[{"data":1,"prerenderedAt":698},["ShallowReactive",2],{"site-footer-common":3,"glossary:stack-breeching":45,"glossary-related:stack-breeching":178},{"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":53,"category":158,"description":159,"extension":160,"meta":161,"navigation":162,"path":163,"relatedTerms":164,"seo":168,"sources":171,"stem":175,"term":176,"__hash__":177},"glossary\u002Fglossary\u002Fstack-breeching.md","Stack \u002F breeching",[49,50,51,52],"stack","breeching","flue","chimney",{"type":54,"value":55,"toc":151},"minimark",[56,73,78,118,122,130,134],[57,58,59,60,63,64,66,67,72],"p",{},"The ",[61,62,49],"strong",{}," (chimney) is the vertical structure that releases flue gas to atmosphere at sufficient height to comply with dispersion-modelling regulations and prevent ground-level concentrations of pollutants. 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The breeching is the horizontal duct that connects the ID fan discharge (or boiler outlet on natural-draught units) to the stack inlet.","md",{},true,"\u002Fglossary\u002Fstack-breeching",[165,166,167],"id-fan","opacity","boiler",{"title":169,"description":170},"Stack and breeching — final flue-gas discharge to atmosphere","The stack is the vertical chimney that releases flue gas to atmosphere. The breeching is the duct connecting the ID fan or boiler outlet to the stack.",[172],{"title":173,"url":174},"Wikipedia — Chimney","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FChimney","glossary\u002Fstack-breeching","Stack and breeching","8X_FaZweD3XeySmQLzmLBICJRSpQCuBmnJLs7DleD5U",[179,347,456],{"id":180,"title":140,"aliases":181,"body":187,"category":158,"description":191,"extension":160,"meta":333,"navigation":162,"path":70,"relatedTerms":334,"seo":337,"sources":340,"stem":344,"term":345,"__hash__":346},"glossary\u002Fglossary\u002Fid-fan.md",[182,183,184,71,185,186],"induced draft fan","forced draft fan","primary air fan","FD fan","PA fan",{"type":54,"value":188,"toc":328},[189,192,268,272,292,300,304,310,312],[57,190,191],{},"Industrial boilers use three principal fans to manage gas and air movement:",[193,194,195,211],"table",{},[196,197,198],"thead",{},[199,200,201,205,208],"tr",{},[202,203,204],"th",{},"Fan",[202,206,207],{},"Function",[202,209,210],{},"Location",[212,213,214,242,255],"tbody",{},[199,215,216,222,229],{},[217,218,219],"td",{},[61,220,221],{},"ID (Induced Draft)",[217,223,224,225],{},"Pulls flue gas through the ",[68,226,228],{"href":227},"\u002Fglossary\u002Fconvective-pass-backpass","convective pass",[217,230,231,232,236,237,241],{},"Downstream of the ",[68,233,235],{"href":234},"\u002Fglossary\u002Felectrostatic-precipitator","ESP"," or ",[68,238,240],{"href":239},"\u002Fglossary\u002Fbaghouse","baghouse",", before the stack",[199,243,244,249,252],{},[217,245,246],{},[61,247,248],{},"FD (Forced Draft)",[217,250,251],{},"Pushes combustion air into the burners",[217,253,254],{},"Ahead of the air heater air-side inlet",[199,256,257,262,265],{},[217,258,259],{},[61,260,261],{},"PA (Primary Air)",[217,263,264],{},"Conveys pulverised coal from mills to burners",[217,266,267],{},"Between the coal mills and the burner deck",[74,269,271],{"id":270},"why-fans-foul","Why fans foul",[79,273,274,280,286],{},[82,275,276,279],{},[61,277,278],{},"Fly-ash deposition on ID fan blades"," unbalances the impeller, causing vibration and bearing wear",[82,281,282,285],{},[61,283,284],{},"PA fan blade build-up"," from sticky coal fines",[82,287,288,291],{},[61,289,290],{},"FD fan inlet vane fouling"," from atmospheric dust accumulating on the air-intake filter or vane assembly",[57,293,294,295,299],{},"ID fans on coal-fired and ",[68,296,298],{"href":297},"\u002Fglossary\u002Fwaste-to-energy","biomass"," plants are particularly prone to blade fouling; a trip-causing imbalance is a regular outage risk.",[74,301,303],{"id":302},"sonic-horns-on-fan-housings","Sonic horns on fan housings",[57,305,306,309],{},[68,307,308],{"href":127},"Sonic horns"," installed on the upstream ducting and at the fan inlet keep the blades clean by preventing the dust from settling onto them in the first place. Cement preheater ID fans are a particularly common