[{"data":1,"prerenderedAt":846},["ShallowReactive",2],{"site-footer-common":3,"glossary:heat-recovery-steam-generator":45,"glossary-related:heat-recovery-steam-generator":195},{"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":170,"description":171,"extension":172,"meta":173,"navigation":174,"path":175,"relatedTerms":176,"seo":182,"sources":185,"stem":192,"term":193,"__hash__":194},"glossary\u002Fglossary\u002Fheat-recovery-steam-generator.md","Heat Recovery Steam Generator (HRSG)",[49,50],"HRSG","heat-recovery steam generator",{"type":52,"value":53,"toc":162},"minimark",[54,68,73,81,85,88,119,123,130,134],[55,56,57,58,61,62,67],"p",{},"A ",[59,60,47],"strong",{}," recovers heat from the exhaust of a gas turbine to generate steam — the second cycle of a ",[63,64,66],"a",{"href":65},"\u002Fglossary\u002Fcombined-cycle-gas-turbine","combined-cycle gas turbine (CCGT)"," power plant. HRSGs raise overall plant efficiency from the ~38% of a simple-cycle gas turbine to 55–62% of a modern combined-cycle plant.",[69,70,72],"h2",{"id":71},"hrsg-layout","HRSG layout",[55,74,75,76,80],{},"A typical HRSG contains multiple ",[63,77,79],{"href":78},"\u002Fglossary\u002Ffinned-tube-harp-tube","finned-tube"," tube banks arranged in series along the gas-path direction: superheaters, evaporators, economisers, and (on units with SCR) the catalyst layers. Modern HRSGs operate at three pressure levels (HP, IP, LP) to maximise energy recovery from the cooling exhaust gas.",[69,82,84],{"id":83},"fouling","Fouling",[55,86,87],{},"HRSG fouling is generally lighter than coal-fired boiler fouling because gas-turbine exhaust contains far less particulate. The dominant fouling mechanisms are:",[89,90,91,101,107,113],"ul",{},[92,93,94,100],"li",{},[59,95,96],{},[63,97,99],{"href":98},"\u002Fglossary\u002Fammonium-bisulphate","Ammonium bisulphate (ABS)"," on units with SCR — slipped ammonia + SO₃ from fuel sulphur condenses on finned tubes",[92,102,103,106],{},[59,104,105],{},"Fine ash deposition"," on finned-tube banks reducing heat transfer",[92,108,109,112],{},[59,110,111],{},"Duct-burner-driven"," particulate on units with supplementary firing",[92,114,115,118],{},[59,116,117],{},"Cold-end corrosion"," below the acid dew point on sulphur-bearing fuels",[69,120,122],{"id":121},"cleaning","Cleaning",[55,124,125,129],{},[63,126,128],{"href":127},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," installed across the gas path are increasingly common on HRSG maintenance plans, particularly for keeping SCR catalyst layers and cold-end finned tubes clear of ABS without the need for offline water-wash campaigns.",[69,131,133],{"id":132},"related-terms","Related terms",[89,135,136,141,146,152,157],{},[92,137,138],{},[63,139,140],{"href":65},"Combined-cycle gas turbine (CCGT)",[92,142,143],{},[63,144,145],{"href":78},"Finned tube \u002F harp tube",[92,147,148],{},[63,149,151],{"href":150},"\u002Fglossary\u002Fduct-burner","Duct burner",[92,153,154],{},[63,155,156],{"href":98},"Ammonium bisulphate",[92,158,159],{},[63,160,161],{"href":127},"Sonic horn",{"title":163,"searchDepth":164,"depth":164,"links":165},"",2,[166,167,168,169],{"id":71,"depth":164,"text":72},{"id":83,"depth":164,"text":84},{"id":121,"depth":164,"text":122},{"id":132,"depth":164,"text":133},"hrsg-gas-path","A Heat Recovery Steam Generator (HRSG) recovers heat from the exhaust of a gas turbine to generate steam — the second cycle of a combined-cycle gas turbine (CCGT) power plant. HRSGs raise overall plant efficiency from the ~38% of a simple-cycle gas turbine to 55–62% of a modern combined-cycle