Main Causes and Mechanism of Filter Bag Aging

As the core equipment for industrial dust removal, the stable performance of filter bags in baghouse dust collectors directly determines emission compliance and operation and maintenance costs.Aging and failure are the primary causes of shortened filter bag service life, typically manifested as embrittlement, damage, clogging, corrosion, and more, which eventually lead to reduced dust removal efficiency and frequent equipment malfunctions.

1. Main Causes and Mechanism of Filter Bag Aging

1.1 High-Temperature Thermal Damage (Thermal Aging / Thermal Oxidation)

Long-term operation of flue gas temperature beyond the material’s heat resistance causes pyrolysis and molecular chain breakage of fibers, or thermal oxidation in an oxygen-containing environment, resulting in hardening, shrinkage and embrittlement of filter bags. Typical symptoms include hardened, cracked filter bags with obvious strength loss and yellowish or carbonized traces on the surface.

1.2 Chemical Corrosion (Acid / Alkali / Oxidative Erosion)

Acid gases such as SOₓ, NOₓ, HF or alkaline dust in flue gas react chemically with filter fibers under high temperature and humidity, leading to fiber degradation and sharp strength reduction. The filter bags show pulverization, delamination, spotted corrosion and rapid attenuation of tensile strength.

1.3 Mechanical Abrasion (Physical Aging)

High-speed dust-laden airflow carries high-hardness particles and continuously scours the filter bags, causing groove-shaped damage. Burrs, welding slag or mismatched cage frames also scratch and abrade the bags severely. Typical damage includes regular wear marks and holes on the windward side, bottom and contact positions with the cage.

1.4 Improper Cleaning Parameters (Over-Cleaning or Insufficient Cleaning)

Excessively high pulse pressure and frequent cleaning cause fiber breakage and bag mouth tearing. Insufficient cleaning leads to dust caking, increased resistance and permanent clogging.

1.5 Hydrolysis and Aging (Combined Effect of Heat and Moisture)

Under high temperature and high humidity, polymer fibers such as polyester undergo hydrolysis, which accelerates fiber degradation. Condensation and oil contamination further lead to sticky, mildewed and completely clogged filter bags.

1.6 Installation and Operation Defects

Improper installation, loose or over-tight fitting, skewed placement and lack of regular inspection often result in early damage and abnormal differential pressure fluctuations.

2. Targeted Solutions and Countermeasures

2.1 Optimize Material Selection to Avoid Aging Risks at the Source

2.2 Process and Operating Condition Control

Strictly control operating temperature to keep it within the material’s allowable range and above the acid dew point to avoid condensation and corrosion. Optimize filtration velocity and install air distribution plates to reduce airflow scouring. Pre-coating can be applied to form a protective layer for highly abrasive dust.

2.3 Upgrade the Cleaning System

Standardize pulse cleaning pressure within 0.3–0.5 MPa and adopt differential pressure-based control instead of fixed timing to avoid over-cleaning. Use polished or Teflon-coated cages to reduce friction and wear. Regularly maintain pulse valves and nozzles to ensure uniform cleaning.

2.4 Standardize Installation and Operation Management

Install filter bags gently to avoid scratching and ensure tight sealing with the tube sheet. Monitor differential pressure, temperature and emission concentration daily. Carry out regular strength testing and predictive maintenance to extend service life and reduce unexpected shutdowns.

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Ms Yanice Yu

Qingdao Star Machine Technology Co.,Ltd.

Whatsapp/ Wechat ID: +8617852092959

Email:Yanice@starmachinechina.com