The adjustment of the injection pressure for a baghouse dust collector must be carried out in accordance with standardized procedures: first inspect the basic
conditions of the air source, then calibrate the pressure values step by step, and finally conduct joint commissioning of the ash cleaning logic, so as to avoid filter
bag damage or ash cleaning failure caused by blind pressure adjustment.
Safety and Pre-Checks Before Pressure Regulation
First confirm that the dust collector is in normal on-load operation. Blind pressure adjustment under shutdown and empty bin conditions is strictly prohibited.
Check in advance that there is no air leakage in the air storage tank and pneumatic pipelines, and the pulse valve diaphragm is free from damage and jamming,
so as to avoid unstable and falsely high pressure after pressure regulation.
Verify that the oil mist device and filter of the pneumatic triple unit are working properly, and the compressed air does not contain large amounts of accumulated
water and oil, preventing impurities from entering the valve components and causing damage after pressure regulation.
Step-by-Step Pressure Regulation Operation Procedure
Rough Adjustment at Air Source End: Locate the air source pressure regulating valve on the main outlet pipeline of the air storage tank. Turn the handle of the
pressure regulating valve clockwise to gradually increase the pressure, while observing the pressure gauge on the air bag. First adjust the pressure to the reference
value of the target working condition (for example, adjust it to 0.4MPa for conventional polyester filter bags).
Fine Adjustment on Branch Pipelines: If the dust collector adopts a multi-bin independent pneumatic circuit structure, adjust the branch pressure regulating valves
on the branch pipelines of each bin respectively, to ensure that the deviation of the injection pressure of each bin does not exceed ±0.05MPa, and avoid the dead
zone with uneven local ash cleaning pressure.
On-Load Verification and Adjustment: After the pressure regulation is completed, run the dust collector continuously for 2 to 4 hours, and observe the change of the
pressure difference between the inlet and outlet of the dust collector:
If the pressure difference remains above 1500Pa with no downward trend, increase the pressure by a small increment of 0.03~0.05MPa each time, until the pressure
difference drops back to the reasonable range of 800~1200Pa.
If the pressure difference stays below 600Pa for a long time and the filter bag shakes excessively during injection, decrease the pressure by a small increment of
0.05MPa each time, so as to prevent the high-pressure airflow from excessively impacting the fibers of the filter bag.
Coordinated Optimization of Supporting Parameters
After adjusting the injection pressure, synchronously calibrate the pulse width (injection duration): appropriately shorten the injection duration when the pressure is
relatively high, and slightly extend the injection duration when the pressure is relatively low, so as to avoid the reduction of ash cleaning effect caused by mismatched
parameters.
Enable the pressure difference-linked intelligent ash cleaning logic, abandon the fixed-sequence ash cleaning mode, and dynamically trigger injection according to the
real-time pressure difference, so that the adjusted pressure parameters can maximize the ash cleaning efficiency.
For the working condition of fine dust from dry quenching of coke, confirm that the nozzles of the injection pipes are fully aligned with the center of the filter bags
after pressure regulation, to ensure that the high-pressure airflow injects vertically into the interior of the filter bags, and prevent the deflected airflow from scouring
the bag mouth and causing partial damage to the filter bags.
Long-Term Management After Pressure Regulation
Establish an inspection ledger for injection pressure, and record the air bag pressure and operating pressure difference data for each shift, so as to avoid large deviation
of the pressure caused by the fluctuation of the air source.
Drain the accumulated water at the bottom of the air storage tank and pipelines once a week, to prevent oil-water impurities from entering the pulse valve, which
would cause valve jamming and inaccurate pressure reading.
When the seasonal temperature difference exceeds 10℃ or the production load fluctuates significantly, re-fine-tune the injection pressure to adapt to the change
of working conditions.
