Alternative cleaning
Shock-pulse generator
Also known as SPG, Valmet SPG, shock pulse generator.
A shock-pulse generator (SPG) — most commonly the Valmet SPG — generates high-energy gas-detonation shock waves inside a recovery boiler for periodic deep cleaning of superheater and generating-bank deposits. The technology shares its physical principle with detonation cleaning but is specifically engineered for kraft-recovery-boiler service.
Where SPG fits
- Recovery-boiler superheater (high-value, deep cavities)
- Recovery-boiler generating bank
- Some industrial-boiler convective passes
The SPG is positioned as a complement to existing IK long-retract sootblowers, extending intervals between chill-and-blow campaigns by handling consolidated deposits that sootblowers cannot dislodge.
Position relative to sonic horns
Sonic horns work before deposits consolidate — they keep ash friable so it can be dislodged by mild cleaning. SPG works after consolidation — it breaks hardened deposits that sonic horns could not have prevented. The two technologies operate at opposite ends of the same fouling cycle and are complementary rather than competitive.
Related terms
Related terms
- Detonation cleaningDetonation cleaning uses a controlled pulse-detonation device to generate high-energy shock waves that dislodge boiler deposits. Best-known commercial offering is Bang & Clean.
- 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.
- SuperheaterA superheater is a tube bank that raises steam temperature beyond the saturation point using flue-gas heat. Sticky alkali ash and slag deposits are the dominant fouling concerns.
- 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.