How to Treat High Dust Concentration Gas with Baghouse Dust Collectors?

High dust concentration gas (dust concentration ≥1000g/m³, even up to 5000g/m³) is common in mines, foundries, boilers and other occasions. Direct treatment with baghouse dust collectors will cause rapid filter bag wear, blockage and shortened service life. To effectively treat high dust concentration gas, it is necessary to adopt the combination of "pre-treatment + core purification + optimization of operation parameters", and the specific measures are as follows:

1. Pre-Treatment: Reduce Dust Concentration (Key Step)
The core of pre-treatment is to remove large-particle dust (≥10μm) and reduce the dust concentration entering the filter bag to below 500g/m³, reducing the load of the baghouse dust collector. Commonly used pre-treatment devices are as follows:
1. Cyclone dust collector: The most commonly used pre-treatment equipment, which uses centrifugal force to separate large-particle dust from the gas, with a dust removal efficiency of 85-95% for large-particle dust (≥10μm). It has the advantages of simple structure, low investment, wear resistance and no need for frequent maintenance, suitable for most high dust concentration occasions.
2. Multi-tube ceramic dust collector: Suitable for high-temperature, high-abrasion high dust concentration gas (such as boiler flue gas, mine dust), which is composed of multiple ceramic cyclone tubes, with high wear resistance and high-temperature resistance, and the dust removal efficiency for large-particle dust is ≥90%.
3. Gravity dust collector: Suitable for ultra-large particle dust (≥50μm), such as foundry dust, which uses gravity to make dust settle, with simple structure and low cost, but low efficiency, generally used as the first-level pre-treatment.

For extremely high dust concentration gas (≥3000g/m³), a two-stage pre-treatment can be adopted: gravity dust collector (first-level) + cyclone dust collector (second-level), which can reduce the dust concentration to below 300g/m³, effectively protecting the filter bag.

 2. Core Purification: Optimize Baghouse Dust Collector Configuration
1. Filter bag selection: Select wear-resistant, high-air-permeability filter bags to adapt to high dust concentration. Commonly used materials include FMS, PPS wear-resistant type, and PTFE coated filter bags. The filter bag should have a thick texture and high dust holding capacity to avoid rapid blockage; for high-temperature gas, select high-temperature resistant filter bags (PPS, PTFE) to avoid bag burning.
2. Filter bag area: Increase the filter bag area appropriately (10-20% more than the standard area), reduce the air flow per unit area of the filter bag (filter wind speed ≤1.0m/min), reduce the dust accumulation speed and wear, and extend the service life of the filter bag.
3. Flower plate and filter cage: The flower plate should be smooth and free of burrs to avoid scratching the filter bag; the filter cage should be made of galvanized steel or stainless steel, with firm structure and no deformation, ensuring that the filter bag is fully expanded and the air flow is uniform.

 3. Optimize Operation Parameters: Improve Cleaning Effect
1. Cleaning system adjustment: Increase the cleaning frequency appropriately (from the normal 30-60s/time to 20-40s/time) to timely remove the dust on the filter bag surface and avoid excessive dust accumulation; the spray pressure is set to 0.4-0.6MPa, which ensures thorough cleaning without excessive impact on the filter bag.
2. Compressed air quality: Ensure that the compressed air is dry, pure and free of water, oil and impurities (install air dryer, oil-water separator), avoid the pulse valve and spray pipe being blocked, and prevent the filter bag from being damp and blocked.
3. Air volume and negative pressure: The air volume of the fan should be 10-20% higher than the actual gas volume to ensure that the gas flows smoothly; the negative pressure of the equipment should be controlled within 1500Pa to avoid excessive negative pressure causing dust penetration into the filter bag.

 4. Auxiliary Measures: Extend Service Life and Ensure Stability
1. Wear resistance treatment: The air inlet, ash hopper and other parts of the dust collector are lined with wear-resistant plates to avoid wear caused by high-speed dust impact.
2. Ash discharge system: Use automatic ash discharge devices (star-shaped ash discharge valve + spiral conveyor) to discharge the collected dust in a timely manner, avoid dust backflow and accumulation on the filter bag, and reduce resistance.
3. Daily maintenance: Regularly check the filter bag for wear and blockage, and replace the damaged filter bag in time; clean the pre-treatment device and air duct regularly to avoid blockage; record the operation parameters (resistance, dust concentration, spray pressure) and adjust them in time.