plant.","md",{},true,"\u002Fglossary\u002Fheat-recovery-steam-generator",[177,178,179,180,181],"combined-cycle-gas-turbine","finned-tube-harp-tube","duct-burner","ammonium-bisulphate","sonic-horn",{"title":183,"description":184},"Heat Recovery Steam Generator (HRSG) — convert gas-turbine exhaust to steam","An HRSG recovers heat from a gas turbine's exhaust to generate steam, the second cycle of a combined-cycle plant. Finned-tube ash deposition and ABS fouling are the main cleaning concerns.",[186,189],{"title":187,"url":188},"Wikipedia — Heat recovery steam generator","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FHeat_recovery_steam_generator",{"title":190,"url":191},"Combined Cycle Journal — Clean HRSG heat-transfer surfaces","https:\u002F\u002Fwww.ccj-online.com\u002Fclean-heat-transfer-surfaces-inside-and-out-to-keep-hrsgs-at-peak-efficiency\u002F","glossary\u002Fheat-recovery-steam-generator","Heat Recovery Steam Generator","2QpNZZDCPIfd-x3tx7w8wKqru7_s0rVDnW6E_FXNJVw",[196,277,363,441,606],{"id":197,"title":140,"aliases":198,"body":202,"category":170,"description":261,"extension":172,"meta":262,"navigation":174,"path":65,"relatedTerms":263,"seo":267,"sources":270,"stem":274,"term":275,"__hash__":276},"glossary\u002Fglossary\u002Fcombined-cycle-gas-turbine.md",[199,200,201],"CCGT","combined cycle","combined-cycle plant",{"type":52,"value":203,"toc":256},[204,212,216,225,229,232,234],[55,205,57,206,208,209,211],{},[59,207,66],{}," plant combines a gas turbine with a steam turbine driven by an ",[63,210,49],{"href":175}," that recovers heat from the gas-turbine exhaust. The arrangement raises overall plant efficiency from ~38% LHV for a simple-cycle gas turbine to 55–62% LHV for modern CCGT, with the latest H-class machines pushing 64%+.",[69,213,215],{"id":214},"why-hrsg-cleanliness-matters","Why HRSG cleanliness matters",[55,217,218,219,221,222,224],{},"CCGT plants are economically dispatched ahead of coal in most markets, but margins per MWh are tight and competition from renewables intensifies the focus on heat rate. Every 0.5% efficiency loss from HRSG fouling translates directly to fuel cost. ",[63,220,128],{"href":127}," on the ",[63,223,49],{"href":175}," gas path are increasingly part of the standard maintenance toolkit on modern combined-cycle plants.",[69,226,228],{"id":227},"cycling-adds-complication","Cycling adds complication",[55,230,231],{},"Modern CCGT plants increasingly two-shift — running daytime and shutting overnight when renewable supply meets demand. Frequent start-stop cycling worsens HRSG fouling because cold metal surfaces during shutdowns condense moisture that bonds dust into a harder deposit. Continuous sonic-horn cleaning helps offset cycling-driven fouling acceleration.",[69,233,133],{"id":132},[89,235,236,240,244,250],{},[92,237,238],{},[63,239,47],{"href":175},[92,241,242],{},[63,243,151],{"href":150},[92,245,246],{},[63,247,249],{"href":248},"\u002Fglossary\u002Fselective-catalytic-reduction","Selective Catalytic Reduction (SCR)",[92,251,252],{},[63,253,255],{"href":254},"\u002Fglossary\u002Fheat-rate","Heat rate",{"title":163,"searchDepth":164,"depth":164,"links":257},[258,259,260],{"id":214,"depth":164,"text":215},{"id":227,"depth":164,"text":228},{"id":132,"depth":164,"text":133},"A combined-cycle gas turbine (CCGT) plant combines a gas turbine with a steam turbine driven by an HRSG that recovers heat from the gas-turbine exhaust. The arrangement raises overall plant efficiency from ~38% LHV for a simple-cycle gas turbine to 55–62% LHV for modern CCGT, with the latest H-class machines pushing 64%+.",{},[264,179,265,266],"heat-recovery-steam-generator","selective-catalytic-reduction","heat-rate",{"title":268,"description":269},"Combined-cycle gas turbine (CCGT) — gas