Boiler specific PPS bag

PPS (polyphenylene sulfide) bag for boilers is a mainstream filter bag suitable for high-temperature sulfur-containing, high humidity, and high dust conditions of coal-fired/biomass/waste incineration boilers. It is made of PPS needle felt as the core, impregnated/coated with PTFE and shaped at high temperatures. It can withstand temperatures of 190-200 ℃ continuously and 230-260 ℃ instantly, resist SO ₂/NO ₓ corrosion, and has a filtration efficiency of ≥ 89.90%. It is a cost-effective solution for boiler flue gas purification.

Core Structure and Process

Main body of filter material

Substrate: 90% PPS fiber needle punched felt (450-600g/㎡), with PPS or PTFE as the base fabric for enhanced strength; Excellent PTFE microporous film (pore size 0.1-1 μ m) is used to improve efficiency and cleaning performance.

Post treatment: High temperature setting (200 ℃ × 60 minutes) to prevent shrinkage, PTFE impregnation/calendering to enhance stable performance and low viscosity, optional three proofing (based on actual reports) (based on actual reports) blended with conductive fibers.

Sewing: Double stitching with PTFE thread, stainless steel elastic expansion ring at the bag opening, double-layer reinforcement of 100mm at the bag bottom, and longitudinal reinforcement to prevent tearing.

Adaptive skeleton

Conventional: Low carbon steel+(based on actual reports) silicon coating (resistant to 200-280 ℃), 8-16 longitudinal bars, wire diameter 3.2-3.8mm, corrosion (based on actual reports) anti adhesion.

High sulfur/high humidity: stainless steel+(based on actual reports) silicon/PTFE coating, extending the lifespan of the skeleton and avoiding adhesion with the filter bag.

Key performance parameters (typical values)

Adaptation scenario

Coal fired boiler: Suitable for sulfur-containing flue gas (≤ 3000ppm SO ₂), dry/semi dry flue gas purification after desulfurization, with good cost-effectiveness.

Biomass boiler: resistant to high humidity and alkali corrosion, suitable for straw/sawdust combustion flue gas.

Garbage incineration/hazardous waste boiler: resistant to acid corrosion, combined with PTFE coating to enhance the capture efficiency of dioxins and fine dust.

Industrial boilers: medium and large boilers for coking, metallurgy, building materials, etc. The recommended gas to cloth ratio is 3-5m/min (online cleaning) and 5-6m/min (offline cleaning).

Key selection points

Base fabric: High sulfur/high humidity PTFE base fabric is selected to enhance hydrolysis resistance and strength.

Weight: Conventional 500-550g/㎡, High Dust/High Grinding Choose 600g/㎡.

Post processing: For high humidity/high viscosity dust, choose PTFE coating+(based on actual reports) (based on actual reports); Selection of operating conditions for low and low temperature economizer (based on actual reports).

Avoiding pitfalls: Long term overheating (>200 ℃) and high oxygen (>8%) are strictly prohibited, otherwise the filter bag is prone to brittleness and fracture.

Installation, maintenance, and lifespan improvement

Installation: The skeleton is free of burrs and the coating is not damaged. The gap between the filter bag and the skeleton is 2-5mm, and the bag mouth is sealed in place to avoid air leakage and wear.

Dust cleaning: pressure 0.2-0.4MPa, frequency adjusted according to pressure difference (800-1200Pa) to avoid excessive dust cleaning damaging the filter material.

Maintenance: Regularly check the flue gas temperature, oxygen content, and SO ₂ concentration, and adjust operating parameters in a timely manner if they exceed the threshold; Check for damaged or stuck filter bags when there is a sudden change in pressure difference.