油气混合相表观密度与分离筒锥角对旋流气浮装置流场及分离性能的数值研究

Numerical Study of the Effects of Oil-Gas Mixture Apparent Density and Separation-Chamber Cone Angle on Flow and Separation Performance in a Swirling Flotation Device

摘要: 为明确油气混合相表观密度与分离筒锥角对旋流气浮装置流动及分离性能的影响，建立三维Eulerian两相数值模型，对基准流场进行分析，并设置700、720、740、760和780 kg/m³五组表观密度以及90˚、88˚、86˚和84˚四组分离筒锥角进行对比。结果表明，装置内可形成稳定的三维螺旋流动和由外向内降低的径向压力梯度。表观密度由700 kg/m³增至780 kg/m³时，切向速度和轴向速度变化较小，但径向滑移速度平均绝对值降低约24%，分离效率由92.99%降至57.03%，油相富集倍数由22.28降至13.35。锥角变化对流场影响具有明显空间性，其中90˚工况的分离效率约为76%，油相富集倍数约为17.35，综合性能最佳。研究表明，表观密度主要通过改变两相相对迁移影响分离性能，760 kg/m³可作为具有工程代表性的基准表观密度；在本文研究范围内，90˚分离筒为较优结构。

Abstract: To clarify the effects of oil-gas mixture apparent density and separation-chamber cone angle on the flow and separation performance of a swirling flotation device, a three-dimensional Eulerian two-phase numerical model was established. The baseline flow field was analyzed, and five apparent densities (700, 720, 740, 760, and 780 kg/m³) and four cone angles (90˚, 88˚, 86˚, and 84˚) were compared. The device developed a stable three-dimensional swirling flow with a radial pressure gradient decreasing toward the center. As the apparent density increased from 700 to 780 kg/m³, the tangential and axial velocities changed only slightly, whereas the mean absolute radial slip velocity decreased by about 24%, the separation efficiency fell from 92.99% to 57.03%, and the oil enrichment factor decreased from 22.28 to 13.35. The cone-angle effect was spatially dependent, and the 90˚ configuration showed the best overall performance, with a separation efficiency of about 76% and an oil enrichment factor of about 17.35. These results indicate that apparent density mainly affects separation through interphase relative migration; 760 kg/m³ is suitable as a representative baseline apparent density, and the 90˚ separation chamber is preferred within the investigated range.