[{"data":1,"prerenderedAt":905},["ShallowReactive",2],{"site-footer-common":3,"glossary:acoustic-horn":45,"glossary-related:acoustic-horn":184},{"id":4,"extension":5,"footer":6,"meta":40,"navbar":41,"stem":43,"__hash__":44},"common\u002Fcommon.yml","yml",{"tagline":7,"links":8,"sections":9},"Acoustic cleaning intelligence for industrial fouling, soot, ash, dust and build-up.",[],[10,19,31],{"title":11,"links":12},"Product",[13,16],{"label":14,"to":15},"How it works","\u002F#product",{"label":17,"to":18},"Cost assessment","\u002F#hero",{"title":20,"links":21},"Company",[22,25,28],{"label":23,"to":24},"What we build","\u002F#about",{"label":26,"to":27},"Careers","\u002F#careers",{"label":29,"to":30},"Contact","\u002F#contact",{"title":32,"links":33},"Resources",[34,37],{"label":35,"to":36},"Blog","\u002Fresources\u002Fblog",{"label":38,"to":39},"Glossary","\u002Fglossary",{},{"links":42},[],"common","YocmZRy1AYfBbpgGVms-zhdiABlF8VTxHx6h4rDmZBA",{"id":46,"title":47,"aliases":48,"body":51,"category":161,"description":162,"extension":163,"meta":164,"navigation":165,"path":166,"relatedTerms":167,"seo":172,"sources":175,"stem":182,"term":47,"__hash__":183},"glossary\u002Fglossary\u002Facoustic-horn.md","Acoustic horn",[49,50],"acoustic horns","industrial acoustic horn",{"type":52,"value":53,"toc":154},"minimark",[54,74,79,82,104,107,111,126,130],[55,56,57,58,62,63,68,69,73],"p",{},"An ",[59,60,61],"strong",{},"acoustic horn"," is the broader engineering term for a horn-shaped sound emitter that projects high-intensity low-frequency sound for industrial cleaning duty. In day-to-day procurement and trade-press writing the term is used interchangeably with ",[64,65,67],"a",{"href":66},"\u002Fglossary\u002Fsonic-horn","sonic horn","; academic and European specification documents tend to prefer \"acoustic horn\" while North American power-industry literature prefers \"sonic horn\" or \"",[64,70,72],{"href":71},"\u002Fglossary\u002Fsonic-sootblower","sonic sootblower","\".",[75,76,78],"h2",{"id":77},"why-the-two-names-co-exist","Why the two names co-exist",[55,80,81],{},"Three lineages converge on the same device:",[83,84,85,92,98],"ul",{},[86,87,88,91],"li",{},[59,89,90],{},"Acoustical engineering"," literature describes any directional sound source with an exponential or conical flare as an \"acoustic horn\", regardless of frequency or intended use.",[86,93,94,97],{},[59,95,96],{},"Power-industry practice"," in the United States adopted \"sonic horn\" as the catalogue term in the 1980s, paralleling \"sonic sootblower\".",[86,99,100,103],{},[59,101,102],{},"European industrial procurement"," has retained \"acoustic horn\" and \"acoustic cleaner\" as the dominant phrasing in tender specifications.",[55,105,106],{},"The hardware, frequencies, sound-pressure levels, mounting and control logic are identical across all three usages.",[75,108,110],{"id":109},"seo-and-search-behaviour","SEO and search behaviour",[55,112,113,114,117,118,120,121,125],{},"Specifiers searching ",[115,116,61],"code",{}," typically land on industrial, audio-engineering and signalling (ship's horn, alarm-horn) results in the same SERP — the term is more ambiguous than ",[115,119,67],{},". Pages targeting this query benefit from disambiguation copy in the first paragraph (industrial cleaning duty, not signalling) and from cross-linking to the ",[64,122,124],{"href":123},"\u002Fglossary\u002Findustrial-sonic-horn","industrial sonic horn"," disambiguator.",[75,127,129],{"id":128},"related-terms","Related terms",[83,131,132,137,143,149],{},[86,133,134],{},[64,135,136],{"href":66},"Sonic horn",[86,138,139],{},[64,140,142],{"href":141},"\u002Fglossary\u002Facoustic-cleaner","Acoustic cleaner",[86,144,145],{},[64,146,148],{"href":147},"\u002Fglossary\u002Fbell-horn","Bell horn",[86,150,151],{},[64,152,153],{"href":123},"Industrial sonic