Research on the friction characteristics of mechanical-hydraulic hybrid vertical lifting system for deep-sea minerals

Deep-sea mineral resource exploitation is an important field of the mining sector and marine economic strategy. It has far-reaching significance for alleviating the world' s shortage of rare metal resources and guaranteeing sustainable development. However, how to quickly, reliably, and environment-friendly lift wet and sticky deep-sea minerals from seabed to surface production vessels is key technical challenge. In this paper, new type of deep-sea minerals lifting machine-mechanical-hydraulic hybrid vertical lifting system was proposed, and its friction resistance characteristics were studied. A frictional resistance model between minerals and the pipe wall was established based on the Janssen model. The resistance between the minerals and the fluid was established based on the Ergun Equation. The resistance between the fluid and pipeline wall was established based on the Darcy-Weisbach Equation. Finally, a frictional resistance calculation model for the whole system was constructed. A mechanical-hydraulic hybrid lifting experimental device was designed and experiments were conducted to verify the model. The results show that the frictional resistance calculation model matche s to the experimental results reasonably well with an average error of 13.3%. Therefore, the proposed frictional resistance model was verified and can be used to predict the resistance of the mechanical-hydraulic hybrid vertical lifting system.