Balance of Efficiency and Security-influence on Slurry Transport from the Diffusion of Flow Passages of a Deep-sea Mining Pump

Slurry transport pumps, the central equipment of deep-sea mining (DSM) systems, provide the lifting power required for lifting mineral ores from the seafloor to the surface. The current technical challenges are associated with transport security and the economic aspects of coarse ore particles in pumps and pipelines. This paper focuses on the transportation characteristics of slurry pumps and uses theoretical methods, numerical calculations, and experimental methods to identify a feasible working mode. The geometric parameters of impeller channels in pump hydraulics significantly influence the migration properties of particles which in turn affects the overall security and economy of the system. The ratio of the impeller cross-sectional area F۲/F۱ (F۱: cross-sectional area of the impeller outlet; F۲: cross-sectional area of the impeller inlet) affects the particle passing capacity but negatively impacts pump efficiency. The percent of particles in the excellent passage interval of ۰.۲ s to ۰.۲۵ s increases from ۲۵ to ۴۳% when the number increases from ۱.۵۷ to ۲.۵۱. The pump behavior increases of the head by ۵–۱۰ m, and the efficiency decreases by ۵–۱۰%. So, the recommended span of F۲/F۱ is ۱.۵۷–۲.۰۰, and satisfying particle passing ability and efficiency can be achieved in this range. This study can provide a reference for the commercial transportation of slurry ores for deep-sea mining systems.