horn",{"title":155,"searchDepth":156,"depth":156,"links":157},"",2,[158,159,160],{"id":77,"depth":156,"text":78},{"id":109,"depth":156,"text":110},{"id":128,"depth":156,"text":129},"core-technology","An acoustic horn is the broader engineering term for a horn-shaped sound emitter that projects high-intensity low-frequency sound for industrial cleaning duty. In day-to-day procurement and trade-press writing the term is used interchangeably with sonic horn; academic and European specification documents tend to prefer \"acoustic horn\" while North American power-industry literature prefers \"sonic horn\" or \"sonic sootblower\".","md",{},true,"\u002Fglossary\u002Facoustic-horn",[168,169,170,171],"sonic-horn","acoustic-cleaner","bell-horn","low-frequency-acoustic-cleaner",{"title":173,"description":174},"Acoustic horn — definition and how it differs from a sonic horn","An acoustic horn is the broader term for any low-frequency horn-shaped sound emitter used in industrial cleaning. In commercial practice it is interchangeable with sonic horn.",[176,179],{"title":177,"url":178},"Power Magazine — The Theory and Application of Acoustic Cleaners","https:\u002F\u002Fwww.powermag.com\u002Fthe-theory-and-application-of-acoustic-cleaners\u002F",{"title":180,"url":181},"Wikipedia — Acoustic cleaning","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAcoustic_cleaning","glossary\u002Facoustic-horn","k-_lUmlIQZ_60EsbB3p9XJ15z-UxJ7SG7xyX-jsbd2o",[185,418,581,712],{"id":186,"title":136,"aliases":187,"body":190,"category":161,"description":397,"extension":163,"meta":398,"navigation":165,"path":66,"relatedTerms":399,"seo":403,"sources":406,"stem":416,"term":136,"__hash__":417},"glossary\u002Fglossary\u002Fsonic-horn.md",[188,189,124],"sonic horns","sonic cleaning horn",{"type":52,"value":191,"toc":390},[192,225,229,237,241,309,313,350,354,362,364],[55,193,194,195,197,198,201,202,206,207,206,211,206,215,219,220,224],{},"A ",[59,196,67],{}," is a pneumatically-driven sound emitter that produces high-intensity, low-frequency sound waves — typically between 60 and 400 Hz at sound pressure levels of 140 to 180 dB — used to dislodge particulate fouling from inside industrial process equipment. Sonic horns are the most common form of ",[64,199,200],{"href":141},"acoustic cleaner"," and the default specification for cleaning ",[64,203,205],{"href":204},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",", ",[64,208,210],{"href":209},"\u002Fglossary\u002Ffabric-filter","baghouses",[64,212,214],{"href":213},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[64,216,218],{"href":217},"\u002Fglossary\u002Fsuperheater","boiler heat-transfer surfaces"," and ",[64,221,223],{"href":222},"\u002Fglossary\u002Fhopper","hoppers and silos",".",[75,226,228],{"id":227},"how-a-sonic-horn-works","How a sonic horn works",[55,230,231,232,236],{},"Compressed plant air admitted through a ",[64,233,235],{"href":234},"\u002Fglossary\u002Fsolenoid-valve","solenoid valve"," drives a metal diaphragm — typically titanium or 316 stainless — into resonant oscillation at the horn's fundamental frequency. The oscillating pressure field is amplified by an exponential bell horn and projected into the vessel as a near-spherical sound wave. Particulate already deposited on internal surfaces receives an oscillating acceleration that overcomes adhesion; loosened material is then carried out with the gas flow before it can sinter, bridge or bond. Because the cleaning is acoustic and non-contact, the horn can fire while the plant is online without tube erosion, refractory damage or thermal shock.",[75,238,240],{"id":239},"key-parameters","Key parameters",[242,243,244,257],"table",{},[245,246,247],"thead",{},[248,249,250,254],"tr",{},[251,252,253],"th",{},"Parameter",[251,255,256],{},"Typical range",[258,259,260,269,277,285,293,301],"tbody",{},[248,261,262,266],{},[263,264,265],"td",{},"Fundamental