[{"data":1,"prerenderedAt":1076},["ShallowReactive",2],{"site-footer-common":3,"glossary:catalyst-masking":45,"glossary-related:catalyst-masking":240},{"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":52,"category":216,"description":217,"extension":218,"meta":219,"navigation":220,"path":221,"relatedTerms":222,"seo":228,"sources":231,"stem":238,"term":47,"__hash__":239},"glossary\u002Fglossary\u002Fcatalyst-masking.md","Catalyst masking",[49,50,51],"SCR catalyst masking","catalyst fouling","face plugging",{"type":53,"value":54,"toc":208},"minimark",[55,68,73,137,140,144,160,164,176,180],[56,57,58,61,62,67],"p",{},[59,60,47],"strong",{}," is the deposition of a thin blanket of fine ash on the face of an ",[63,64,66],"a",{"href":65},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalyst"," that physically blocks ammonia and NOx molecules from reaching the underlying active sites. Gas continues to flow through the catalyst cells, but the active surface area is shadowed and reaction efficiency falls.",[69,70,72],"h2",{"id":71},"how-masking-differs-from-related-failure-modes","How masking differs from related failure modes",[74,75,76,92],"table",{},[77,78,79],"thead",{},[80,81,82,86,89],"tr",{},[83,84,85],"th",{},"Failure mode",[83,87,88],{},"Mechanism",[83,90,91],{},"Reversible?",[93,94,95,109,123],"tbody",{},[80,96,97,103,106],{},[98,99,100],"td",{},[59,101,102],{},"Masking",[98,104,105],{},"Ash blanket on the active surface",[98,107,108],{},"Yes — cleaning restores activity",[80,110,111,117,120],{},[98,112,113],{},[63,114,116],{"href":115},"\u002Fglossary\u002Fcatalyst-pluggage","Pluggage",[98,118,119],{},"Particles physically block catalyst channels",[98,121,122],{},"Sometimes (depends on hardness)",[80,124,125,131,134],{},[98,126,127],{},[63,128,130],{"href":129},"\u002Fglossary\u002Fcatalyst-poisoning","Poisoning",[98,132,133],{},"Chemical species bind to active sites",[98,135,136],{},"Usually no — catalyst replacement",[56,138,139],{},"Masking is the most operationally manageable of the three because it responds to cleaning.",[69,141,143],{"id":142},"what-deposits-cause-masking","What deposits cause masking",[145,146,147,151,154,157],"ul",{},[148,149,150],"li",{},"Calcium-rich fly ash (Western US sub-bituminous, biomass)",[148,152,153],{},"Ammonium-salt films on tail-end SCRs",[148,155,156],{},"Sub-micron silica from biomass fuels",[148,158,159],{},"Iron-oxide carry-over from blast-furnace or sinter-plant SCR applications",[69,161,163],{"id":162},"sonic-horns-and-masking-control","Sonic horns and masking control",[56,165,166,170,171,175],{},[63,167,169],{"href":168},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," positioned upstream of each catalyst layer continuously dislodge the developing ash blanket before it consolidates. Combined with periodic steam ",[63,172,174],{"href":173},"\u002Fglossary\u002Fsonic-sootblower","sootblowing",", this two-tier cleaning typically restores catalyst activity by 10–30% within months of installation.",[69,177,179],{"id":178},"related-terms","Related terms",[145,181,182,187,192,197,203],{},[148,183,184],{},[63,185,186],{"href":65},"Selective Catalytic Reduction (SCR)",[148,188,189],{},[63,190,191],{"href":115},"Catalyst pluggage",[148,193,194],{},[63,195,196],{"href":129},"Catalyst poisoning",[148,198,199],{},[63,200,202],{"href":201},"\u002Fglossary\u002Fhoneycomb-catalyst","Honeycomb catalyst",[148,204,205],{},[63,206,207],{"href":168},"Sonic horn",{"title":209,"searchDepth":210,"depth":210,"links":211},"",2,[212,213,214,215],{"id":71,"depth":210,"text":72},{"id":142,"depth":210,"text":143},{"id":162,"depth":210,"text":163},{"id":178,"depth":210,"text":179},"scr-sncr","Catalyst