Baghouses
Pulse-jet baghouse
Also known as pulse jet baghouse, pulse-jet filter, PJBH.
A pulse-jet baghouse is a fabric filter design in which each filter bag is cleaned by a brief, high-pressure pulse of compressed air directed downwards into the open top of the bag. The pulse momentarily reverses the gas flow through the bag wall, dislodges the dust cake, and lets it fall into the hopper. Pulse-jet is the dominant industrial baghouse design for new installations.
How a pulse-jet cycle runs
Solenoid valves on a manifold above the tubesheet fire one row at a time, typically every 1–10 minutes during normal operation, more often when differential pressure climbs. Pulse duration is 100–300 ms at 4–7 bar. The cleaning is online: the rest of the baghouse continues filtering during each pulse. See pulse-jet cleaning cycle.
Where pulse-jet underperforms
Pulse-jet cleaning is highly effective on the bag surface directly under the venturi nozzle, but weaker on:
- Bag rows at the back of the compartment, furthest from the manifold
- The top and bottom inches of each bag where the pulse loses momentum
- Tubesheet area between rows where airborne dust resettles
- Compartment hoppers, which the pulse cannot reach at all
Adding sonic horns at the compartment roof and at the hopper wall closes these gaps, reducing total compressed-air consumption per kg of dust cleaned and extending bag life.
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.
- 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.
- Pulse-jet cleaning cycleThe pulse-jet cleaning cycle is the firing pattern of compressed-air pulses across a baghouse. Tuned by pulse duration, interval and ΔP set-point to balance cleaning against bag wear.
- 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.
- Sonic hornA sonic horn is a pneumatically-driven low-frequency sound emitter (typically 60–400 Hz at 140–180 dB SPL) used to dislodge particulate fouling from boilers, ESPs, baghouses and process vessels.