[{"data":1,"prerenderedAt":800},["ShallowReactive",2],{"site-footer-common":3,"glossary:opacity":45,"glossary-related:opacity":176},{"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":156,"description":157,"extension":158,"meta":159,"navigation":160,"path":161,"relatedTerms":162,"seo":166,"sources":169,"stem":173,"term":174,"__hash__":175},"glossary\u002Fglossary\u002Fopacity.md","Opacity",[49,50],"stack opacity","opacity excursion",{"type":52,"value":53,"toc":149},"minimark",[54,67,72,75,111,115,122,126],[55,56,57,60,61,66],"p",{},[58,59,47],"strong",{}," is the percentage of light obscured by particulate matter in stack flue gas, measured continuously by a transmissometer (opacity monitor) installed in the stack. Opacity is the headline visual KPI for ",[62,63,65],"a",{"href":64},"\u002Fglossary\u002Felectrostatic-precipitator","ESP"," performance and is permit-limited in most jurisdictions — typically 20–40% on a 6-minute rolling average, with absolute peaks limited to 60% for shorter periods.",[68,69,71],"h2",{"id":70},"opacity-excursions","Opacity excursions",[55,73,74],{},"Opacity excursions are typically driven by:",[76,77,78,91,98,105,108],"ul",{},[79,80,81,85,86,90],"li",{},[62,82,84],{"href":83},"\u002Fglossary\u002Fesp-rapper","ESP rapping"," ",[62,87,89],{"href":88},"\u002Fglossary\u002Fre-entrainment","re-entrainment"," puffs",[79,92,93,97],{},[62,94,96],{"href":95},"\u002Fglossary\u002Fbaghouse","Baghouse"," bag failure (sudden particulate breakthrough)",[79,99,100,104],{},[62,101,103],{"href":102},"\u002Fglossary\u002Fback-corona","ESP back-corona"," collapse",[79,106,107],{},"Combustion upsets producing unusually high inlet particulate",[79,109,110],{},"Soot-blower-triggered re-entrainment",[68,112,114],{"id":113},"how-sonic-horns-reduce-opacity","How sonic horns reduce opacity",[55,116,117,121],{},[62,118,120],{"href":119},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," deliver continuous gentle dust release rather than periodic aggressive rapping puffs. Plants retrofitting horns on opacity-limited ESPs commonly see 20–40% opacity-peak reduction without other changes — the headline business case for many sonic-horn ESP installations.",[68,123,125],{"id":124},"related-terms","Related terms",[76,127,128,134,139,144],{},[79,129,130],{},[62,131,133],{"href":132},"\u002Fglossary\u002Fcems","CEMS",[79,135,136],{},[62,137,138],{"href":64},"Electrostatic precipitator",[79,140,141],{},[62,142,143],{"href":88},"Re-entrainment",[79,145,146],{},[62,147,148],{"href":119},"Sonic horn",{"title":150,"searchDepth":151,"depth":151,"links":152},"",2,[153,154,155],{"id":70,"depth":151,"text":71},{"id":113,"depth":151,"text":114},{"id":124,"depth":151,"text":125},"kpis-measurements","Opacity is the percentage of light obscured by particulate matter in stack flue gas, measured continuously by a transmissometer (opacity monitor) installed in the stack. Opacity is the headline visual KPI for ESP performance and is permit-limited in most jurisdictions — typically 20–40% on a 6-minute rolling average, with absolute peaks limited to 60% for shorter periods.","md",{},true,"\u002Fglossary\u002Fopacity",[163,164,89,165],"cems","electrostatic-precipitator","sonic-horn",{"title":167,"description":168},"Opacity — visual stack-emission KPI measured by continuous monitor","Opacity is the percentage of light obscured by particulate in stack flue gas. The headline visual KPI for ESP performance; continuously monitored and permit-limited.",[170],{"title":171,"url":172},"Wikipedia — Opacity","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FOpacity_(optics)","glossary\u002Fopacity","Opacity (stack)","-4RIuJbd3zg7kip6GHWTZ5efGSK8D9bOiK_nb9oMGWo",[177,296,474,560],{"id":178,"title":179,"aliases":180,"body":182,"category":156,"description":280,"extension":158,"meta":281,"navigation":160,"path":132,"relatedTerms":282,"seo":286,"sources":289,"stem":293,"term":294,"__hash__":295},"glossary\u002Fglossary\u002Fcems.md","Continuous Emissions Monitoring System (CEMS)",[133,181],"continuous emissions monitor",{"type":52,"value":183,"toc":275},[184,203,207,210,235,239,252,254],[55,185,186,187,189,190,193,194,193,198,202],{},"A ",[58,188,179],{}," is the suite of instruments that measures stack emissions in real time. A typical industrial CEMS measures ",[62,191,192],{"href":161},"opacity",", ",[62,195,197],{"href":196},"\u002Fglossary\u002Fparticulate-matter","particulate matter",[62,199,201],{"href":200},"\u002Fglossary\u002Fnox-sox-co","NOx, SOx, CO",", O₂, moisture and gas flow. CEMS data is the primary basis for environmental-compliance reporting under most jurisdictions' emission permits.",[68,204,206],{"id":205},"cems-quality-assurance","CEMS quality assurance",[55,208,209],{},"CEMS instruments are governed by quality-assurance frameworks:",[76,211,212,223,229],{},[79,213,214,217,218,222],{},[58,215,216],{},"EU"," — ",[62,219,221],{"href":220},"\u002Fglossary\u002Fen-14181-en-13284","EN 14181"," (QAL1, QAL2, QAL3 and AST)",[79,224,225,228],{},[58,226,227],{},"US"," — EPA Reference Method 6, 7, 19 etc. plus Part 75 CEMS requirements",[79,230,231,234],{},[58,232,233],{},"National regulators"," — various local specifics",[68,236,238],{"id":237},"how-cleaning-intersects-with-cems-data","How cleaning intersects with CEMS data",[55,240,241,242,244,245,248,249,251],{},"Operators see fouling-driven degradation of ",[62,243,65],{"href":64}," or ",[62,246,247],{"href":95},"baghouse"," performance in near-real-time on the CEMS trace. A rising opacity baseline, more frequent excursions, or trended particulate increase all indicate worsening collection. Active ",[62,250,165],{"href":119}," cleaning that defends collection efficiency shows up on CEMS as flatter, lower, more predictable traces.",[68,253,125],{"id":124},[76,255,256,260,265,270],{},[79,257,258],{},[62,259,47],{"href":161},[79,261,262],{},[62,263,264],{"href":196},"Particulate matter",[79,266,267],{},[62,268,269],{"href":200},"NOx \u002F SOx \u002F CO",[79,271,272],{},[62,273,274],{"href":220},"EN 14181 \u002F EN 13284",{"title":150,"searchDepth":151,"depth":151,"links":276},[277,278,279],{"id":205,"depth":151,"text":206},{"id":237,"depth":151,"text":238},{"id":124,"depth":151,"text":125},"A Continuous Emissions Monitoring System (CEMS) is the suite of instruments that measures stack emissions in real time. A typical industrial CEMS measures opacity, particulate matter, NOx, SOx, CO, O₂, moisture and gas flow. CEMS data is the primary basis for environmental-compliance reporting under most jurisdictions' emission permits.",{},[192,283,284,285],"particulate-matter","nox-sox-co","en-14181-en-13284",{"title":287,"description":288},"Continuous Emissions Monitoring System (CEMS) — real-time stack emissions measurement","CEMS instruments measure stack emissions in real time — opacity, PM, NOx, SOx, CO, O2, moisture — providing the data on which environmental compliance is judged.",[290],{"title":291,"url":292},"Wikipedia — Continuous emissions monitoring system","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FContinuous_emissions_monitoring_system","glossary\u002Fcems","Continuous Emissions Monitoring System","d4nlsLBIEd3NGEvGY4Qyqp_PhX2UOjgAnwxx__vQ_V4",{"id":297,"title":298,"aliases":299,"body":302,"category":449,"description":450,"extension":158,"meta":451,"navigation":160,"path":64,"relatedTerms":452,"seo":459,"sources":462,"stem":472,"term":138,"__hash__":473},"glossary\u002Fglossary\u002Felectrostatic-precipitator.md","Electrostatic precipitator (ESP)",[65,300,301],"electrostatic precipitators","dry ESP",{"type":52,"value":303,"toc":443},[304,320,324,342,346,380,384,415,417],[55,305,306,307,310,311,315,316,319],{},"An ",[58,308,309],{},"electrostatic precipitator (ESP)"," is an air-pollution-control device that removes particulate matter from a flue-gas stream by electrostatically charging dust particles and collecting them on grounded plate electrodes. ESPs are the dominant particulate-control technology on coal-fired boilers, cement