When to replace industrial dust filter bags？

1. Sustained Abnormal System Pressure Differential

System pressure differential (also known as resistance) is the primary indicator of filter bag condition.

Sustained High Pressure Differential: When the pressure differential of a dust collector remains significantly higher than its initial design value for an extended period (for example, a normal value of 1000-1500 Pa is consistently above 2000 Pa), and standard cleaning procedures (such as pulse jets) are unable to effectively reduce it, this typically indicates that the filter bags are severely clogged. The blockage may be caused by dust agglomeration, oil adhesion, or moisture buildup. In this case, the fan must work harder, energy consumption increases dramatically, and dust removal efficiency decreases. At this point, the filter bags should be replaced.

Abnormally Low Pressure Differential: If the system pressure differential suddenly becomes abnormally low, this is not necessarily a good sign. It may indicate that the filter bags are damaged or falling off. This is because the loss of resistance means that dust is passing through without being filtered, which can directly lead to excessive emissions.

2. Damage or Defects in Industrial Dust Filter Bags

Hole and Tears: This is the most common problem. Any holes, tears, or burns on the filter bag surface must be replaced immediately. Even small holes can rapidly expand under negative pressure, directly releasing large amounts of dust and damaging adjacent, healthy filter bags.

Excessive Wear: Focus on inspecting the bottom, inner seams, and areas near the bag opening. Severe wear typically indicates uneven airflow distribution, burrs or bends in the cage (frame), or improper installation. Wear can weaken the filter bag and eventually cause it to rupture.

Chemical Corrosion and High-Temperature Damage: If the filter bag surface becomes brittle, loses its elasticity, breaks easily, or undergoes an unusual color change (such as yellowing or blackening), this could be due to corrosion from acidic or alkaline components in the flue gas, or prolonged operation in an environment exceeding the filter media's resistance temperature, leading to material aging. These filter bags have lost their filtering function and must be replaced in batches.

3. Excessive Emissions

This is a mandatory signal for filter bag replacement. Chimney "Dust Emissions": If dust can be seen escaping from the chimney or exhaust port of the dust collector, forming a noticeable plume, this is direct evidence of filter bag failure. This indicates the filter bags are either severely damaged or poorly sealed, failing to effectively capture dust.

Environmental Monitoring Data Exceeding Standards: Many companies now have online monitoring systems installed. When data shows that particulate matter emission concentrations consistently exceed national or local environmental standards, the operation must be shut down for inspection and filter bag replacement; failure to do so will result in environmental penalties.

4. Planned Replacement at End of Life

Even without the aforementioned emergency situations, filter bags have a normal service life.
Based on operating time: Different types of filter bags have a rough range of service lives under their design conditions (e.g., 1-3 years under normal operating conditions, and even shorter under severe operating conditions). Preventive batch replacements can be performed at the end of their expected lifespans, based on manufacturer recommendations and your own experience. This is a planned maintenance stop that avoids unplanned downtime caused by sudden filter bag failure during peak production periods, making it more economical and manageable.

Based on product batch requirements: In industries such as food, pharmaceuticals, and fine chemicals, dust collector filter bags are replaced as part of the process when switching between product categories to prevent cross-contamination between batches. This is a quality management requirement.

5. Precautions When Replacing Filter Bags

Safety First: Before replacing a filter bag, ensure the dust collection system is completely shut down, powered off, and depressurized. Lock and tag out the system. Personnel must wear protective equipment such as dust masks, goggles, and gloves.
Inspecting Components: When replacing filter bags, always inspect the cage frame for signs of bending, corrosion, or burrs. Any damaged cage frame must be replaced as well, as it will quickly wear out the new filter bag like a file.

Proper Installation: Ensure the new filter bag is the same size and material as the original. During installation, ensure the seal fits snugly against the panel to prevent air leaks. Handle the bag with care during installation to avoid damage.
Record and Analyze: Record the time, location, and reason for each filter bag replacement. Analyze the cause of frequent damage (is it the wrong material, airflow issues, or improper operating temperature?). Addressing the root cause will extend the life of subsequent filter bags.