Research on Particle Motion Characteristics in a Spiral-Vane-Type Multiphase Pump Based on CFD-DEM

In oil–gas mixed transportation using spiral-vane-type multiphase pumps, high sand content often causes wear on flow-passing components. To reveal the motion patterns of particles, a three-stage spiral-vane-type multiphase pump was selected as the research subject. A visualization test bench was constructed, and the pump’s performance curve was obtained by experimental measurements. High-speed photography was used to capture the flow process of a single particle within the pump, and CFD-DEM was used to study the motion characteristics of four particle sizes (0.5 mm, 1 mm, 1.5 mm, and 2 mm). The results showed that 0.5 mm and 1 mm particles had smaller trajectory angles in the guide vanes, while 1.5 mm and 2 mm particles had larger angles, with wall collisions observed. Velocity changes were similar: When they just enter the impeller, the circumferential velocity increases sharply and then stabilizes around 15 m/s. After entering the guide vane passage, the circumferential velocity exhibits an initial abrupt decrease followed by a gradual reduction. The axial velocity increases gradually along the impeller passage, reaches the highest value at the impeller outlet, and begins to decrease gradually after entering the guide vane. The particles had higher volume fractions in the guide vane and collided more with impeller walls. Collisions with guide vane walls increased with particle size.