frequency",[263,267,268],{},"60–400 Hz",[248,270,271,274],{},[263,272,273],{},"Sound pressure level",[263,275,276],{},"140–180 dB",[248,278,279,282],{},[263,280,281],{},"Compressed-air consumption",[263,283,284],{},"8–14 Nm³\u002Fmin at 4–7 bar",[248,286,287,290],{},[263,288,289],{},"Operating temperature (with appropriate materials)",[263,291,292],{},"−40 °C to +500 °C",[248,294,295,298],{},[263,296,297],{},"Firing cycle",[263,299,300],{},"5–15 s burst, repeated every 3–15 minutes",[248,302,303,306],{},[263,304,305],{},"Mass",[263,307,308],{},"15–60 kg depending on horn size",[75,310,312],{"id":311},"frequency-selection","Frequency selection",[55,314,315,316,206,320,324,325,206,329,333,334,206,337,341,342,219,346,224],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[64,317,319],{"href":318},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[64,321,323],{"href":322},"\u002Fglossary\u002Frecovery-boiler","recovery-boiler superheaters",", large ",[64,326,328],{"href":327},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[64,330,332],{"href":331},"\u002Fglossary\u002Fsilo","silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[64,335,336],{"href":209},"fabric-filter compartments",[64,338,340],{"href":339},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[64,343,345],{"href":344},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[64,347,349],{"href":348},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[75,351,353],{"id":352},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[55,355,356,357,361],{},"Sonic horns are increasingly specified alongside or in place of ",[64,358,360],{"href":359},"\u002Fglossary\u002Fsteam-sootblower","steam sootblowers"," because they consume no boiler-grade steam, cause no tube erosion, require almost no moving parts and can fire every few minutes without operator intervention. They are less effective on hard, fused slag than retractable steam lances, so on furnace waterwalls and high-temperature superheaters they typically complement rather than replace mechanical cleaning.",[75,363,129],{"id":128},[83,365,366,370,375,379,385],{},[86,367,368],{},[64,369,142],{"href":141},[86,371,372],{},[64,373,374],{"href":71},"Sonic sootblower",[86,376,377],{},[64,378,148],{"href":147},[86,380,381],{},[64,382,384],{"href":383},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[86,386,387],{},[64,388,389],{"href":344},"Low-frequency acoustic cleaner",{"title":155,"searchDepth":156,"depth":156,"links":391},[392,393,394,395,396],{"id":227,"depth":156,"text":228},{"id":239,"depth":156,"text":240},{"id":311,"depth":156,"text":312},{"id":352,"depth":156,"text":353},{"id":128,"depth":156,"text":129},"A sonic horn is a pneumatically-driven sound emitter that produces high-intensity, low-frequency sound waves — typically between 60 and 400 Hz at sound pressure levels of 140 to 180 dB — used to dislodge particulate fouling from inside industrial process equipment. Sonic horns are the most common form of acoustic cleaner and the default specification for cleaning ESPs, baghouses, SCR catalysts, boiler heat-transfer surfaces and hoppers and silos.",{},[169,400,401,170,402,171],"acoustic-cleaning-system","sonic-sootblower","diaphragm-horn",{"title":404,"description":405},"Sonic horn — definition, frequency, SPL and industrial applications","A 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.",[407,410,413],{"title":408,"url":409},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":411,"url":412},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":414,"url":415},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",{"id":419,"title":142,"aliases":420,"body":423,"category":161,"description":567,"extension":163,"meta":568,"navigation":165,"path":141,"relatedTerms":569,"seo":572,"sources":575,"stem":579,"term":142,"__hash__":580},"glossary\u002Fglossary\u002Facoustic-cleaner.md",[421,422],"acoustic