Visualizing test on the pass-through and collision characteristics of coarse particles in a double blade pump

As the key equipment in deep ocean mining, the slurry pump suffers from wear and blocking problems. In this paper, high-speed photography technique is applied to track the movement rule of single particle of the coarse particle solid–liquid two-phase flow in a double blade slurry pump. The influences of particle diameter and particle density on the pass-through and collision characteristics of particles are analyzed as well. The results show that the average of the passing pump time first decreases and then increases when the particle diameter increases. The average of the passing pump time decreases by 22.7%, when the particle density increases from 1.09 g/cm3 to 1.75 g/cm3. Besides, the particle density has great influence on the location where the particle hits the tongue. Most particles of 1.09 g/cm3 hit the tongue on the left side, while collision location of particles of 1.75 g/cm3 is mainly on the top and at the right side of the tongue. The research can provide a basis for the optimization design of slurry pump in deep ocean mining system. [Display omitted] High-speed photography technique is applied to track the movement rule of single particle of the coarse particle solid–liquid two-phase flow in an organic-glass-made double blade slurry pump. And the influence of particle diameter and particle density on the pass-through and collision characteristics of particles is analyzed in both statistics method and specific method as well. •High-speed photography technique is applied to track the movement rule of single particle of the coarse particle solid–liquid two-phase flow in a double blade slurry pump. And the influences of particle diameters and particle density on the pass-through and collision characteristics of particles are analyzed as well.•For the convenience of photography, the pump shaft and the pump inlet are at the same side and both the impeller and the volute are made of organic glass to make sure the particles in the pictures could be easily distinguished.•A special particle orientation filter is installed in the pump, which can help guide particles to get into the impeller one by one. This provides convenience for obtaining the progress of single particle passing through the channel.•Each experiment is repeated hundreds of time to pick up credible results that can be analyzed in a statistics method to reveal inherent characteristics. And several typical collision situations are also shown to illustrate the progress of collision.