[{"data":1,"prerenderedAt":1244},["ShallowReactive",2],{"site-footer-common":3,"glossary:frequency":45,"glossary-related:frequency":260},{"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":239,"description":240,"extension":241,"meta":242,"navigation":243,"path":244,"relatedTerms":245,"seo":251,"sources":254,"stem":258,"term":61,"__hash__":259},"glossary\u002Fglossary\u002Ffrequency.md","Frequency (Hz)",[49,50,51],"Hz","acoustic frequency","sonic horn frequency",{"type":53,"value":54,"toc":232},"minimark",[55,74,79,174,178,190,194],[56,57,58,62,63,68,69,73],"p",{},[59,60,61],"strong",{},"Frequency"," is the number of acoustic cycles per second, measured in hertz (Hz). For industrial acoustic cleaning it is the single most important selection parameter after ",[64,65,67],"a",{"href":66},"\u002Fglossary\u002Fsound-pressure-level","SPL",": frequency determines ",[64,70,72],{"href":71},"\u002Fglossary\u002Fwavelength","wavelength",", which in turn governs how the sound wave penetrates the vessel.",[75,76,78],"h2",{"id":77},"industrial-cleaning-bands","Industrial cleaning bands",[80,81,82,101],"table",{},[83,84,85],"thead",{},[86,87,88,92,95,98],"tr",{},[89,90,91],"th",{},"Band",[89,93,94],{},"Range",[89,96,97],{},"Wavelength in air",[89,99,100],{},"Typical use",[102,103,104,128,153],"tbody",{},[86,105,106,110,113,116],{},[107,108,109],"td",{},"Infrasonic",[107,111,112],{},"12–30 Hz",[107,114,115],{},"11–28 m",[107,117,118,122,123,127],{},[64,119,121],{"href":120},"\u002Fglossary\u002Frecovery-boiler","Recovery boilers",", ",[64,124,126],{"href":125},"\u002Fglossary\u002Fwaste-to-energy","WtE"," flue paths",[86,129,130,133,136,139],{},[107,131,132],{},"Low frequency",[107,134,135],{},"60–250 Hz",[107,137,138],{},"1.4–5.7 m",[107,140,141,122,145,122,149],{},[64,142,144],{"href":143},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",[64,146,148],{"href":147},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[64,150,152],{"href":151},"\u002Fglossary\u002Fsilo","silos",[86,154,155,158,161,164],{},[107,156,157],{},"High frequency",[107,159,160],{},"250–450 Hz",[107,162,163],{},"0.75–1.4 m",[107,165,166,122,170],{},[64,167,169],{"href":168},"\u002Fglossary\u002Ffabric-filter","Fabric filters",[64,171,173],{"href":172},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[75,175,177],{"id":176},"trade-off","Trade-off",[56,179,180,181,185,186,189],{},"Long wavelengths diffract around obstructions and penetrate further; short wavelengths concentrate more energy in a smaller volume. The frequency choice is therefore a trade between ",[182,183,184],"em",{},"reach"," and ",[182,187,188],{},"energy density",". Many real installations combine both bands: low-frequency horns clean the bulk volume; high-frequency horns clean dense bag rows or catalyst faces.",[75,191,193],{"id":192},"related-terms","Related terms",[195,196,197,203,208,214,220,226],"ul",{},[198,199,200],"li",{},[64,201,202],{"href":71},"Wavelength",[198,204,205],{},[64,206,207],{"href":66},"Sound pressure level",[198,209,210],{},[64,211,213],{"href":212},"\u002Fglossary\u002Ffundamental-frequency","Fundamental frequency",[198,215,216],{},[64,217,219],{"href":218},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","Low-frequency acoustic cleaner",[198,221,222],{},[64,223,225],{"href":224},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","High-frequency acoustic cleaner",[198,227,228],{},[64,229,231],{"href":230},"\u002Fglossary\u002Finfrasonic-cleaner","Infrasonic cleaner",{"title":233,"searchDepth":234,"depth":234,"links":235},"",2,[236,237,238],{"id":77,"depth":234,"text":78},{"id":176,"depth":234,"text":177},{"id":192,"depth":234,"text":193},"acoustics-physics","Frequency is the number of acoustic cycles per second, measured in hertz (Hz). For industrial acoustic cleaning it is the single most important selection parameter after SPL: frequency determines