cleaners","acoustic cleaning device",{"type":52,"value":424,"toc":561},[425,430,434,437,441,444,521,525,537,539],[55,426,57,427,429],{},[59,428,200],{}," 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.",[75,431,433],{"id":432},"how-an-acoustic-cleaner-works","How an acoustic cleaner works",[55,435,436],{},"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.",[75,438,440],{"id":439},"where-acoustic-cleaners-are-used","Where acoustic cleaners are used",[55,442,443],{},"Acoustic cleaners are installed throughout the gas path and bulk-solids path of heavy industry:",[83,445,446,463,477,494,509],{},[86,447,448,451,452,206,456,206,459],{},[59,449,450],{},"Combustion plant"," — boilers, ",[64,453,455],{"href":454},"\u002Fglossary\u002Feconomiser","economisers",[64,457,458],{"href":217},"superheaters",[64,460,462],{"href":461},"\u002Fglossary\u002Fair-heater","air heaters",[86,464,465,468,469,206,472,206,475],{},[59,466,467],{},"Air-pollution control"," — ",[64,470,471],{"href":204},"electrostatic precipitators",[64,473,474],{"href":209},"fabric filters",[64,476,214],{"href":213},[86,478,479,468,482,485,486,219,490],{},[59,480,481],{},"Bulk solids",[64,483,484],{"href":222},"hoppers, silos and bunkers"," prone to ",[64,487,489],{"href":488},"\u002Fglossary\u002Fbridging","bridging",[64,491,493],{"href":492},"\u002Fglossary\u002Frat-holing","rat-holing",[86,495,496,468,499,206,501,206,505],{},[59,497,498],{},"Cement",[64,500,319],{"href":318},[64,502,504],{"href":503},"\u002Fglossary\u002Fcalciner","calciners",[64,506,508],{"href":507},"\u002Fglossary\u002Fkiln-inlet-riser-duct","kiln inlets",[86,510,511,468,514,206,517],{},[59,512,513],{},"Pulp and paper",[64,515,516],{"href":322},"kraft recovery boilers",[64,518,520],{"href":519},"\u002Fglossary\u002Flime-kiln","lime kilns",[75,522,524],{"id":523},"acoustic-cleaners-are-not-ultrasonic-cleaners","Acoustic cleaners are not ultrasonic cleaners",[55,526,527,528,532,533,224],{},"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 ",[529,530,531],"em",{},"in situ"," with airborne sound. Ultrasonic cleaners operate above 20 kHz inside a liquid bath and clean small parts off-line by cavitation. See ",[64,534,536],{"href":535},"\u002Fglossary\u002Facoustic-cleaning-vs-ultrasonic-cleaning","acoustic cleaning vs ultrasonic cleaning",[75,538,129],{"id":128},[83,540,541,547,551,555],{},[86,542,543],{},[64,544,546],{"href":545},"\u002Fglossary\u002Facoustic-cleaning-system","Acoustic cleaning system",[86,548,549],{},[64,550,136],{"href":66},[86,552,553],{},[64,554,374],{"href":71},[86,556,557],{},[64,558,560],{"href":559},"\u002Fglossary\u002Finfrasonic-cleaner","Infrasonic cleaner",{"title":155,"searchDepth":156,"depth":156,"links":562},[563,564,565,566],{"id":432,"depth":156,"text":433},{"id":439,"depth":156,"text":440},{"id":523,"depth":156,"text":524},{"id":128,"depth":156,"text":129},"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.",{},[400,168,401,570,171,571],"infrasonic-cleaner","high-frequency-acoustic-cleaner",{"title":573,"description":574},"Acoustic cleaner — definition, principle, industrial uses","An 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.",[576,577,578],{"title":177,"url":178},{"title":411,"url":412},{"title":180,"url":181},"glossary\u002Facoustic-cleaner","MwPOKb4JllxnhygiJ3--SHn7B_zEw8BdkQXIXUCoV0E",{"id":582,"title":148,"aliases":583,"body":587,"category":161,"description":697,"extension":163,"meta":698,"navigation":165,"path":147,"relatedTerms":699,"seo":702,"sources":705,"stem":710,"term":148,"__hash__":711},"glossary\u002Fglossary\u002Fbell-horn.md",[584,585,586],"bell-shaped horn","exponential bell horn","exponential horn",{"type":52,"value":588,"toc":692},[589,607,611,625,629,671,673],[55,590,194,591,594,595,597,598,601,602,606],{},[59,592,593],{},"bell horn"," is the conical or exponential