Baghouse dust collectors are the "heart" of dust control in industrial production.  A malfunction can range from affecting the production environment to causing a complete shutdown.

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 blinding."

Learning to diagnose and address these issues will solve 40% of your dust collection problems!

High and persistent resistance – "Bag Blinding"

This is one of the most typical fault phenomena: the system pressure difference (resistance) continuously rises abnormally, increasing the fan load, causing energy consumption to skyrocket, while the treated air volume is significantly insufficient.

Professional Phenomenon Diagnosis:

Core indicator: The pressure difference gauge reading at the dust collector's inlet and outlet consistently exceeds 1500 Pa (the normal range is usually 800-1200 Pa), and the decrease after cleaning is not significant.

Intuitive feeling: The suction of the dust hood weakens, and the fan noise is abnormal.

In-depth professional analysis of the causes (it's not just "clogging"):

The essence of "bag blinding" is that dust adheres deeply and stubbornly to the inside of the filter bag fibers, rather than normally remaining on the surface to form a loose dust cake layer.

There are three main types of causes:

Condensation-induced "bag blinding" (the most common culprit):

Mechanism: When processing high-temperature and high-humidity flue gas, if the flue gas temperature drops below the dew point, moisture will condense on the filter bag fibers.

Consequences: The wet fibers, after capturing dust, will form a muddy adhesive substance, firmly blocking the filter bag pores.

Contributing factors: Poor insulation of the dust collector housing, cold air intrusion, sudden temperature changes during startup/shutdown, and compressed air containing water and oil.

Sticky dust "bag blinding":

Mechanism: The flue gas contains oil mist, tar, or certain sticky chemical dusts (such as certain resins, sugar powder).

Consequences: These substances act like "glue," directly causing the dust to clump together and preventing it from being dislodged by normal pulse cleaning.

"Pseudo bag blinding" caused by cleaning system failure:

Mechanism: Insufficient cleaning pressure, damaged pulse valves, clogged spray pipes, or excessively long cleaning cycles. Consequences: Excessive accumulation and caking of the surface dust layer, exhibiting symptoms consistent with "bag blinding."

Systematic Solution:

Solving "bag blinding" requires a targeted approach, progressing from operation to modification:

Addressing Condensation:

Insulation and Heating: Ensure good insulation of the dust collector casing and hopper. If necessary, add a preheating device at the inlet to ensure that the flue gas temperature is more than 20°C above the dew point before entering the dust collector.

Operating Procedures: After shutdown, keep the fan running for a period to blow away internal moisture. For long-term shutdowns, the hopper should be emptied, and a desiccant may be added.

Air Source Treatment: Strictly ensure that the compressed air is dry (install a high-efficiency refrigerated or adsorption dryer) and clean (filter out oil).

Addressing Sticky Dust:

Filter Bag Selection:  The first choice is a smooth-surfaced, oil- and water-repellent membrane filter material (such as PTFE membrane). The membrane layer prevents dust from penetrating into the fiber.

Pre-treatment: Before the flue gas enters the dust collector, a pre-coating technique can be used to cover the surface of the filter bags with a layer of inert powder (such as lime powder) to form a protective layer.

General Maintenance and Adjustment:

Check the Cleaning System: Regularly check whether the pulse valves and cylinders are functioning normally, and measure whether the cleaning pressure meets the design requirements (usually 0.4-0.6 MPa).

Optimize the Cleaning Procedure: While ensuring that emissions meet standards, appropriately increase the cleaning frequency or use a high-pressure cleaning mode. Avoid setting the cleaning interval to "manual" or an extremely long cycle to save time.