The pulse bag filter is the "air purifier" of the quartz sand production
line, responsible for capturing the dust generated during the crushing and
screening process (with a required emission concentration of ≤ 10mg/m ³). If the
dust removal efficiency is low (emission concentration exceeds 30mg/m ³) and the
filter bag is prone to clogging (needs to be replaced after one month of use),
it will cause dust pollution and increase equipment energy consumption. Based on
practical experience, summarize the three-step troubleshooting method to quickly
restore dust removal performance.
Step 1: Check the filter bag and filtration system - the filtration core
determines the dust removal effect
Improper selection or installation of filter bags is the main cause of poor
dust removal and blockage.
Mismatch of filter bag material or aperture: Ordinary polyester filter bags
cannot withstand wear from quartz sand dust (Mohs 7 grade), and the aperture is
too large (>10 μ m), making it easy for fine powder to penetrate; If PTFE
material is not selected for the laminated filter bag, it is prone to dust
adhesion and blockage. It is recommended to use PTFE coated needle punched felt
filter bags for quartz sand dust removal (pore size 3-5 μ m, wear resistance
twice higher than polyester), with a filtration accuracy of 99.9%. Ensure that
the filter bag is tightly attached to the flower board during installation, and
the bag mouth clamp is tightened to prevent dust from leaking out through gaps;
The verticality deviation of the filter bag is ≤ 3mm to prevent mutual friction
and damage during operation.
Filter bag sticking or condensation: When the moisture content of the
material exceeds 8%, dust is prone to adhere to the filter bag and form a
"sticking bag"; The insulation of the dust collector is insufficient, and the
flue gas temperature is below the dew point (<60 ℃), which can cause
condensation and lead to dust agglomeration and blockage. It is necessary to add
a drying process before dust removal (reducing the moisture content of the
material to below 5%), and install a rock wool insulation layer (thickness 50mm)
on the dust collector shell to ensure that the flue gas temperature is
maintained at 70-90 ℃ and avoid condensation.
Step 2: Calibrate the dust cleaning system and parameters - Effective dust
cleaning is key to preventing blockages
Improper setting of pulse valve and spray parameters can lead to incomplete
dust cleaning.
Pulse valve malfunction or insufficient injection pressure: The aging of the
pulse valve diaphragm (after more than 6 months of use) can cause weak
injection; When the blowing pressure is below 0.4 MPa, compressed air cannot
effectively remove the dust on the surface of the filter bag. Replace the
high-quality electromagnetic pulse valve (diaphragm material selected from
nitrile rubber), adjust the pressure of the air storage tank to 0.5-0.6MPa, and
ensure strong injection airflow.
Unreasonable spraying frequency or width: The frequency is too low (spraying
once every 30 minutes), and the dust accumulation is too thick, blocking the
filter bag; Excessive spraying (once every 5 minutes) can cause the filter bag
to wear out easily; Spray width less than 0.1 seconds, incomplete dust cleaning.
Adjust according to dust concentration: high concentration dust is sprayed once
every 10-15 minutes, with a spraying width of 0.15-0.2 seconds; Spray low
concentration once every 20-25 minutes, precisely set through a pulse
controller.
Step 3: Optimize airflow organization and daily maintenance - airflow
stability+proper maintenance to prevent malfunctions
Uneven airflow distribution and lack of maintenance can exacerbate equipment
problems.
Improper airflow velocity or guide plate: filtering wind speed exceeding
1.2m/min, dust easily penetrates the filter bag; Below 0.6m/min, the dust
removal efficiency is low and the energy consumption is high. Adjust to
0.8-1.0m/min and control the speed of the induced draft fan through a frequency
converter. Deformation or absence of the guide plate can cause airflow to
directly hit the filter bag, resulting in severe local wear and tear; Short
circuiting of airflow can cause dust to be discharged unfiltered. Re calibrate
the angle of the deflector (30 ° to the airflow direction), complete the missing
deflector, and ensure that the airflow is evenly distributed in the filter
chamber.
Maintenance deficiency: If the ash accumulation in the ash hopper exceeds
1/2, it will cause secondary dust; The pulse valve air source contains oil and
water, which pollutes the filter bag. Check the operation status of the ash
hopper unloading valve every day to ensure timely discharge of accumulated ash;
Install an oil-water separator in the gas source pipeline to discharge oil and
accumulated water on a weekly basis; Check the wear of the filter bag every
month and replace it promptly if it is found to be broken to avoid dust leakage
affecting the dust removal effect.
By following the above three steps, the dust emission concentration can be
reduced to below 8mg/m ³, and the service life of the filter bag can be extended
to more than 6 months. If there are still problems, it is recommended to contact
the manufacturer to test the distribution of the airflow field to ensure
accurate matching between the equipment and the characteristics of quartz sand
dust.