[{"data":1,"prerenderedAt":781},["ShallowReactive",2],{"site-footer-common":3,"glossary:smelt-dissolving-tank":45,"glossary-related:smelt-dissolving-tank":158},{"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":139,"description":140,"extension":141,"meta":142,"navigation":143,"path":144,"relatedTerms":145,"seo":148,"sources":151,"stem":155,"term":156,"__hash__":157},"glossary\u002Fglossary\u002Fsmelt-dissolving-tank.md","Smelt dissolving tank (SDT)",[49,50,51],"SDT","smelt dissolving tanks","dissolving tank",{"type":53,"value":54,"toc":132},"minimark",[55,85,90,93,97,104,108],[56,57,58,59,63,64,69,70,74,75,79,80,84],"p",{},"A ",[60,61,62],"strong",{},"smelt dissolving tank (SDT)"," receives molten ",[65,66,68],"a",{"href":67},"\u002Fglossary\u002Fsmelt","smelt"," discharged from the ",[65,71,73],{"href":72},"\u002Fglossary\u002Frecovery-boiler","recovery boiler"," bottom and dissolves it into weak wash water to form ",[76,77,78],"em",{},"green liquor"," (the alkaline solution sent on to the ",[65,81,83],{"href":82},"\u002Fglossary\u002Frecausticising","recausticising"," plant). Internal agitators and shatter jets break the smelt stream into small droplets to control the otherwise-violent quench reaction.",[86,87,89],"h2",{"id":88},"sdt-vent-stack","SDT vent stack",[56,91,92],{},"The dissolution is exothermic and steamy. SDT vent gas carries sodium-rich fume that condenses on the vent stack walls as a fine sticky deposit. Over time the build-up narrows the stack and disrupts vent flow.",[86,94,96],{"id":95},"sonic-horn-duty","Sonic-horn duty",[56,98,99,103],{},[65,100,102],{"href":101},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," mounted on the SDT vent stack keep the sodium-fume deposit from consolidating, preventing the periodic outages otherwise needed for vent cleaning.",[86,105,107],{"id":106},"related-terms","Related terms",[109,110,111,117,122,127],"ul",{},[112,113,114],"li",{},[65,115,116],{"href":67},"Smelt",[112,118,119],{},[65,120,121],{"href":72},"Recovery boiler",[112,123,124],{},[65,125,126],{"href":82},"Recausticising",[112,128,129],{},[65,130,131],{"href":101},"Sonic horn",{"title":133,"searchDepth":134,"depth":134,"links":135},"",2,[136,137,138],{"id":88,"depth":134,"text":89},{"id":95,"depth":134,"text":96},{"id":106,"depth":134,"text":107},"pulp-paper","A smelt dissolving tank (SDT) receives molten smelt discharged from the recovery boiler bottom and dissolves it into weak wash water to form green liquor (the alkaline solution sent on to the recausticising plant). Internal agitators and shatter jets break the smelt stream into small droplets to control the otherwise-violent quench reaction.","md",{},true,"\u002Fglossary\u002Fsmelt-dissolving-tank",[68,146,83,147],"recovery-boiler","sonic-horn",{"title":149,"description":150},"Smelt dissolving tank (SDT) — quench tank that converts smelt to green liquor","An SDT receives molten smelt from the recovery boiler and dissolves it into weak wash to form green liquor. The vent stack accumulates sodium fume; sonic horns prevent stack-line plugging.",[152],{"title":153,"url":154},"Wikipedia — Recovery boiler","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FRecovery_boiler","glossary\u002Fsmelt-dissolving-tank","Smelt dissolving tank","FWvHPD8ZbLOg2d-uphcTK_-LT70su9VULlLehqK5XtY",[159,260,439,543],{"id":160,"title":116,"aliases":161,"body":164,"category":139,"description":247,"extension":141,"meta":248,"navigation":143,"path":67,"relatedTerms":249,"seo":252,"sources":255,"stem":257,"term":258,"__hash__":259},"glossary\u002Fglossary\u002Fsmelt.md",[162,163],"kraft smelt","recovery boiler smelt",{"type":53,"value":165,"toc":242},[166,178,182,208,212,220,222],[56,167,168,170,171,174,175,177],{},[60,169,116],{}," is the molten inorganic phase recovered from