Development Of New Coalescence Fuel/water Separation Filter

Nowadays almost all commercial and passenger vehicles are equipped with diesel engines with high pressure common rail fuel injection system,and fuel has the lower surface tension and fuel/water separability with the upgrade of emission regulations,the continuous decrease of diesel sulphur content and the increase of additive and biodiesel content,etc.So,better fuel/water separation performance is required for filter.The long life system is the development focus and the trend of the area.In order to prolong the fuel/water separation efficiency of the filter,the three-stage filter element structure is currently the mainstream scheme in European and American countries.The paper mainly studied the effect of different filter combinations on particle filtration efficiency and fuel/water separation efficiency.In order to simulate the actual fuel conditions,A3 dust was used to simulate the solid particles in the fuel system,and the effects of different filter materials on the fuel/water separation efficiency were investigated.The structure design of the three-stage filter element is completed through laboratory research and road test.The design can meet the needs of the market for the maintenance of the long-life fuel/water separator for 100,000 km.The successful development of the filter has very important practical significance for the revision of the filter industry standard.In this paper,the performance of traditional single-stage fuel/water separator is compared and studied.The results show that the performance of single-stage filter is affected by particle pollutants.With the increase of the intercepted particulate pollutants,the pressure drop of the product increases continuously,causing the fuel/water separation efficiency of filters begin to fail when it is far from 40 kPa pressure drop of the end life.In the actual road test,the traditional single-stage fuel/water separator can only normal working 40,000 km with 95% fuel/water separation efficiency.After the 100,000 km road test,although the pressure drop did not rise to 40 kPa,its fuel/water separation efficiency has been reduced to less than 30%.Therefore,the traditional single-stage fuel/water separator can not meet the design requirements of the long-life filter.The paper puts forward the design scheme of the new fuel/water separator,determines the selection standard of the filter material,probes into the internal structure of the filter material and the kind of fiber,the wettability of the filter material.Screens out filter materials for different stages filter that meet the requirements,and carries on the combination match to the filter material.And different stage filters are made by the selected materials.The results show that the three-stage fuel/water separator,which consists of 4F#,5S# and 9T#,can always keep 95% fuel/water separation efficiency in the test of fuel/water separation by adding A3 dust to 40 kPa pressure drop.The actual road test of the filter show that the pressure drop of the fuel/water separator increases with the increase of driving distance.And at the end of 100,000 km,the end pressure drop did not reach to 40 kPa.Through the analysis of appearance,bubble point value and burst strength of filter paper,no damage of filter was found in the three-stage coalescence fuel/water separator(T1#)that used for 100,000 km,and the fuel/water separation efficiency can still maintain 95%.Therefore,the three-stage fuel/water separator T1# fully meets the needs of long life filter maintained 100,000 km.