Glossary
Steel and refining
Blast-furnace gas cleaning
Also known as BF gas cleaning, top-gas cleaning, BFG cleaning.
Blast-furnace gas cleaning is the multi-stage flue-gas treatment train that removes particulate from the blast furnace's top gas before the gas is used as a fuel in the steelworks' downstream boilers and stoves. The high pressure and high dust loading of blast-furnace top gas demand a sequence of progressively finer cleaning steps:
| Stage | Equipment | Function |
|---|---|---|
| 1 | Dust catcher | Large inertial separator removing coarse particulate |
| 2 | Venturi scrubber | High-energy wet scrubbing for fine particulate |
| 3 | Wet ESP | Final polish for sub-micron particulate |
Sonic-horn duty
Sonic horns on the dust-catcher hopper prevent bridging of the coarse iron-oxide dust. Some installations also use horns on the wet-ESP sludge handling hoppers.
Related terms
Related terms
- Dust catcherA dust catcher is a large vertical inertial separator used in blast-furnace gas cleaning to remove coarse particulate before downstream wet scrubbers or fabric filters.
- Venturi scrubberA Venturi scrubber atomises scrubbing liquid into a high-velocity throat where it intercepts and traps fine particulate. Common on blast-furnace gas cleaning and chemical off-gas duty.
- Wet electrostatic precipitatorA wet electrostatic precipitator continuously washes its collecting surfaces with water, used for sub-micron particulate, acid mist and sticky aerosols downstream of FGD or biomass scrubbers.
- 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.