When mining the ocean for rare minerals, one of the key challenges is developing the required technologies needed to operate on the seabed at depths of 1,500–3,000 meters. One key area of development focuses on pumps that can lift the nodules from the seafloor to surface vessels. The Institute of Marine Engineering, Science & Technology is researching design options for a lifting motor pump that meets the required high pressure required and prevents clogging, while providing high-head wear resistance and efficiency.

Structure

The proposed structure of the Lifting Pump includes seven main components: Flang of suction, a motor, an annular channel, nut and bolt, a multistage pump, a pump barrel, and a flang of spit out. The multistage pump is tightly connected to the motor shaft by the sleeve coupling. The impeller of the pump is connected to an annular channel with the final guide vane of the multistage pump connected to the flang of spit out by bolts. Both, the flang of suction and flang of spit out are connected to riser pipes. (Figure 1)

Performance Simulation

The most important part of a lifting pump system for ocean mining is the impeller, but its performance depends largely on the shape, flow, and rotation speed. To develop the best performing impeller design, researchers at the Institute of Marine Engineering, Science & Technology developed computational fluid dynamic (CFD) software program to study pump performance. Different calculation models were used to imitate flow, turbulence and particle wear. The program further studied the effects of exit angle of the vane on the impeller performance and effect of particle size on impeller wear, as well as the effect of rotating speed on the impeller performance.

Researchers conclude that this lifting motor pump meets the necessary requirements to become a meaningful tool for ocean mining. The highly efficient pump reduces energy consumption and the current computerized simulations provide the basis for the optimal parameters of the impeller.

The full details can be found in the Journal of Marine Engineering & Technology. Reference: Hengling Yang & Shaojun Liu (2020) A new lifting pump for deep-sea mining, Journal of Marine Engineering & Technology, 19:2, 102-108, DOI: 10.1080/20464177.2019.1709276