| In order to know about the fluid field and laws of motion of sediments in the sorting device, the article studies on the fluid field by numerical simulation and compares the characteristics of fluid field under different operating conditions. In addition, the results of simulation after adding sediments to the device can be compared with the results of physical experiments, which providing the technical suggestions to improve the device.The fluid field in the device is rotational flow, so the simulation work with the RNG k-ε turbulent model and the area of stirring is divided by the MRF model.What’s more, the sediments in the fluid field can be simulated with DPM.When there is only water in the sorting device, the streamline on the XY and XZ planes are gained by simulating, which shows that the streamlines on the XY planes rotating around the axis and the XZ planes in the centre contain four circulations; the whole distribution of streamline in the device is inferred to be periodic and rotational.Also, the distribution of velocity in the flow field, including the laws of variation of velocity in the radical and vertical directions, are studied by simulating and the results show the laws of variation of velocity on the and vertical directions. The influences of both the rotational frequencies of stirring blades and the heights of sorting bucket are learned under different working conditions and the results illustrate the the rotational frequencies of stirring blades make little effect on the distribution of streamlines, but the influence which they make on the velocity is very significant. In addition, the heights of sorting bucket only influence the distribution of streamlines on the XY plane and the effcets which the heights make on velocity are different on different vertical positions.The laws of motion of sediments with different diameters are gained after adding sediments into the device by DPM, which shows there are three different kinds of pathlines in the device. And the percentages of coarse sand, medium sand and fine sand in the coarse, medium and fine holes are gained by simulating. The results showthat the effect of sorting of simulation is better than the effect of physical experiments. |
