Rising Differential Pressure Across Dust Filter Bags: Diagnostic Checklist
Rising Differential Pressure Across Dust Filter Bags: Diagnostic Checklist
A higher differential pressure is a system symptom, not proof that the filter bags alone are defective. Check the measurement, process and cleaning system in a consistent order before changing bags or settings.
1. Verify the reading
Confirm the pressure instrument, tubing and reference points are clear and correctly connected. Compare current values with the normal operating trend under similar airflow and production load.
2. Check airflow and dust loading
Review fan settings, dampers, process throughput, air-to-cloth ratio and inlet dust concentration. A change in system load can raise differential pressure even when the bags are unchanged.
3. Look for condensation or sticky dust
Compare gas temperature with dew-point conditions and inspect for air leakage, wet dust, hardened cake and hopper buildup. Moisture can change dust release behavior and block the media surface.
4. Review pulse-cleaning performance
Check compressed-air pressure and quality, pulse valves, manifolds, nozzles, sequencing, duration and differential-pressure set points. Do not increase cleaning intensity without confirming the equipment design and bag condition.
5. Inspect hopper and discharge equipment
A full hopper, bridging dust or failed discharge device can allow dust to re-enter the bag section. Verify level indicators, rotary valves, screws and airlocks.
6. Assess the filter media and dust cake
Inspect representative bags for blinding, chemical attack, oil contamination or an unsuitable surface treatment. Media changes should be based on dust properties, temperature, moisture and gas chemistry.
Record airflow, differential-pressure trends, process load, temperature, humidity, cleaning settings and inspection photos. Use this evidence to identify the cause before selecting corrective action.
