Development of a bench-scale liquid metal wiping pilot system for understanding and optimizing the jet wiping process during hot dip galvanizing

开发小型液态金属擦拭试点系统，用于了解和优化热浸镀锌过程中的喷射擦拭过程

• 批准号: 565310-2021
• 负责人: Chattopadhyay, Kinnor
• 金额: $ 1.82万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=722200
• 关键词: Development; bench; scale; liquid; metal

In the case of hot-dip galvanizing, a continuously-moving steel strip is coated with a thin layer of zinc in orderto resist to oxidization. The protective metal is applied in its liquid state, by dipping the substrate into a bath ofcoating. However, at common strip speeds, the liquid layer dragged by the moving web is far too thick anduneven for the applications considered. The final coating thickness is therefore controlled by an air knife,which impinges a two-dimensional high-speed gas jet on the liquid layer. The forces imposed in the liquid bythe air knife jet results in the formation of a runback flow down to the bath, leaving a more uniform andconstant coating thickness dowsntream on the substrate. Nevertheless, operational constraints and processparameter variation can still result in significant coating non-uniformity and excess zinc consumption. Thisresearch program will focus on developing a bench scale galvanizing pilot where a low melting point liquidmetal will be used as an analogue to zinc and a rotating belt arrangement will be combined with an air knife tovisualize the jet wiping process in more detail. State of the art imaging techniques developed at the applicant'slaboratory will be used to visualize the wiping process, coating waviness and solution strategies will beproposed for optimizing the wiping system in terms of process parameters and air knife design. With manyexisting problems at the hot dip galvanizing lines it is difficult to meet the market demands. The results of thisproject are expected to help galvanized strip producers like AM Dofasco to determine, and control theoptimum coating properties that will allow them obtaining the highest productivity and simultaneously achievehigh quality strips with desired product quality. Proper understanding of the jet wiping process and itsinfluence on galvanized product quality has profound impacts on the commercial aspects of hot dipgalvanizing. Based on the current interests in this process optimization, and enhanced productivity (expressedby AM Dofasco hot dip galvanizing lines), an economic impact of $6 million /year is expected from the resultsof this research, which translates to $30 million within five years after completion of this project

在热浸镀锌的情况下，将连续移动的钢条涂有薄薄的锌层，以抵抗氧化。保护金属以其液态施加，通过将基板浸入涂料浴中。但是，在常见的条速度下，被移动的网拖动的液体层太厚了，对于所考虑的应用而言。因此，最终的涂层厚度由气刀控制，这会在液态层上撞击二维的高速燃气射流。空气刀射流在液体中施加的力导致倒回浴的形成，从而在基板上留下了更均匀和恒定的涂层厚度。然而，操作约束和过程参数变化仍然会导致涂层明显的不均匀性和过量的锌消耗。本研究计划将着重于开发基准尺度镀锌飞行员，在该试点中，低熔点液体将用作对锌的类似物，并且将与旋转皮带排列相结合，将飞机刀具详细介绍。在申请人的餐饮技术中开发的最先进的成像技术将用于可视化擦拭工艺，涂料波浪和解决方案策略将被提出，以优化流程参数和空中刀设计的擦拭系统。由于在热浸镀锌线上有许多问题，因此很难满足市场需求。预计该项目的结果将帮助镀锌的带状生产商（如AM Dofasco）来确定并控制theoptimus涂层特性，从而使它们获得最高的生产率，并同时获得具有所需产品质量的高质量条。对喷气式擦拭工艺的适当了解及其对镀锌产品质量的影响对热型双谷化的商业方面产生了深远的影响。基于此过程优化的当前利益和提高生产率（由Dofasco Hot Dip Galvanizing Lines表示），这项研究的结果预计每年将产生600万美元的经济影响，该研究在完成后五年内转化为3000万美元这个项目