When dust fails to discharge from the hopper of a baghouse dust collector, the root cause lies in that the dust cannot be smoothly discharged out of the hopper.
Rapid fault location and troubleshooting can be achieved by following the sequence: "First inspect the dust cleaning system → Then check the hopper body → Finally
examine the ash discharge device".
Malfunction of Dust Cleaning System (the Most Common Trigger)
Pulse Valve Failure: The diaphragm of the pulse valve is cracked, or the solenoid coil is burnt out, which leads to the failure of injection. The dust on the surface of filter
bags cannot be stripped and all accumulates on the filter bags, with almost no new dust falling into the dust hopper. It is necessary to replace the damaged diaphragm
or coil, and keep the injection pressure stably at 0.4-0.6MPa.
Abnormal Injection Parameters: If the dust cleaning interval is set too long and the pulse injection time is too short, the dust will excessively accumulate and
agglomerate on the surface of the filter bag, which cannot be blown off by normal injection. It is required to adjust the dust cleaning interval to 5-30min and set the
pulse width to 0.05-0.2s.
Misalignment/Blockage of Injection Pipe: The injection nozzle shifts and aligns with the edge of the filter bag, or the injection pipe is blocked by sundries, so that the
local filter bags cannot get dust cleaning at all, and the dust continues to adhere and cannot fall off. It is necessary to re-calibrate the position of the injection pipe and
clean up the blocked sundries inside the pipe.
Dust Blockage in Dust Hopper Body
Dust Bridging and Agglomeration: Too much accumulated dust in the dust hopper is not discharged in time, and the dust forms an "arch"-shaped suspended structure
above the ash discharge port, making new dust unable to fall down. The rapping device on the hopper wall can be turned on, or the bridging structure can be broken
manually with a long rod through the access opening.
Insufficient Angle of Dust Hopper: The inclination angle of the dust hopper of old equipment is less than 60°, so the dust cannot slide down naturally by gravity and
continues to stay and accumulate on the inclined wall. The inclination angle can be increased by installing lining plates and carrying out local transformation, so as to
ensure the free sliding of dust.
Condensation and Wall Adhesion: The equipment has poor heat preservation, the internal temperature is lower than the dew point, and water vapor condenses and
mixes with dust to form mud, which firmly sticks to the inner wall of the dust hopper. It is required to install a 10cm thick rock wool insulation layer on the shell, and
keep the fan running for 10 minutes before shutdown to completely discharge the internal moisture.
Malfunction of Ash Discharge Device
Jamming of Star Discharging Valve: Foreign matters enter the interior of the ash unloader, the blades are worn or the motor breaks down, so that it cannot rotate
normally to discharge ash, and the dust in the dust hopper accumulates more and more. It is necessary to clean up the internal foreign matters in time, replace the
worn blades, and regularly add grease to the transmission parts.
Blockage of Ash Conveying Channel: Dust agglomerates and gets stuck in the screw conveyor and ash conveying pipeline, so that the ash discharged from the dust
hopper cannot be smoothly conveyed away, blocking the ash discharge port of the dust hopper in reverse. It is required to disassemble and clean the dust agglomerates
in the ash conveying channel, and check the operating state of the conveyor motor.
Key Points for Daily Prevention
Open the drain valves of the air storage tank and gas distribution bag at fixed time every day to discharge the internal oil and water, so as to avoid the dust getting
damp caused by moisture in the compressed air.
Formulate a fixed ash discharge cycle: discharge ash every 2 hours under high-dust working conditions to avoid excessive accumulated dust in the dust hopper.
Check the air leakage rate of the dust collector regularly to ensure that the air leakage rate is lower than 3%, preventing external cold air from entering and causing
condensation.