wavelength, which in turn governs how the sound wave penetrates the vessel.","md",{},true,"\u002Fglossary\u002Ffrequency",[72,246,247,248,249,250],"sound-pressure-level","fundamental-frequency","low-frequency-acoustic-cleaner","high-frequency-acoustic-cleaner","infrasonic-cleaner",{"title":252,"description":253},"Frequency (Hz) — selection bands for industrial sonic horns","Frequency is the number of acoustic cycles per second, measured in hertz. Industrial acoustic cleaners operate at 12–30 Hz (infrasonic), 60–250 Hz (low) or 250–450 Hz (high).",[255],{"title":256,"url":257},"Wikipedia — Frequency","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FFrequency","glossary\u002Ffrequency","7P2gkJzmA_x2ddonur2FhvOEPYFBCmPrnuK_ZNv8mqc",[261,412,596,679,878,1046],{"id":262,"title":202,"aliases":263,"body":266,"category":239,"description":399,"extension":241,"meta":400,"navigation":243,"path":71,"relatedTerms":401,"seo":403,"sources":406,"stem":410,"term":202,"__hash__":411},"glossary\u002Fglossary\u002Fwavelength.md",[264,265],"acoustic wavelength","sound wavelength",{"type":53,"value":267,"toc":394},[268,277,281,350,353,357,368,370],[56,269,270,272,273,276],{},[59,271,202],{}," is the spatial distance over which one full cycle of a wave repeats. It is calculated as λ = c \u002F f, where c is the speed of sound in the medium (~343 m\u002Fs in air at 20 °C) and f is the ",[64,274,275],{"href":244},"frequency"," in hertz. For industrial acoustic cleaning the wavelength is the single most informative dimension because it predicts how the horn's sound field will fill the vessel.",[75,278,280],{"id":279},"wavelengths-for-industrial-sonic-horns","Wavelengths for industrial sonic horns",[80,282,283,292],{},[83,284,285],{},[86,286,287,289],{},[89,288,61],{},[89,290,291],{},"Wavelength in air at 20 °C",[102,293,294,302,310,318,326,334,342],{},[86,295,296,299],{},[107,297,298],{},"12 Hz",[107,300,301],{},"~28 m",[86,303,304,307],{},[107,305,306],{},"30 Hz",[107,308,309],{},"~11 m",[86,311,312,315],{},[107,313,314],{},"60 Hz",[107,316,317],{},"~5.7 m",[86,319,320,323],{},[107,321,322],{},"75 Hz",[107,324,325],{},"~4.6 m",[86,327,328,331],{},[107,329,330],{},"125 Hz",[107,332,333],{},"~2.7 m",[86,335,336,339],{},[107,337,338],{},"230 Hz",[107,340,341],{},"~1.5 m",[86,343,344,347],{},[107,345,346],{},"400 Hz",[107,348,349],{},"~0.85 m",[56,351,352],{},"Wavelengths in hot flue gas are longer than in cool air because the speed of sound rises with temperature — at 200 °C the speed of sound is about 436 m\u002Fs, stretching a 75 Hz wave to roughly 5.8 m.",[75,354,356],{"id":355},"why-long-wavelengths-penetrate-further","Why long wavelengths penetrate further",[56,358,359,360,363,364,367],{},"Acoustic energy diffracts efficiently around obstructions smaller than its wavelength. A 5-metre 60 Hz wave bends around tube rows, electrode spacings and baffles that would scatter or absorb a 1-metre 350 Hz wave. This is the underlying physics of why ",[64,361,362],{"href":218},"low-frequency acoustic cleaners"," clean large open vessels better than ",[64,365,366],{"href":224},"high-frequency"," units.",[75,369,193],{"id":192},[195,371,372,376,380,386,390],{},[198,373,374],{},[64,375,61],{"href":244},[198,377,378],{},[64,379,207],{"href":66},[198,381,382],{},[64,383,385],{"href":384},"\u002Fglossary\u002Fstanding-wave","Standing wave",[198,387,388],{},[64,389,219],{"href":218},[198,391,392],{},[64,393,225],{"href":224},{"title":233,"searchDepth":234,"depth":234,"links":395},[396,397,398],{"id":279,"depth":234,"text":280},{"id":355,"depth":234,"text":356},{"id":192,"depth":234,"text":193},"Wavelength is the spatial distance over which one full cycle of a wave repeats. It is calculated as λ = c \u002F f, where c is the speed of sound in the medium (~343 m\u002Fs in air at 20 °C) and f is the frequency in hertz. For industrial acoustic cleaning the wavelength is the