installation.",[74,311,133],{"id":132},[79,313,314,318,323],{},[82,315,316],{},[68,317,150],{"href":149},[82,319,320],{},[68,321,322],{"href":227},"Convective pass \u002F backpass",[82,324,325],{},[68,326,327],{"href":127},"Sonic horn",{"title":152,"searchDepth":153,"depth":153,"links":329},[330,331,332],{"id":270,"depth":153,"text":271},{"id":302,"depth":153,"text":303},{"id":132,"depth":153,"text":133},{},[167,335,336],"convective-pass-backpass","sonic-horn",{"title":338,"description":339},"ID, FD and PA fans — the three principal boiler fans explained","Boilers use three fans: ID (induced draft) pulls flue gas through the convective pass, FD (forced draft) pushes combustion air, PA (primary air) conveys pulverised coal to the burners.",[341],{"title":342,"url":343},"Wikipedia — Boiler","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FBoiler","glossary\u002Fid-fan","ID, FD and PA fans","YjfqFgTbzrQzwlPIf72ZoVKgmffznjVyqIloOT6aaMo",{"id":348,"title":110,"aliases":349,"body":352,"category":440,"description":441,"extension":160,"meta":442,"navigation":162,"path":109,"relatedTerms":443,"seo":446,"sources":449,"stem":453,"term":454,"__hash__":455},"glossary\u002Fglossary\u002Fopacity.md",[350,351],"stack opacity","opacity excursion",{"type":54,"value":353,"toc":435},[354,362,366,369,402,406,411,413],[57,355,356,358,359,361],{},[61,357,110],{}," 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 ",[68,360,235],{"href":234}," 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.",[74,363,365],{"id":364},"opacity-excursions","Opacity excursions",[57,367,368],{},"Opacity excursions are typically driven by:",[79,370,371,383,389,396,399],{},[82,372,373,377,378,382],{},[68,374,376],{"href":375},"\u002Fglossary\u002Fesp-rapper","ESP rapping"," ",[68,379,381],{"href":380},"\u002Fglossary\u002Fre-entrainment","re-entrainment"," puffs",[82,384,385,388],{},[68,386,387],{"href":239},"Baghouse"," bag failure (sudden particulate breakthrough)",[82,390,391,395],{},[68,392,394],{"href":393},"\u002Fglossary\u002Fback-corona","ESP back-corona"," collapse",[82,397,398],{},"Combustion upsets producing unusually high inlet particulate",[82,400,401],{},"Soot-blower-triggered re-entrainment",[74,403,405],{"id":404},"how-sonic-horns-reduce-opacity","How sonic horns reduce opacity",[57,407,408,410],{},[68,409,308],{"href":127}," 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.",[74,412,133],{"id":132},[79,414,415,421,426,431],{},[82,416,417],{},[68,418,420],{"href":419},"\u002Fglossary\u002Fcems","CEMS",[82,422,423],{},[68,424,425],{"href":234},"Electrostatic precipitator",[82,427,428],{},[68,429,430],{"href":380},"Re-entrainment",[82,432,433],{},[68,434,327],{"href":127},{"title":152,"searchDepth":153,"depth":153,"links":436},[437,438,439],{"id":364,"depth":153,"text":365},{"id":404,"depth":153,"text":405},{"id":132,"depth":153,"text":133},"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.",{},[444,445,381,336],"cems","electrostatic-precipitator",{"title":447,"description":448},"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.",[450],{"title":451,"url":452},"Wikipedia — Opacity","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FOpacity_(optics)","glossary\u002Fopacity","Opacity (stack)","-4RIuJbd3zg7kip6GHWTZ5efGSK8D9bOiK_nb9oMGWo",{"id":457,"title":150,"aliases":458,"body":462,"category":167,"description":678,"extension":160,"meta":679,"navigation":162,"path":149,"relatedTerms":680,"seo":688,"sources":691,"stem":696,"term":150,"__hash__":697},"glossary\u002Fglossary\u002Fboiler.md",[459,460,461],"industrial boiler","utility boiler","steam generator",{"type":54,"value":463,"toc":673},[464,490,494,606,610,642,644],[57,465,466,467,469,470,473,474,476,477,481,482,476,486,489],{},"A ",[61,468,167],{}," is a closed vessel in which fuel chemical energy is converted to steam by transferring heat into water flowing through tube banks. Industrial and utility boilers serve electricity generation, district heating, process steam, ",[68,471,472],{"href":297},"WtE",", ",[68,475,298],{"href":297}," and ",[68,478,480],{"href":479},"\u002Fglossary\u002Frecovery-boiler","pulp-and-paper"," operations. All of them foul; the only variables are ",[483,484,485],"em",{},"how