Electrostatic Problems and Explosion Prevention Measures of Baghouse Dust Collectors

During operation, baghouse dust collectors may generate electrostatic discharge, which can ignite combustible dust and cause explosions. This article analyzes the causes, mechanisms, and characteristics of dust explosions and proposes corresponding explosion prevention measures.

1. Mechanism and Characteristics of Dust Explosion

A dust explosion typically develops in three stages:

• Thermal Decomposition or Gasification – Suspended dust rapidly vaporizes under a heat source, generating combustible gases.

• Combustion – The combustible gases mix with air and ignite.

• Chain Reaction – The heat and flame radiation ignite surrounding suspended dust, accelerating combustion and leading to an explosion.

As this reaction progresses, the flame speed, explosion pressure, and shock wave intensity increase rapidly, resulting in a violent explosion.

Main characteristics of dust explosions include:

• High frequency and strong destructiveness.

• Tendency for secondary explosions.

• Incomplete combustion — many dusts contain unburned residues and decomposition gases.

• Production of toxic gases such as carbon monoxide or toxic decomposition products (e.g., from plastics).

2. Electrostatic Problems in Baghouse Dust Collectors

As dust travels through pipelines, friction and collision with walls generate static electricity. Charged dust particles adhere to filter bags. Since baghouse dust collectors typically use intermittent cleaning, electrostatic accumulation increases over time, enhancing the electric field strength.

When the dust layer becomes thick enough, the field strength may exceed the dielectric breakdown voltage of air, leading to electrostatic discharge. If dust is dispersed during cleaning and its concentration reaches the explosive limit, a dust explosion can occur.

Main electrostatic risks include:

• Charged dust accumulation: In the dust hopper, surface electric field intensity increases, potentially triggering discharge.

• Poor grounding: If filters or dust hoppers are insulated or grounded improperly, discharge cannot dissipate safely, increasing the risk of spark propagation and large-scale ionization.

• Presence of conductive materials: If metal objects enter the dust hopper without proper separation, isolated conductors may amplify discharge energy, creating explosion hazards.

Explosion Prevention Measures

• To reduce electrostatic hazards and prevent dust explosions:

• Use antistatic filter materials and ensure reliable grounding of all conductive parts.

• Install metal separators at the system inlet to prevent metal particles from entering.

• Maintain proper humidity levels to minimize static buildup.

• Conduct regular inspections to ensure grounding continuity and system integrity.