Baghouses
Plenum
Also known as clean plenum, dirty plenum, clean side, dirty side.
A plenum is a gas-flow chamber inside a baghouse. Every baghouse has at least two:
- Dirty plenum — below the tubesheet; accepts the incoming flue-gas flow; surrounds the outside of the filter bags; contains the bag-and-cage assemblies
- Clean plenum — above the tubesheet; collects filtered gas leaving the inside of each bag; routes to the outlet duct and ID fan
The pressure difference between the two plenums is the baghouse differential pressure, the headline operational KPI.
In a pulse-jet baghouse
A pulse-jet baghouse adds a small inlet plenum above the clean plenum that houses the air-receiver tank and the manifold of pulse valves. Each valve fires downward through a venturi into the open top of a bag, momentarily reversing flow.
In a reverse-air baghouse
A reverse-air baghouse compartment alternates between filtration mode (gas flows from dirty plenum, through the bag wall, into the clean plenum) and cleaning mode (compartment isolated; reverse-air fan flows clean gas back through the bags into the dirty plenum).
Related terms
Related terms
- BaghouseA baghouse is the structural enclosure that holds the bags, cages, tubesheet, cleaning system and hoppers of a fabric-filter dust collector. Sized in compartments for online isolation.
- TubesheetThe tubesheet is the perforated steel plate that separates the clean and dirty plenums of a baghouse. Filter bags hang from holes in the tubesheet, sealed by snap-band collars.
- Filter bagA filter bag is the cylindrical fabric sock that traps particulate inside a fabric filter. Media selection depends on temperature, gas chemistry, dust load and cleaning cycle.
- Differential pressure (baghouse)Differential pressure (ΔP) across a baghouse is the pressure drop between dirty and clean plenums. It is the headline operational KPI: too low signals broken bags, too high signals fouling.