Follow the following step-by-step baghouse restart procedures as the final step to bring the baghouse back onlin.
1. Complete Pre-Coating:
- Ensure the dust cake is stable and meets the desired thickness (approximately 1/16 inch). This may require monitoring the differential pressure across the bags, which should be around 3–4 inches SPWG before initiating the cleaning cycle.
- Verify that the pre-coat material has formed a porous, three-dimensional dust cake to enhance filtration efficiency and protect the bags from fine particulates, moisture, or sticky particles.
2. Activate Dust Removal Equipment
Turn on the dust removal equipment (e.g., airlock, rotary valves, or screw conveyors) to begin removing accumulated dust from the hopper.
3. Resume Normal Operation:
- Introduce Process Gas Gradually:
- Once pre-coating is complete and the dust cake is stable, slowly open the inlet dampers to introduce process gas.
- Monitor temperature and humidity to ensure they are within the manufacturer’s specified range (e.g., 118–128°C, with short-term allowances of 112–135°C) to prevent bag damage or condensation.
- Increase Airflow: Bring the baghouse fan to full design airflow to resume normal filtration operations.
- Enable Cleaning System: Reactivate the pulse-jet, reverse air, or shaker cleaning system, depending on the baghouse type. Do not start the cleaning cycle until the differential pressure reaches 3–4 inches SPWG to ensure the dust cake is well-established.
- Monitor Pressure Drop: Record the differential pressure daily to establish baseline performance and detect any issues early. A creeping increase in pressure post-cleaning may indicate dust buildup or bag blinding, while a sudden drop could suggest a bag breach.
4. System Monitoring and Adjustments:
- Stabilize Operations: Monitor the pressure drop across the bags and adjust the cleaning system’s on-time and off-time pulse settings to maintain stable pressure (typically below 6 inches W.G.).
- Record Data: Log differential pressure readings daily to track performance trends and identify potential issues, such as bag wear or leaks.
- Fine-Tune Cleaning: Adjust the cleaning frequency and intensity based on pressure drop data to optimize bag life and filtration efficiency. For pulse-jet systems, ensure compressed air pulses (80–100 psig) are short (about 0.1 seconds) to effectively dislodge dust without damaging bags.
5. Special Considerations for Specific Applications:
- For dryers or dryer cooler applications, follow a modified start-up procedure, potentially without a pre-coating agent, as recommended by the OEM. Refer to the manufacturer guidelines or resources like Sly Inc.’s YouTube video for specific instructions.
- Ensure the baghouse operates within the manufacturer’s specified temperature range (e.g., 118–128°C for some systems, with short-term allowances of 112–135°C) to prevent bag damage from high temperatures or condensation due to low temperatures.