旋风分离器环形空间壁面磨损的数值研究

采用包括流场计算、颗粒轨迹追踪和磨损值计算的数值模拟方法,研究了气固两相流对不同入口结构旋风分离器环形空间壁面磨损情况,计算得出的气相时均速度以及环形空间磨损区域与实验结果基本吻合。计算结果表明,不同入口结构分离器环形空间壁面都是以"局部磨损"为主,但磨损区域略有不同。在圆周方向上,蜗壳式入口结构壁面磨损主要发生在60°~200°,其中90°~180°磨损最为严重;单入口直切式结构磨损范围较广,主要集中在60°~210°;双入口直切式结构壁面磨损在环行空间分成两个区域,分别集中在60°~120°和240°~300°,磨损相对均匀;环形空间壁面磨损率沿周向的变化曲线完全不同,最大磨损率的周向位置也各不相同,蜗壳式结构最大磨损率相对较小。通过研究找到了一种有效的计算分离器壁面磨损的方法;改变分离器入口结构,可以改善环形空间壁面磨损情况,为分离器环形空间的防磨提供依据。

Numerical Study on Wall Erosion of the Annular Space in Cyclone Separators

The measures of internal flow field calculation,particle trajectory tracking and erosion rate computation were applied to numerically simulate the wall erosion caused by gas-solid two phase flow on the inlet annular space of the cyclone separators with different inlet structure.The simulate results of the time mean gas velocity and the eroded regions of annular space agree well with the experimental results.The results show that the "local erosion" is the main wall eroded form of the annular space in the cyclone separators with different inlet structures,but their eroded regions are at different azimuths.For separators with volute inlet structure,the wall erosion appears in 60°~200° of the circumferential direction,where the most severe erosion appears in 90°~180°.For separators with single tangential inlet structure,there is a wide eroded region mainly concentrating in 60°~210° of the circumferential direction.For separators with double tangential inlet structure,since the annular space is divided by the double inlets,the eroded regions are relatively uniform and mainly distribute in 60°~120° and 240°~300°.Moreover,for cyclones with different inlet structures,in their annular spaces the changes of erosion rate along the circumferential direction and the locations of the maximum erosion rate are respectively different;and the erosion rate of the cyclone separators with volute inlet structure is relatively small.Through the study,an effective method for calculating the wall erosion of cyclone separators was obtained,and it was found that the erosion of annular space in cyclone separator could be improved by changing its inlet structure.The study provides the base for improving and preventing the erosion of annular space in cyclone separators.