Study on Large Particle Slurry Transport in Jumper for Subsea Mining

Abstract For design and operation of subsea mining system, it is important to predict pressure loss due to the hydraulic transport of solid particles in the flexible jumper which connects the mining tool to the vertical lifting pipe via subsea slurry pump. The configurations of jumper would change according to the motions of the mining tool and the slurry pump, which may be easier to cause the pipe blockage than the vertical pipe. In the present paper, we investigated the effects of jumper configuration on the pressure loss. We assumed the 100 m long flexible jumper of which outer and inner diameters are 0.254 m and 0.200 m, respectively. PMS ore, of which density and diameter are 3,440 kg/m3 and 0.03 m respectively, were assumed as the solid particles. We varied the slurry transport conditions such as slurry concentration and slurry velocity under the condition of a constant production rate of 5,000 t/day. The effects of jumper configuration on internal slurry flow were studied from the viewpoint of pressure loss and specific energy consumption. The allowable slurry velocity in jumper system was also investigated considering pipe inclination by referring to the past literature. Finally, the most desirable operational slurry flow condition was discussed for the jumper system studied.