the bottom of a ",[65,172,173],{"href":72},"kraft recovery boiler",". It consists primarily of sodium carbonate (Na₂CO₃) and sodium sulphide (Na₂S) at ~800 °C and is the chemical-recovery product of black-liquor combustion. Smelt is discharged from the boiler bottom through spouts into a ",[65,176,62],{"href":144}," where it is quenched into water to form green liquor.",[86,179,181],{"id":180},"smelt-carry-over","Smelt carry-over",[56,183,184,185,189,190,194,195,199,200,204,205,207],{},"A portion of the inorganic burden — sodium sulphate, sodium chloride, fume — does not settle as smelt but is entrained upward in the flue gas as ",[65,186,188],{"href":187},"\u002Fglossary\u002Fcarry-over","carry-over",". This carry-over is what fouls the ",[65,191,193],{"href":192},"\u002Fglossary\u002Fgenerating-bank","generating bank",", ",[65,196,198],{"href":197},"\u002Fglossary\u002Fsuperheater","superheater"," and ",[65,201,203],{"href":202},"\u002Fglossary\u002Feconomiser","economiser",", and is the target of ",[65,206,147],{"href":101}," cleaning.",[86,209,211],{"id":210},"safety","Safety",[56,213,214,215,219],{},"Molten smelt contact with water is the leading documented cause of catastrophic recovery-boiler explosions. ",[65,216,218],{"href":217},"\u002Fglossary\u002Fblrbac","BLRBAC"," Recommended Good Practices govern smelt-handling procedures and any change to cleaning systems — including acoustic-horn additions — requires review against the smelt-water-explosion protocols.",[86,221,107],{"id":106},[109,223,224,228,234,238],{},[112,225,226],{},[65,227,121],{"href":72},[112,229,230],{},[65,231,233],{"href":232},"\u002Fglossary\u002Fblack-liquor","Black liquor",[112,235,236],{},[65,237,47],{"href":144},[112,239,240],{},[65,241,126],{"href":82},{"title":133,"searchDepth":134,"depth":134,"links":243},[244,245,246],{"id":180,"depth":134,"text":181},{"id":210,"depth":134,"text":211},{"id":106,"depth":134,"text":107},"Smelt is the molten inorganic phase recovered from the bottom of a kraft recovery boiler. It consists primarily of sodium carbonate (Na₂CO₃) and sodium sulphide (Na₂S) at ~800 °C and is the chemical-recovery product of black-liquor combustion. Smelt is discharged from the boiler bottom through spouts into a smelt dissolving tank (SDT) where it is quenched into water to form green liquor.",{},[146,250,251,83],"black-liquor","smelt-dissolving-tank",{"title":253,"description":254},"Smelt — molten inorganic recovered from kraft recovery boilers","Smelt is the molten sodium carbonate and sulphide mixture that accumulates in the bottom of a kraft recovery boiler. It is dissolved into green liquor and recausticised to pulping reagent.",[256],{"title":153,"url":154},"glossary\u002Fsmelt","Smelt (recovery boiler)","5L_O2eD74h-akmEsbjqyXkvnBQBYbTR5ZDvCt6_gCD4",{"id":261,"title":121,"aliases":262,"body":265,"category":423,"description":424,"extension":141,"meta":425,"navigation":143,"path":72,"relatedTerms":426,"seo":429,"sources":432,"stem":437,"term":121,"__hash__":438},"glossary\u002Fglossary\u002Frecovery-boiler.md",[173,263,264],"black-liquor recovery boiler","BLRB",{"type":53,"value":266,"toc":417},[267,280,284,291,322,333,337,366,368,374,376],[56,268,58,269,271,272,194,274,276,277,279],{},[60,270,73],{}," (also ",[76,273,173],{},[76,275,263],{},", or ",[76,278,264],{},") is a unique industrial boiler at the centre of every kraft pulp mill. It burns concentrated black liquor — the spent cooking-chemicals stream — to generate steam, electrical power and to recover the sodium and sulphur compounds that re-enter the pulping cycle as smelt. Recovery boilers are large, complex, expensive and irreplaceable to mill operation.",[86,281,283],{"id":282},"the-iconic-sonic-horn-application","The iconic sonic-horn application",[56,285,286,287,290],{},"Recovery