表观气速对疏油型聚结滤芯性能的影响及结构改进

Effect of apparent gas velocity on performance of oleophobic coalescence filter cartridge and its structure improvement

天然气储运过程中,气体流量频繁波动易导致过滤器滤芯服役寿命缩短甚至失效。根据相关测试标准建立聚结滤芯过滤性能实验装置,分析表观气速及其动态变化对疏油型聚结滤芯饱和度、液体分布与下游液滴状态的影响,提出滤芯内部设置挡板的新方法,并探究了可显著提升滤芯性能的最佳挡板高度。结果表明:随着表观气速升高,滤芯首层饱和度减小且下部区域最为明显;表观气速的动态变化对滤芯首层和末层的饱和度影响较大,在实验许可范围内,适当提高表观气速可加快液体运移,但当表观气速达到0.5 m/s时,纤维对液滴的黏附力相对减弱,液滴容易脱离而出现二次夹带,导致过滤效率明显下降;滤芯内部设置挡板结构可有效避免较高表观气速下的液滴二次夹带现象,且在挡板高度为15 cm时,滤芯过滤性能提升最为显著,下游液滴计数浓度相比无挡板结构降低97.3%。研究成果可为高效聚结滤芯研制和天然气储运工艺优化提供重要指导。

The frequent fluctuation of gas flow during the storage and transportation can easily lead to the failure of filter cartridge and the shortening of its service life. Thus, an experimental device for the filtration performance of coalescence filter cartridge was established according to the relevant test standards. On this basis, the effects of apparent gas velocity and its dynamic change on the saturation of oleophobic coalescence filter cartridge, the liquid distribution and the state of downstream droplets were analyzed, and a new method of setting baffle inside the filter cartridge was proposed. In addition, the optimal baffle height that could greatly improve the performance of filter cartridge was explored. The results show that the saturation of the first layer, especially the lower part, of the filter cartridge decreases with the increase of apparent gas velocity. The dynamic change of apparent gas velocity has a great influence on the saturation of the first and last layers of filter cartridge.Increasing the apparent gas velocity appropriately within the acceptable range of experiment can accelerate the migration of liquid. However, the adhesion of fiber to droplets is relatively weakened when the apparent gas velocity reaches 0.5 m/s, and thus the droplets are easy to detach from the fiber, leading to the re-entrainment and further reducing the filtration efficiency.The baffle structure inside the filter cartridge can effectively avoid the re-entrainment of droplets at high apparent gas velocity.The filtration performance of the filter cartridge is improved most significantly at the baffle height of 15 cm, and the number concentration of downstream droplets is also decreased by 97.3% compared with the structure without baffle. Conclusively,the research results could provide important guidance to the development of efficient coalescence filter cartridge and the optimization of storage and transportation process of natural gas.(10 Figures, 2 Tables, 23 References)