transport characteristics. Materials such as glass particles, sand, aluminum oxide, and nickel oxide will comprise slurry components in studying density ratios of heavier to lighter material in the range of 1.2 to 5.0. Different particle sizes of slurry components in the range of 50m to 500m and different relative component concentrations in the slurry will be tested. In addition, we will study solids concentrations in the range of 5% to 40% by volume for each slurry recipe. A flow loop for slurry transport experiments will be constructed. The flow loop and its instrumentation will be calibrated by performing experiments with clear water. Next, slurry transport experiments in the flow loop will be performed. Important engineering parameters such as critical deposition velocity and pressure drop versus flow velocity will be of interest. Flow patterns associated with different flow regimes will be examined by using flow visualization techniques such as Particle Image Velocimetry (PIV). A wide range of Reynolds numbers from 500 to 100000 will be considered to cover laminar, transitional, and turbulent flow regimes. Critical deposition velocity will be determined by visual observations of particle settling and from the turn point on the pressure drop versus mean flow velocity curve. Rheology studies of slurries under investigation will be performed. A reasonable numerical model of multi-species slurry flow will be developed. Experimental data will be used to improve numerical model. Improved model will then be used for parametric study to obtain detailed information about the effects of solids densities, particle sizes, and solids concentrations on slurry transport characteristics. In addition, we will study re-suspension phenomenon to investigate pipeline restart feasibility and characteristics. Slurry will be allowed to fully settle in the loop and then mean slurry velocity will be increased gradually until the settled bed is completely removed.Correlations and numerical models obtained from this research will be useful in designing next-generation pipeline systems for multi-species slurry transportation. The study will also contribute to the improved fundamental understanding of physical phenomena associated with multi-phase flows.This award is made under the Exploratory Research on Engineering the Transport Industries (ETI) program solicitation.