single most informative dimension because it predicts how the horn's sound field will fill the vessel.",{},[275,246,402,248,249],"standing-wave",{"title":404,"description":405},"Wavelength — how long is a sonic horn's wave inside a vessel?","Wavelength is the distance a sound wave travels in one cycle. At 60 Hz in air a wave is 5.7 m long; at 400 Hz it is 0.85 m. Wavelength governs how far a sonic horn's cleaning reach extends.",[407],{"title":408,"url":409},"Wikipedia — Wavelength","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FWavelength","glossary\u002Fwavelength","yrWaX9232a1ZSNJwMET2GxJuJPt98k9__zwmIHdRPuk",{"id":413,"title":414,"aliases":415,"body":417,"category":239,"description":577,"extension":241,"meta":578,"navigation":243,"path":66,"relatedTerms":579,"seo":584,"sources":587,"stem":594,"term":207,"__hash__":595},"glossary\u002Fglossary\u002Fsound-pressure-level.md","Sound pressure level (SPL)",[67,416],"sound pressure level dB",{"type":53,"value":418,"toc":571},[419,439,443,513,517,526,530,547,549],[56,420,421,423,424,428,429,433,434,438],{},[59,422,414],{}," is the logarithmic measure of sound pressure relative to the 20 µPa human-hearing reference, expressed in ",[64,425,427],{"href":426},"\u002Fglossary\u002Fdecibel","decibels",". It is the primary specification figure for any ",[64,430,432],{"href":431},"\u002Fglossary\u002Fsonic-horn","sonic horn"," or ",[64,435,437],{"href":436},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the metric used to size noise-exposure controls at the work area.",[75,440,442],{"id":441},"industrial-reference-values","Industrial reference values",[80,444,445,455],{},[83,446,447],{},[86,448,449,452],{},[89,450,451],{},"SPL (dB)",[89,453,454],{},"Reference",[102,456,457,465,473,481,489,497,505],{},[86,458,459,462],{},[107,460,461],{},"0",[107,463,464],{},"Threshold of human hearing",[86,466,467,470],{},[107,468,469],{},"60",[107,471,472],{},"Normal conversation",[86,474,475,478],{},[107,476,477],{},"120",[107,479,480],{},"Threshold of pain",[86,482,483,486],{},[107,484,485],{},"140",[107,487,488],{},"Industrial sonic horn (lower-output models)",[86,490,491,494],{},[107,492,493],{},"160",[107,495,496],{},"Typical cement \u002F ESP sonic horn",[86,498,499,502],{},[107,500,501],{},"180",[107,503,504],{},"Upper limit of pneumatic industrial sonic horns",[86,506,507,510],{},[107,508,509],{},"194",[107,511,512],{},"Theoretical maximum for an undistorted sine wave in air",[75,514,516],{"id":515},"spl-and-cleaning-effectiveness","SPL and cleaning effectiveness",[56,518,519,520,522,523,525],{},"Cleaning energy scales with intensity, which doubles for every 3 dB rise. A 150 dB horn delivers roughly twice the energy of a 147 dB horn at the same distance. SPL is not, however, the only selection criterion: ",[64,521,275],{"href":244}," determines ",[64,524,72],{"href":71}," and therefore penetration. A 150 dB low-frequency horn typically out-cleans a 160 dB high-frequency horn in a large open vessel.",[75,527,529],{"id":528},"spl-and-exposure","SPL and exposure",[56,531,532,533,537,538,185,542,546],{},"Reported nameplate SPL is measured at 1 m on the bell axis. Real exposure at the work area falls with distance per the ",[64,534,536],{"href":535},"\u002Fglossary\u002Finverse-square-law","inverse-square law"," and through enclosure attenuation. Compliance with ",[64,539,541],{"href":540},"\u002Fglossary\u002Fosha-29-cfr-1910-95","OSHA 29 CFR 1910.95",[64,543,545],{"href":544},"\u002Fglossary\u002Feu-directive-2003-10-ec","EU Directive 2003\u002F10\u002FEC"," is calculated from exposure, not from nameplate SPL.",[75,548,193],{"id":192},[195,550,551,556,560,566],{},[198,552,553],{},[64,554,555],{"href":426},"Decibel",[198,557,558],{},[64,559,61],{"href":244},[198,561,562],{},[64,563,565],{"href":564},"\u002Fglossary\u002Fsound-power-vs-sound-pressure","Sound power vs sound