Corrosion-resistant high-temperature dust filter bag

Corrosion-Resistant High-Temperature Dust Filter Bags

I. Core Features and Application Positioning

Corrosion-resistant high-temperature dust filter bags are high-efficiency filtration materials designed for high-temperature (150°C-280°C) and highly corrosive (acids, alkalis, solvents, sulfides, etc.) industrial flue gas environments. They address core issues such as short lifespan and rapid efficiency degradation of traditional filter bags in complex working conditions, and are widely used in demanding scenarios such as chemical processing, metallurgy, waste incineration, and desulfurization and denitrification in power plants.

II. Key Materials and Performance Parameters

(I) Comparison and Selection of Main Filter Materials

Corrosion-Resistant High-Temperature Dust Filter Bags

(II) Composite Enhancement Technologies

PTFE Membrane Modification: A 1-3μm PTFE film is applied to the base fabric surface to achieve "surface filtration," increasing dust release rate to 99%, while enhancing anti-adhesion and chemical resistance (e.g., resistance to hydrofluoric acid, sulfuric acid, etc.).

Anti-static Treatment: Incorporation of carbon fibers or conductive fibers (≤5%), with surface resistance ≤10⁹Ω, meeting safety filtration requirements for flammable and explosive dust (e.g., coal dust, aluminum powder).

Water and Oil Repellent Coating: Using PTFE emulsion impregnation process to achieve surface tension ≥72mN/m, preventing filter clogging caused by oily flue gas (e.g., asphalt mixing plants).

III. Structural Design and Filtration Principles

(I) Typical Structural Parameters

Sewing Process: PTFE sewing thread (temperature resistance 260°C), stitch spacing ≤8 stitches/10cm, bag mouth reinforcement ring made of 304 stainless steel or polyetheretherketone (PEEK) material to resist high-temperature deformation.

Filtration Precision: Conventional needle felt filter materials achieve ≥99.5% filtration efficiency for dust ≥1μm; after membrane coating, efficiency for 0.3μm dust reaches ≥99.9%.

Air Permeability: 8-15m³/(㎡・min), resistance coefficient ≤200Pa・m²・min/m³, balancing filtration efficiency and energy consumption.

(II) Working Principles

Deep Filtration Stage: Dust-laden flue gas penetrates the filter material from outside to inside; particles >5μm are mechanically intercepted by base fabric fibers, while fine dust (0.1-5μm) is captured by the fiber layer through diffusion and inertial collision.

Surface Filtration Stage: As the dust layer (filter cake) forms, PTFE membrane or smooth surface filter materials sieve sub-micron particles; during cleaning, the dust layer peels off entirely, reducing internal clogging of the filter material.

Corrosion Resistance Mechanism: Molecular structure lacks active groups (e.g., PTFE's C-F bond energy up to 485kJ/mol), avoiding chemical reactions with corrosive gases such as SO₂, NOx, and HCl.