棒磨山铁矿选矿厂二段磨矿分级设备改造

介绍了棒磨山铁矿选矿厂二段磨矿分级设备的改造过程。生产实践证明：用高频细筛取代旋流器作为二段磨矿分级设备,不仅提高了铁精矿品位,而且取得了可观的经济效益。     

往复泵作用下结构参数对旋流器流场特性影响

流量脉动条件下,对不同长度稳涡罩气液分离器的流场特性进行数值模拟和试验研究。研究结果显示：稳涡罩柱段长度为39 mm的旋流器分离性能最佳,分离效率达到95%,随着稳涡罩柱段长度的增加,分离效率逐渐降低;无罩时分离效率最差,且流场极不稳定,分离效率随时间而波动变化。运用高速摄像技术和室内试验系统进行试验研究,使用高速摄像机对旋流场中的气核形态进行可视化观测,并应用室内试验系统测得不同柱段长度稳涡罩的分离效率,试验效率略低于模拟效率,误差在可接受范围内;应用Origin软件对柱段长度与其所对应的分离效率进行拟合,得到其关系表达式,相关系数R2高达0.99,并且应用旋流强度S对分离器内部流动形态进行数学描述,得到稳涡罩柱段长度与旋流强度的关系。     

Multi-cyclonic vacuum cleaners as a pedagogic case study of process intensification

Process intensification has emerged as a strategy to satisfy the objectives of process efficiency, sustainable development and economic competitiveness. Unfortunately, intensified technologies are too numerous to fit in a time-constrained academic syllabus. For high pedagogic impact, appropriate case studies should be favored to cover a wide range of strategies while demonstrating these opportunities, using accessible tools and concepts.The developed case study demonstrates the gain of sustainability offered by applying multi-scale design to a cyclonic separation, enabling miniaturization at constant efficiency. The analysis leads to well-known multi-cyclonic systems. This example is particularly striking for students since multi-cyclonic vacuum cleaners are a domestic illustration of this strategy.The analysis aims to miniaturize the separator, at constant efficiency and dissipated mechanical power. By applying a scale factor to cyclone dimensions, while maintaining the efficiency, a first strategy demonstrates that miniaturization alone cannot be sustainable. The best strategy considers parallel miniature cyclones, which enables to satisfy all objectives: the volume and dissipated mechanical power can be reduced simultaneously, requiring a multi-objective optimization.Scenarios for integration of the case study in various curricula are proposed, by differentiating the learning outcomes as a function of student level and course objectives.