boilers are the iconic application for ",[65,288,289],{"href":101},"sonic horns",". Three features combine to make them so:",[109,292,293,305,316],{},[112,294,295,298,299,199,301,304],{},[60,296,297],{},"Sticky, alkali-rich ash"," — sodium-sulphate carry-over deposits aggressively on ",[65,300,198],{"href":197},[65,302,303],{"href":192},"generating-bank"," tubes",[112,306,307,310,311,315],{},[60,308,309],{},"Long-run-time targets"," — mills target 12–18 months between ",[65,312,314],{"href":313},"\u002Fglossary\u002Fchill-and-blow","chill-and-blow"," wash cycles, and every extra week of run time is worth tens of thousands of dollars",[112,317,318,321],{},[60,319,320],{},"Deep cavities"," — the superheater bundles are tall and bafflingly inaccessible to short-throw cleaning",[56,323,324,325,327,328,332],{},"Both conventional ",[65,326,289],{"href":101}," at 60–125 Hz and ",[65,329,331],{"href":330},"\u002Fglossary\u002Finfrasonic-cleaner","infrasonic cleaners"," below 30 Hz are deployed on recovery boilers. Major OEM aftermarket teams (ANDRITZ, Valmet, Babcock & Wilcox Vølund) all integrate acoustic cleaning into their service portfolios.",[86,334,336],{"id":335},"other-applications-inside-the-recovery-island","Other applications inside the recovery island",[109,338,339,345,351,361],{},[112,340,341,344],{},[60,342,343],{},"ESP hoppers"," — sodium-rich fly-ash bridging",[112,346,347,350],{},[60,348,349],{},"Economiser pluggage"," — salt-cake build-up on tube bundles",[112,352,353,356,357],{},[60,354,355],{},"Lime kiln preheater"," — see ",[65,358,360],{"href":359},"\u002Fglossary\u002Flime-kiln","lime kiln",[112,362,363,365],{},[60,364,156],{}," vent stack — sodium-fume build-up",[86,367,211],{"id":210},[56,369,370,371,373],{},"Recovery-boiler operations are governed by ",[65,372,218],{"href":217}," Recommended Good Practices. Any cleaning intervention — including acoustic — is reviewed against BLRBAC water-side-incident and emergency-shutdown protocols.",[86,375,107],{"id":106},[109,377,378,384,389,394,399,404,408,412],{},[112,379,380],{},[65,381,383],{"href":382},"\u002Fglossary\u002Fboiler","Boiler",[112,385,386],{},[65,387,388],{"href":192},"Generating bank",[112,390,391],{},[65,392,393],{"href":197},"Superheater",[112,395,396],{},[65,397,398],{"href":202},"Economiser",[112,400,401],{},[65,402,403],{"href":313},"Chill-and-blow",[112,405,406],{},[65,407,218],{"href":217},[112,409,410],{},[65,411,131],{"href":101},[112,413,414],{},[65,415,416],{"href":330},"Infrasonic cleaner",{"title":133,"searchDepth":134,"depth":134,"links":418},[419,420,421,422],{"id":282,"depth":134,"text":283},{"id":335,"depth":134,"text":336},{"id":210,"depth":134,"text":211},{"id":106,"depth":134,"text":107},"boiler","A recovery boiler (also kraft recovery boiler, black-liquor recovery boiler, or BLRB) is a unique industrial boiler at the centre of every kraft pulp mill. It burns concentrated black liquor — the spent cooking-chemicals stream — to generate steam, electrical power and to recover the sodium and sulphur compounds that re-enter the pulping cycle as smelt. Recovery boilers are large, complex, expensive and irreplaceable to mill operation.",{},[423,303,198,203,314,427,147,428],"blrbac","infrasonic-cleaner",{"title":430,"description":431},"Recovery boiler — kraft pulp mill steam-and-chemicals plant","A recovery boiler burns kraft black liquor to generate steam, electrical power and recovered pulping chemicals. Iconic application for sonic horns on superheater cleaning.",[433,434],{"title":153,"url":154},{"title":435,"url":436},"BLRBAC — Recovery Boilers in