Study on Separation Performance of Gas-Liquid Cyclone Separator with Pulsating Feeds

Background: In recent years, a kind of drilling method of solid-liquid separation combined with pulsating vacuum formed by vibrating screen and compressed air injection has emerged in oil drilling, which profoundly improves the gas, solid, and liquid separation ability of the drilling fluid vibration screen. Objective: Based on the above ideas, a kind of hydrocyclone used for gas-liquid separation with the pulsating feed boundary was proposed. The separation performance of gas-liquid hydrocyclone may change significantly due to the mixed pulsation of the gas-liquid fluid transported by the jet pump. Therefore, the flow characteristics of the pulsating feed hydrocyclone need to be analyzed and explored to provide basic data for further improvement of the structure. Methods: The development status of cyclone separators are summarized through related literature and patent investigation. The Computational Fluid Dynamics (CFD) software ANSYS Fluent 2019 R3 is used to analyze the flow field characteristics and optimize the parameters of the hydrocyclone with stable feed. Then, the programming by the User-Define-Function (UDF) of Fluent is used to simulate the flow field of the separator under the condition of pulsating feed. Meanwhile, the flow field analysis and parameter optimization are carried out accordingly. Results: The optimal parameters in a stable state and pulsed state are obtained from the analysis of the efficiency curve. The results show that the flow field can be stabilized in the pulsating feed state, and the sinusoidal pulsing with a frequency of 0.4 Hz is used to achieve the highest separation efficiency, i.e., 85.5%. Conclusion: The separators with pulsating feed and stable feed have similar flow field characteristics, and the optimal structural parameters under pulsating feed are obtained. Compared with the stable feed condition, the pulsating feed condition can connect multiple cyclone separators, which can separate more drilling fluid in unit time and improve the work efficiency. It has strong practicability, which provides a critical foundation for structure optimization in the future. © 2022 Bentham Science Publishers.