Core technology
Infrasonic cleaner
Also known as infrasound cleaner, infrasonic cleaning system, sub-audible acoustic cleaner.
An infrasonic cleaner (also written infrasound cleaner) is an acoustic cleaner that operates below the threshold of human hearing — typically 12 to 30 Hz, against the 60–400 Hz range of a conventional sonic horn. The very long wavelength of an infrasonic wave (above 10 metres at 30 Hz) fills a large vessel almost uniformly and penetrates further into deep, baffled or obstructed cavities than higher-frequency horns can reach.
How it differs from a sonic horn
| Attribute | Infrasonic cleaner | Sonic horn |
|---|---|---|
| Frequency | 12–30 Hz (sub-audible) | 60–400 Hz (audible) |
| Wavelength | 10–28 m | 0.85–5.7 m |
| Penetration | Excellent, fills the whole vessel | Directional, projected from the bell |
| Audible noise at the work area | Very low (mostly inaudible) | Significant, often requires hearing protection |
| Bell size | Large (low cut-off frequency demands physical bulk) | Compact |
| Typical applications | Recovery boilers, WtE flue paths, HRSGs, marine boilers | Cross-application; default specification |
Where infrasonic cleaners are preferred
Infrasonic technology was popularised by Swedish suppliers (Infrafone / Heat Management) on pulp-and-paper kraft recovery boilers, where the combination of deep superheater cavities and the strict need to extend the interval between chill-and-blow wash cycles rewards the deeper penetration of long waves. The same logic carries over to large WtE boilers with sticky chloride-laden ash, to HRSG harp tube banks and to large marine boilers where work-area noise must be kept low.
When to choose a sonic horn instead
For most baghouse, ESP, hopper and silo applications, a 60–250 Hz low-frequency sonic horn projects enough penetration with a smaller bell, lower capital cost, lower air consumption and simpler integration. Infrasonic cleaners earn their cost where vessel geometry, deposit depth or noise-exposure limits make the long wavelength specifically valuable.
Related terms
Related terms
- Acoustic cleanerAn acoustic cleaner is any device that uses high-intensity sound waves to dislodge particulate fouling from inside industrial process equipment such as boilers, ESPs, baghouses and silos.
- 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.
- Low-frequency acoustic cleanerLow-frequency acoustic cleaners operate at 60–250 Hz. The long wavelength penetrates deep into large open vessels such as ESPs, recovery boilers and cement preheater cyclones.
- 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.
- Waste-to-energyWtE plants burn municipal solid waste, RDF, SRF and biomass to generate steam and electricity. Sticky chloride-rich ash defeats conventional cleaning; sonic horns are the dominant fit.