Structure Improvement Of Gas-liquid Coalescence Filter Element And Influence Analysis Of Filtration Gas Velocity

In the natural gas storage and transportation process,a large number of liquid impurities would be entrained in the gas,which posed a threat to the safe operation of the storage and transportation process.The natural gas station was equipped with gas-solid separator,filter separator and coalescence filter.Among them,the coalescence filter has short service life,high operation and maintenance cost and low filtration efficiency of micro and nano droplets under high gas velocity conditions.Therefore,using the experimental device of coalescence filter element filtration performance,this the thesis studied the filtration performance of different types of filter elements under normal and high gas velocity conditions by adjusting the arrangement of coalescence layer and changing the structure of coalescence layer.For the glass fiber filter element,under the working condition of gas velocity of0.15 m/s,the coalescence layer arrangement of oil drainage in front and oil affinity in back can improve the filter efficiency of the filter element and reduce the secondary entrainment of droplets.The filter efficiency of the filter element staggered with two layers of the same filter material was significantly higher than that of the filter element staggered with one layer of filter material,and the pressure drop was relatively low;Increasing the number of oil drainage filter layers at the inlet side can delay the increased of pressure drop,prolonged the service life,and made the steady-state quality factor of the filter element reach the maximum value(0.34 k Pa^-1);Under the same filter material arrangement and operating conditions,the folded filter element ha higher filtration efficiency and lower process pressure drop,and the quality factor has been increased by 8%～20%,so it has better comprehensive filtration performance.When the gas velocity was 0.3 m/s,the coalescence layer arrangement mode of oil drainage in front and oil affinity in back can still improve the filtering efficiency of the filter element.Compared with the winding filter element,the folded filter element has higher filtering efficiency and lower process pressure drop,and still has better comprehensive filtering performance;When the gas velocity increases,the liquid channel increases,the channel geometry decreases,and the ratio of the channel pressure drop to the initial pressure drop decreases,which reduces the energy consumption in the process of droplet migration.For the sintered metal fiber filter element,the smaller the pore diameter of the filter element composed of a single sintered felt,the better the filtration effect on submicron droplets,but the more serious the secondary entrainment,and with the increase of gas velocity,the filtration efficiency decreases,the channel pressure drop increases,and the jump pressure drop did not change significantly;The sintered metal filter element with increasing pore size can effectively improve the filtration efficiency of large droplets and reduce the occurrence of secondary entrainment.With the increase of gas velocity,the secondary entrainment is serious and the filtration efficiency of large droplets decreases.The research results aim to provide theoretical guidance and data support for the design and development of new and high-efficiency coalescence filter elements.