What Are the Common Faults of Boiler Baghouse Dust Collectors and Their Handling Methods?

Boiler baghouse dust collectors operate in harsh environments such as high temperature, high humidity and high dust concentration for a long time, and are prone to various faults, which affect the dust removal effect and stable operation of the equipment. The common faults mainly include high equipment resistance, poor dust removal effect, filter bag damage, ash discharge failure and cleaning system failure. The specific fault phenomena, causes and handling methods are detailed as follows:

1. Fault 1: High Operating Resistance (Resistance ＞1800Pa)
 Phenomenon
The fan current increases, the air volume decreases, the dust removal effect deteriorates, and the equipment operates with high load, which may lead to fan overheating in severe cases.
 Common Causes
(1) Filter bag blockage (most common): High dust concentration, high viscosity or high humidity of flue gas leads to dust adhesion and crusting on the filter bag; improper cleaning parameters (too low pressure, too low frequency, too short time) result in incomplete dust removal.
(2) Cleaning system failure: Pulse valve/solenoid valve failure (no action, air leakage), air bag blockage, spray pipe deviation or blockage, leading to ineffective cleaning.
(3) Air duct or air inlet blockage: Dust accumulation in the air duct or pre-treatment device leads to poor air flow.
(4) Filter bag aging or damage: The filter bag is aged and brittle, with reduced air permeability; damaged filter bags cause dust leakage and secondary adhesion to other filter bags.
 Handling Methods
(1) Check the filter bag: Clean or replace blocked filter bags; adjust cleaning parameters (spray pressure 0.4-0.6MPa, frequency 20-60s/time, time 0.1-0.2s/time) according to dust characteristics.
(2) Repair the cleaning system: Overhaul pulse valve/solenoid valve (replace damaged parts), clean air bag and spray pipe, ensure uniform and effective spray; drain water and oil in compressed air to ensure air quality.
(3) Clear blockage: Stop the machine to clean the air duct and pre-treatment device (cyclone dust collector), remove accumulated dust and debris.
(4) Replace filter bags: Replace aged or damaged filter bags with new ones that match the working conditions.

2. Fault 2: Poor Dust Removal Effect (Exhaust Emission Concentration ＞30mg/m³)
 Phenomenon
There is obvious dust emission at the exhaust port of the dust collector, the surrounding environment is polluted, and the dust concentration detected by the online monitoring device exceeds the standard.
 Common Causes
(1) Filter bag damage: Filter bag is broken, perforated or loose, leading to dust leakage.
(2) Improper filter bag selection: The filter bag material does not match the flue gas characteristics (e.g., normal-temperature polyester bags used in high-temperature flue gas), leading to premature damage or poor dust removal efficiency.
(3) Cleaning system failure: Uneven spray, insufficient spray pressure or too high cleaning frequency leads to filter bag damage or dust re-entrainment.
(4) Poor equipment sealing: Air leakage at the flower plate, inspection door, ash discharge valve or air duct leads to unfiltered dusty flue gas bypassing and discharging.
(5) High dust concentration exceeding processing capacity: The pre-treatment device fails, leading to excessive dust concentration entering the filter bag, which cannot be completely captured.
 Handling Methods
(1) Replace filter bags: Find and replace damaged or loose filter bags; check the tightness of the filter bag installation to ensure no leakage.
(2) Re-select filter bags: Replace with filter bags that match the flue gas temperature, dust characteristics and corrosion degree (e.g., PPS bags for medium-high temperature, PTFE bags for corrosion).
(3) Adjust cleaning system: Repair faulty components, adjust spray pressure and frequency to ensure thorough cleaning without causing filter bag damage or dust re-entrainment.
(4) Strengthen sealing: Check the sealing parts of the equipment, replace aging sealing gaskets, tighten loose bolts, and repair air leakage points.
(5) Repair pre-treatment device: Overhaul the cyclone dust collector or other pre-treatment equipment, ensure normal operation, and reduce the dust concentration entering the filter bag.