flare bolted to the driver of an industrial ",[64,596,67],{"href":66},". Its job is to transform the high-impedance, small-area pressure pulse from the ",[64,599,600],{"href":383},"diaphragm"," or ",[64,603,605],{"href":604},"\u002Fglossary\u002Fpiston-whistle-horn","piston-whistle"," into a lower-impedance, larger-area sound wave that couples efficiently into the gas inside the vessel.",[75,608,610],{"id":609},"why-the-geometry-matters","Why the geometry matters",[55,612,613,614,616,617,601,621,624],{},"The bell is not decorative. Its flare profile — usually exponential, sometimes catenoidal or tractrix — sets the horn's cut-off frequency: below the cut-off, the bell stops behaving as a horn and the radiated sound power collapses. A 60 Hz ",[64,615,345],{"href":344}," therefore needs a physically larger bell than a 230 Hz unit, which is why low-frequency horns are noticeably bulkier and heavier. Mounting orientation, flange standard (",[64,618,620],{"href":619},"\u002Fglossary\u002Fflange-standards-dn-ansi","DN",[64,622,623],{"href":619},"ANSI 150",") and the bell's projection distance into the vessel are all selected to match the cleaning target geometry.",[75,626,628],{"id":627},"materials","Materials",[83,630,631,642,651],{},[86,632,633,636,637,219,639],{},[59,634,635],{},"Carbon steel"," for ambient-temperature mounting on cool-side ducts, ",[64,638,332],{"href":331},[64,640,641],{"href":222},"hoppers",[86,643,644,650],{},[59,645,646],{},[64,647,649],{"href":648},"\u002Fglossary\u002Faisi-316-316l-stainless","316 stainless steel"," for corrosive or food-grade environments",[86,652,653,659,660,206,663,666,667,670],{},[59,654,655],{},[64,656,658],{"href":657},"\u002Fglossary\u002Finconel-625-718","Inconel 625 or 718"," for hot-side service above 350 °C, including ",[64,661,662],{"href":213},"SCR reactors",[64,664,665],{"href":461},"air heater"," penthouses and ",[64,668,669],{"href":322},"recovery-boiler"," flue paths",[75,672,129],{"id":128},[83,674,675,679,683,688],{},[86,676,677],{},[64,678,136],{"href":66},[86,680,681],{},[64,682,384],{"href":383},[86,684,685],{},[64,686,687],{"href":604},"Piston-whistle horn",[86,689,690],{},[64,691,47],{"href":166},{"title":155,"searchDepth":156,"depth":156,"links":693},[694,695,696],{"id":609,"depth":156,"text":610},{"id":627,"depth":156,"text":628},{"id":128,"depth":156,"text":129},"A bell horn is the conical or exponential flare bolted to the driver of an industrial sonic horn. Its job is to transform the high-impedance, small-area pressure pulse from the diaphragm or piston-whistle into a lower-impedance, larger-area sound wave that couples efficiently into the gas inside the vessel.",{},[168,402,700,701],"piston-whistle-horn","acoustic-horn",{"title":703,"description":704},"Bell horn — definition, geometry and role in acoustic cleaning","A bell horn is the conical or exponential flare that amplifies and projects sound from an industrial sonic horn's driver into the vessel being cleaned.",[706,709],{"title":707,"url":708},"Wikipedia — Horn (acoustic)","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FHorn_(acoustic)",{"title":177,"url":178},"glossary\u002Fbell-horn","gKEabZrcxtpNiaEXB65PC50sPq3KHeDc-fyn9OvYp4I",{"id":713,"title":389,"aliases":714,"body":718,"category":161,"description":894,"extension":163,"meta":895,"navigation":165,"path":344,"relatedTerms":896,"seo":897,"sources":900,"stem":903,"term":389,"__hash__":904},"glossary\u002Fglossary\u002Flow-frequency-acoustic-cleaner.md",[715,716,717],"low frequency sonic horn","low-frequency horn","LF acoustic cleaner",{"type":52,"value":719,"toc":888},[720,731,735,741,745,798,802,863,865],[55,721,194,722,724,725,727,728,730],{},[59,723,345],{}," is an industrial ",[64,726,67],{"href":66}," whose fundamental frequency sits in the 60–250 Hz band. The long acoustic wavelength — between 1.4 and 5.7 metres in air — projects further from the ",[64,729,593],{"href":147}," than higher-frequency designs, fills large open vessels more uniformly and is the default choice for cleaning bulky industrial equipment.",[75,732,734],{"id":733},"why-frequency-choice-matters","Why frequency choice matters",[55,736,737,738,740],{},"Acoustic energy at long wavelengths diffracts around obstructions (tube banks, electrode rows, baffles) instead of being absorbed or scattered. That makes low-frequency horns the appropriate selection where the cleaning target is several metres deep and partly obstructed — most large industrial vessels fall into this category. Higher-frequency horns concentrate more energy per unit volume but lose effectiveness in deep cavities; see ",[64,739,349],{"href":348}," for the complementary case.",[75,742,744],{"id":743},"typical-applications","Typical applications",[83,746,747,753,761,772,778,791],{},[86,748,749,752],{},[64,750,751],{"href":204},"Electrostatic precipitators"," — collecting-plate cleaning, hopper de-bridging",[86,754,755,219,758,760],{},[64,756,757],{"href":318},"Preheater cyclones",[64,759,504],{"href":503}," in cement plants",[86,762,763,766,767,771],{},[64,764,765],{"href":322},"Kraft recovery boilers"," — superheaters, ",[64,768,770],{"href":769},"\u002Fglossary\u002Fgenerating-bank","generating banks",", economisers",[86,773,774,777],{},[64,775,776],{"href":461},"Air heater"," cold-end basket cleaning",[86,779,780,781,206,785,219,787],{},"Large ",[64,782,784],{"href":783},"\u002Fglossary\u002Ffly-ash-hopper","fly-ash hoppers",[64,786,332],{"href":331},[64,788,790],{"href":789},"\u002Fglossary\u002Fbunker-coal-bunker","bunkers",[86,792,793,797],{},[64,794,796],{"href":795},"\u002Fglossary\u002Fheat-recovery-steam-generator","HRSG harp-tube banks"," in combined-cycle plants",[75,799,801],{"id":800},"indicative-selection-bands","Indicative selection bands",[242,803,804,817],{},[245,805,806],{},[248,807,808,811,814],{},[251,809,810],{},"Band",[251,812,813],{},"Wavelength in air at 20 °C",[251,815,816],{},"Typical use",[258,818,819,830,841,852],{},[248,820,821,824,827],{},[263,822,823],{},"60 Hz",[263,825,826],{},"~5.7 m",[263,828,829],{},"Very large ESPs, recovery boilers, deep silos",[248,831,832,835,838],{},[263,833,834],{},"75 Hz",[263,836,837],{},"~4.6 m",[263,839,840],{},"ESPs, preheater cyclones, large hoppers",[248,842,843,846,849],{},[263,844,845],{},"125 Hz",[263,847,848],{},"~2.7 m",[263,850,851],{},"Mid-size ESPs, baghouse compartments, calciners",[248,853,854,857,860],{},[263,855,856],{},"230 Hz",[263,858,859],{},"~1.5 m",[263,861,862],{},"Boiler convective passes, smaller hoppers, baghouses",[75,864,129],{"id":128},[83,866,867,871,875,880,884],{},[86,868,869],{},[64,870,136],{"href":66},[86,872,873],{},[64,874,142],{"href":141},[86,876,877],{},[64,878,879],{"href":348},"High-frequency acoustic cleaner",[86,881,882],{},[64,883,560],{"href":559},[86,885,886],{},[64,887,148],{"href":147},{"title":155,"searchDepth":156,"depth":156,"links":889},[890,891,892,893],{"id":733,"depth":156,"text":734},{"id":743,"depth":156,"text":744},{"id":800,"depth":156,"text":801},{"id":128,"depth":156,"text":129},"A low-frequency acoustic cleaner is an industrial sonic horn whose fundamental frequency sits in the 60–250 Hz band. The long acoustic wavelength — between 1.4 and 5.7 metres in air — projects further from the bell horn than higher-frequency designs, fills large open vessels more uniformly and is the default choice for cleaning bulky industrial equipment.",{},[169,168,571,570,170],{"title":898,"description":899},"Low-frequency acoustic cleaner — 60–250 Hz horn selection guide","Low-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.",[901,902],{"title":408,"url":409},{"title":411,"url":412},"glossary\u002Flow-frequency-acoustic-cleaner","m6cj771ScgiY0798OZ0cdR03A65ardaL1YsF3e8jwFM",1782613733104]