[{"data":1,"prerenderedAt":843},["ShallowReactive",2],{"site-footer-common":3,"glossary:cyclone-dipleg":45,"glossary-related:cyclone-dipleg":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":167,"sources":170,"stem":174,"term":47,"__hash__":175},"glossary\u002Fglossary\u002Fcyclone-dipleg.md","Cyclone dipleg",[49,50],"dipleg","cyclone discharge leg",{"type":52,"value":53,"toc":149},"minimark",[54,79,84,87,103,111,115,122,126],[55,56,57,58,62,63,68,69,73,74,78],"p",{},"The ",[59,60,61],"strong",{},"cyclone dipleg"," is the vertical pipe at the bottom of a ",[64,65,67],"a",{"href":66},"\u002Fglossary\u002Fcyclone-separator","cyclone separator"," that carries separated solids out of the cyclone — either back into a recirculation loop (in ",[64,70,72],{"href":71},"\u002Fglossary\u002Fcfb-boiler","CFB boilers"," and ",[64,75,77],{"href":76},"\u002Fglossary\u002Fpreheater-cyclone","cement preheaters",") or into a discharge hopper.",[80,81,83],"h2",{"id":82},"pluggage-problems","Pluggage problems",[55,85,86],{},"Dipleg pluggage is one of the most operationally disruptive failures in any cyclone system. Once the dipleg blocks:",[88,89,90,94,97,100],"ul",{},[91,92,93],"li",{},"Separated solids back up into the cyclone cone",[91,95,96],{},"Re-entrainment into the gas stream rises",[91,98,99],{},"Collection efficiency collapses",[91,101,102],{},"Process flow imbalance follows immediately",[55,104,105,106,110],{},"A single plugged dipleg can knock out an entire ",[64,107,109],{"href":108},"\u002Fglossary\u002Fmulti-cyclone-multiclone","multi-cyclone"," tube or a major CFB combustor.",[80,112,114],{"id":113},"cleaning","Cleaning",[55,116,117,121],{},[64,118,120],{"href":119},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," mounted at the dipleg keep separated material flowing. On large industrial cyclones, multiple horns are sometimes distributed along the dipleg length to address pluggage at any elevation.",[80,123,125],{"id":124},"related-terms","Related terms",[88,127,128,133,138,144],{},[91,129,130],{},[64,131,132],{"href":66},"Cyclone separator",[91,134,135],{},[64,136,137],{"href":108},"Multi-cyclone \u002F multiclone",[91,139,140],{},[64,141,143],{"href":142},"\u002Fglossary\u002Fbridging","Bridging",[91,145,146],{},[64,147,148],{"href":119},"Sonic horn",{"title":150,"searchDepth":151,"depth":151,"links":152},"",2,[153,154,155],{"id":82,"depth":151,"text":83},{"id":113,"depth":151,"text":114},{"id":124,"depth":151,"text":125},"hrsg-gas-path","The cyclone dipleg is the vertical pipe at the bottom of a cyclone separator that carries separated solids out of the cyclone — either back into a recirculation loop (in CFB boilers and cement preheaters) or into a discharge hopper.","md",{},true,"\u002Fglossary\u002Fcyclone-dipleg",[163,164,165,166],"cyclone-separator","multi-cyclone-multiclone","bridging","sonic-horn",{"title":168,"description":169},"Cyclone dipleg — discharge pipe carrying separated solids out of a cyclone","The cyclone dipleg is the vertical pipe at the bottom of a cyclone separator that carries separated solids back to a hopper or recirculation circuit. Pluggage is a chronic operational issue.",[171],{"title":172,"url":173},"Wikipedia — Cyclonic separation","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FCyclonic_separation","glossary\u002Fcyclone-dipleg","M5divQ_NkwLJVAAZQxTpbV41FvTKt5prwB1smwi2GSM",[177,302,399,614],{"id":178,"title":132,"aliases":179,"body":183,"category":156,"description":289,"extension":158,"meta":290,"navigation":160,"path":66,"relatedTerms":291,"seo":295,"sources":298,"stem":300,"term":132,"__hash__":301},"glossary\u002Fglossary\u002Fcyclone-separator.md",[180,181,182],"cyclone","cyclones","gas cyclone",{"type":52,"value":184,"toc":283},[185,194,198,227,231,251,253,258,260],[55,186,187,188,190,191,193],{},"A ",[59,189,67],{}," removes