Filter Bag Failure Modes and Field Troubleshooting Guide

Diagnostic field handbook identifying visual signatures, root causes, and corrective actions for the 6 primary baghouse failure modes: abrasive bottom wear, cage collar abrasion, acid hydrolysis rotting, thermal melting, and high-pressure jet blowouts.

When filter bags fail prematurely, diagnosing the precise root cause is critical to prevent repeating identical failures with the replacement set. Most failures leave distinct visual signatures.

1. Bottom Ring Abrasion (底部环向磨损)

Visual Signature: A clean circular wear pattern or tear 50–200mm above the bottom disk. Root Cause: Excessive inlet flue gas velocity directly striking the bottom of the bags, or dust hopper overfilling where accumulated dust swirls abrasively against bag tips. Corrective Action: Install inlet airflow diffusers/baffles, increase hopper angle, and optimize rotary airlock discharging.

2. Vertical Line Abrasion (竖向筋条磨损)

Visual Signature: Continuous vertical worn lines matching the cage wires along the body of the bag. Root Cause: Corroded, rusted, or bent cage wires; insufficient cage wire count (e.g., 8–10 wires on Ø160 bag allowing fabric to flex deeply during suction). Corrective Action: Upgrade to 16–20 wire cages with hot-dip galvanizing or stainless steel.

3. Acid Hydrolysis Rotting (酸水解与烂袋)

Visual Signature: Fabric becomes extremely soft, loses all tensile strength, tears like wet paper with no mechanical abrasions. Root Cause: Operating temperature dropped below acid dew point, causing SOx/water condensation. Corrective Action: Improve casing insulation, eliminate cold air leakage, and switch to PTFE-impregnated or 100% PTFE media.

4. Spark Erosion & Thermal Holes (火星烧蚀点穿)

Visual Signature: Localized circular melted or burned holes with charred edges, predominantly on bags nearest the inlet duct. Root Cause: Lack of spark arrester upstream of the baghouse during furnace tapping or burner malfunction. Corrective Action: Install cyclone pre-separators or labyrinth spark arresters in the main duct.