Bag filters are the "heart" of dust control in industrial production.  A malfunction can range from affecting the production environment to causing a complete shutdown of the entire production line.

Today, we won't discuss complex theories, but instead focus on one of the most common and troublesome core problems in on-site operation and maintenance: "bag rupture."

Smoke stack emitting dust, exceeding emission standards – "bag rupture"

This is the most obvious malfunction: the chimney emission concentration suddenly increases, a visible plume of dust is emitted, and environmental monitoring data triggers an alarm.

Professional Phenomenon Diagnosis:

Core Indicators: Abnormal sudden changes or continuous increase in online emission monitoring instrument readings.

Offline Inspection (Leak Detection Method): Using fluorescent powder leak detection or a laser particle counter to scan each compartment in the dust collector's clean air chamber can accurately locate the compartment containing the ruptured filter bag.

Traditional methods involve manually inspecting the top of each filter bag one by one, which is inefficient and dangerous.

In-depth Professional Analysis of the Causes (Where the rupture occurred and the reasons behind it vary greatly)

The location of the damage directly points to the root cause:

Damage at the bag opening (most common in pulse jet dust collectors):

Cause: Improper installation is the main reason. The bag opening is not tightly fitted to the tube sheet hole, causing the filter bag to experience high-frequency friction with the tube sheet under repeated pulse jet cleaning, leading to breakage.

Secondary cause: The blowpipe is not properly installed, causing the nozzle to directly face the bag opening, and the airflow directly impacts it.

Localized damage to the bag body (e.g., V-shaped or circular holes):

Cause: Mechanical wear. This is mainly due to friction between the filter bag and adjacent components (such as broken cage ribs, burrs, or steel plates of the housing), or vibration and collision between adjacent filter bags. Spark erosion can also form regular holes.

Key inspection point: The quality of the bag cage (verticality, surface finish) is paramount.

Damage within 300mm from the bottom of the bag:

Cause: Airflow erosion. The dust hopper's air inlet method is unreasonable, or the internal baffle plate is detached, causing the dust-laden airflow to directly impact the bottom of the filter bag at high speed.

Phenomenon: The damage is from the inside out, often accompanied by obvious wear marks.

Severe overall weakening of the filter bag (breaks easily upon touch):

Cause: Chemical corrosion or hydrolysis. Acidic/alkaline components, oxides in the flue gas, or specific temperature and humidity conditions react with the filter material fibers, causing them to become brittle.

Judgment: Observe whether the overall color and texture of the filter bag have changed.

Systematic solution:

Addressing "bag breakage" requires finding the root cause; otherwise, replacing with new bags will result in repeated breakage.

Standardized installation and maintenance:

Bag opening sealing: Special tools must be used to ensure that the elastic ring of the filter bag opening is tightly fitted to the tube sheet hole at 360 degrees. After installation, check for gaps by touch.

Bag cage inspection: Before each bag replacement, each bag cage must be inspected to ensure there is no bending, no welding defects, and no burrs. High-quality bag cages with silicone coating or stainless steel material should be prioritized.

Blowpipe alignment: After installation and maintenance, be sure to calibrate the blowpipe to ensure that the nozzle is aligned with the center of the filter bag. Optimized Design and Operation:

Airflow Distribution: Check the baffles inside the dust collector to ensure even airflow and prevent excessively high local air velocities.

Pre-dust Removal: For issues involving sparks or coarse particles, install a spark arrestor or gravity settling chamber before the inlet.

Filter Media Selection and Upgrade: Select corrosion-resistant and hydrolysis-resistant filter media (such as P84, PTFE, Metamax, etc.) based on the chemical properties of the flue gas (e.g., SOx, NOx content, humidity).

Emergency Leak Detection and Replacement:

If excessive emissions are detected, immediately use fluorescent powder to locate the ruptured bag compartment.

Close the inlet and outlet valves of the affected compartment for online isolation and replacement, avoiding a complete system shutdown.

Important Principle: When replacing damaged filter bags, be sure to simultaneously inspect and replace any potentially damaged filter bags and their corresponding cages in the same compartment.