masking is the deposition of a thin blanket of fine ash on the face of an SCR catalyst that physically blocks ammonia and NOx molecules from reaching the underlying active sites. Gas continues to flow through the catalyst cells, but the active surface area is shadowed and reaction efficiency falls.","md",{},true,"\u002Fglossary\u002Fcatalyst-masking",[223,224,225,226,227],"selective-catalytic-reduction","catalyst-pluggage","catalyst-poisoning","honeycomb-catalyst","sonic-horn",{"title":229,"description":230},"Catalyst masking — fine-ash blanket that suppresses SCR activity","Catalyst masking is the deposition of a thin ash layer on the SCR catalyst face that blocks ammonia and NOx from reaching the active sites. Distinct from pluggage and poisoning.",[232,235],{"title":233,"url":234},"Power Engineering — SCR Catalyst Cleaning: Sootblowers vs. Acoustic Horns","https:\u002F\u002Fwww.power-eng.com\u002Foperations-maintenance\u002Fscr-catalyst-cleaningsootblowers-vs-acoustic-horns\u002F",{"title":236,"url":237},"Integrated Global Services — SCR Fouling Solved","https:\u002F\u002Fintegratedglobal.com\u002Fen\u002Fcase_studies\u002Fscr-performance\u002F","glossary\u002Fcatalyst-masking","WbNY355NxnwGZ3FW-bDAalSFTSrruJrjYN-62Fgc5Ig",[241,397,545,690,847],{"id":242,"title":186,"aliases":243,"body":247,"category":216,"description":378,"extension":218,"meta":379,"navigation":220,"path":65,"relatedTerms":380,"seo":386,"sources":389,"stem":394,"term":395,"__hash__":396},"glossary\u002Fglossary\u002Fselective-catalytic-reduction.md",[244,245,246],"SCR","SCR system","SCR reactor",{"type":53,"value":248,"toc":373},[249,268,272,288,292,295,320,337,339],[56,250,251,253,254,258,259,263,264,267],{},[59,252,186],{}," is the dominant flue-gas NOx-control technology on coal-fired and gas-fired utility boilers, ",[63,255,257],{"href":256},"\u002Fglossary\u002Fheat-recovery-steam-generator","HRSGs"," in combined-cycle plants, ",[63,260,262],{"href":261},"\u002Fglossary\u002Fwaste-to-energy","waste-to-energy"," and ",[63,265,266],{"href":261},"biomass"," boilers, cement plants and major refining furnaces. Ammonia or aqueous urea is injected upstream of a catalyst bed; the catalyst lowers the activation energy for the reaction NOx + NH₃ → N₂ + H₂O, achieving 80–95% NOx reduction across the reactor.",[69,269,271],{"id":270},"reactor-layout","Reactor layout",[56,273,274,275,279,280,283,284,287],{},"A typical SCR reactor is a vertical or horizontal duct containing 2–4 layers of catalyst modules. Upstream of the catalyst sits the ",[63,276,278],{"href":277},"\u002Fglossary\u002Fammonia-injection-grid","ammonia injection grid (AIG)"," that distributes the ammonia evenly into the flue gas. Most installations operate in the ",[59,281,282],{},"high-dust"," position (between economiser and air heater) where catalyst temperature is around 300–400 °C; ",[59,285,286],{},"tail-end"," SCRs sit downstream of particulate control at lower temperatures, with the trade-off of needing flue-gas reheating.",[69,289,291],{"id":290},"fouling-and-cleaning","Fouling and cleaning",[56,293,294],{},"SCR catalysts foul in two ways:",[145,296,297,313],{},[148,298,299,303,304,263,308,312],{},[59,300,301],{},[63,302,116],{"href":115}," — fly ash, ",[63,305,307],{"href":306},"\u002Fglossary\u002Fpopcorn-ash","popcorn ash",[63,309,311],{"href":310},"\u002Fglossary\u002Flarge-particle-ash","large-particle ash"," wedge into the catalyst cells, blocking the gas path",[148,314,315,319],{},[59,316,317],{},[63,318,102],{"href":221}," — a thin layer of deposit covers the active sites; gas flow continues but catalytic activity falls",[56,321,322,323,327,328,332,333,336],{},"Both reduce NOx-reduction