Common Problems and Solutions for Baghouse Dust Collectors (Part 3)

Filter Bag Combustion

Main causes and troubleshooting: 

(1) Stratified distribution of hot and cold gas: Install baffles in pipelines to create turbulent flow and eliminate stratification. 

(2) Sparks entering the dust collector: Fit a spark arrester. 

(3）Malfunctioning thermocouple: Replace it and identify the root cause of failure.

 (4)  Cooling device failure: Check design specifications and consult the manufacturer.

Frequent Filter Bag Rupture

Cause analysis: 

(1) Excessively narrow spacing between filter bags causes collision and wear between bags and between bags and wall panels.

 It also disrupts the upward air flow velocity in the housing, leading to high local filtration load, insufficient cleaning intensity and frequent pulse jet cleaning. 

(2) High temperature sensitivity: Flue gas temperature exceeding the allowable limit will damage the filter media in a short time and loss its structural strength. 

Filter media is oxygen-sensitive at high temperatures; flue gas oxygen content exceeding the critical value will cause thermal oxidative decomposition and damage of the filter media over a period of time.

 (3) Excessively high pulse jet pressure causes severe local damage to the filter media and drastically shortens its service life.

 (4) Uneven air flow distribution.

Troubleshooting: 

(1) Adjust filter bag spacing; based on experience, the spacing between bag edges should be at least the radius of the filter bag itself. 

(2) Adopt high-temperature resistant, high-strength filter media. The oxygen content of flue gas during normal boiler operation is generally lower than the critical value 

of the filter media; therefore, design the system to use flue gas after the baghouse as the air source to avoid drawing in a large amount of fresh air. 

(3) Pulse jet pressure should not exceed 0.20MPa and is preferably kept as low as possible on the premise of ensuring effective cleaning. 

(4) Identify the root cause and carry out targeted modification.

Moisture Buildup Inside the Dust Collector

Main causes and troubleshooting: 

(1) Insufficient heating: Introduce hot air into the system before starting gas treatment. 

(2) No purging after shutdown: Run the fan for 15~20 minutes after the system shuts down. 

(3) Housing temperature below dew point: Raise the gas temperature, insulate the unit, or reduce moisture in the system to lower the dew point. 

(4) Extraneous air ingress: Inspect the housing for leaks and worn door gaskets. 

(5) Cold objects penetrating the insulation layer: Eliminate direct metal linings. 

(6) Moisture in compressed air: Check the automatic drainer, install a secondary cooler or dryer. 

(7) Deteriorated process conditions: Inject conditioning powder.

Material Bridging in the Hopper

(1) Main causes and troubleshooting: 

(2) Moisture buildup inside the dust collector: Refer to the above solutions. 

(3) Poor hopper design hindering material flow: Install acoustic horns or vibrators to facilitate material movement.

(4)  Dust accumulation in the hopper: Discharge dust continuously and avoid storing dust in the hopper. 

(5) Excessively small conveyor opening: Use wide flared trough-shaped blades. 

(6) Malfunctioning or undersized feeder/rotary airlock valve: Repair or replace the equipment with a properly sized one.

Excessive Emission Concentration

Main causes and troubleshooting: 

(1) Damaged filter bags: Inspect, repair and replace the filter bags; maintain a proper gap between the outer diameter of the bag cage and the inner diameter of the filter bag. 

(2)  Dust leakage: Identify the cause and resolve it, reduce the filtration air velocity. 

(3) Overlong pulse jet time or frequent cleaning: Shorten the pulse jet time and extend the cleaning cycle. 

(4) Excessive cleaning intensity causing secondary dust resuspension: Reduce the cleaning intensity. 

(5)  Air leakage at pulse valve installation due to unreasonable air tank structure: Appropriately enlarge the housing and raise the hopper, ensure the hopper inclination angle is not less than 60 degrees.

 For sites with high flue gas humidity and sticky dust, install vibrators at the dust collector hoppers to prevent dust buildup, which is especially suitable for humid weather in southern regions.