kilns, ",[62,312,314],{"href":313},"\u002Fglossary\u002Fwaste-to-energy","waste-to-energy"," plants, ",[62,317,318],{"href":313},"biomass"," plants, sinter strands and many other heavy-industry off-gas streams.",[68,321,323],{"id":322},"how-an-esp-works","How an ESP works",[55,325,326,327,331,332,336,337,341],{},"Flue gas flows horizontally between a parallel array of vertical ",[62,328,330],{"href":329},"\u002Fglossary\u002Fcollecting-electrode","collecting electrodes"," (plates) and ",[62,333,335],{"href":334},"\u002Fglossary\u002Fdischarge-electrode","discharge electrodes"," (high-voltage wires or rigid spikes). A negative DC potential of 40–80 kV applied to the discharge electrodes generates a ",[62,338,340],{"href":339},"\u002Fglossary\u002Fcorona-discharge","corona discharge"," that ionises the gas. Charged dust particles drift to the collecting plates, accumulate as a dust layer, are rapped down into hoppers below and removed by ash-handling equipment.",[68,343,345],{"id":344},"where-sonic-horns-fit","Where sonic horns fit",[55,347,348,349,353,354,356,357,361,362,365,366,369,370,374,375,379],{},"ESPs accumulate dust faster than mechanical rapping can release it, and hoppers below ESP fields routinely ",[62,350,352],{"href":351},"\u002Fglossary\u002Fbridging","bridge"," and choke. ",[62,355,120],{"href":119}," installed on the ESP ",[62,358,360],{"href":359},"\u002Fglossary\u002Fesp-penthouse","penthouse"," and on hopper walls keep dust dislodged, supplement ",[62,363,364],{"href":83},"rappers",", prevent ",[62,367,368],{"href":102},"back-corona"," by limiting plate dust thickness, and eliminate hopper ",[62,371,373],{"href":372},"\u002Fglossary\u002Frat-holing","rat-holing"," without the structural fatigue of ",[62,376,378],{"href":377},"\u002Fglossary\u002Ftumbling-hammer-rapper","tumbling-hammer rappers",".",[68,381,383],{"id":382},"common-failure-modes","Common failure modes",[76,385,386,392,398,403,409],{},[79,387,388,391],{},[58,389,390],{},"High opacity \u002F particulate emissions"," from thick dust layers reducing collection efficiency",[79,393,394,397],{},[58,395,396],{},"Back-corona"," in high-resistivity ash that reverses ionisation and collapses collection",[79,399,400,402],{},[58,401,143],{}," as rapper puffs return dust to the gas stream",[79,404,405,408],{},[58,406,407],{},"Hopper bridging"," that stops ash extraction and triggers field shutdowns",[79,410,411,414],{},[58,412,413],{},"Discharge-electrode breakage"," from rapper fatigue or sparking",[68,416,125],{"id":124},[76,418,419,424,429,433,439],{},[79,420,421],{},[62,422,423],{"href":329},"Collecting electrode",[79,425,426],{},[62,427,428],{"href":334},"Discharge electrode",[79,430,431],{},[62,432,396],{"href":102},[79,434,435],{},[62,436,438],{"href":437},"\u002Fglossary\u002Fesp-hopper","ESP hopper",[79,440,441],{},[62,442,148],{"href":119},{"title":150,"searchDepth":151,"depth":151,"links":444},[445,446,447,448],{"id":322,"depth":151,"text":323},{"id":344,"depth":151,"text":345},{"id":382,"depth":151,"text":383},{"id":124,"depth":151,"text":125},"esp","An electrostatic precipitator (ESP) is an air-pollution-control device that removes particulate matter from a flue-gas stream by electrostatically charging dust particles and collecting them on grounded plate electrodes. ESPs are the dominant particulate-control technology on coal-fired boilers, cement kilns, waste-to-energy plants, biomass plants, sinter strands and many other heavy-industry off-gas streams.",{},[453,454,455,456,457,458,368,165],"wet-esp","collecting-electrode","discharge-electrode","corona-discharge","esp-hopper","esp-rapper",{"title":460,"description":461},"Electrostatic precipitator (ESP) — how it works and how it fouls","An ESP removes particulate from flue gas by charging dust and collecting it on plate electrodes. Sonic horns are widely used to dislodge ash from plates and to keep hoppers from bridging.",[463,466,469],{"title":464,"url":465},"Wikipedia — Electrostatic precipitator","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FElectrostatic_precipitator",{"title":467,"url":468},"EPA — Monitoring Knowledge Base: Electrostatic Precipitators","https:\u002F\u002Fwww.epa.gov\u002Fair-emissions-monitoring-knowledge-base\u002Fmonitoring-control-technique-electrostatic-precipitators",{"title":470,"url":471},"Babcock & Wilcox — Basics of ESP Operation","https:\u002F\u002Fwww.babcock.com\u002Fhome\u002Fabout\u002Fresources\u002Flearning-center\u002Fbasic-esp-operation","glossary\u002Felectrostatic-precipitator","hT_C4hmid3iZaYWhLpiSJ2tBfL0bSJ-uhzn7TY4Vtj4",{"id":475,"title":143,"aliases":476,"body":479,"category":449,"description":549,"extension":158,"meta":550,"navigation":160,"path":88,"relatedTerms":551,"seo":552,"sources":555,"stem":558,"term":143,"__hash__":559},"glossary\u002Fglossary\u002Fre-entrainment.md",[477,478],"rapping re-entrainment","dust re-entrainment",{"type":52,"value":480,"toc":544},[481,495,499,510,514,519,521],[55,482,483,485,486,488,489,491,492,379],{},[58,484,143],{}," is the recapture of just-released dust by the flue-gas stream before it can fall into the ",[62,487,438],{"href":437},". It is the dominant cause of ",[62,490,192],{"href":161}," spikes on rapped ESPs and a major reason continuous acoustic cleaning is increasingly preferred over (or alongside) mechanical ",[62,493,494],{"href":83},"rapping",[68,496,498],{"id":497},"how-re-entrainment-happens","How re-entrainment happens",[55,500,501,502,505,506,509],{},"When a ",[62,503,504],{"href":83},"rapper"," impacts a ",[62,507,508],{"href":329},"collecting plate",", a sheet of dust detaches and slides down the plate. Some of this falling dust is caught by the horizontal gas flow and carried out of the field instead of reaching the hopper. The faster and harder the rap, the larger the released sheet and the worse the re-entrainment.",[68,511,513],{"id":512},"why-sonic-horns-reduce-re-entrainment","Why sonic horns reduce re-entrainment",[55,515,516,518],{},[62,517,120],{"href":119}," firing every few minutes deliver small, frequent dust releases instead of large, occasional ones. The released particles are smaller in aggregate per event, fall more gently and have time to settle into the hopper before being picked up. Plants that retrofit horns to back-corona- or re-entrainment-limited ESPs commonly see opacity reductions of 20–40% with no other process change.",[68,520,125],{"id":124},[76,522,523,527,532,536,540],{},[79,524,525],{},[62,526,138],{"href":64},[79,528,529],{},[62,530,531],{"href":83},"ESP rapper",[79,533,534],{},[62,535,423],{"href":329},[79,537,538],{},[62,539,47],{"href":161},[79,541,542],{},[62,543,148],{"href":119},{"title":150,"searchDepth":151,"depth":151,"links":545},[546,547,548],{"id":497,"depth":151,"text":498},{"id":512,"depth":151,"text":513},{"id":124,"depth":151,"text":125},"Re-entrainment is the recapture of just-released dust by the flue-gas stream before it can fall into the ESP hopper. It is the dominant cause of opacity spikes on rapped ESPs and a major reason continuous acoustic cleaning is increasingly preferred over (or alongside) mechanical rapping.",{},[164,458,454,192,165],{"title":553,"description":554},"Re-entrainment — why rapping spikes ESP opacity and how to reduce it","Re-entrainment is the recapture of just-rapped dust by the flue-gas stream before it falls into the hopper. It causes opacity spikes and is the main reason continuous sonic cleaning is preferred.",[556,557],{"title":467,"url":468},{"title":470,"url":471},"glossary\u002Fre-entrainment","WGUvUI6GbyUbof8DdYEOwylwqKzZZprnpNkuX3GAMzo",{"id":561,"title":148,"aliases":562,"body":566,"category":775,"description":776,"extension":158,"meta":777,"navigation":160,"path":119,"relatedTerms":778,"seo":785,"sources":788,"stem":798,"term":148,"__hash__":799},"glossary\u002Fglossary\u002Fsonic-horn.md",[563,564,565],"sonic horns","sonic cleaning horn","industrial sonic horn",{"type":52,"value":567,"toc":768},[568,599,603,611,615,683,687,724,728,736,738],[55,569,186,570,573,574,578,579,193,582,193,586,193,590,594,595,379],{},[58,571,572],{},"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 ",[62,575,577],{"href":576},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the default specification for cleaning ",[62,580,581],{"href":64},"ESPs",[62,583,585],{"href":584},"\u002Fglossary\u002Ffabric-filter","baghouses",[62,587,589],{"href":588},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[62,591,593],{"href":592},"\u002Fglossary\u002Fsuperheater","boiler heat-transfer surfaces"," and ",[62,596,598],{"href":597},"\u002Fglossary\u002Fhopper","hoppers and silos",[68,600,602],{"id":601},"how-a-sonic-horn-works","How a sonic horn works",[55,604,605,606,610],{},"Compressed plant air admitted through a ",[62,607,609],{"href":608},"\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.",[68,612,614],{"id":613},"key-parameters","Key parameters",[616,617,618,631],"table",{},[619,620,621],"thead",{},[622,623,624,628],"tr",{},[625,626,627],"th",{},"Parameter",[625,629,630],{},"Typical range",[632,633,634,643,651,659,667,675],"tbody",{},[622,635,636,640],{},[637,638,639],"td",{},"Fundamental frequency",[637,641,642],{},"60–400 Hz",[622,644,645,648],{},[637,646,647],{},"Sound pressure level",[637,649,650],{},"140–180 dB",[622,652,653,656],{},[637,654,655],{},"Compressed-air consumption",[637,657,658],{},"8–14 Nm³\u002Fmin at 4–7 bar",[622,660,661,664],{},[637,662,663],{},"Operating temperature (with appropriate materials)",[637,665,666],{},"−40 °C to +500 °C",[622,668,669,672],{},[637,670,671],{},"Firing cycle",[637,673,674],{},"5–15 s burst, repeated every 3–15 minutes",[622,676,677,680],{},[637,678,679],{},"Mass",[637,681,682],{},"15–60 kg depending on horn size",[68,684,686],{"id":685},"frequency-selection","Frequency selection",[55,688,689,690,193,694,698,699,193,703,707,708,193,711,715,716,594,720,379],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[62,691,693],{"href":692},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[62,695,697],{"href":696},"\u002Fglossary\u002Frecovery-boiler","recovery-boiler superheaters",", large ",[62,700,702],{"href":701},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[62,704,706],{"href":705},"\u002Fglossary\u002Fsilo","silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[62,709,710],{"href":584},"fabric-filter compartments",[62,712,714],{"href":713},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[62,717,719],{"href":718},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[62,721,723],{"href":722},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[68,725,727],{"id":726},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[55,729,730,731,735],{},"Sonic horns are increasingly specified alongside or in place of ",[62,732,734],{"href":733},"\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.",[68,737,125],{"id":124},[76,739,740,745,751,757,763],{},[79,741,742],{},[62,743,744],{"href":576},"Acoustic cleaner",[79,746,747],{},[62,748,750],{"href":749},"\u002Fglossary\u002Fsonic-sootblower","Sonic sootblower",[79,752,753],{},[62,754,756],{"href":755},"\u002Fglossary\u002Fbell-horn","Bell horn",[79,758,759],{},[62,760,762],{"href":761},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[79,764,765],{},[62,766,767],{"href":718},"Low-frequency acoustic cleaner",{"title":150,"searchDepth":151,"depth":151,"links":769},[770,771,772,773,774],{"id":601,"depth":151,"text":602},{"id":613,"depth":151,"text":614},{"id":685,"depth":151,"text":686},{"id":726,"depth":151,"text":727},{"id":124,"depth":151,"text":125},"core-technology","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.",{},[779,780,781,782,783,784],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn","low-frequency-acoustic-cleaner",{"title":786,"description":787},"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.",[789,792,795],{"title":790,"url":791},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":793,"url":794},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":796,"url":797},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613746466]