Analysis of the Root Causes of Reduced Dust Collector Bag Filter Efficiency and Corresponding Systemic Optimization Solutions

Part One: Analysis of Five Major Categories of Reasons for Reduced Filtration Efficiency

We can analyze the causes from five dimensions: "gas, fabric, dust, cleaning, and human factors."

1. Failure of the filter bag itself

This is the most direct cause.

Damage (puncture, wear):  The appearance of pinholes, cracks, or large-area tears, leading to direct dust penetration.

Reasons: Improper installation (friction with the cage), blowing airflow/dust erosion (excessive inlet air velocity), sparks or high-temperature burning, chemical corrosion, cage burrs, excessive cleaning.

Clogging (bag blinding): The pores of the filter bag are blocked, severely reducing air permeability. Although emissions may decrease in the short term, the system airflow drops sharply, leading to overall failure in the long term.

Reasons: Condensation (flue gas temperature below the dew point, moisture and dust sticking together), oil mist adhesion (such as in sintering machine flue gas), dust deliquescence, and prolonged low filtration velocity leading to deep dust embedding.

Aging: Degradation of the filter material performance.

Reasons: Long-term high-temperature operation exceeding the filter material's tolerance limit, acid and alkaline gas corrosion, oxidation reactions.

2. Improper design and selection

This is a problem of "inherent deficiencies."

Excessive filtration velocity (air-to-cloth ratio): This is the most common design error. High velocity forces fine dust deep into the filter material, making cleaning difficult and accelerating physical wear, leading to reduced efficiency.

Incorrect filter material selection: Failure to select a matching filter material based on flue gas characteristics (temperature, humidity, chemical composition, dust characteristics). For example, using non-waterproof and non-oil-resistant filter material in humid flue gas, or not using flame-retardant filter material in conditions with sparks.

Poor matching of bag specifications and cage:  Bags that are too long lead to bottom swaying and wear, or are too tight/loose with the cage, affecting cleaning efficiency and easily causing wear.

3. Operating conditions deviating from design conditions

This is a problem of "acquired imbalance." Changes in flue gas properties: Inlet dust concentration far exceeds the design value, sudden changes in flue gas temperature (especially low-temperature condensation), increased humidity, and the presence of unexpected chemical components (such as sulfur oxides and nitrogen oxides).

System air leakage: Cold air leaks into the dust collector casing, inspection doors, and ash discharge valves, causing the local temperature to drop below the dew point, leading to condensation and bag blinding.

Cleaning system failure: Insufficient/excessive cleaning pressure, malfunction of pulse valves/lifting valves, or displacement or blockage of spray pipes, resulting in uneven or incomplete cleaning, leaving an excessively thick dust layer on the filter bags or localized bag blinding.

4. Improper installation and maintenance

This is a "human error" problem.

Poor installation quality: Filter bag openings are not sealed to the tube sheet, filter bags are stepped on or scratched, and the cage welding is weak or has burrs.

Inadequate maintenance: Damaged bags are not inspected and replaced in time ("broken window effect," one damaged bag will erode and damage adjacent filter bags), excessive dust accumulation in the hopper submerges the filter bags, and improper air source treatment leads to oil and water entering the filter bags.

5. Changes in dust characteristics

Changes in materials or processes lead to changes in dust particle characteristics (particle size distribution, viscosity, specific gravity), making the original filter material and cleaning parameters no longer suitable.

Part Two: Systematic Optimization Solutions and Action Guidelines

Solving efficiency problems must follow the principles of "diagnosis first, targeted treatment, and systematic optimization."

Step One: Accurate Diagnosis (Finding the "Root Cause")

Data Inspection: Analyze historical operating data, focusing on abnormal fluctuations in pressure difference, inlet and outlet concentrations, temperature, and dust removal pressure.

Status Detection:

Fluorescent Powder Leak Detection: Introduce fluorescent powder into the clean air chamber, and after operation, use a UV lamp to detect the exhaust pipe to accurately locate the broken bag.

Portable Dust Meter Detection: Conduct partitioned testing in the chimney or clean air chamber to determine if there is localized failure.

Infrared Thermal Imaging: Inspect the casing to identify areas with abnormal temperatures caused by blockage or leakage.

Sampling and Analysis:

Filter Bag Sampling: Cut off a sample of the old bag and analyze the composition of the blockage in the laboratory (to determine whether it is condensation, oil stains, or chemical corrosion).

Dust Analysis: Compare the particle size distribution and composition of the current dust with the original design.

Step Two: Targeted Optimization Measures (Prescribing the "Treatment")

Step 3: Establish a Long-Term Optimization Mechanism

Operation Log and Data Analysis: Record all key parameters and events (such as process changes and equipment shutdowns/startups). This provides valuable data for problem analysis.

Standardization of Key Spare Parts: Use high-quality filter bags and seals that have undergone performance verification as standard spare parts.

In-depth Cooperation with Filter Bag Suppliers: Provide operational data and samples of used bags, invite them to conduct technical diagnostics, and jointly develop selection and optimization plans.