The Influence Of Oleophilic Fabric On Filtration Performance Of Superoleophobic Medium

Oil droplets carried by the natural gas impact sealing system of compressor,turbine blade and flowmeter during the exploration and transportation process of natural gas,and the coalescence equipment can remove the droplets to ensure the safe running of the system.To improve the efficiency and lower down the pressure drop of high-pressure natural gas coalescence filtration elements,this dissertation investigates the filtration characteristics of the combination of oleophilic fabric and superoleophobic mediums,analyzing the influence of fabric's structure and location on the coalescence filtration performance.Compared with oleophilic filtration materials,efficiency and quality factor of superoleophobic mediums are both improved.Filtration efficiency of droplets with various diameter grows with the material thickness,especially the small droplets.Suitable thickness of large and small droplets filtration is determined respectively.Because the oleophobicity changes the form of droplets within the filtration medium,the steady-state pressure drop rises slightly.Targeting the impact of film on jump pressure,the oleophilic fabric is used as the front-attachment and closely contacts the first layer,which decreases pressure drop sharply and enlarges the quality factor.The close-attachment between the fabric and first layer enables the fabric to absorb the film to lower down jump pressure drop,thus decreasing the steady pressure drop.The upstream air blows off the liquid accumulated in the fabric,lowering the efficiency but within a small range.Although the efficiency is reduced,the quality factor is improved due to the much smaller pressure drop.As the pore size of the front non-woven fabric increases,the steady-state pressure drop shows a “wedge” curve.Smallest value of pressure drop is achieved when pore size is 18.6?m,and further increasing the pore size wakens the capillary effect.When pore size lying within 3.6?m-5.90?m,the filter has highest efficiency.Re-entrainment of droplets reduces the efficiency when increasing the pore size to 18.6?m.When pore size is larger than 18.6?m,negative factors fade away and efficiency coincides with controlled experimental results.Adding different mass ratio of crisscross-shaped fibers in the front-attachment increases its ability to absorb the film and transfer the liquid,reducing the pressure drop of superoleophobic mediums.This is the first time that non-circular fibers applying in the liquid-gas filtration area.When the mass ratio of crisscross fiber rises to 75%,the pressure drop is the smallest because of the strong wicking ability that crisscross fibers have.Further increasing the ratio can't improve the wicking ability to a higher level.This dissertation analyzes the characteristics of the combination of oleophilic fabric and super-oleophobic filtration mediums,investigating crisscross-shaped fibers' influence on liquid-gas coalescence filtration.The results provide guidance for the advanced design and performance optimization of high-pressure natural gas filtration elements.