particulate from a gas stream by centrifugal force: gas enters tangentially at the top of a vertical cylinder, spirals downward, and exits axially at the top through an inner pipe (vortex finder); heavier particles are thrown outward to the wall, slide down the conical bottom, and discharge through the ",[64,192,49],{"href":161}," below.",[80,195,197],{"id":196},"where-cyclones-are-used","Where cyclones are used",[88,199,200,206,212,224],{},[91,201,202,205],{},[64,203,204],{"href":71},"CFB boiler"," primary separators — large-diameter, high-temperature",[91,207,208,211],{},[64,209,210],{"href":76},"Cement preheater cyclones"," — multi-stage gas-to-meal heat exchange",[91,213,214,215,73,219,223],{},"Pre-cleaners ahead of ",[64,216,218],{"href":217},"\u002Fglossary\u002Fbaghouse","baghouses",[64,220,222],{"href":221},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs"," — knock out coarse dust to reduce downstream load",[91,225,226],{},"Process gas separation in chemical and refining duty",[80,228,230],{"id":229},"cyclone-fouling","Cyclone fouling",[88,232,233,239,245],{},[91,234,235,238],{},[59,236,237],{},"Wall build-up"," — dust accretes on the wall and gradually narrows the gas path; flow re-organises and efficiency drops",[91,240,241,244],{},[59,242,243],{},"Dipleg pluggage"," — separated material backs up in the dipleg, eventually re-entraining",[91,246,247,250],{},[59,248,249],{},"Vortex finder fouling"," — alters internal swirl pattern",[80,252,114],{"id":113},[55,254,255,257],{},[64,256,120],{"href":119}," installed on the cyclone shell or dipleg keep wall deposits from consolidating. On cement preheater cyclones particularly, sonic horns are the standard preventive against the coatings that form under alternative-fuel firing.",[80,259,125],{"id":124},[88,261,262,266,270,274,279],{},[91,263,264],{},[64,265,137],{"href":108},[91,267,268],{},[64,269,47],{"href":161},[91,271,272],{},[64,273,204],{"href":71},[91,275,276],{},[64,277,278],{"href":76},"Preheater cyclone",[91,280,281],{},[64,282,148],{"href":119},{"title":150,"searchDepth":151,"depth":151,"links":284},[285,286,287,288],{"id":196,"depth":151,"text":197},{"id":229,"depth":151,"text":230},{"id":113,"depth":151,"text":114},{"id":124,"depth":151,"text":125},"A cyclone separator removes particulate from a gas stream by centrifugal force: gas enters tangentially at the top of a vertical cylinder, spirals downward, and exits axially at the top through an inner pipe (vortex finder); heavier particles are thrown outward to the wall, slide down the conical bottom, and discharge through the dipleg below.",{},[164,292,293,294,166],"cyclone-dipleg","cfb-boiler","preheater-cyclone",{"title":296,"description":297},"Cyclone separator — centrifugal particulate-removal device","A cyclone separator removes particulate from a gas stream by centrifugal force. Wall build-up and re-entrainment from the dipleg are the dominant operational issues.",[299],{"title":172,"url":173},"glossary\u002Fcyclone-separator","q8drrAFN5eVbx6KETEHT-VxRny2DelPTSLsYv0Fj2dU",{"id":303,"title":304,"aliases":305,"body":309,"category":156,"description":388,"extension":158,"meta":389,"navigation":160,"path":108,"relatedTerms":390,"seo":391,"sources":394,"stem":396,"term":397,"__hash__":398},"glossary\u002Fglossary\u002Fmulti-cyclone-multiclone.md","Multi-cyclone (multiclone)",[306,307,308],"multiclone","multicyclone","cyclone bank",{"type":52,"value":310,"toc":383},[311,328,332,361,363,371,373],[55,312,187,313,315,316,318,319,322,323,73,325,327],{},[59,314,109],{}," (or ",[59,317,306],{},") is a parallel array of many small ",[64,320,321],{"href":66},"cyclone separators"," housed in a single enclosure. The arrangement gives higher collection efficiency than a single large cyclone of the same gas-handling capacity, because efficiency improves as cyclone