Design optimization of a deep-sea manganese nodules hydraulic pick-up device using Coanda effect

Abstract

Manganese nodules are buried in part or in whole under the surface of the deep-seabed sediments which has extremely high water content. To separate nodule from sediments efficiently, the followings should be considered. Deep-seabed sediments are composed of very fine particles, even shear stress is very low, 5~10 kPa, it show high adhesion. Thus, collecting nodule method should consider wear and breakdown of devices and disturbance of deep-sea ecosystems. In addition the productivity of commercial mining system in order to ensure a certain level or higher (being evaluated 80% or more) collecting rate of nodules. In this paper, we modeled simply lifting force due to pressure drop following cross-flow principle. Calculated lifting force of nodules is optimized with respect to design factors to minimize energy consumption and influence on the deep-sea ecosystem.s are composed of very fine particles, even shear stress is very low, 5~10 kPa, it show high adhesion. Thus, collecting nodule method should consider wear and breakdown of devices and disturbance of deep-sea ecosystems. In addition the productivity of commercial mining system in order to ensure a certain level or higher (being evaluated 80% or more) collecting rate of nodules. In this paper, we modeled simply lifting force due to pressure drop following cross-flow principle. Calculated lifting force of nodules is optimized with respect to design factors to minimize energy consumption and influence on the deep-sea ecosystem.