Glossary
Steel and refining
Basic oxygen furnace
Also known as BOF, LD converter, basic oxygen steelmaking.
A basic oxygen furnace (BOF) — historically the LD converter after the Linz-Donawitz process — refines molten pig iron from the blast furnace into steel by blowing high-purity oxygen onto the bath through a water-cooled lance. Each "heat" takes 30–45 minutes and produces 250–300 tonnes of steel.
Off-gas
BOF off-gas is intermittent, very high-temperature (>1,600 °C at the converter mouth) and dust-laden. Two cleaning approaches:
- Suppressed combustion — gas is collected as fuel after partial cleaning
- Open combustion — gas is combusted in a waste-heat boiler and the products cleaned in an ESP or baghouse
Cleaning targets
- Primary BOF baghouse hopper — fine iron-oxide dust
- Secondary BOF baghouse — fume capture during charging, tapping and slag operations
- Waste-heat boiler convective pass (open-combustion designs)
Sonic horns on BOF baghouse hoppers are increasingly specified to defend against the bridging risk associated with fine, hot iron-oxide dust.
Related terms
Related terms
- Electric arc furnaceAn EAF melts steel scrap and DRI in a refractory-lined vessel using an electric arc. Dust collection is via a roof-evacuation duct to a large baghouse, prone to compartment fouling.
- 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.
- Waste-heat boilerA waste-heat boiler recovers heat from a process gas stream — Claus SRU exhaust, BOF off-gas, sulphuric-acid converter — to generate steam. Fouling pattern depends on the source process.