High moisture flue gas (15–40 %) + acid dew point destroys polyester bags in weeks. The only two proven high moisture dust collector bags that survive and perform are Nomex filter bags (meta-aramid) and PTFE filter bags (100 % Teflon).
Nomex vs PTFE Filter Bag – Direct Comparison (2025)
| Item | Nomex Filter Bag (Meta-Aramid) | PTFE Filter Bag (100 % Teflon) |
|---|---|---|
| Max continuous temperature | 204 °C | 260 °C |
| Hydrolysis resistance | ★★★★ Very good (much better than polyester) | ★★★★★ Excellent (completely inert) |
| Acid resistance | Good (weak point in strong mineral acids) | ★★★★★ Best in class |
| Moisture tolerance | Handles 20–30 % moisture very well | Unlimited – no hydrolysis ever |
| Typical emission (with membrane) | <10 mg/Nm³ | <2–5 mg/Nm³ |
| Bag life in high-moisture biomass/coal + scrubber | 2–3 years | 4–6 years |
| Pressure drop | Low–medium | Lowest (especially with ePTFE membrane) |
| Relative price (Nomex = 100 %) | 100 % | 250–350 % |
| Most common applications | Biomass boilers, cement kilns, metal smelting with moderate moisture | Waste incineration, coal-fired with wet scrubber, hazardous waste, ultra-long life projects |
When to Choose Which High Moisture Dust Collector Bag
| Condition | Recommended Bag | Reason |
|---|---|---|
| 160–200 °C + high moisture + budget limit | Nomex filter bag + PTFE membrane | Best cost/life balance for most plants |
| Constant wet acid gas, NOx, SOx, HF | PTFE filter bag (100 % PTFE fiber + membrane) | Only material that never hydrolyzes or corrodes |
| Need >4 years bag life & <5 mg emission | PTFE filter bag | Proven 5–6 years in toughest conditions |
| Temperature spikes >220 °C occasionally | PTFE only | Nomex will degrade above 204 °C long-term |
Real 2025 References
- 60 MW biomass plant (UK) → Nomex + membrane → 38 months life, emission 6.8 mg/Nm³
- 400 t/d waste incinerator (Germany) → 100 % PTFE filter bags → 62 months zero failure, emission 1.2 mg/Nm³
Quick Answer
- Budget + good performance → Nomex filter bag (with PTFE membrane)
- Maximum durability & harshest high-moisture acid gas → PTFE filter bag
Both are excellent high moisture dust collector bags — just pick according to temperature and how aggressive your flue gas really is.
Need free samples of Nomex or PTFE high moisture dust collector bags? Contact us with your exact temperature/moisture data and we will recommend the perfect one!