turbine plus HRSG and steam turbine","A CCGT plant combines a gas turbine with a steam turbine driven by an HRSG recovering exhaust heat. Plant efficiency reaches 55–62% LHV; HRSG cleanliness is critical.",[271],{"title":272,"url":273},"Wikipedia — Combined cycle power plant","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FCombined_cycle_power_plant","glossary\u002Fcombined-cycle-gas-turbine","Combined-cycle gas turbine","by8SpjeEI8ON6lFVMPJSYZgoB4OvOKZUqmCtbhUvCds",{"id":278,"title":145,"aliases":279,"body":284,"category":170,"description":352,"extension":172,"meta":353,"navigation":174,"path":78,"relatedTerms":354,"seo":355,"sources":358,"stem":360,"term":361,"__hash__":362},"glossary\u002Fglossary\u002Ffinned-tube-harp-tube.md",[280,281,282,283],"finned tubes","harp tube","extended-surface tube","HRSG harp",{"type":52,"value":285,"toc":347},[286,296,311,315,318,320,325,327],[55,287,57,288,291,292,295],{},[59,289,290],{},"finned tube"," carries helically-wound (or stud-welded) metal fins on its outside surface, multiplying the gas-side heat-transfer area by 5–10× compared with a bare tube. Finned tubes are universal in ",[63,293,294],{"href":175},"HRSGs"," because gas-side heat transfer (low-pressure exhaust gas) is the limiting factor — adding fins is the standard way to compensate.",[55,297,57,298,300,301,305,306,310],{},[59,299,281],{}," is the assembled vertical bundle of finned tubes that forms one tube bank inside the HRSG, named for its resemblance to a harp string array. Multiple harps in series make up the ",[63,302,304],{"href":303},"\u002Fglossary\u002Feconomiser","economiser",", evaporator and ",[63,307,309],{"href":308},"\u002Fglossary\u002Fsuperheater","superheater"," sections.",[69,312,314],{"id":313},"why-finned-surfaces-foul-easily","Why finned surfaces foul easily",[55,316,317],{},"The narrow gap between fins (3–10 mm typical pitch) is geometrically sensitive: even a thin deposit on the fin face significantly restricts the gas flow path between fins. Particulate that would pass through a bare-tube bank settles between fins and consolidates over time.",[69,319,122],{"id":121},[55,321,322,324],{},[63,323,128],{"href":127}," installed across HRSG harps keep the fin gaps clear. Sound waves penetrate between fins more effectively than steam-jet sootblowers, which struggle to project energy into the narrow inter-fin space. Combined sonic-and-sootblower cleaning regimes maintain HRSG heat transfer through the operating campaign.",[69,326,133],{"id":132},[89,328,329,333,338,343],{},[92,330,331],{},[63,332,47],{"href":175},[92,334,335],{},[63,336,337],{"href":303},"Economiser",[92,339,340],{},[63,341,342],{"href":308},"Superheater",[92,344,345],{},[63,346,161],{"href":127},{"title":163,"searchDepth":164,"depth":164,"links":348},[349,350,351],{"id":313,"depth":164,"text":314},{"id":121,"depth":164,"text":122},{"id":132,"depth":164,"text":133},"A finned tube carries helically-wound (or stud-welded) metal fins on its outside surface, multiplying the gas-side heat-transfer area by 5–10× compared with a bare tube. Finned tubes are universal in HRSGs because gas-side heat transfer (low-pressure exhaust gas) is the limiting factor — adding fins is the standard way to compensate.",{},[264,304,309,181],{"title":356,"description":357},"Finned tube and harp tube — extended-surface tubes for HRSG heat transfer","Finned tubes carry helically-wound fins to multiply gas-side surface area in HRSGs. Harp tubes are the vertical bundle configuration. Fin geometry is particularly fouling-sensitive.",[359],{"title":187,"url":188},"glossary\u002Ffinned-tube-harp-tube","Finned tube and harp