充填料浆瞬时流速过大导致管道堵塞的原因分析

Analysis of pipeline blockage resulting from excessive instantaneous flow velocity of filling slurry

针对充填管道易发生堵塞,对悦洋银多金属矿发生的一次典型事故进行研究。根据流速—流量公式、动量定理及两相流紊流特性,发现料浆瞬时流速过大是导致充填管道堵塞的重要因素。研究结果表明,瞬时流速过大,充填料浆中水的紊流特性将发生突变;管道内壁磨损将加剧,脱落的碎屑会混入料浆;管道内壁冲击将加剧,不平整度增大,固体颗粒与内壁碰撞几率增加。多种影响因素互相叠加,料浆中固体颗粒悬浮平衡将遭到破坏,导致颗粒沉降,进而堵塞充填管道。因此,控制充填料浆流量在110m3/h以内,严格检测二次利用的充填管道内壁平整度可有效预防此类充填管道堵塞事故再次发生。

A study on a typical accident happened in Yueyang Ag-polymetallic Mine is carried out for the filling pipes prone to clogging. According to the formula of velocity-flow, the momentum theorem and the turbulence char- acteristics of two-phase flow, it＇s found that the excessive instantaneous velocity of the slurry is the main factor causing the blockage of the filling pipeline. The result shows that when the instantaneous velocity of the slurry is heavily large, the turbulence characteristics of water in the backfilling slurry will be suddenly changed. The pipeline inwall will be worn acutely, and the debris falling off will be mixed in the slurry. The impact on the pipeline inwall will be intensified, which leads to the increase of the roughness of surface and the risk of solid particles colliding with walls. Combined with a number of factors, the equilibrium of suspended solid particles in slurry will be destroyed, resulting in particles settling and the filling pipe blocked at last. Therefore, it can effectively prevent this kind of backfilling pipeline blockage accident occurring again if the flow of backfilling slurry is controlled within 110 m2/h and the inwall surface roughness of the secondary utilized filling pipeline is tested.