From principle to application: How does acrylic needle felt achieve efficient dust removal?

1. Dust removal principle of acrylic needle felt

Physical interception mechanism

Three-dimensional fiber network: The acrylic fibers are intertwined through the needle punching process to form a porous structure, which directly intercepts dust particles (especially particles with a particle size of >1μm).

Surface filtration: Dust forms a "cake layer" on the surface of the filter bag, further improving the filtration accuracy (can capture particles larger than 0.3μm).

Electrostatic adsorption assistance

Fiber charge: Acrylic fibers generate static electricity during friction, which can adsorb charged dust (such as coal powder, metal oxides) and improve the capture efficiency.

Deep filtration and dust cleaning balance

Gradient density design: The filter bag consists of a dense surface layer (intercepting large particles) and a loose bottom layer (storing ash), which not only ensures filtration efficiency, but also avoids clogging too quickly.

Pulse cleaning compatibility: The acrylic felt structure is fluffy, and dust is easy to fall off during cleaning, restoring air permeability.

2. Core performance advantages of acrylic needle felt

High temperature resistance and chemical stability

3.Application scenarios and typical cases

• Cement industry

Challenges: high alkaline dust (K₂O, Na₂O) + high temperature (120-140℃).

Solution: Acrylic filter bags are highly alkali-resistant and can replace easily corrosive polyester filter bags, increasing their service life by 50%.

• Coal-fired boilers

Challenges: Flue gas contains sulfur oxides (SO₃) and has large humidity fluctuations.

Solution: Acrylic felt is resistant to acid hydrolysis and is equipped with a pulse cleaning system, with an emission concentration of <10mg/m³.

• Chemical industry

Challenges: Organic solvent vapor (such as acetone and benzene) corrodes the filter material.

Solution: Modified acrylic (adding antioxidants) to extend service life.

4. Precautions when using acrylic needle felt filter bags

Inspection and preparation before installation

Filter bag inspection: Before installation, make sure that the filter bag is not damaged, off-line or deformed, and the bag opening matches the size of the flower plate hole.

Equipment cleaning: Remove sharp objects such as welding slag and burrs inside the dust collector to prevent scratches on the filter bag.

Pre-coating treatment: For sticky dust (such as asphalt smoke), it is recommended to pre-coat the dust layer (such as lime powder) to prevent the bag from sticking.

Temperature control during operation

Avoid low-temperature condensation:

Keep the flue gas temperature higher than the dew point by 25-35℃ to prevent water vapor condensation from causing the filter bag to harden.

When shutting down, the moisture in the system needs to be emptied to prevent the filter bag from getting damp.

High temperature protection:

Continuous operating temperature ≤140℃, instantaneous peak ≤160℃. Overtemperature will cause fiber embrittlement, and an overtemperature alarm needs to be set.

Cleaning and maintenance specifications

Cleaning frequency:

Periodic pulse cleaning (pressure ≤0.4MPa) to avoid excessive cleaning to damage the fiber.

Observe the pressure difference change. A sudden increase in pressure difference may indicate that the filter bag is blocked or damaged.

Cleaning method:

Mechanical cleaning: Use compressed air to blow away the dust on the surface and avoid hard brush friction.

Chemical cleaning: Stubborn stains can be soaked with neutral detergent. Strong acids and alkalis are prohibited.

Chemical corrosion and wear protection

Acid and alkali environment:

Acrylic filter bags are acid-resistant (pH ≥ 3) but not resistant to strong alkalis (pH ≤ 11). Alkaline working conditions require blended PPS or PTFE filter bags.

Wear prevention:

Under high-concentration dust conditions, guide plates need to be installed to disperse the airflow and reduce direct scouring of the filter bag.

Shutdown and long-term storage

Shutdown maintenance:

Before long-term shutdown, the dust must be thoroughly cleaned to keep the filter bag dry to prevent mildew.

Check whether the bag cage is deformed to avoid uneven force on the filter bag when it is reused.

Storage conditions:

Place in a ventilated and dry place, away from direct ultraviolet rays and chemicals.