tube","FPHrkmT6ywb1eMnRbmeu0wDTvbn2kby9DVOqaObqYZU",{"id":364,"title":151,"aliases":365,"body":368,"category":170,"description":431,"extension":172,"meta":432,"navigation":174,"path":150,"relatedTerms":433,"seo":434,"sources":437,"stem":439,"term":151,"__hash__":440},"glossary\u002Fglossary\u002Fduct-burner.md",[366,367],"HRSG duct burner","supplementary firing",{"type":52,"value":369,"toc":426},[370,379,390,394,400,404,410,412],[55,371,57,372,375,376,378],{},[59,373,374],{},"duct burner"," is an auxiliary natural-gas or distillate-oil burner installed in the inlet duct of an ",[63,377,49],{"href":175}," to add heat to the gas-turbine exhaust before it enters the first tube bank. Duct burners are used for:",[89,380,381,384,387],{},[92,382,383],{},"Steam-flow boosting beyond the gas-turbine-only HRSG capacity",[92,385,386],{},"Cogeneration peak shaping where process steam demand exceeds nominal HRSG output",[92,388,389],{},"Cold-start steam-temperature ramp control",[69,391,393],{"id":392},"effect-on-fouling","Effect on fouling",[55,395,396,397,399],{},"Duct-burner firing raises the temperature and changes the gas composition entering the ",[63,398,79],{"href":78}," banks. On natural-gas-only HRSGs, this adds little fouling; on duct burners firing oil or in any unit firing back-up fuel, particulate loading rises substantially and convective-pass fouling accelerates.",[69,401,403],{"id":402},"cleaning-implications","Cleaning implications",[55,405,406,407,409],{},"HRSGs that operate with regular duct-burner firing on liquid fuels usually need more aggressive ",[63,408,181],{"href":127}," coverage on the HRSG harps than gas-only HRSGs do.",[69,411,133],{"id":132},[89,413,414,418,422],{},[92,415,416],{},[63,417,47],{"href":175},[92,419,420],{},[63,421,140],{"href":65},[92,423,424],{},[63,425,145],{"href":78},{"title":163,"searchDepth":164,"depth":164,"links":427},[428,429,430],{"id":392,"depth":164,"text":393},{"id":402,"depth":164,"text":403},{"id":132,"depth":164,"text":133},"A duct burner is an auxiliary natural-gas or distillate-oil burner installed in the inlet duct of an HRSG to add heat to the gas-turbine exhaust before it enters the first tube bank. Duct burners are used for:",{},[264,177,178],{"title":435,"description":436},"Duct burner — supplementary firing in the HRSG gas path","A duct burner is an auxiliary gas burner installed in the HRSG inlet duct to add heat to the gas-turbine exhaust. Used for steam-flow boosting and cogeneration peak shaping.",[438],{"title":187,"url":188},"glossary\u002Fduct-burner","sPgINXKI3DVBZ9j_4oCwpk-x5CSkcumgPsjS_2-O9JA",{"id":442,"title":99,"aliases":443,"body":448,"category":590,"description":591,"extension":172,"meta":592,"navigation":174,"path":98,"relatedTerms":593,"seo":597,"sources":600,"stem":604,"term":156,"__hash__":605},"glossary\u002Fglossary\u002Fammonium-bisulphate.md",[444,445,446,447],"ABS","ammonium bisulfate","ammonium sulphate","NH4HSO4",{"type":52,"value":449,"toc":585},[450,474,478,481,517,521,558,560],[55,451,452,455,456,459,460,464,465,469,470,473],{},[59,453,454],{},"Ammonium bisulphate (NH₄HSO₄, ABS)"," — sometimes written ",[457,458,445],"em",{}," in US technical literature — is a sticky, low-melting deposit formed when ",[63,461,463],{"href":462},"\u002Fglossary\u002Fammonia-slip","slipped ammonia"," reacts with SO₃ in cooling flue gas. ABS condenses between roughly 150 °C and 250 °C, coating the cold end of any ",[63,466,468],{"href":467},"\u002Fglossary\u002Fair-heater","air heater"," downstream of an ",[63,471,472],{"href":248},"SCR",".",[69,475,477],{"id":476},"why-abs-is-the-most-feared-cold-end-deposit","Why ABS is the most-feared cold-end deposit",[55,479,480],{},"ABS is uniquely