Steel and refining
Reformer furnace
Also known as steam methane reformer, SMR, primary reformer.
A reformer furnace — almost always a steam methane reformer (SMR) in modern refineries and ammonia plants — produces hydrogen by reacting natural gas with steam at ~850 °C over a nickel catalyst inside vertical tubes. The radiant box delivers the reaction heat from burner walls; flue gas leaves to a convection section recovering remaining heat into process steam and feed preheat.
Fouling in the convection bank
The SMR convection bank is particularly fouling-prone because:
- High-temperature flue-gas surfaces sit above the ammonium bisulphate dew point but cool sufficiently below it on the cold-end
- SO₃ from any sulphur leaving the desulphurisers reacts with ammonia slip from upstream SCR (if installed) to form ABS
- Deposits consolidate on finned-tube banks reducing heat recovery
Cleaning
Sonic horns on the SMR convection-bank cold end keep ABS deposits from consolidating. Hydrogen-plant reliability is critical to refinery operation (any unit upstream that needs hydrogen will derate without it), so the value of avoided outages is high.
Related terms
Related terms
- EconomiserAn economiser is the final tube bank in a boiler's convective pass that recovers heat from the flue gas by preheating feedwater. Ash bridging in the economiser is a routine cleaning challenge.
- Ammonium bisulphateAmmonium bisulphate is a sticky low-melting deposit formed when slipped ammonia reacts with SO3 in cooling flue gas. The dominant cold-end fouling species on SCR-equipped boilers.
- 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.