efficiency, raise ",[63,324,326],{"href":325},"\u002Fglossary\u002Fammonia-slip","ammonia slip",", and shorten catalyst life. Cleaning options include steam ",[63,329,331],{"href":330},"\u002Fglossary\u002Fsteam-sootblower","sootblowers",", ",[63,334,335],{"href":168},"sonic horns"," and offline campaigns (vacuum \u002F water wash \u002F regeneration). Sonic horns are increasingly favoured because they continuously dislodge ash before it cements onto the catalyst face, without the steam erosion of mechanical sootblowing.",[69,338,179],{"id":178},[145,340,341,347,352,357,361,365,369],{},[148,342,343],{},[63,344,346],{"href":345},"\u002Fglossary\u002Fselective-non-catalytic-reduction","Selective Non-Catalytic Reduction (SNCR)",[148,348,349],{},[63,350,351],{"href":277},"Ammonia injection grid",[148,353,354],{},[63,355,356],{"href":325},"Ammonia slip",[148,358,359],{},[63,360,47],{"href":221},[148,362,363],{},[63,364,191],{"href":115},[148,366,367],{},[63,368,202],{"href":201},[148,370,371],{},[63,372,207],{"href":168},{"title":209,"searchDepth":210,"depth":210,"links":374},[375,376,377],{"id":270,"depth":210,"text":271},{"id":290,"depth":210,"text":291},{"id":178,"depth":210,"text":179},"Selective Catalytic Reduction (SCR) is the dominant flue-gas NOx-control technology on coal-fired and gas-fired utility boilers, HRSGs in combined-cycle plants, waste-to-energy and biomass boilers, cement plants and major refining furnaces. Ammonia or aqueous urea is injected upstream of a catalyst bed; the catalyst lowers the activation energy for the reaction NOx + NH₃ → N₂ + H₂O, achieving 80–95% NOx reduction across the reactor.",{},[381,382,383,384,385,224,226,227],"selective-non-catalytic-reduction","denox","ammonia-injection-grid","ammonia-slip","catalyst-masking",{"title":387,"description":388},"Selective Catalytic Reduction (SCR) — how the dominant NOx-control technology works","SCR is the dominant NOx-control technology on industrial combustion plant. Ammonia is injected upstream of a catalyst that converts NOx to nitrogen and water.",[390,393],{"title":391,"url":392},"Wikipedia — Selective catalytic reduction","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSelective_catalytic_reduction",{"title":233,"url":234},"glossary\u002Fselective-catalytic-reduction","Selective Catalytic Reduction","fmMCMd4NY3eZdSk_UYlbZ9ryi-9CR2Os6DivQjXEPCU",{"id":398,"title":191,"aliases":399,"body":403,"category":216,"description":531,"extension":218,"meta":532,"navigation":220,"path":115,"relatedTerms":533,"seo":536,"sources":539,"stem":543,"term":191,"__hash__":544},"glossary\u002Fglossary\u002Fcatalyst-pluggage.md",[400,401,402],"catalyst plugging","catalyst channelling","SCR catalyst pluggage",{"type":53,"value":404,"toc":526},[405,417,421,456,460,497,499],[56,406,407,409,410,412,413,416],{},[59,408,191],{}," is the physical blockage of ",[63,411,66],{"href":65}," channels by particulate material. Unlike ",[63,414,415],{"href":221},"catalyst masking"," (a thin surface blanket), pluggage fills the catalyst channels themselves, stopping gas flow through affected cells. The result is ΔP rise across the SCR, gas-flow maldistribution into the remaining open cells, and channelling effects that reduce overall NOx reduction.",[69,418,420],{"id":419},"sources-of-pluggage-material","Sources of pluggage material",[145,422,423,431,439,450],{},[148,424,425,430],{},[59,426,427],{},[63,428,429],{"href":310},"Large-particle ash (LPA)"," — slag fragments and agglomerated ash carried over from the boiler",[148,432,433,438],{},[59,434,435],{},[63,436,437],{"href":306},"Popcorn ash"," — porous low-density ash particles that wedge into honeycomb