In modern industrial flue gas purification systems, baghouses frequently face challenges from various corrosive mediums, primarily hazardous gases and particulates. For example, during the combustion of coal or heavy oil fuels, sulfuric acid gases generated due to the presence of sulfur can be highly corrosive. Simultaneously, certain dust particles react with moisture to form salts, causing severe corrosion risks to the equipment.

 

Baghouses, as core equipment for flue gas purification, have their performance and lifespan significantly influenced by anti-corrosion design and material selection. Therefore, it is essential to develop suitable anti-corrosion measures for baghouses based on different industrial application scenarios and flue gas compositions. These measures include:

 

1.Controlling Flue Gas Temperature

 

Corrosion typically occurs when the flue gas temperature drops below the acid dew point. Ensuring that the bag filter operates above the dew point temperature is a fundamental anti-corrosion strategy.

 

2.Selecting Corrosion-Resistant Filter Media

 

The choice of filter media for a dust collector depends on the composition of the flue gas. For acidic and neutral gases, polyester or polypropylene filter media are recommended due to their excellent resistance to most inorganic and organic acids. Polyester can withstand temperatures up to 130°C, while polypropylene is suitable for conditions below 80°C. For temperatures exceeding 130°C, fiberglass or heat-resistant Nomex nylon may be used, though caution is required in environments with high concentrations of SO₂ or phosphoric acid gases.

 

3.Optimizing Material Selection

 

In industries with high corrosion resistance requirements, such as pharmaceuticals, food processing, and carbon black production, stainless steel is recommended for constructing key components of the bag filter, including the housing, hopper, and valves. This enhances the overall corrosion resistance of the dust collector.

 

4.Applying Protective Coatings

 

To combat corrosion from sulfur oxides generated by heavy oil and coal combustion, protective coatings such as silicone resin or epoxy resin can be applied to steel surfaces. These high-temperature and acid-resistant coatings significantly extend the baghouse's operational life.

 

5.Adding Internal Linings

 

In environments with highly corrosive gases, the internal components of the baghouse, such as the housing and hopper, can be lined with materials like plastic, rubber, or fiberglass. However, it is crucial to ensure that high-temperature gases do not damage the lining materials.

 

6.Corrosion Protection for Bag Cages

 

Bag cages in a bag filter can be treated with anionic electrophoresis, coated with acid-resistant paint, or made of stainless steel wire to improve reliability and durability.

 

Through scientific design and careful material selection, baghouses can effectively handle corrosive gases, ensuring long equipment life while significantly improving the efficiency of flue gas purification. These measures make bag filters and dust collectors indispensable for industrial environmental protection.