3. Fault 3: Filter Bag Damage (Broken, Perforated, Aged)
 Phenomenon
Dust leakage at the exhaust port, poor dust removal effect, increased equipment resistance, and broken filter bag fragments can be found in the ash hopper.
 Common Causes
(1) Excessive flue gas temperature: Exceeding the temperature resistance limit of the filter bag, leading to bag burning and aging.
(2) Improper cleaning parameters: Too high spray pressure (＞0.6MPa) or too frequent cleaning leads to excessive impact on the filter bag, resulting in wear and breakage.
(3) Poor filter cage quality: Deformed, corroded or sharp-edged filter cage scratches the filter bag.
(4) High dust abrasion: The dust has strong abrasiveness (e.g., boiler fly ash), and the filter bag material has poor wear resistance.
(5) Corrosion of flue gas: The flue gas contains strong acid and alkali, leading to corrosion and damage of the filter bag.
Handling Methods
(1) Control flue gas temperature: Check and repair the boiler flue gas cooling device, install a temperature sensor and alarm, and start the cooling device in time when the temperature is too high.
(2) Adjust cleaning parameters: Reduce the spray pressure to 0.4-0.6MPa, adjust the cleaning frequency according to the dust accumulation, and avoid excessive impact.
(3) Replace filter cage: Replace deformed, corroded or sharp-edged filter cages with high-quality, smooth-surfaced filter cages (galvanized steel or stainless steel).
(4) Replace filter bags: Select filter bags with excellent wear resistance (e.g., FMS bags) for high-abrasion dust; replace damaged filter bags in time.
(5) Take anti-corrosion measures: Replace with corrosion-resistant filter bags (e.g., PTFE bags), and apply anti-corrosion coating to the equipment body to reduce flue gas corrosion.

 4. Fault 4: Ash Discharge Failure
 Phenomenon
Dust accumulates in the ash hopper, overflows from the inspection door, the equipment resistance increases, and the ash discharge valve does not operate or discharges abnormally.
 Common Causes
(1) Ash discharge valve failure: The star-shaped ash discharge valve is jammed by large-particle dust or debris, the motor is damaged, or the reducer fails.
(2) Dust hardening: High humidity of flue gas leads to dust dampening and hardening in the ash hopper, which cannot be discharged normally.
(3) Ash conveying pipeline blockage: The spiral conveyor or ash conveying pipeline is blocked by dust accumulation, leading to ash backflow.
(4) Level gauge failure: The level gauge of the ash hopper is faulty, failing to detect the dust level in time, resulting in excessive dust accumulation.
 Handling Methods
(1) Overhaul ash discharge valve: Stop the machine to clear the jammed dust and debris, check the motor and reducer, replace damaged parts, and ensure smooth operation.
(2) Remove dust hardening: Install a heating device in the ash hopper to melt the hardened dust; manually clean the ash hopper if necessary, and take dehumidification measures for the flue gas to avoid re-hardening.
(3) Clear pipeline blockage: Stop the machine to clean the spiral conveyor and ash conveying pipeline, remove accumulated dust, and check the pipeline for leakage or deformation.
(4) Repair level gauge: Calibrate or replace the faulty level gauge, ensure accurate detection of dust level, and set up an alarm to remind timely ash discharge.

 5. Fault 5: Cleaning System Failure
 Phenomenon
The pulse valve does not act, the spray is uneven, the cleaning effect is poor, the filter bag is blocked, and the equipment resistance increases.
 Common Causes
(1) Pulse valve/solenoid valve failure: The pulse valve diaphragm is damaged, the solenoid valve is stuck or the coil is burned, leading to no action or air leakage.
(2) Air bag problem: The air bag is blocked by water, oil or impurities, or air leakage occurs, leading to unstable spray pressure.
(3) Spray pipe blockage or deviation: The spray pipe nozzle is blocked by dust or impurities, or the spray pipe is deviated, resulting in uneven spray.
(4) Compressed air quality is poor: Contains water, oil or impurities, which block the pulse valve and spray pipe, and damage the diaphragm of the pulse valve.
 Handling Methods
(1) Overhaul pulse valve/solenoid valve: Replace the damaged diaphragm and solenoid valve coil, clean the stuck solenoid valve, and ensure normal action and no air leakage.
(2) Maintain air bag: Clean the air bag, remove water, oil and impurities, repair air leakage points, and install an oil-water separator to ensure stable air pressure.
(3) Clean and adjust spray pipe: Clean the blocked nozzle, adjust the spray pipe to ensure accurate alignment with the filter bag, and uniform spray.
(4) Improve compressed air quality: Install an air dryer and oil-water separator to remove water and oil in the compressed air; regularly drain the water and oil in the air pipeline and air bag.

 6. Fault Prevention Measures
1. Regular inspection and maintenance: Establish a regular maintenance system for the equipment, inspect key components (filter bags, cleaning system, ash discharge system) on a daily, weekly, monthly and annual basis, and handle potential faults in advance.
2. Optimize operating parameters: Adjust the cleaning frequency, spray pressure and air volume according to the flue gas parameters and dust characteristics to ensure stable operation of the equipment.
3. Strengthen pre-treatment: Ensure the normal operation of the pre-treatment device, reduce the dust concentration, temperature and humidity of the flue gas entering the dust collector, and reduce the load of the equipment.
4. Select high-quality components: Choose high-quality filter bags, filter cages, pulse valves and other components that match the working conditions to extend the service life and reduce fault frequency.
5. Train operators: Train equipment operators to master the operating procedures and fault handling methods, and avoid improper operation leading to faults.