Experimental study on hydraulic performance of hybrid pick-up device of manganese nodule collector

Abstract

This paper deals with experimental approaches for enhanced understanding of the hydraulic performance of a hybrid pick-up device developed at KRISO. The experiments were conducted in a 2-D flume tank. The hydraulic nodule lifter of the hybrid pick-up device consisting of water-jet piping and baffle plates was manufactured and tested. Flow rate of water-jets, tow speed, bottom clearance, and position and shape of baffle plates were chosen as experiment parameters. Through a series of experiments, the pick-up efficiency of the hydraulic lifter has been analyzed as function of the experiment parameters, and operation condition assuring high pick-up efficiency has been identified. In order to investigate the working principle of water-jets, the bottom pressures fluctuating due to water-jets were measured with varying conditions of water-jets flow rate, tow speed and bottom clearance. The characteristics of bottom pressure distribution were studied in correlation with the pick-up efficiency. It was recognized that there is a correlation between high pick-up efficiency and longitudinal pressure distribution.