cells",[148,440,441,444,445,449],{},[59,442,443],{},"Ammonium-salt deposits"," — ",[63,446,448],{"href":447},"\u002Fglossary\u002Fammonium-bisulphate","ammonium bisulphate"," on tail-end SCRs at lower temperatures",[148,451,452,455],{},[59,453,454],{},"Refractory debris"," — fragments from upstream furnace or duct repairs",[69,457,459],{"id":458},"prevention","Prevention",[145,461,462,468,474,480,489],{},[148,463,464,467],{},[59,465,466],{},"LPA screens"," — coarse mesh screens upstream of the catalyst trap large particles",[148,469,470,473],{},[59,471,472],{},"Guard layers"," — sacrificial top catalyst layer with larger pitch absorbs the initial particulate",[148,475,476,479],{},[59,477,478],{},"Larger pitch on the top layer"," — wider cell openings on the first catalyst layer pass LPA through to a removable screen below",[148,481,482,488],{},[59,483,484,485,487],{},"Periodic ",[63,486,227],{"href":168}," cleaning"," — dislodges accumulating ash before it cements",[148,490,491,496],{},[59,492,493,494],{},"Steam ",[63,495,174],{"href":173}," — for harder deposits",[69,498,179],{"id":178},[145,500,501,505,510,514,518,522],{},[148,502,503],{},[63,504,186],{"href":65},[148,506,507],{},[63,508,509],{"href":310},"Large-particle ash",[148,511,512],{},[63,513,437],{"href":306},[148,515,516],{},[63,517,47],{"href":221},[148,519,520],{},[63,521,202],{"href":201},[148,523,524],{},[63,525,207],{"href":168},{"title":209,"searchDepth":210,"depth":210,"links":527},[528,529,530],{"id":419,"depth":210,"text":420},{"id":458,"depth":210,"text":459},{"id":178,"depth":210,"text":179},"Catalyst pluggage is the physical blockage of SCR catalyst channels by particulate material. Unlike catalyst masking (a thin surface blanket), pluggage fills the catalyst channels themselves, stopping gas flow through affected cells. The result is ΔP rise across the SCR, gas-flow maldistribution into the remaining open cells, and channelling effects that reduce overall NOx reduction.",{},[223,534,535,385,226,227],"large-particle-ash","popcorn-ash",{"title":537,"description":538},"Catalyst pluggage — channel blockage that reduces SCR gas flow","Catalyst pluggage is the physical blockage of SCR catalyst channels by large-particle ash, popcorn ash or ammonium-salt deposits. It causes ΔP rise and gas-flow maldistribution.",[540],{"title":541,"url":542},"Airflow Sciences — SCR Catalyst Pluggage Reduction at Roxboro Unit 3","https:\u002F\u002Fwww.airflowsciences.com\u002Fsites\u002Fdefault\u002Ffiles\u002Fdocs\u002F2010_MEGA_Symposium_Roxboro_U3.pdf","glossary\u002Fcatalyst-pluggage","m2viiLe19KKcTBiDWhyUc38xPIzoOiMpL15r0i_ayHg",{"id":546,"title":196,"aliases":547,"body":550,"category":216,"description":677,"extension":218,"meta":678,"navigation":220,"path":129,"relatedTerms":679,"seo":681,"sources":684,"stem":688,"term":196,"__hash__":689},"glossary\u002Fglossary\u002Fcatalyst-poisoning.md",[548,549],"SCR catalyst poisoning","catalyst deactivation",{"type":53,"value":551,"toc":672},[552,568,572,634,638,656,658],[56,553,554,556,557,559,560,563,564,567],{},[59,555,196],{}," is the chemical deactivation of ",[63,558,66],{"href":65}," active sites by trace species in the flue gas. Unlike ",[63,561,562],{"href":221},"masking"," (physical blanket) or ",[63,565,566],{"href":115},"pluggage"," (channel blockage), poisoning is a chemical process that binds molecules to the catalyst's vanadium, tungsten or titanium active centres. Cleaning cannot reverse it; the affected layer must be regenerated off-site or replaced.",[69,569,571],{"id":570},"common-poisons","Common poisons",[74,573,574,584],{},[77,575,576],{},[80,577,578,581],{},[83,579,580],{},"Poison",[83,582,583],{},"Source",[93,585,586,594,602,610,618,626],{},[80,587,588,591],{},[98,589,590],{},"Arsenic",[98,592,593],{},"Coal-fired