Service","https:\u002F\u002Fblrbac.net\u002Frecovery-boilers-in-service\u002F","glossary\u002Frecovery-boiler","mXzBGZ7hSMEgl58wabmRAArKMR06mHldZvB1HJLRt0g",{"id":440,"title":126,"aliases":441,"body":446,"category":139,"description":530,"extension":141,"meta":531,"navigation":143,"path":82,"relatedTerms":532,"seo":534,"sources":537,"stem":541,"term":126,"__hash__":542},"glossary\u002Fglossary\u002Frecausticising.md",[442,443,444,445],"recausticizing","causticising","causticizing","causticising plant",{"type":53,"value":447,"toc":526},[448,462,466,469,500,505,507],[56,449,450,271,452,454,455,458,459,461],{},[60,451,126],{},[76,453,442],{}," in US spelling) is the chemical step that regenerates kraft cooking liquor by reacting green liquor (sodium carbonate from the ",[65,456,457],{"href":144},"smelt dissolving tank",") with burnt lime (CaO from the ",[65,460,360],{"href":359},") to produce white liquor (sodium hydroxide + sodium sulphide) and lime mud (CaCO₃). The white liquor is returned to the digester for pulping; the lime mud goes back to the lime kiln for re-calcination.",[86,463,465],{"id":464},"the-closed-chemical-cycle","The closed chemical cycle",[56,467,468],{},"Kraft recovery is a closed loop:",[470,471,472,478,483,491,494,497],"ol",{},[112,473,474,475],{},"Pulping consumes white liquor; produces ",[65,476,477],{"href":232},"black liquor",[112,479,480,481],{},"Black liquor concentrated in evaporators, burned in the ",[65,482,73],{"href":72},[112,484,485,486,488,489],{},"Recovery boiler produces ",[65,487,68],{"href":67},", which dissolves into green liquor in the ",[65,490,49],{"href":144},[112,492,493],{},"Recausticising converts green liquor + burnt lime → white liquor + lime mud",[112,495,496],{},"Lime kiln calcines lime mud → burnt lime",[112,498,499],{},"Burnt lime returns to recausticising",[56,501,502,504],{},[65,503,102],{"href":101}," appear at several points around this loop, principally on the recovery boiler, SDT vent stack, lime-kiln preheater and lime-kiln ESP hopper.",[86,506,107],{"id":106},[109,508,509,513,517,521],{},[112,510,511],{},[65,512,233],{"href":232},[112,514,515],{},[65,516,116],{"href":67},[112,518,519],{},[65,520,47],{"href":144},[112,522,523],{},[65,524,525],{"href":359},"Lime kiln",{"title":133,"searchDepth":134,"depth":134,"links":527},[528,529],{"id":464,"depth":134,"text":465},{"id":106,"depth":134,"text":107},"Recausticising (also recausticizing in US spelling) is the chemical step that regenerates kraft cooking liquor by reacting green liquor (sodium carbonate from the smelt dissolving tank) with burnt lime (CaO from the lime kiln) to produce white liquor (sodium hydroxide + sodium sulphide) and lime mud (CaCO₃). The white liquor is returned to the digester for pulping; the lime mud goes back to the lime kiln for re-calcination.",{},[250,68,251,533],"lime-kiln",{"title":535,"description":536},"Recausticising — regenerating kraft cooking liquor from green liquor and lime","Recausticising converts green liquor (sodium carbonate) and burnt lime back into white liquor (sodium hydroxide and sulphide) for re-use in kraft pulping.",[538],{"title":539,"url":540},"Wikipedia — Kraft process","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FKraft_process","glossary\u002Frecausticising","JpSdvS8pBLnO_IYyDt3rZMJhESv-c65so_nB-QqIwiI",{"id":544,"title":131,"aliases":545,"body":548,"category":756,"description":757,"extension":141,"meta":758,"navigation":143,"path":101,"relatedTerms":759,"seo":766,"sources":769,"stem":779,"term":131,"__hash__":780},"glossary\u002Fglossary\u002Fsonic-horn.md",[289,546,547],"sonic cleaning horn","industrial sonic horn",{"type":53,"value":549,"toc":749},[550,581,585,593,597,665,669,705,709,717,719],[56,551,58,552,555,556,560,561,194,565,194,569,194,573,199,576,580],{},[60,553,554],{},"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 ",[65,557,559],{"href":558},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the default specification for