How to Maintain Filter Bags of Boiler Baghouse Dust Collectors?

The filter bag is the core component of the boiler baghouse dust collector, and its service life and performance directly affect the dust removal effect and operating cost of the equipment. Boiler flue gas has the characteristics of high temperature, high humidity, slight corrosion and high dust concentration, so the maintenance of filter bags must focus on anti-aging, anti-blockage, anti-corrosion and anti-wear. The specific maintenance measures are divided into daily maintenance, regular maintenance and abnormal maintenance, as follows:

 1. Daily Maintenance (Daily Inspection and Record)
1. Check the operating parameters: Record the equipment resistance, flue gas temperature, spray pressure and cleaning frequency every day. The normal operating resistance of the filter bag is 1200-1500Pa; if the resistance exceeds 1800Pa, it indicates that the filter bag may be blocked, and timely inspection and handling are required. The flue gas temperature should not exceed the long-term temperature resistance limit of the filter bag (e.g., PPS bags ≤180℃), and an alarm will be triggered if the temperature is too high, and the cooling device should be started immediately to avoid bag burning.
2. Observe the emission status: Check the exhaust port of the dust collector every day. If there is obvious dust emission (black smoke, gray smoke), it indicates that the filter bag is damaged or leaking, and the damaged filter bag should be found and replaced in time.
3. Check the cleaning system: Ensure that the pulse valve, solenoid valve and spray pipe operate normally, with uniform spray and no air leakage. Drain the water and oil in the air bag every day to avoid the compressed air containing water and oil adhering to the filter bag, causing dampness and blockage.
4. Check the ash discharge system: Ensure that the ash hopper is free of dust accumulation and hardening, and the ash discharge valve operates smoothly. Timely discharge the collected dust to avoid dust backflow and accumulation on the filter bag, increasing resistance.

2. Regular Maintenance (Periodic Inspection and Treatment)
1. Weekly inspection: Open the inspection door of the dust collector to check the surface condition of the filter bag, whether there is dust adhesion, deformation or damage; check the tightness of the filter bag and filter cage, and re-fix or replace if there is looseness or deformation. Clean the spray pipe and pulse valve nozzle to avoid blockage affecting the cleaning effect.
2. Monthly maintenance: Check the wear condition of the filter bag mouth (easy to wear due to friction with the flower plate), and replace the worn filter bag mouth or the entire filter bag if necessary. Inspect the filter cage for corrosion and deformation, and replace the corroded or deformed filter cage to avoid scratching the filter bag. Clean the pre-treatment device (cyclone dust collector) to avoid blockage leading to high dust concentration entering the filter bag.
3. Quarterly maintenance: Conduct a comprehensive inspection of all filter bags, sort out the filter bags with serious adhesion, blockage or slight damage, and clean or repair them (reusable filter bags can be cleaned with compressed air or water, and dried thoroughly before reinstallation). Check the corrosion and wear of the flower plate, and polish or replace it if there are burrs or wear to avoid scratching the filter bag.
4. Annual maintenance: Replace the filter bags that have reached the service life (e.g., polyester bags 1-2 years, PPS bags 2-3 years, FMS bags 3-4 years) in a unified manner. For filter bags that have not reached the service life but have poor performance (such as reduced air permeability, frequent blockage), they should also be replaced. Overhaul the entire cleaning system and ash discharge system to ensure that all components operate normally, providing a good operating environment for the new filter bags.

 3. Abnormal Maintenance (Handling of Special Faults)
1. Filter bag blockage: If the filter bag is blocked due to high humidity, viscous dust or improper cleaning parameters, first stop the machine and remove the blocked filter bag. For slightly blocked filter bags, use dry compressed air (pressure ≤0.3MPa) to blow and clean them from the inside out; for severely blocked filter bags (hard crust on the surface), they should be replaced directly. At the same time, adjust the cleaning parameters (increase frequency, appropriately increase spray pressure) and optimize the flue gas pre-treatment (increase dehumidification, reduce dust concentration) to avoid re-blockage.
2. Filter bag burning or aging: If the filter bag is burned due to excessive flue gas temperature, check and repair the cooling device of the boiler flue gas, ensure that the flue gas temperature is controlled within the allowable range, and replace the burned filter bag. If the filter bag is aged in advance due to corrosion, replace it with a filter bag with better corrosion resistance (such as PTFE bags) and take anti-corrosion measures for the equipment body.
3. Filter bag damage and dust leakage: If individual filter bags are damaged (broken, perforated), find the damaged filter bags through the emission status and resistance change, and replace them in time. If multiple filter bags are damaged, check whether there are problems such as excessive spray pressure, deformed filter cages or sharp edges on the flower plate, and solve the root cause while replacing the filter bags.
4. Filter bag adhesion: If the filter bag adheres to dust due to high viscosity of dust, clean the filter bag with a special cleaning agent (avoid corrosive cleaning agents), and optimize the cleaning system (increase cleaning frequency, use PTFE coated anti-adhesion filter bags) to reduce adhesion.

4. Maintenance Precautions
1. Safety operation: Before maintenance, cut off the power supply of the dust collector and fan, hang a "maintenance in progress" sign, and ensure that the equipment stops completely to avoid electric shock or injury.
2. Avoid improper operation: Do not use high-pressure air (＞0.5MPa) to blow the filter bag, so as not to damage the filter bag fiber; do not clean the filter bag with high-temperature water (＞80℃), so as not to cause shrinkage and deformation.
3. Storage of spare filter bags: Spare filter bags should be stored in a dry, ventilated and clean warehouse, away from high temperature, humidity and corrosive substances, and placed flat to avoid deformation.
4. Record and summarize: Establish a filter bag maintenance record, record the inspection time, maintenance content, replacement quantity and operating parameters, summarize the wear and damage rules of filter bags, and optimize the maintenance plan and filter bag selection.