diameter decreases. Multi-cyclones are common as pre-cleaners ahead of ",[64,324,222],{"href":221},[64,326,218],{"href":217}," on coal-fired and biomass plants.",[80,329,331],{"id":330},"operational-issues","Operational issues",[88,333,334,340,346,356],{},[91,335,336,339],{},[59,337,338],{},"Tube-to-tube flow imbalance"," — uneven gas distribution leaves some cyclones overloaded and under-performing",[91,341,342,345],{},[59,343,344],{},"Individual cyclone pluggage"," — a single fouled cyclone bypasses gas to its neighbours and reduces overall collection",[91,347,348,351,352],{},[59,349,350],{},"Common hopper bridging"," below the array — see ",[64,353,355],{"href":354},"\u002Fglossary\u002Fhopper","hopper",[91,357,358,360],{},[59,359,249],{}," in individual tubes",[80,362,114],{"id":113},[55,364,365,367,368,370],{},[64,366,120],{"href":119}," installed on the common housing project sound across the cyclone array. They keep individual cyclone walls free of build-up and prevent the common hopper from ",[64,369,165],{"href":142},".",[80,372,125],{"id":124},[88,374,375,379],{},[91,376,377],{},[64,378,132],{"href":66},[91,380,381],{},[64,382,47],{"href":161},{"title":150,"searchDepth":151,"depth":151,"links":384},[385,386,387],{"id":330,"depth":151,"text":331},{"id":113,"depth":151,"text":114},{"id":124,"depth":151,"text":125},"A multi-cyclone (or multiclone) is a parallel array of many small cyclone separators housed in a single enclosure. The arrangement gives higher collection efficiency than a single large cyclone of the same gas-handling capacity, because efficiency improves as cyclone diameter decreases. Multi-cyclones are common as pre-cleaners ahead of ESPs and baghouses on coal-fired and biomass plants.",{},[163,292],{"title":392,"description":393},"Multi-cyclone (multiclone) — parallel array of small cyclones","A multi-cyclone is a parallel array of many small cyclones in a common housing, used as a pre-cleaner ahead of ESPs and baghouses on coal and biomass plants.",[395],{"title":172,"url":173},"glossary\u002Fmulti-cyclone-multiclone","Multi-cyclone","7d6Ix4ItZdlgIpJDsebu9-hGxGcOvq5BSjD0MKZoPlk",{"id":400,"title":143,"aliases":401,"body":406,"category":595,"description":596,"extension":158,"meta":597,"navigation":160,"path":142,"relatedTerms":598,"seo":601,"sources":604,"stem":611,"term":612,"__hash__":613},"glossary\u002Fglossary\u002Fbridging.md",[402,403,404,405],"arching","arch formation","hopper bridging","silo bridging",{"type":52,"value":407,"toc":589},[408,427,431,434,456,460,474,478,559,561],[55,409,410,412,413,416,417,419,420,416,422,426],{},[59,411,143],{}," (also ",[414,415,402],"em",{}," or ",[414,418,403],{},") is the formation of a stable mechanical arch of bulk-solid material above the discharge outlet of a ",[64,421,355],{"href":354},[64,423,425],{"href":424},"\u002Fglossary\u002Fsilo","silo",". Once a bridge forms, no material flows out of the outlet even though the vessel above is full. Bridging is the universal failure mode of bulk-solids storage.",[80,428,430],{"id":429},"how-a-bridge-forms","How a bridge forms",[55,432,433],{},"Cohesive forces between particles — moisture films, electrostatic charge, chemical bonding — combine with the converging-flow geometry to lock particles into an arch shape. The arch is self-supporting against the load above. Cohesion increases with:",[88,435,436,444,447,450,453],{},[91,437,438,439,443],{},"Fine particle size (especially Geldart-C powders — see ",[64,440,442],{"href":441},"\u002Fglossary\u002Fgeldart-classification","Geldart classification",")",[91,445,446],{},"Moisture",[91,448,449],{},"Hygroscopic chemistry (urea, ammonium nitrate, lime)",[91,451,452],{},"Long residence time (consolidation under sustained load)",[91,454,455],{},"Temperature cycling",[80,457,459],{"id":458},"diagnosing-a-bridge","Diagnosing