Research on backwashing technology of high water-based filter based on multihole jet impact

In order to improve the backwashing cleaning effect of high water based filter and ensure the normal operation of each actuator of fully mechanized mining hydraulic support, a water jet cleaning technology was used to design a rotary backwashing filter with a working cycle divided into two states: filtration and backwashing.The deposition process of filter cake on the surface of the filter element matrix and the mechanism of crushing and removing after the impact were analyzed.The mathematical model of the jet striking pressure and the rotating centrifugal force on the surface of the filter element were established.Using Fluent 6DOF moving grid model, the effects of key jet parameters such as incident angle, jet hole spacing and aperture on the jet strike pressure and the rotational speed characteristics of the filter element were studied.The destructive capacity of backwashing U-shaped tube multi-hole jet to filter cake was discussed.In order to verify the reliability of the simulation results, the qualitative test of the backwashing filter was carried out according to the best jet parameters determined by the simulation and the working environment of underground coal mine.The results show that with the increase of the incident angle and the jet aperture, the striking pressure and the rotational speed of the filter element increase first and then decrease.The rotational speed of the filter element continues to increase with the increase of jet hole spacing, and the striking pressure on the filter element increases first and then decreases with the increase of the jet hole spacing.When the jet incident angle is 24 degrees, the jet aperture is 1.5 mm, the jet hole spacing is 19.6 mm, and the 20 jet holes are uniformly distributed on both sides of the U-shaped tube, the filter element has the largest and stable rotation speed.The maximum impact pressure on the filter element is about 0.1 MPa.After the filter element is rotated by jet impingement for 2 seconds, the rotation speed is stable at 8 r/s.After the test, the backwashing filter is disassembled and observed that the deposition on the filter element surface have been cleaned.The multi-hole jet backwashing technology can effectively clean the filter cake deposited on the surface of filter element.