Low Pressure Drop(Sudden Differential Pressure Drop)of Baghouse Dust Collector:Filter Bag Breakage or System Air Leakage?

The differential pressure value of the baghouse dust collector directly reflects the operating state of filter bags,dust accumulation and system airtightness.A sudden abnormal drop in pressure drop is a typical on-site fault.Many operators confuse two core causes:damaged filter bags and large-scale system air leakage.Their fault mechanisms,performance characteristics,distinguishing methods and treatment measures are obviously different.This paper analyzes and distinguishes them in detail.

1.Fault Phenomenon Overview

Under normal working conditions,the differential pressure remains stable within a reasonable range with regular pulse cleaning.When the pressure drop suddenly drops sharply and remains at an extremely low level,it is necessary to accurately judge whether it is caused by broken filter bags or external air leakage of the system.

2.Characteristics of Sudden Pressure Drop Caused by Broken Filter Bags

After filter bag rupture,dusty raw flue gas directly penetrates the broken position and enters the clean air chamber without filtration.

The differential pressure drops rapidly and keeps low value.

Exhaust smoke emission increases obviously,visible smoke and dust escape from the chimney.

The inlet and outlet air volume changes slightly,and the internal airflow distribution is disordered.

Pulse cleaning frequency and working state of pulse valves have no obvious abnormal change.

Ash accumulation on the surface of intact filter bags is still normal,but overall system resistance decreases sharply.

3.Characteristics of Sudden Pressure Drop Caused by System Air Leakage

Large air leakage occurs in the shell,flange joints,ash hopper,access door,unloading pipeline and connecting ducts of the dust collector.A large amount of normal-temperature clean air outside the system is sucked in.

Differential pressure drops suddenly and stays at low level.

No obvious dust emission from chimney,exhaust gas remains clean.

Overall system air volume increases abnormally,inlet wind pressure decreases.

The temperature of flue gas inside the collector drops significantly due to mixed cold air.

Filter bags are intact,dust layer on bag surface is normal,and pulse cleaning system works normally.

Air leakage at shell welding seams,door gaps and flange connections can be detected on site.

4.Rapid On-Site Distinguishing Methods

Observe chimney emission:heavy dust smoke=filter bag breakage;clean exhaust=system air leakage.

Check internal flue gas temperature:obvious temperature drop=external cold air leakage;no temperature change=broken bag.

Inspect ash hopper and pipeline airtightness:gap air leakage,loose flanges,damaged sealing gaskets=system leakage.

Check filter bag chamber by chamber:locate broken bags through single chamber shut-down detection.

5.Corresponding Solutions

For broken filter bags

Stop the faulty chamber,open the inspection door to locate and mark damaged filter bags.

Replace broken filter bags and damaged cages in time.

Check pulse injection parameters to avoid excessive airflow impact damaging new filter bags.

For system air leakage

Seal air leakage positions including shell welds,access doors,flange interfaces,hopper joints and pipeline connections.

Replace aging,cracked sealing gaskets and fasten loose bolts.

Optimize sealing of star unloader and ash discharge pipelines to eliminate negative pressure suction leakage.

References

1.GB/T 7714

Wang Y,Zhou L.Differential Pressure Abnormality Diagnosis of Baghouse Dust Collector:Filter Bag Damage and System Air Leakage[J].Environmental Engineering,2022,46(3):146-150.

2.MLA

Wang,Yu,and Lin Zhou."Differential Pressure Abnormality Diagnosis of Baghouse Dust Collector:Filter Bag Damage and System Air Leakage."Environmental Engineering,vol.46,no.3,2022,pp.146-150.

3.APA

Wang,Y.,&Zhou,L.(2022).Differential pressure abnormality diagnosis of baghouse dust collector:filter bag damage and system air leakage.Environmental Engineering,46(3),146-150.