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<< Self-Cleaning Pulse Filter
<< Cartridges
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As contaminants build up on the surface of the filter media, the differential pressure in the plenum, relative to ambient, will increase. When the differential pressure reaches a preset limit, a pressure switch activates the timer/sequencer board. The timer/sequencer board signals a solenoid valve to open, releasing the pressure holding a pneumatic air valve closed. The opening of the air valve allows a blast of clean, dry, compressed air to leave the air header and proceed: 1) through the air valve, 2) into the distribution blow pipe, and 3) out through the accelerator / inducer nozzles. The blast of compressed air enters the cartridge, and, for a fraction of a second, effectively stops the airflow into the cartridges. The compressed air pressure wave continues down into the cartridges and radially outward, impacting the accumulated dust off the cartridge.
The low velocity of the entering airflow allows only surface loading of the filter media, thus enabling the compressed air pressure wave, from the cleaning pulse, to effectively remove any accumulated particulate. Some of the finer particles may become
re-entrained on adjacent filter cartridges, however, the tendency is for the dust to collect and blow off in particles large enough to fall away from the adjacent cartridges.
Cartridges in the first row are pulsed first, then the timer/sequencer selects the next row and the pulse-cleaning procedure is repeated. The number of elements cleaned at any instant and the time interval between pulses are chosen so that no significant degradation of the airflow is evident. The timer/sequencer board continues to sequence the cleaning operation throughout the cartridges until the overall differential pressure reaches a preset lower limit. At that time the cleaning process ceases until called upon again by a high differential pressure reading. |
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