[{"data":1,"prerenderedAt":605},["ShallowReactive",2],{"site-footer-common":3,"glossary:vertical-roller-mill":45,"glossary-related:vertical-roller-mill":175},{"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":165,"sources":168,"stem":172,"term":173,"__hash__":174},"glossary\u002Fglossary\u002Fvertical-roller-mill.md","Vertical roller mill (VRM)",[49,50],"VRM","vertical roller mills",{"type":52,"value":53,"toc":148},"minimark",[54,69,74,93,97,100,104,124,131,135],[55,56,57,58,62,63,68],"p",{},"A ",[59,60,61],"strong",{},"vertical roller mill (VRM)"," grinds material between rotating tyres and a static grinding table inside a single vertical housing. Hot gas from the ",[64,65,67],"a",{"href":66},"\u002Fglossary\u002Fpreheater-tower","preheater tower"," or kiln exhaust dries the material during grinding and entrains the ground product upward to a classifier that separates fines for collection.",[70,71,73],"h2",{"id":72},"why-vrm-displaces-ball-mills","Why VRM displaces ball mills",[75,76,77,81,84,87,90],"ul",{},[78,79,80],"li",{},"30–40% lower specific energy consumption",[78,82,83],{},"Smaller footprint",[78,85,86],{},"Built-in drying of damp raw materials",[78,88,89],{},"Easier integration with kiln-exhaust heat",[78,91,92],{},"Lower maintenance for the same throughput",[70,94,96],{"id":95},"where-ball-mills-persist","Where ball mills persist",[55,98,99],{},"Cement grinding (clinker + gypsum) is still partly handled by ball mills because the very fine particle-size distribution required is harder to achieve with a VRM. Many plants run a hybrid: VRM for raw and coal, ball mill or VRM for cement.",[70,101,103],{"id":102},"fouling-on-vrms","Fouling on VRMs",[75,105,106,112,118],{},[78,107,108,111],{},[59,109,110],{},"Hot-gas duct fouling"," between preheater and VRM inlet",[78,113,114,117],{},[59,115,116],{},"Classifier fouling"," disrupting the fines separation",[78,119,120,123],{},[59,121,122],{},"Discharge-chute coating"," during high-moisture periods",[55,125,126,130],{},[64,127,129],{"href":128},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," on the inlet ducting and discharge chute keep the gas and material paths free of build-up.",[70,132,134],{"id":133},"related-terms","Related terms",[75,136,137,143],{},[78,138,139],{},[64,140,142],{"href":141},"\u002Fglossary\u002Fraw-mill-cement-mill-coal-mill","Raw mill \u002F cement mill \u002F coal mill",[78,144,145],{},[64,146,147],{"href":128},"Sonic horn",{"title":149,"searchDepth":150,"depth":150,"links":151},"",2,[152,153,154,155],{"id":72,"depth":150,"text":73},{"id":95,"depth":150,"text":96},{"id":102,"depth":150,"text":103},{"id":133,"depth":150,"text":134},"cement","A vertical roller mill (VRM) grinds material between rotating tyres and a static grinding table inside a single vertical housing. Hot gas from the preheater tower or kiln exhaust dries the material during grinding and entrains the ground product upward to a classifier that separates fines for collection.","md",{},true,"\u002Fglossary\u002Fvertical-roller-mill",[163,164],"raw-mill-cement-mill-coal-mill","sonic-horn",{"title":166,"description":167},"Vertical roller mill (VRM) — modern cement and coal grinding technology","A vertical roller mill grinds material between rotating tyres and a static table inside a single vertical housing. 