cleaning ",[65,562,564],{"href":563},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",[65,566,568],{"href":567},"\u002Fglossary\u002Ffabric-filter","baghouses",[65,570,572],{"href":571},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[65,574,575],{"href":197},"boiler heat-transfer surfaces",[65,577,579],{"href":578},"\u002Fglossary\u002Fhopper","hoppers and silos",".",[86,582,584],{"id":583},"how-a-sonic-horn-works","How a sonic horn works",[56,586,587,588,592],{},"Compressed plant air admitted through a ",[65,589,591],{"href":590},"\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.",[86,594,596],{"id":595},"key-parameters","Key parameters",[598,599,600,613],"table",{},[601,602,603],"thead",{},[604,605,606,610],"tr",{},[607,608,609],"th",{},"Parameter",[607,611,612],{},"Typical range",[614,615,616,625,633,641,649,657],"tbody",{},[604,617,618,622],{},[619,620,621],"td",{},"Fundamental frequency",[619,623,624],{},"60–400 Hz",[604,626,627,630],{},[619,628,629],{},"Sound pressure level",[619,631,632],{},"140–180 dB",[604,634,635,638],{},[619,636,637],{},"Compressed-air consumption",[619,639,640],{},"8–14 Nm³\u002Fmin at 4–7 bar",[604,642,643,646],{},[619,644,645],{},"Operating temperature (with appropriate materials)",[619,647,648],{},"−40 °C to +500 °C",[604,650,651,654],{},[619,652,653],{},"Firing cycle",[619,655,656],{},"5–15 s burst, repeated every 3–15 minutes",[604,658,659,662],{},[619,660,661],{},"Mass",[619,663,664],{},"15–60 kg depending on horn size",[86,666,668],{"id":667},"frequency-selection","Frequency selection",[56,670,671,672,194,676,679,680,194,684,688,689,194,692,696,697,199,701,580],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[65,673,675],{"href":674},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[65,677,678],{"href":72},"recovery-boiler superheaters",", large ",[65,681,683],{"href":682},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[65,685,687],{"href":686},"\u002Fglossary\u002Fsilo","silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[65,690,691],{"href":567},"fabric-filter compartments",[65,693,695],{"href":694},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[65,698,700],{"href":699},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[65,702,704],{"href":703},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[86,706,708],{"id":707},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[56,710,711,712,716],{},"Sonic horns are increasingly specified alongside or in place of ",[65,713,715],{"href":714},"\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.",[86,718,107],{"id":106},[109,720,721,726,732,738,744],{},[112,722,723],{},[65,724,725],{"href":558},"Acoustic cleaner",[112,727,728],{},[65,729,731],{"href":730},"\u002Fglossary\u002Fsonic-sootblower","Sonic sootblower",[112,733,734],{},[65,735,737],{"href":736},"\u002Fglossary\u002Fbell-horn","Bell horn",[112,739,740],{},[65,741,743],{"href":742},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[112,745,746],{},[65,747,748],{"href":699},"Low-frequency acoustic cleaner",{"title":133,"searchDepth":134,"depth":134,"links":750},[751,752,753,754,755],{"id":583,"depth":134,"text":584},{"id":595,"depth":134,"text":596},{"id":667,"depth":134,"text":668},{"id":707,"depth":134,"text":708},{"id":106,"depth":134,"text":107},"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.",{},[760,761,762,763,764,765],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn","low-frequency-acoustic-cleaner",{"title":767,"description":768},"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.",[770,773,776],{"title":771,"url":772},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":774,"url":775},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":777,"url":778},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613749001]