Filter bag failure analysis, find the cause, not just the hole.
A filter bag autopsy is a laboratory examination of bags pulled from a baghouse to find out why they failed or why pressure drop rose. It separates the cause, such as chemical attack, heat damage, abrasion or a cage defect, from the symptom. Masturlal autopsies pulled bags as part of its condition surveys and uses the findings to specify the next set of bags.
- Part of
- Condition surveys and AMC
- Output
- Report with cause and next-set specification
Common failure modes
| What you see | Likely cause | Typical fix |
|---|---|---|
| Holes near the bag bottom | Abrasion from inlet gas or bags rubbing | Inlet baffle, wear cuff, heavier felt |
| Brittle, discoloured felt | Chemical attack or oxidation | Change fibre (for example PPS to P-84) |
| Felt weak and crumbly after moist service | Hydrolysis | Hydrolysis-resistant fibre; control dew point |
| Shrunk or glazed felt | Temperature excursion | Higher-rated fibre; temperature control |
| Wear lines along the length | Damaged or wrong cage | Replace or match cages |
| High ΔP, bag intact | Blinding by fine or sticky dust | Smoother surface, ultra-microfibre layer, pulse tuning |
| Burn holes | Sparks or hot particles | Spark arrestor; flame-retardant media |
What the analysis covers
- Visual and microscopic examination of the felt, seams and top and bottom
- Remaining strength and air permeability compared with new felt
- Dust penetration into the felt and the state of the dust cake
- Review of operating data: temperature, ΔP history and cleaning settings
How to send bags
- Pull bags from the worst and an average location, and mark their row and column.
- Bag them separately with the dust left on.
- Include an unused bag from the same set if available.
- Send operating data: temperature trend, ΔP, cleaning pressure and cycle.
Questions, answered.
Why do baghouse filter bags fail early?
The most common causes are abrasion, chemical attack, hydrolysis, temperature excursions, damaged cages and blinding. An autopsy tells you which one it is.
What is a filter bag autopsy?
A laboratory examination of used bags to find the cause of failure or high pressure drop, so the next set can be specified to last longer.
Can an autopsy lower pressure drop?
Yes. If bags are blinding, the report points to a better surface finish, media or cleaning setting, which lowers differential pressure and fan power.
Send us your dust profile.
Temperature, chemistry, moisture, particle size and your emissions target. An application engineer replies within one working day, usually with a media specification within two.