flue gas, especially sub-bituminous",[80,595,596,599],{},[98,597,598],{},"Alkali metals (K, Na)",[98,600,601],{},"Biomass, agricultural-residue and waste-fuel ash",[80,603,604,607],{},[98,605,606],{},"Phosphorus",[98,608,609],{},"Animal-fat biofuels, sewage-sludge co-firing",[80,611,612,615],{},[98,613,614],{},"Calcium",[98,616,617],{},"Wet limestone scrubbers upstream, biomass",[80,619,620,623],{},[98,621,622],{},"Sulphur trioxide (high concentration)",[98,624,625],{},"SO₂ + V₂O₅ oxidation at high SCR temperature",[80,627,628,631],{},[98,629,630],{},"Lead and zinc",[98,632,633],{},"Waste-to-energy, some industrial off-gas streams",[69,635,637],{"id":636},"mitigation","Mitigation",[145,639,640,643,646,649],{},[148,641,642],{},"Fuel selection \u002F blending to control fuel-bound poison content",[148,644,645],{},"Guard layers (sacrificial top catalyst layers protecting layers below)",[148,647,648],{},"Catalyst formulation tuned to expected poisons (e.g. alkali-resistant for biomass)",[148,650,651,655],{},[63,652,654],{"href":653},"\u002Fglossary\u002Fcatalyst-regeneration-vs-replacement","Catalyst regeneration vs replacement"," campaigns to extend catalyst life",[69,657,179],{"id":178},[145,659,660,664,668],{},[148,661,662],{},[63,663,186],{"href":65},[148,665,666],{},[63,667,47],{"href":221},[148,669,670],{},[63,671,654],{"href":653},{"title":209,"searchDepth":210,"depth":210,"links":673},[674,675,676],{"id":570,"depth":210,"text":571},{"id":636,"depth":210,"text":637},{"id":178,"depth":210,"text":179},"Catalyst poisoning is the chemical deactivation of SCR catalyst active sites by trace species in the flue gas. Unlike masking (physical blanket) or pluggage (channel blockage), poisoning is a chemical process that binds molecules to the catalyst's vanadium, tungsten or titanium active centres. Cleaning cannot reverse it; the affected layer must be regenerated off-site or replaced.",{},[223,385,680],"catalyst-regeneration-vs-replacement",{"title":682,"description":683},"Catalyst poisoning — chemical deactivation of SCR active sites","Catalyst poisoning is the chemical binding of trace species (arsenic, alkali metals, phosphorus, sulphur) to SCR active sites. Usually irreversible — the catalyst layer must be replaced.",[685],{"title":686,"url":687},"Power Engineering — Selective Catalytic Reduction: Operational Issues","https:\u002F\u002Fwww.power-eng.com\u002Fenvironmental-emissions\u002Fselective-catalytic-reduction-operational-issues-and-guidelines\u002F","glossary\u002Fcatalyst-poisoning","bDfLprEkBdDowKQkBMNA0KvZrpMlXenCOlLhfqJMgdQ",{"id":691,"title":202,"aliases":692,"body":695,"category":216,"description":834,"extension":218,"meta":835,"navigation":220,"path":201,"relatedTerms":836,"seo":840,"sources":843,"stem":845,"term":202,"__hash__":846},"glossary\u002Fglossary\u002Fhoneycomb-catalyst.md",[693,694],"honeycomb SCR catalyst","extruded catalyst",{"type":53,"value":696,"toc":828},[697,707,711,760,764,767,781,785,799,801],[56,698,699,700,703,704,706],{},"A ",[59,701,702],{},"honeycomb catalyst"," is a monolithic extruded ceramic block containing a dense grid of parallel square channels through which flue gas flows. The active catalytic material — typically vanadium pentoxide and tungsten trioxide on a titanium-dioxide carrier — is incorporated into the bulk ceramic. Honeycomb is the most common form of ",[63,705,66],{"href":65},".",[69,708,710],{"id":709},"strengths-and-weaknesses","Strengths and weaknesses",[74,712,713,723],{},[77,714,715],{},[80,716,717,720],{},[83,718,719],{},"Strength",[83,721,722],{},"Weakness",[93,724,725,736,744,752],{},[80,726,727,730],{},[98,728,729],{},"Very