When do industrial dust removal filter bags need to be replaced?

1. Signals That Industrial Dust Removal Filter Bags Need Replacement

Any of the following indicates that the filter bags may need replacement:
Persistently High System Differential Pressure
Symptom: The differential pressure gauge reading of the dust collector remains above the design maximum for an extended period, and the differential pressure does not decrease significantly or quickly rebounds after cleaning.
Cause: The micropores of the filter bag are permanently blocked by fine dust, preventing effective cleaning and obstructing airflow.

Visible Dust Escape ("Dust Emission")
Symptom: Visible dust is observed emanating from the dust collector's exhaust port or chimney.
Cause: The filter bag may be damaged, torn, aged, or have loose stitching, allowing dust to penetrate directly. This is one of the most urgent signs requiring immediate attention.

Physical Damage to the Filter Bag
Symptom: During regular inspections, burn marks, holes, abrasion (usually at the bottom, opening, or contact area with the frame) are found on the filter bags, or the material becomes brittle or hardened. Causes: May be caused by sparks, high temperature, chemical corrosion, burrs on the filter bag frame, or airflow erosion.

Production Process Changes
Phenomenon: Changes in the production process cause variations in the temperature, humidity, corrosiveness, or dust characteristics of the treated gas, exceeding the original design range of the filter bag material.
Examples: A sudden increase in temperature may burn the filter bag; increased humidity may cause bag clogging and compaction; highly corrosive dust will rapidly damage the filter media.

Reaching the End of Service Life
Phenomenon: Although the system appears to be operating normally, the filter bags have been used continuously beyond the manufacturer's recommended lifespan (usually 1-3 years, depending on operating conditions).
Causes: The material itself will naturally age, and its performance will slowly decline over time. Preventative replacement can avoid sudden failures.

2. Indirect Manifestations of System Performance Degradation

These are problems easily observed on the production floor, and their root cause often points to filter bag failure:
Significantly weakened suction at the dust inlet.
Increased dust concentration in the production environment, leading to numerous employee complaints.
Increased fan load, resulting in a significant increase in energy consumption.
Abnormally high frequency of dust collector cleaning. 

3. Precautions for Replacing Industrial Dust Collector Filter Bags

Safety First:
Shutdown and Isolation: Completely shut down the dust collection system, disconnect the power and air supply, and hang a "Do Not Power On" warning sign.
Cooling and Ventilation: Allow the equipment to cool down completely, and open the inspection door for ventilation, ensuring there are no toxic or harmful gases or oxygen deficiency inside.
Personal Protective Equipment: Workers must wear appropriate PPE, including dust masks, protective glasses, gloves, and safety helmets.

Replacement Operation Points:
Clean the Chamber: Thoroughly remove accumulated dust from the clean air chamber and ash hopper.
Replace Bags One by One: It is not recommended to remove all old bags at once to prevent a large amount of dust from entering the clean air chamber.
Inspect the Cage: Before installing new bags, be sure to check the bag cage (frame) for burrs, deformation, or rust. If there are any problems, they must be repaired or replaced, otherwise, the new bags will be damaged.
Correct Installation: Ensure that the filter bag is well sealed to the tube sheet, the bag cage is vertically supported, and the installation tightness is appropriate.