Before beginning any removal process, safety is paramount. The dust collected in baghouses can be hazardous. Make sure that you follow the step-by-step instructions to remove the old filter cages and bags.
Removal Preparation
- Shut Down and Cool Down
- Ensure the baghouse has been shut down for a sufficient period to cool down, especially if processing hot gases.
- Allow the system to run through a final cleaning cycle to dislodge as much dust as possible from the bags.
- Empty the Hopper
- Completely empty the dust collection hopper. This may involve running the rotary valve or screw conveyor until no more dust is discharged.
- Ensure the dust disposal system is ready to receive the removed dust.
- Depressurize the Air System
- Turn off the compressed air supply to the pulse-jet cleaning system.
- Bleed off any residual air pressure from the manifold and air lines.
- Access the Baghouse
- Open the access doors to the appropriate plenum (clean air for top-load, dirty air for bottom-load).
- Set up temporary lighting if needed.
- Prepare Waste Containers: Have appropriate containers (e.g., heavy-duty bags, drums) ready for the old, dust-laden filter bags and cages. Label them if the dust is hazardous.
Removal
- Access the Clean Air Plenum: Enter the clean air plenum (above the tubesheet).
- Disconnect Blowpipes: In some designs, the blowpipes might need to be moved and disconnected to provide better access to the cages and bags.
- Remove the Cage
- Grasp the cage firmly.
- Lift the cage straight up until it clears the tubesheet.
- Carefully pull the cage out of the filter bag. Be mindful of any sharp wires or dust.
- If the bag is stuck to the cage, you may need to loosen it by shaking or twisting it gently.
- Place the dirty cage into a designated waste container or a separate area for cleaning or disposal.
- Remove the Filter Bag
- Once the cage is removed, the filter bag will be unsupported.
- For snap-band bags: Reach down and gently deform (bend) the snap-band ring at the top of the bag.
- Pull the snap-band and the top of the bag straight up until it clears the tubesheet hole.
- Carefully pull the entire bag out and place it into a waste container.
- For raw edge/gasket-seal bags: Release any hold-down clamps or rings securing the bag to the tubesheet, then pull the bag through.
- Clean the Tubesheet Hole: After each bag and cage is removed, thoroughly clean the tubesheet hole and the surrounding area to remove any residual dust or debris. This ensures a proper seal for the new bags. Use a brush or vacuum.