Investigation of transient gas-solid flow characteristics and particle erosion in a square gate valve

Abstract

As an important component in industrial pneumatic conveying pipelines, gate valves are seriously affected by gas–solid two-phase flow. Solid matter not only affects the flow resistance characteristics and flow field distribution of the gate valve, but also collides with the gate cavity and the gate plate surface, sliding friction and other effects, leading to serious wear and tear of the internal valve body, resulting in the fall off of the gate valve wall material, affecting the sealing performance of the gate valve, reducing its service life, and affecting the safety and reliability of the pipeline transportation system. Based on the consideration of gas–solid two-phase flow and particle–wall collision, combined with wear prediction model, the flow field, particle trajectory, flow resistance characteristics and wear distribution of main wall in gate valve pipeline system are studied in this paper. The accuracy of this method is verified by flow resistance experiment. The results show that the existence of groove structure at the bottom of gate valve has an important influence on the distribution of flow field inside gate valve and the wear of main wall in the flow field of pneumatic conveying pipeline. At the bottom of the groove, there is a low pressure zone, which makes the gas pressure decrease and increases the cost of pneumatic conveying when the fluid passes through the gate valve; the distribution of velocity and flow field is not uniform, resulting in swirling flow; there are different sizes of swirling flow and secondary flow, resulting in unstable flow; at the groove, particles impact on the groove perpendicular to the flow direction at a larger speed under the action of swirling flow. On the wall, the wear is the most serious here, which reduces the sealing performance of the gate valve. In the groove, the velocity distribution decreases, resulting in the accumulation of triangular particles.