Boilers
Generating bank
Also known as boiler bank, boiler generating bank.
The generating bank (sometimes simply boiler bank) is the array of evaporator tubes between the upper steam drum and the lower mud drum of a recovery boiler or older two-drum industrial boiler. Flue gas passing through the bank gives up heat to the water-and-steam mixture rising through the tubes, performing bulk evaporation between the furnace and the economiser.
Fouling on the generating bank
Recovery-boiler generating banks suffer characteristic alkali-rich ash bridging. The narrow tube spacing makes bridges form quickly, ΔP rises, gas flow channels through residual gaps and bypasses cleaner tubes. Plants targeting 12–18 months between chill-and-blow campaigns spend significant effort keeping the generating bank clean.
Cleaning
Sonic horns and infrasonic cleaners are well-established on recovery-boiler generating banks. They typically complement existing IK retract sootblowers by providing continuous gentle dislodging between the more aggressive periodic blow.
Related terms
Related terms
- Recovery boilerA recovery boiler burns kraft black liquor to generate steam, electrical power and recovered pulping chemicals. Iconic application for sonic horns on superheater cleaning.
- BoilerA boiler is a vessel that converts fuel chemical energy into steam by heating water. Coal-fired, biomass, oil, gas and recovery boilers all foul; sonic horns clean heat-transfer surfaces.
- Convective pass and backpassThe convective pass is the downstream section of a boiler where heat transfer is by conduction across tube banks: superheater, reheater, economiser. The primary zone for sonic-horn cleaning.
- 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.