Differential Pressure Measurement across a filter is very important to determine the filtering efficiency of the baghouse. The increased differential pressure across the baghouse ( bag dust collector) or filter shows that there is jamming inside the bags. Jamming may be due to the clogging of the bags.
The manufacturer specifies the rated pressure drop across BDC (Baghouse dust collector).
WHAT IS A BAGHOUSE DUST COLLECTOR?
The baghouse dust collector or a filter has long, cylindrical bags. The bags are made of fabric. The main function of the bags is to filter dust particles out of the air stream. The dust-laden air- the air that has lots of dust, smoke, and impurities- enters the baghouse. A differential pressure transmitter is installed across a filter to ensure the healthiness of the filter.
The baghouse fan creates the suction or draft to direct the dust-laden air into the BDC. Dirty air enters the inlet of BDC, passes through the bags, gets cleaned here, and exits from the outlet of the BDC. The dust collected in the bags dislodges into the BDC hopper during the purging of the air through the solenoid valve. The clean air can be released into the environment or reused in the process. The efficiency of the dust collectors also depends on the air purging cycle.
The increased differential pressure across a filter shows bags dp has increased are not sufficiently cleaned.
Differential Pressure Measurement Across Filter
The differential pressure measures the flow in the stream. The clogged bags cause hindrance to flow of air stream. As a result, the differential pressure increases across the baghouse. The DP transmitter’s pressure measurement indicates how clogged the bags are. Thus, the differential pressure across a filter shows the hindrance to air.
The DP transmitter gives a signal to the BDC controller when the differential pressure across a filter reaches above the set point. The BDC controller issues command to the solenoid valve at a faster rate to bring the differential pressure down.
The bag choking problem increases if the bag’s cleaning is not perfect during purging. The pressure of the purge air is very important in the cleaning process. If the control air pressure is low than the rated purge air pressure, it can beget the problem of bags choking gradually.
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