Natural gas extracted from formations often contains sand grains and other solid impurities (such as rust) as well as harmful substances such as water, steam, sulfides and carbon dioxide. Sand, iron and other dust particles move with the air flow in the pipeline, wearing compressor, pipeline and instrumentation components, resulting in damage, damage, and sometimes gathered in some parts, affecting the normal operation of gas transmission; if mixed water gathered in the low-lying pipeline, it will reduce the pipeline cross-section, increase gas transmission resistance, but also will A layer of water film is formed on the inner wall of the pipeline, and the acidic gas (H2S, CO2, etc.) forms an acidic aqueous solution, which corrodes the inner wall of the pipeline and causes the pipeline to be destroyed. The water mixed with the pipeline can also form ice-snow hydrate with some components of natural gas under certain temperature and pressure conditions, resulting in ice plugging of the pipeline.
Therefore, it is an important task to filter out the solid impurities and other harmful substances in the natural gas pipeline to ensure the safe operation of the gas pipeline. The liquid and solid impurities in natural gas transportation system mainly come from three aspects: first, condensate oil, condensate water and rock debris dust brought from underground during gas production; second, dirt (dirt) and welding slag left in pipeline during pipeline construction; third, corrosion products of pipeline and related equipment and instruments.
Usually, separators, dust collectors and filters are installed at gas collection stations, compressor stations, gas distribution stations and pressure regulating and metering stations to remove all kinds of solid (liquid) impurities. Natural gas pipeline filters are generally used to remove less than 5 mm of solid particles and droplets. The selected polyester fiber filter core has a long life and high filtration efficiency. It has been widely used in domestic natural gas transmission projects with good results.
Structure features and working principle of filter
The structure of natural gas pipeline filter is mainly composed of shell, quick opening blind plate, filter assembly, liquid accumulation tank and other internal and external components, generally using horizontal structure (Fig. 1). Filter module is composed of filter element, filter element base, pressure cover and separator. The shell is divided into filter chamber and exhaust chamber by separator of filter element. The core component is filter element which is fixed on the separator element base according to certain arrangement. The filter element is changed periodically to ensure its filtering efficiency.