What is the reason for the short service life of dust filter bags?

The short service life of dust removal filter bags is not caused by a single factor.The core is the combination of four major problems:mismatched filter material selection and working conditions,improper control of operating parameters,equipment structure/cleaning system failures,and inadequate daily operation and maintenance.The mild problems can accelerate the aging and wear of filter bags,while the severe problems can directly cause filter bag damage and failure.The following is a three-stage summary of the core causes,covering common problems in various industrial dust removal working conditions,and the various factors are often interrelated and form chain damage:

1、The basic deviation between filter material selection and finished product processing determines the upper limit of filter bag service life from the source

Inconsistent selection of filter media is the core root cause of premature failure of filter bags.If they are not in line with the temperature,composition,and dust characteristics of the flue gas,the filter bag will suffer irreversible damage in a short period of time.One is the temperature adaptation error.Using normal temperature polyester filter bags to treat high-temperature flue gas,or operating high-temperature filter bags for a long time beyond their rated temperature resistance,can cause the filter fiber to melt,become brittle,and age,resulting in a rapid decrease in physical strength;Secondly,the material of the filter material does not match the composition of the flue gas.If PPS,PTFE and other corrosion-resistant filter materials are not selected for highly corrosive flue gas,it will cause the filter fiber to be corroded and broken by acid and alkali.If hydrolysis resistant filter materials are not selected for high humidity conditions,it is easy to cause filter bag sticking and compaction;Thirdly,the process was not matched according to the characteristics of the dust.The fine sticky powder was not covered with film filter material,which led to the infiltration of dust into the pores of the filter material.The coarse hard powder was not thickened with wear-resistant filter material to accelerate erosion and wear.The flammable and explosive dust was not treated with anti-static treatment,which caused damage to the filter material due to static accumulation.In addition,poor processing quality of finished filter bags can also shorten their lifespan,such as weak stitching of stitches,replacing temperature and corrosion resistant threads with ordinary stitching,not installing wear-resistant bottom rings at the bottom,and poor material of bag sealing gaskets,which can easily lead to problems such as loose threads,local wear,and sealing failure of filter bags.

2、Improper control of operating parameters and cleaning system is the main cause of accelerated failure of filter bags

Deviation of dust collector operating parameters from design values,combined with dust removal failure or excessive cleaning caused by operation/malfunction of the dust removal system,will continue to cause double damage to the filter bag.On the one hand,the parameters of smoke and dust are out of control.Long term overheating and sudden temperature changes in smoke can cause thermal expansion,contraction,and fatigue of filter fiber.Excessive moisture content or air leakage in the shell can lead to condensation,causing viscous dust to adhere to the filter bag and form a paste bag.Moreover,condensation can accelerate the hydrolysis of filter material and rusting of cage bones,leading to the abrasion of the filter bag;Excessive concentration of dust at the inlet and wind speed on the surface of the filter bag exceeding the design value will cause a sharp increase in the filtering load of the filter bag.The dust layer will quickly thicken and solidify,and if the dust is not cleaned in time,it will push up the resistance.At the same time,high-speed airflow will carry coarse dust and form a"sandblasting effect",flushing the air inlet and bottom of the filter bag.On the other hand,improper operation or malfunction of the dust cleaning system,such as high dust cleaning pressure or long spraying time,can directly tear the filter fiber.High dust cleaning frequency can lead to repeated stretching and fatigue of the filter bag,while insufficient dust cleaning pressure,pulse valve failure,and misaligned spraying pipe can cause dust cleaning failure and long-term accumulation and compaction of the dust layer;More importantly,compressed air carrying water and oil during dust cleaning can form oil sludge and cement like adhesives on the surface of the filter bag,resulting in permanent sticking of the bag and inability to restore breathability through dust cleaning.

3、Equipment structural failures and omissions in daily operation and maintenance have caused continuous mechanical damage to the filter bag,and hidden dangers have not been promptly investigated

The mechanical friction and airflow erosion caused by structural defects in the dust collector equipment,coupled with the expansion of small hidden dangers caused by inadequate daily operation and maintenance,are important reasons for the early damage of filter bags.At the equipment level,firstly,the airflow distribution is uneven.The air inlet is not equipped with a guide plate or distribution plate,and high-speed airflow directly hits the air inlet and bottom of the filter bag,causing local erosion and wear;Secondly,the improper fit between the cage bone and the filter bag may result in deformation,burrs,open welding,or dimensional deviation of the filter bag,leading to a loose fit between the cage bone and the filter bag.During the operation of the dust collector,the filter bag and cage bone continue to rub against each other,causing the surface of the filter bag to be worn down;The third issue is the malfunction of the ash hopper and sealing system.The ash hopper accumulates and fills the bottom of the filter bag,causing both air flow erosion and continuous dust adhesion.Leakage of the shell,manhole door,and flange introduces cold air,causing condensation.The offline valve is not tightly closed,causing air flow to enter and exacerbating the wear of the filter bag.At the operational level,the core issue is the lack of daily inspections.The pressure difference between the inlet and outlet of the dust collector,as well as the temperature and humidity of the flue gas,were not monitored in a timely manner.When the filter bag was worn thin,fell off,or had small cracks,it was not detected and replaced in a timely manner,resulting in the damage expanding and affecting the surrounding filter bags;The compressed air system did not regularly drain water,oil,and clean the filter element.The ash hopper did not unload ash in a timely manner,and the bridge accumulated ash was not cleared.The cage bone deformation and pulse valve aging faults were not repaired in a timely manner,and various small hidden dangers continued to accumulate,ultimately causing the filter bag to fail prematurely and significantly shortening its overall service life.

GB/T 7714:

LI D M,TIAN Y J,GUO Y,et al.Analysis of factors affecting the service life of filter bags in baghouse dust collectors[J].Thermal Power Generation,2013,42(4):104-106.

MLA 9th:

Li,Dongmei,et al."Analysis of Factors Affecting the Service Life of Filter Bags in Baghouse Dust Collectors."Thermal Power Generation,vol.42,no.4,2013,pp.104–106.

APA 7th:

Li,D.,Tian,Y.,Guo,Y.,Li,W.,Li,Y.,&Wu,W.(2013).Analysis of factors affecting the service life of filter bags in baghouse dust collectors.Thermal Power Generation,42(4),104–106.