30–40% lower energy than ball mills; dominant for raw and coal grinding.",[169],{"title":170,"url":171},"Wikipedia — Cement mill","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FCement_mill","glossary\u002Fvertical-roller-mill","Vertical roller mill","_cKAuzt0mb6rPiaiJPm2j7Z0d-9eNgJ3za8QgyG9YnQ",[176,368],{"id":177,"title":142,"aliases":178,"body":183,"category":156,"description":187,"extension":158,"meta":355,"navigation":160,"path":141,"relatedTerms":356,"seo":360,"sources":363,"stem":365,"term":366,"__hash__":367},"glossary\u002Fglossary\u002Fraw-mill-cement-mill-coal-mill.md",[179,180,181,182],"raw mill","cement mill","coal mill","ball mill (cement)",{"type":52,"value":184,"toc":350},[185,188,273,277,280,295,299,325,330,332],[55,186,187],{},"Cement plants run three principal mills, each grinding a different material:",[189,190,191,210],"table",{},[192,193,194],"thead",{},[195,196,197,201,204,207],"tr",{},[198,199,200],"th",{},"Mill",[198,202,203],{},"Input",[198,205,206],{},"Output",[198,208,209],{},"Destination",[211,212,213,233,253],"tbody",{},[195,214,215,221,224,227],{},[216,217,218],"td",{},[59,219,220],{},"Raw mill",[216,222,223],{},"Limestone + clay + sand + iron",[216,225,226],{},"Raw meal (cement-fineness powder)",[216,228,229,232],{},[64,230,231],{"href":66},"Preheater tower"," feed",[195,234,235,240,247,250],{},[216,236,237],{},[59,238,239],{},"Cement mill",[216,241,242,246],{},[64,243,245],{"href":244},"\u002Fglossary\u002Fclinker","Clinker"," + gypsum + additives",[216,248,249],{},"Finished cement powder",[216,251,252],{},"Bagging \u002F despatch",[195,254,255,260,263,266],{},[216,256,257],{},[59,258,259],{},"Coal mill",[216,261,262],{},"Raw coal or petcoke",[216,264,265],{},"Pulverised fuel",[216,267,268,272],{},[64,269,271],{"href":270},"\u002Fglossary\u002Frotary-kiln","Rotary kiln"," main burner",[70,274,276],{"id":275},"mill-technology","Mill technology",[55,278,279],{},"Two technologies dominate:",[75,281,282,288],{},[78,283,284,287],{},[59,285,286],{},"Ball mill"," — rotating cylinder containing steel balls; mature, robust, energy-intensive",[78,289,290,294],{},[59,291,292],{},[64,293,47],{"href":161}," — modern preferred design; 30–40% lower energy use; dominant for raw and coal mills",[70,296,298],{"id":297},"mill-related-fouling","Mill-related fouling",[75,300,301,307,313,319],{},[78,302,303,306],{},[59,304,305],{},"Mill duct fouling"," — fine powder coats hot-gas ducts, reducing flow",[78,308,309,312],{},[59,310,311],{},"Coarse-fines bridging"," in mill discharge silos",[78,314,315,318],{},[59,316,317],{},"Sticky cement coating"," in cement-mill ducting during high-humidity periods",[78,320,321,324],{},[59,322,323],{},"Coal-mill blade and classifier fouling"," — fire hazard",[55,326,327,329],{},[64,328,129],{"href":128}," on mill exhaust ducting and discharge silos prevent the build-up that disrupts mill throughput.",[70,331,134],{"id":133},[75,333,334,338,342,346],{},[78,335,336],{},[64,337,47],{"href":161},[78,339,340],{},[64,341,245],{"href":244},[78,343,344],{},[64,345,231],{"href":66},[78,347,348],{},[64,349,147],{"href":128},{"title":149,"searchDepth":150,"depth":150,"links":351},[352,353,354],{"id":275,"depth":150,"text":276},{"id":297,"depth":150,"text":298},{"id":133,"depth":150,"text":134},{},[357,358,359,164],"vertical-roller-mill","clinker","preheater-tower",{"title":361,"description":362},"Raw mill, cement mill and coal mill — the three principal mills in a cement plant","Cement plants run three principal mills: raw mill (limestone+clay→raw meal), cement mill (clinker→cement), coal mill (raw coal→pulverised fuel for the kiln burner).",[364],{"title":170,"url":171},"glossary\u002Fraw-mill-cement-mill-coal-mill","Raw mill, cement mill and coal mill","iJ4kLnTA_LvBQqMbpIg6l2W4nYjA-XKyyHSgPxOI7Ww",{"id":369,"title":147,"aliases":370,"body":374,"category":580,"description":581,"extension":158,"meta":582,"navigation":160,"path":128,"relatedTerms":583,"seo":590,"sources":593,"stem":603,"term":147,"__hash__":604},"glossary\u002Fglossary\u002Fsonic-horn.md",[371,372,373],"sonic horns","sonic cleaning horn","industrial sonic horn",{"type":52,"value":375,"toc":573},[376,410,414,422,426,488,492,529,533,541,543],[55,377,57,378,381,382,386,387,391,392,391,396,391,400,404,405,409],{},[59,379,380],{},"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 ",[64,383,385],{"href":384},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the default specification