a bridge",[88,461,462,465,468,471],{},[91,463,464],{},"Outlet flow stops while the level above remains high",[91,466,467],{},"Mass-flow indicators report no movement",[91,469,470],{},"A simple tap on the hopper outside the discharge cone produces a hollow sound",[91,472,473],{},"Borescope inspection from the inlet shows the arch directly",[80,475,477],{"id":476},"remedies","Remedies",[479,480,481,494],"table",{},[482,483,484],"thead",{},[485,486,487,491],"tr",{},[488,489,490],"th",{},"Technique",[488,492,493],{},"Notes",[495,496,497,507,518,529,540,551],"tbody",{},[485,498,499,504],{},[500,501,502],"td",{},[64,503,148],{"href":119},[500,505,506],{},"Continuous prevention; non-contact; minimal infrastructure",[485,508,509,515],{},[500,510,511],{},[64,512,514],{"href":513},"\u002Fglossary\u002Fair-cannon-air-blaster","Air cannon",[500,516,517],{},"High-intensity periodic; effective on hard bridges; structural stress",[485,519,520,526],{},[500,521,522],{},[64,523,525],{"href":524},"\u002Fglossary\u002Fbin-vibrator","Bin vibrator",[500,527,528],{},"Continuous vibration; can compact powder further if poorly sized",[485,530,531,537],{},[500,532,533],{},[64,534,536],{"href":535},"\u002Fglossary\u002Fwhip-hammer","Whip hammer",[500,538,539],{},"Manual; legacy; HSE concerns",[485,541,542,548],{},[500,543,544],{},[64,545,547],{"href":546},"\u002Fglossary\u002Ffluidisation-pad-aeration-pad","Fluidisation pad",[500,549,550],{},"Aerates the lower vessel; not suitable for wet material",[485,552,553,556],{},[500,554,555],{},"Mechanical screw extractor",[500,557,558],{},"Bypasses the bridge entirely; high capex",[80,560,125],{"id":124},[88,562,563,568,573,579,585],{},[91,564,565],{},[64,566,567],{"href":354},"Hopper",[91,569,570],{},[64,571,572],{"href":424},"Silo",[91,574,575],{},[64,576,578],{"href":577},"\u002Fglossary\u002Frat-holing","Rat-holing",[91,580,581],{},[64,582,584],{"href":583},"\u002Fglossary\u002Fmass-flow-vs-funnel-flow","Mass flow vs funnel flow",[91,586,587],{},[64,588,148],{"href":119},{"title":150,"searchDepth":151,"depth":151,"links":590},[591,592,593,594],{"id":429,"depth":151,"text":430},{"id":458,"depth":151,"text":459},{"id":476,"depth":151,"text":477},{"id":124,"depth":151,"text":125},"hoppers-silos","Bridging (also arching or arch formation) is the formation of a stable mechanical arch of bulk-solid material above the discharge outlet of a hopper or silo. Once a bridge forms, no material flows out of the outlet even though the vessel above is full. Bridging is the universal failure mode of bulk-solids storage.",{},[355,425,599,600,166],"rat-holing","mass-flow-vs-funnel-flow",{"title":602,"description":603},"Bridging — stable arch above the discharge of a hopper or silo","Bridging (also arching) is the formation of a stable arch of bulk solids above the discharge outlet of a hopper or silo, stopping material flow. The universal failure mode of bulk-solids storage.",[605,608],{"title":606,"url":607},"Powder & Bulk Solids — Preventing Rat-Holing and Bridging in Powder Silos","https:\u002F\u002Fsgsystemsglobal.com\u002Fglossary\u002Fsilo-rat-holing-and-bridging\u002F",{"title":609,"url":610},"Accendo Reliability — Bridging in Silos and Hoppers","https:\u002F\u002Faccendoreliability.com\u002Fbridging-silos-hoppers\u002F","glossary\u002Fbridging","Bridging (bulk-solids)","qG-iJwvR3z5_NliCxfeui3lEL9wxjVY3kU3rO9JWn8g",{"id":615,"title":148,"aliases":616,"body":620,"category":818,"description":819,"extension":158,"meta":820,"navigation":160,"path":119,"relatedTerms":821,"seo":828,"sources":831,"stem":841,"term":148,"__hash__":842},"glossary\u002Fglossary\u002Fsonic-horn.md",[617,618,619],"sonic horns","sonic cleaning horn","industrial sonic horn",{"type":52,"value":621,"toc":811},[622,650,654,662,666,728,732,767,771,779,781],[55,623,187,624,627,628,632,633,635,636,635,639,635,643,73,647,370],{},[59,625,626],{},"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 ",[64,629,631],{"href":630},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the default specification for cleaning ",[64,634,222],{"href":221},", ",[64,637,218],{"href":638},"\u002Fglossary\u002Ffabric-filter",[64,640,642],{"href":641},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[64,644,646],{"href":645},"\u002Fglossary\u002Fsuperheater","boiler heat-transfer surfaces",[64,648,649],{"href":354},"hoppers and silos",[80,651,653],{"id":652},"how-a-sonic-horn-works","How a sonic horn works",[55,655,656,657,661],{},"Compressed plant air admitted through a ",[64,658,660],{"href":659},"\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.",[80,663,665],{"id":664},"key-parameters","Key parameters",[479,667,668,678],{},[482,669,670],{},[485,671,672,675],{},[488,673,674],{},"Parameter",[488,676,677],{},"Typical range",[495,679,680,688,696,704,712,720],{},[485,681,682,685],{},[500,683,684],{},"Fundamental frequency",[500,686,687],{},"60–400 Hz",[485,689,690,693],{},[500,691,692],{},"Sound pressure level",[500,694,695],{},"140–180 dB",[485,697,698,701],{},[500,699,700],{},"Compressed-air consumption",[500,702,703],{},"8–14 Nm³\u002Fmin at 4–7 bar",[485,705,706,709],{},[500,707,708],{},"Operating temperature (with appropriate materials)",[500,710,711],{},"−40 °C to +500 °C",[485,713,714,717],{},[500,715,716],{},"Firing cycle",[500,718,719],{},"5–15 s burst, repeated every 3–15 minutes",[485,721,722,725],{},[500,723,724],{},"Mass",[500,726,727],{},"15–60 kg depending on horn size",[80,729,731],{"id":730},"frequency-selection","Frequency selection",[55,733,734,735,635,738,742,743,635,747,750,751,635,754,758,759,73,763,370],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[64,736,737],{"href":76},"preheater cyclones",[64,739,741],{"href":740},"\u002Fglossary\u002Frecovery-boiler","recovery-boiler superheaters",", large ",[64,744,746],{"href":745},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[64,748,749],{"href":424},"silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[64,752,753],{"href":638},"fabric-filter compartments",[64,755,757],{"href":756},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[64,760,762],{"href":761},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[64,764,766],{"href":765},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[80,768,770],{"id":769},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[55,772,773,774,778],{},"Sonic horns are increasingly specified alongside or in place of ",[64,775,777],{"href":776},"\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.",[80,780,125],{"id":124},[88,782,783,788,794,800,806],{},[91,784,785],{},[64,786,787],{"href":630},"Acoustic cleaner",[91,789,790],{},[64,791,793],{"href":792},"\u002Fglossary\u002Fsonic-sootblower","Sonic sootblower",[91,795,796],{},[64,797,799],{"href":798},"\u002Fglossary\u002Fbell-horn","Bell horn",[91,801,802],{},[64,803,805],{"href":804},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[91,807,808],{},[64,809,810],{"href":761},"Low-frequency acoustic cleaner",{"title":150,"searchDepth":151,"depth":151,"links":812},[813,814,815,816,817],{"id":652,"depth":151,"text":653},{"id":664,"depth":151,"text":665},{"id":730,"depth":151,"text":731},{"id":769,"depth":151,"text":770},{"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.",{},[822,823,824,825,826,827],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn","low-frequency-acoustic-cleaner",{"title":829,"description":830},"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.",[832,835,838],{"title":833,"url":834},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":836,"url":837},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":839,"url":840},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613741979]