In industrial dust removal systems, high-temperature working conditions (usually temperatures above 150°C) place higher demands on the heat resistance, chemical stability and structural strength of filter bags. Choosing a high-temperature dust filter bag material suitable for your working conditions is not only related to the dust removal efficiency, but also directly affects the stability of equipment operation and the service life of the filter bag. The following is a detailed explanation of how to scientifically select from multiple dimensions.
1. Clarify the working temperature
First, you need to understand the actual temperature range of the system, including:
Continuous working temperature (long-term operating temperature)
Instantaneous high temperature peak (such as temperature during startup, shutdown or fluctuation)
When selecting filter bag materials, ensure that their "continuous working temperature" is higher than the normal temperature of the system, and can withstand occasional high temperatures in a short period of time to avoid carbonization, softening or embrittlement of the material. For example:
Material continuous working temperature instantaneous temperature resistance characteristics
PPS 160℃～190℃200℃ acid and alkali resistance, poor hydrolysis resistance
FMS 200℃～240℃260℃ excellent comprehensive performance, moderate price
P84 220℃～240℃260℃ heat resistance, strong chemical resistance, high price
PTFE 240℃～260℃280℃ strongest corrosion resistance, high price
Glass fiber needle felt 250℃～280℃300℃ high temperature resistance, but poor folding resistance
2. Analysis of flue gas composition and chemical corrosion
The flue gas in high temperature dust removal environment often contains acid, alkali, oxidant, water vapor, oil, etc. The filter bag material must have corresponding chemical corrosion resistance. For example:
When there are many acidic gases (such as SO₂, HCl), it is more stable to choose P84 or PTFE filter bags;
PPS is not recommended for flue gas with strong oxidizing properties (such as coal-fired boilers) because its anti-oxidation property is weak;
When the humidity is high and there is water vapor condensation, materials with good hydrolysis resistance, such as PTFE, should be selected.
3. Consider dust characteristics and filtration requirements
When the dust particle size is fine and easy to clog, filter materials with smooth surface and easy to clean should be selected, such as PTFE coated filter bags;
When the dust is oily or sticky, filter materials with hydrophobic and oil-proof properties should be selected;
For occasions with high filtration accuracy requirements, fine fiber composite materials or coated filter bags can be selected.
4. Match the cleaning method of dust removal equipment
Different cleaning methods have different requirements for the mechanical strength and fatigue resistance of filter bags:
Pulse jet dust collector: filter bags need to have good folding resistance and resilience;
Mechanical vibration or back-blowing: The mechanical strength of filter bags is higher, and it is recommended to use materials that are resistant to folding and tearing;
High negative pressure system: The tensile strength of filter bags should be high to prevent bag collapse or tearing.
5. Economic efficiency and service life
The price of filter bag materials varies greatly, and should be considered comprehensively in combination with service life:
PPS and FMS are mainstream materials with high cost performance, suitable for most working conditions below 200℃;
P84 and PTFE filter bags are more expensive, but they are more stable and have longer service life under harsh working conditions such as high temperature, high corrosion, and high dust concentration;
If the equipment maintenance cycle is long or the replacement cost is high, it is recommended to give priority to materials with longer service life.
VI. Conclusion and Suggestions
The following factors should be considered when selecting high-temperature dust filter bag materials:
Actual flue gas temperature and peak fluctuation
Flue gas composition (whether there are corrosive gases, oiliness, water vapor, etc.)
Dust particle size and characteristics (viscosity, flammability, etc.)
Dust collector type and cleaning method
Filter bag replacement cycle and total operating cost