Core technology
Acoustic cleaner
Also known as acoustic cleaners, acoustic cleaning device.
An acoustic cleaner is any device that uses high-intensity sound waves — typically at audible low frequencies between 60 and 450 Hz and sound pressure levels of 140 to 180 dB — to dislodge particulate fouling from inside industrial process equipment. The acoustic energy vibrates dust, ash, soot and other accreted solids, keeping them airborne and entrained in the gas flow so they cannot bond, bridge or harden on internal surfaces.
How an acoustic cleaner works
A pneumatic driver — usually compressed air at 4 to 7 bar — sets a metal diaphragm or piston-whistle assembly vibrating at the cleaner's design frequency. The vibration is amplified through an exponential bell horn and projected into the equipment as a near-spherical pressure field. Particulate already deposited on tube banks, plates, catalyst layers or hopper walls receives an oscillating force that overcomes adhesion. Because the cleaner is non-contact, it can run while the plant is online, every few minutes, without thermal shock, tube erosion or refractory damage.
Where acoustic cleaners are used
Acoustic cleaners are installed throughout the gas path and bulk-solids path of heavy industry:
- Combustion plant — boilers, economisers, superheaters, air heaters
- Air-pollution control — electrostatic precipitators, fabric filters, SCR catalysts
- Bulk solids — hoppers, silos and bunkers prone to bridging and rat-holing
- Cement — preheater cyclones, calciners, kiln inlets
- Pulp and paper — kraft recovery boilers, lime kilns
Acoustic cleaners are not ultrasonic cleaners
The two terms are routinely confused but describe completely different technologies. Acoustic cleaners operate in the audible low-frequency band and clean dry industrial surfaces in situ with airborne sound. Ultrasonic cleaners operate above 20 kHz inside a liquid bath and clean small parts off-line by cavitation. See acoustic cleaning vs ultrasonic cleaning.
Related terms
Related terms
- Acoustic cleaning systemAn acoustic cleaning system is the engineered assembly of sonic horns, compressed-air supply, solenoid valves and cycle controllers that delivers programmed acoustic cleaning to industrial process equipment.
- 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.
- Sonic sootblowerA sonic sootblower is a sonic horn used specifically on boiler heat-transfer surfaces. It uses low-frequency sound instead of high-pressure steam, eliminating tube erosion and steam consumption.
- Infrasonic cleanerAn infrasonic cleaner operates below the audible threshold (typically 12–30 Hz). The very long wavelength penetrates further than a conventional sonic horn and is preferred on recovery boilers and WtE flue paths.
- 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.
- High-frequency acoustic cleanerHigh-frequency acoustic cleaners operate at 250–450 Hz. The shorter wavelength carries more energy per unit volume and suits fabric filters, SCR catalysts and small hopper geometries.