high geometric surface area per unit volume",[98,731,732,733,735],{},"Channels susceptible to ",[63,734,566],{"href":115}," by ash",[80,737,738,741],{},[98,739,740],{},"Low pressure drop in clean condition",[98,742,743],{},"Brittle — handle with care during install \u002F replacement",[80,745,746,749],{},[98,747,748],{},"Mature, large supplier base",[98,750,751],{},"Channels are harder to clean than open structures",[80,753,754,757],{},[98,755,756],{},"Wide range of pitch options (3.5–7.4 mm typical)",[98,758,759],{},"Smaller pitch = more risk of pluggage",[69,761,763],{"id":762},"pitch-selection","Pitch selection",[56,765,766],{},"Pitch (centre-to-centre channel spacing) trades surface area against pluggage risk:",[145,768,769,775],{},[148,770,771,774],{},[59,772,773],{},"Smaller pitch (3.5–4.5 mm)"," — high surface area, used on clean gas streams (NGCC HRSGs, gas-fired duty)",[148,776,777,780],{},[59,778,779],{},"Larger pitch (6–7.4 mm)"," — used on dusty coal, biomass and WtE duty where pluggage risk dominates",[69,782,784],{"id":783},"layer-assembly","Layer assembly",[56,786,787,788,792,793,795,796,798],{},"Individual honeycomb blocks are loaded into a ",[63,789,791],{"href":790},"\u002Fglossary\u002Fcatalyst-layer-module","catalyst layer \u002F module"," and stacked 2–4 layers deep inside the SCR reactor. ",[63,794,169],{"href":168}," and steam ",[63,797,331],{"href":173}," are positioned between layers to keep channels clear.",[69,800,179],{"id":178},[145,802,803,807,813,819,824],{},[148,804,805],{},[63,806,186],{"href":65},[148,808,809],{},[63,810,812],{"href":811},"\u002Fglossary\u002Fplate-catalyst","Plate catalyst",[148,814,815],{},[63,816,818],{"href":817},"\u002Fglossary\u002Fcorrugated-catalyst","Corrugated catalyst",[148,820,821],{},[63,822,823],{"href":790},"Catalyst layer \u002F module",[148,825,826],{},[63,827,191],{"href":115},{"title":209,"searchDepth":210,"depth":210,"links":829},[830,831,832,833],{"id":709,"depth":210,"text":710},{"id":762,"depth":210,"text":763},{"id":783,"depth":210,"text":784},{"id":178,"depth":210,"text":179},"A honeycomb catalyst is a monolithic extruded ceramic block containing a dense grid of parallel square channels through which flue gas flows. The active catalytic material — typically vanadium pentoxide and tungsten trioxide on a titanium-dioxide carrier — is incorporated into the bulk ceramic. Honeycomb is the most common form of SCR catalyst.",{},[223,837,838,839,224],"plate-catalyst","corrugated-catalyst","catalyst-layer-module",{"title":841,"description":842},"Honeycomb catalyst — extruded SCR catalyst form factor","A honeycomb catalyst is an extruded ceramic block with parallel square channels, the most common SCR catalyst form. High surface area but susceptible to channel pluggage.",[844],{"title":391,"url":392},"glossary\u002Fhoneycomb-catalyst","_YfmRO7jrh-yc8ZLI7n3Nr5QKYo9e0uBw4yWiXy1uho",{"id":848,"title":207,"aliases":849,"body":852,"category":1051,"description":1052,"extension":218,"meta":1053,"navigation":220,"path":168,"relatedTerms":1054,"seo":1061,"sources":1064,"stem":1074,"term":207,"__hash__":1075},"glossary\u002Fglossary\u002Fsonic-horn.md",[335,850,851],"sonic cleaning horn","industrial sonic horn",{"type":53,"value":853,"toc":1044},[854,884,888,896,900,962,966,1002,1006,1013,1015],[56,855,699,856,859,860,864,865,332,869,332,873,332,876,263,880,706],{},[59,857,858],{},"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 ",[63,861,863],{"href":862},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the default specification for cleaning ",[63,866,868],{"href":867},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",[63,870,872],{"href":871},"\u002Fglossary\u002Ffabric-filter","baghouses",[63,874,875],{"href":65},"SCR