much",[483,487,488],{},"with what",".",[74,491,493],{"id":492},"boiler-families","Boiler families",[193,495,496,509],{},[196,497,498],{},[199,499,500,503,506],{},[202,501,502],{},"Type",[202,504,505],{},"Fuel",[202,507,508],{},"Notes",[212,510,511,525,539,553,566,580,591],{},[199,512,513,519,522],{},[217,514,515],{},[68,516,518],{"href":517},"\u002Fglossary\u002Fpc-boiler","PC boiler",[217,520,521],{},"Pulverised coal",[217,523,524],{},"Dominant utility design",[199,526,527,533,536],{},[217,528,529],{},[68,530,532],{"href":531},"\u002Fglossary\u002Fcfb-boiler","CFB boiler",[217,534,535],{},"Coal, biomass, RDF, lignite",[217,537,538],{},"Tolerates wider fuel range; lower NOx",[199,540,541,547,550],{},[217,542,543],{},[68,544,546],{"href":545},"\u002Fglossary\u002Fbfb-boiler","BFB boiler",[217,548,549],{},"Biomass, sludge, low-grade fuels",[217,551,552],{},"Bubbling fluidised bed",[199,554,555,560,563],{},[217,556,557],{},[68,558,559],{"href":479},"Recovery boiler",[217,561,562],{},"Black liquor (kraft pulp mills)",[217,564,565],{},"Combines chemicals recovery with steam",[199,567,568,574,577],{},[217,569,570],{},[68,571,573],{"href":572},"\u002Fglossary\u002Fhog-fuel-boiler-bark-boiler","Hog-fuel boiler",[217,575,576],{},"Wood waste, bark",[217,578,579],{},"Common at pulp mills as side boilers",[199,581,582,585,588],{},[217,583,584],{},"Gas \u002F oil boiler",[217,586,587],{},"Natural gas, fuel oil",[217,589,590],{},"Lower particulate, less fouling",[199,592,593,596,599],{},[217,594,595],{},"HRSG",[217,597,598],{},"Gas-turbine exhaust",[217,600,601,602],{},"See ",[68,603,605],{"href":604},"\u002Fglossary\u002Fheat-recovery-steam-generator","heat-recovery steam generator",[74,607,609],{"id":608},"where-sonic-horns-sit","Where sonic horns sit",[57,611,612,614,615,473,619,473,623,476,627,631,632,636,637,641],{},[68,613,308],{"href":127}," installed across the convective pass — between ",[68,616,618],{"href":617},"\u002Fglossary\u002Feconomiser","economiser",[68,620,622],{"href":621},"\u002Fglossary\u002Fsuperheater","superheaters",[68,624,626],{"href":625},"\u002Fglossary\u002Freheater","reheater",[68,628,630],{"href":629},"\u002Fglossary\u002Fair-heater","air heater"," — dislodge ash and soot continuously, supplementing or partially replacing steam ",[68,633,635],{"href":634},"\u002Fglossary\u002Fsteam-sootblower","sootblowers",". The benefit shows up as ",[68,638,640],{"href":639},"\u002Fglossary\u002Fheat-rate","heat rate"," recovery, deferred outages and longer intervals between water washes.",[74,643,133],{"id":132},[79,645,646,650,654,658,664,669],{},[82,647,648],{},[68,649,518],{"href":517},[82,651,652],{},[68,653,532],{"href":531},[82,655,656],{},[68,657,559],{"href":479},[82,659,660],{},[68,661,663],{"href":662},"\u002Fglossary\u002Fwaterwall","Waterwall",[82,665,666],{},[68,667,668],{"href":617},"Economiser",[82,670,671],{},[68,672,327],{"href":127},{"title":152,"searchDepth":153,"depth":153,"links":674},[675,676,677],{"id":492,"depth":153,"text":493},{"id":608,"depth":153,"text":609},{"id":132,"depth":153,"text":133},"A boiler is a closed vessel in which fuel chemical energy is converted to steam by transferring heat into water flowing through tube banks. Industrial and utility boilers serve electricity generation, district heating, process steam, WtE, biomass and pulp-and-paper operations. All of them foul; the only variables are how much and with what.",{},[681,682,683,684,685,618,686,687,336],"pc-boiler","cfb-boiler","bfb-boiler","recovery-boiler","waterwall","superheater","air-heater",{"title":689,"description":690},"Boiler — industrial steam generator types and acoustic-cleaning needs","A boiler is a vessel that converts fuel chemical energy into steam by heating water. Coal-fired, biomass, oil, gas and recovery boilers all foul; sonic horns clean heat-transfer surfaces.",[692,693],{"title":342,"url":343},{"title":694,"url":695},"Babcock & Wilcox — Sootblower and Boiler Cleaning Terminology","https:\u002F\u002Fwww.babcock.com\u002Fhome\u002Fabout\u002Fresources\u002Flearning-center\u002Fsootblower-and-boiler-cleaning-terminology-principles-and-applications","glossary\u002Fboiler","pamAnZGo_UeIedDHhYrfv0nP3GCXkNTGi0a197n4b5Q",1782613743608]