Study on Collection Performance of Hydraulic Polymetallic Nodule Collector Based on Solid–Liquid Two-Phase Flow Numerical Simulation

Abstract

The hydraulic collector is an important device for collecting seafloor polymetallic nodules. In this study, a hydraulic polymetallic nodule collector with two acquisition nozzles and one transmission nozzle is described. The numerical model of the hydraulic collector is established based on the solid–liquid two-phase flow method, and it is verified by experimental tests. On this basis, the collection mechanism of the hydraulic collector is analyzed, and the effects of structural parameters and working parameters on its collection performance are explored. The results show that the collection height and slant angle of the acquisition nozzle are key factors for collection efficiency, with optimal heights below 150 mm and angles between 45 and 49∘. The recommended range for the center distance between the two acquisition confluence tubes is 650–730 mm. Excessive acquisition and transmission flow rates make a negligible contribution to improving the collection efficiency, but can also cause a significant increase in energy consumption. Therefore, the recommended ranges for acquisition and transmission flow rates are 140–160 m3/h and less than 80 m3/h, respectively. All of the results indicated that the parameters of the developed hydraulic collector were set reasonably, which thus ensured a balance between the collection efficiency and energy consumption.