This paper investigated the effect of the surface roughness (0.3 μm, 1.1 μm, 2.5 μm, and 4.5 μm) on the oil–gas separation efficiency. Through spraying the oil–gas mixture onto the vertical wall, the droplets impingement in inertial separators was imitated. The impact separation efficiency on a wall was calculated by comparing the volume of the collected oil flowing down from the wall with the volume of the impinging oil. Experiments were conducted three different impingement conditions. The impinging velocity and droplets size distributions on the impingement surface were characterized by the Malvern particle size analyzer and the particle image velocimetry (PIV) technique, respectively. The droplets impinging velocities varied in the range of 3−5 m/s, and the Sauter mean diameter was observed around 40 μm. The collecting process can be divided into the initial stage and the steady stage according to the film flow state. It was found that the surface roughness has both advantages and disadvantages effect on the film flow. These two opposite effects are of different importance at different roughness levels. Under the studied impingement conditions, the separation efficiency was all above 80%, and the surface of the middle roughness (1.1–2.5 μm) performed better than the smoothest 0.3 μm surface and the roughest 4.5 μm surface.

本文研究了表面粗糙度（0.3 μm、1.1 μm、2.5 μm 和 4.5 μm）对油气分离效率的影响。通过将油气混合物喷射到垂直壁上，模拟了惯性分离器中液滴的撞击。通过比较收集的从壁上流下的油的体积与冲击油的体积来计算壁上的冲击分离效率。在三种不同的冲击条件下进行了实验。分别用马尔文粒度分析仪和粒子图像测速（PIV）技术表征了冲击表面上的冲击速度和液滴尺寸分布。液滴撞击速度在 3-5 m/s 范围内变化，在 40 μm 附近观察到 Sauter 平均直径。收集过程根据膜的流动状态可分为初始阶段和稳定阶段。研究发现，表面粗糙度对薄膜流动性的影响既有优​​点也有缺点。这两种相反的效果在不同的粗糙度级别具有不同的重要性。在所研究的冲击条件下，分离效率均在80%以上，中间粗糙度（1.1-2.5 μm）的表面表现优于最光滑的0.3 μm表面和最粗糙的4.5 μm表面。