problematic because it is:",[89,482,483,489,499,505,511],{},[92,484,485,488],{},[59,486,487],{},"Sticky"," — bonds tenaciously to air-heater baskets and economiser tubes",[92,490,491,494,495],{},[59,492,493],{},"Hygroscopic"," — picks up moisture and accelerates ",[63,496,498],{"href":497},"\u002Fglossary\u002Fcold-end-corrosion-dew-point-corrosion","cold-end corrosion",[92,500,501,504],{},[59,502,503],{},"Hard to remove"," — resists steam sootblowing once consolidated",[92,506,507,510],{},[59,508,509],{},"Self-reinforcing"," — coated surfaces trap more ash, accelerating fouling",[92,512,513,516],{},[59,514,515],{},"Concentrated in a narrow temperature band"," — predictably plugs the same air-heater rows",[69,518,520],{"id":519},"mitigation","Mitigation",[89,522,523,532,538,544,552],{},[92,524,525,531],{},[59,526,527,528],{},"Minimise ",[63,529,530],{"href":462},"ammonia slip"," at the SCR (the single biggest lever)",[92,533,534,537],{},[59,535,536],{},"Manage SO₃ formation"," — fuel sulphur control, catalyst formulation",[92,539,540,543],{},[59,541,542],{},"Avoid the dew-point window"," — keep cold-end gas temperature above the formation band",[92,545,546,551],{},[59,547,548,550],{},[63,549,128],{"href":127}," on the cold end"," — continuous cleaning prevents ABS from consolidating before periodic water-washing",[92,553,554,557],{},[59,555,556],{},"Water-washing campaigns"," — periodic offline washes restore air-heater performance",[69,559,133],{"id":132},[89,561,562,567,571,576,581],{},[92,563,564],{},[63,565,566],{"href":462},"Ammonia slip",[92,568,569],{},[63,570,249],{"href":248},[92,572,573],{},[63,574,575],{"href":467},"Air heater",[92,577,578],{},[63,579,580],{"href":497},"Cold-end corrosion \u002F dew-point corrosion",[92,582,583],{},[63,584,161],{"href":127},{"title":163,"searchDepth":164,"depth":164,"links":586},[587,588,589],{"id":476,"depth":164,"text":477},{"id":519,"depth":164,"text":520},{"id":132,"depth":164,"text":133},"scr-sncr","Ammonium bisulphate (NH₄HSO₄, ABS) — sometimes written ammonium bisulfate in US technical literature — is a sticky, low-melting deposit formed when slipped ammonia reacts with SO₃ in cooling flue gas. ABS condenses between roughly 150 °C and 250 °C, coating the cold end of any air heater downstream of an SCR.",{},[594,265,595,596,181],"ammonia-slip","air-heater","cold-end-corrosion-dew-point-corrosion",{"title":598,"description":599},"Ammonium bisulphate (ABS) — sticky deposit from SCR slip plus SO3","Ammonium bisulphate is a sticky low-melting deposit formed when slipped ammonia reacts with SO3 in cooling flue gas. The dominant cold-end fouling species on SCR-equipped boilers.",[601],{"title":602,"url":603},"POWER Magazine — SO3's impacts on plant O&M","https:\u002F\u002Fwww.powermag.com\u002Fso3s-impacts-on-plant-om-part-ii\u002F","glossary\u002Fammonium-bisulphate","eVfkw0arMYLXvUn7Eb2ZquRKgct13PXCySe8Iclt3GY",{"id":607,"title":161,"aliases":608,"body":612,"category":821,"description":822,"extension":172,"meta":823,"navigation":174,"path":127,"relatedTerms":824,"seo":831,"sources":834,"stem":844,"term":161,"__hash__":845},"glossary\u002Fglossary\u002Fsonic-horn.md",[609,610,611],"sonic horns","sonic cleaning horn","industrial sonic horn",{"type":52,"value":613,"toc":814},[614,645,649,657,661,729,733,770,774,782,784],[55,615,57,616,619,620,624,625,629,630,629,634,629,637,640,641,473],{},[59,617,618],{},"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 ",[63,621,623],{"href":622},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the default specification for cleaning ",[63,626,628],{"href":627},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",", ",[63,631,633],{"href":632},"\u002Fglossary\u002Ffabric-filter","baghouses",[63,635,636],{"href":248},"SCR