for cleaning ",[64,388,390],{"href":389},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",", ",[64,393,395],{"href":394},"\u002Fglossary\u002Ffabric-filter","baghouses",[64,397,399],{"href":398},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[64,401,403],{"href":402},"\u002Fglossary\u002Fsuperheater","boiler heat-transfer surfaces"," and ",[64,406,408],{"href":407},"\u002Fglossary\u002Fhopper","hoppers and silos",".",[70,411,413],{"id":412},"how-a-sonic-horn-works","How a sonic horn works",[55,415,416,417,421],{},"Compressed plant air admitted through a ",[64,418,420],{"href":419},"\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.",[70,423,425],{"id":424},"key-parameters","Key parameters",[189,427,428,438],{},[192,429,430],{},[195,431,432,435],{},[198,433,434],{},"Parameter",[198,436,437],{},"Typical range",[211,439,440,448,456,464,472,480],{},[195,441,442,445],{},[216,443,444],{},"Fundamental frequency",[216,446,447],{},"60–400 Hz",[195,449,450,453],{},[216,451,452],{},"Sound pressure level",[216,454,455],{},"140–180 dB",[195,457,458,461],{},[216,459,460],{},"Compressed-air consumption",[216,462,463],{},"8–14 Nm³\u002Fmin at 4–7 bar",[195,465,466,469],{},[216,467,468],{},"Operating temperature (with appropriate materials)",[216,470,471],{},"−40 °C to +500 °C",[195,473,474,477],{},[216,475,476],{},"Firing cycle",[216,478,479],{},"5–15 s burst, repeated every 3–15 minutes",[195,481,482,485],{},[216,483,484],{},"Mass",[216,486,487],{},"15–60 kg depending on horn size",[70,489,491],{"id":490},"frequency-selection","Frequency selection",[55,493,494,495,391,499,503,504,391,508,512,513,391,516,520,521,404,525,409],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[64,496,498],{"href":497},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[64,500,502],{"href":501},"\u002Fglossary\u002Frecovery-boiler","recovery-boiler superheaters",", large ",[64,505,507],{"href":506},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[64,509,511],{"href":510},"\u002Fglossary\u002Fsilo","silos",". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[64,514,515],{"href":394},"fabric-filter compartments",[64,517,519],{"href":518},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[64,522,524],{"href":523},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaner",[64,526,528],{"href":527},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","high-frequency acoustic cleaner",[70,530,532],{"id":531},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[55,534,535,536,540],{},"Sonic horns are increasingly specified alongside or in place of ",[64,537,539],{"href":538},"\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.",[70,542,134],{"id":133},[75,544,545,550,556,562,568],{},[78,546,547],{},[64,548,549],{"href":384},"Acoustic cleaner",[78,551,552],{},[64,553,555],{"href":554},"\u002Fglossary\u002Fsonic-sootblower","Sonic sootblower",[78,557,558],{},[64,559,561],{"href":560},"\u002Fglossary\u002Fbell-horn","Bell horn",[78,563,564],{},[64,565,567],{"href":566},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[78,569,570],{},[64,571,572],{"href":523},"Low-frequency acoustic cleaner",{"title":149,"searchDepth":150,"depth":150,"links":574},[575,576,577,578,579],{"id":412,"depth":150,"text":413},{"id":424,"depth":150,"text":425},{"id":490,"depth":150,"text":491},{"id":531,"depth":150,"text":532},{"id":133,"depth":150,"text":134},"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.",{},[584,585,586,587,588,589],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn","low-frequency-acoustic-cleaner",{"title":591,"description":592},"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.",[594,597,600],{"title":595,"url":596},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":598,"url":599},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":601,"url":602},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613729219]