catalysts",[63,877,879],{"href":878},"\u002Fglossary\u002Fsuperheater","boiler heat-transfer surfaces",[63,881,883],{"href":882},"\u002Fglossary\u002Fhopper","hoppers and silos",[69,885,887],{"id":886},"how-a-sonic-horn-works","How a sonic horn works",[56,889,890,891,895],{},"Compressed plant air admitted through a ",[63,892,894],{"href":893},"\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.",[69,897,899],{"id":898},"key-parameters","Key parameters",[74,901,902,912],{},[77,903,904],{},[80,905,906,909],{},[83,907,908],{},"Parameter",[83,910,911],{},"Typical range",[93,913,914,922,930,938,946,954],{},[80,915,916,919],{},[98,917,918],{},"Fundamental frequency",[98,920,921],{},"60–400 Hz",[80,923,924,927],{},[98,925,926],{},"Sound pressure level",[98,928,929],{},"140–180 dB",[80,931,932,935],{},[98,933,934],{},"Compressed-air consumption",[98,936,937],{},"8–14 Nm³\u002Fmin at 4–7 bar",[80,939,940,943],{},[98,941,942],{},"Operating temperature (with appropriate materials)",[98,944,945],{},"−40 °C to +500 °C",[80,947,948,951],{},[98,949,950],{},"Firing cycle",[98,952,953],{},"5–15 s burst, repeated every 3–15 minutes",[80,955,956,959],{},[98,957,958],{},"Mass",[98,960,961],{},"15–60 kg depending on horn size",[69,963,965],{"id":964},"frequency-selection","Frequency selection",[56,967,968,969,332,973,977,978,332,982,986,987,332,990,993,994,263,998,706],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[63,970,972],{"href":971},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[63,974,976],{"href":975},"\u002Fglossary\u002Frecovery-boiler","recovery-boiler superheaters",", large ",[63,979,981],{"href":980},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[63,983,985],{"href":984},"\u002Fglossary\u002Fsilo","silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[63,988,989],{"href":871},"fabric-filter compartments",[63,991,992],{"href":201},"catalyst layers"," and smaller hopper geometries. See ",[63,995,997],{"href":996},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[63,999,1001],{"href":1000},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[69,1003,1005],{"id":1004},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[56,1007,1008,1009,1012],{},"Sonic horns are increasingly specified alongside or in place of ",[63,1010,1011],{"href":330},"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.",[69,1014,179],{"id":178},[145,1016,1017,1022,1027,1033,1039],{},[148,1018,1019],{},[63,1020,1021],{"href":862},"Acoustic cleaner",[148,1023,1024],{},[63,1025,1026],{"href":173},"Sonic sootblower",[148,1028,1029],{},[63,1030,1032],{"href":1031},"\u002Fglossary\u002Fbell-horn","Bell horn",[148,1034,1035],{},[63,1036,1038],{"href":1037},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[148,1040,1041],{},[63,1042,1043],{"href":996},"Low-frequency acoustic cleaner",{"title":209,"searchDepth":210,"depth":210,"links":1045},[1046,1047,1048,1049,1050],{"id":886,"depth":210,"text":887},{"id":898,"depth":210,"text":899},{"id":964,"depth":210,"text":965},{"id":1004,"depth":210,"text":1005},{"id":178,"depth":210,"text":179},"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.",{},[1055,1056,1057,1058,1059,1060],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn","low-frequency-acoustic-cleaner",{"title":1062,"description":1063},"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.",[1065,1068,1071],{"title":1066,"url":1067},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":1069,"url":1070},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":1072,"url":1073},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613750423]