Comparative study on collection performance of two back-end methods of double-row hydraulic sluicing structure in deep-sea mining

This study aims to investigate two different back-end action methods, induced flow type and suction type for deepsea mining. The nodule collection characteristics of both methods are compared based on the internal flow field, particle movement and comprehensive performance using an inside-outside numerical method that is validated by experimental results. The differences between the two models from these three perspectives strengthen the understanding of the harvesting mechanism. An energy analysis and quantitative evaluation method for hydraulic harvesting are proposed to assess the combined efficiency of the two methods. The results indicate that the energy utilisation rate is 34.68% for the induced flow type and 29.89% for the suction type under the same collection rate and flow rate. Furthermore, the overall efficiency of the induced flow type is 15.89% higher than that of the suction type. Regarding the construction of the flow field, the suction flow under the suction type plays the leading role, and the double jet plays a secondary role, whereas the opposite is true for the induced flow type. The suction type and the induced flow type have their own advantages in terms of their effect on particles in different regional stages. Finally, a qualitative evaluation of the comprehensive performance of the two acquisition methods is performed. (c) 2023 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.