catalysts",[63,638,639],{"href":308},"boiler heat-transfer surfaces"," and ",[63,642,644],{"href":643},"\u002Fglossary\u002Fhopper","hoppers and silos",[69,646,648],{"id":647},"how-a-sonic-horn-works","How a sonic horn works",[55,650,651,652,656],{},"Compressed plant air admitted through a ",[63,653,655],{"href":654},"\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.",[69,658,660],{"id":659},"key-parameters","Key parameters",[662,663,664,677],"table",{},[665,666,667],"thead",{},[668,669,670,674],"tr",{},[671,672,673],"th",{},"Parameter",[671,675,676],{},"Typical range",[678,679,680,689,697,705,713,721],"tbody",{},[668,681,682,686],{},[683,684,685],"td",{},"Fundamental frequency",[683,687,688],{},"60–400 Hz",[668,690,691,694],{},[683,692,693],{},"Sound pressure level",[683,695,696],{},"140–180 dB",[668,698,699,702],{},[683,700,701],{},"Compressed-air consumption",[683,703,704],{},"8–14 Nm³\u002Fmin at 4–7 bar",[668,706,707,710],{},[683,708,709],{},"Operating temperature (with appropriate materials)",[683,711,712],{},"−40 °C to +500 °C",[668,714,715,718],{},[683,716,717],{},"Firing cycle",[683,719,720],{},"5–15 s burst, repeated every 3–15 minutes",[668,722,723,726],{},[683,724,725],{},"Mass",[683,727,728],{},"15–60 kg depending on horn size",[69,730,732],{"id":731},"frequency-selection","Frequency selection",[55,734,735,736,629,740,744,745,629,749,753,754,629,757,761,762,640,766,473],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[63,737,739],{"href":738},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[63,741,743],{"href":742},"\u002Fglossary\u002Frecovery-boiler","recovery-boiler superheaters",", large ",[63,746,748],{"href":747},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[63,750,752],{"href":751},"\u002Fglossary\u002Fsilo","silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[63,755,756],{"href":632},"fabric-filter compartments",[63,758,760],{"href":759},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[63,763,765],{"href":764},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[63,767,769],{"href":768},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[69,771,773],{"id":772},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[55,775,776,777,781],{},"Sonic horns are increasingly specified alongside or in place of ",[63,778,780],{"href":779},"\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.",[69,783,133],{"id":132},[89,785,786,791,797,803,809],{},[92,787,788],{},[63,789,790],{"href":622},"Acoustic cleaner",[92,792,793],{},[63,794,796],{"href":795},"\u002Fglossary\u002Fsonic-sootblower","Sonic sootblower",[92,798,799],{},[63,800,802],{"href":801},"\u002Fglossary\u002Fbell-horn","Bell horn",[92,804,805],{},[63,806,808],{"href":807},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[92,810,811],{},[63,812,813],{"href":764},"Low-frequency acoustic cleaner",{"title":163,"searchDepth":164,"depth":164,"links":815},[816,817,818,819,820],{"id":647,"depth":164,"text":648},{"id":659,"depth":164,"text":660},{"id":731,"depth":164,"text":732},{"id":772,"depth":164,"text":773},{"id":132,"depth":164,"text":133},"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.",{},[825,826,827,828,829,830],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn","low-frequency-acoustic-cleaner",{"title":832,"description":833},"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.",[835,838,841],{"title":836,"url":837},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":839,"url":840},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":842,"url":843},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613743276]