pressure",[198,567,568],{},[64,569,570],{"href":535},"Inverse-square law",{"title":233,"searchDepth":234,"depth":234,"links":572},[573,574,575,576],{"id":441,"depth":234,"text":442},{"id":515,"depth":234,"text":516},{"id":528,"depth":234,"text":529},{"id":192,"depth":234,"text":193},"Sound pressure level (SPL) is the logarithmic measure of sound pressure relative to the 20 µPa human-hearing reference, expressed in decibels. It is the primary specification figure for any sonic horn or acoustic cleaner and the metric used to size noise-exposure controls at the work area.",{},[580,275,581,582,583],"decibel","sound-power-vs-sound-pressure","inverse-square-law","sonic-horn",{"title":585,"description":586},"Sound pressure level (SPL) — definition, industrial-cleaning ranges","SPL is the logarithmic measure of sound pressure in decibels relative to a 20 µPa reference. Industrial sonic horns operate at 140–180 dB SPL.",[588,591],{"title":589,"url":590},"Wikipedia — Sound pressure","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSound_pressure",{"title":592,"url":593},"Acoustical Society of America — Sound Pressure Level","https:\u002F\u002Fasastandards.org\u002F","glossary\u002Fsound-pressure-level","ayEoQNuJweSv9WGpwDPcx5CMESsbiPd4QPUpIoyQA6M",{"id":597,"title":213,"aliases":598,"body":601,"category":239,"description":665,"extension":241,"meta":666,"navigation":243,"path":212,"relatedTerms":667,"seo":670,"sources":673,"stem":677,"term":213,"__hash__":678},"glossary\u002Fglossary\u002Ffundamental-frequency.md",[599,600],"first harmonic","natural frequency (acoustic)",{"type":53,"value":602,"toc":661},[603,626,630,638,640],[56,604,605,606,609,610,612,613,617,618,620,621,625],{},"The ",[59,607,608],{},"fundamental frequency"," is the lowest natural resonant frequency of a vibrating system. For a ",[64,611,432],{"href":431}," it is the nameplate frequency at which the ",[64,614,616],{"href":615},"\u002Fglossary\u002Fdiaphragm-horn","diaphragm"," or piston is designed to oscillate and at which the horn delivers its rated ",[64,619,67],{"href":66},". A horn marked \"60 Hz\" produces a fundamental at 60 Hz plus a series of ",[64,622,624],{"href":623},"\u002Fglossary\u002Fharmonic","harmonics"," at integer multiples (120 Hz, 180 Hz, etc.).",[75,627,629],{"id":628},"why-it-is-the-published-number","Why it is the published number",[56,631,632,633,637],{},"Acoustic energy is concentrated at the fundamental. Harmonics carry progressively less energy. Selection charts, sizing tools and ROI calculations all use the fundamental as the reference. When tuning a multi-horn array, the fundamentals are chosen to avoid coincidence with vessel-tube ",[64,634,636],{"href":635},"\u002Fglossary\u002Fresonance","resonance"," modes that could cause unwanted vibration.",[75,639,193],{"id":192},[195,641,642,646,651,656],{},[198,643,644],{},[64,645,61],{"href":244},[198,647,648],{},[64,649,650],{"href":623},"Harmonic",[198,652,653],{},[64,654,655],{"href":635},"Resonance",[198,657,658],{},[64,659,660],{"href":615},"Diaphragm horn",{"title":233,"searchDepth":234,"depth":234,"links":662},[663,664],{"id":628,"depth":234,"text":629},{"id":192,"depth":234,"text":193},"The fundamental frequency is the lowest natural resonant frequency of a vibrating system. For a sonic horn it is the nameplate frequency at which the diaphragm or piston is designed to oscillate and at which the horn delivers its rated SPL. A horn marked \"60 Hz\" produces a fundamental at 60 Hz plus a series of harmonics at integer multiples (120 Hz, 180 Hz, etc.).",{},[275,668,636,669],"harmonic","diaphragm-horn",{"title":671,"description":672},"Fundamental frequency — the design frequency of a sonic horn","The fundamental frequency is the lowest natural resonant frequency of a system. For a sonic horn it is the published nameplate frequency at which the horn delivers maximum cleaning energy.",[674],{"title":675,"url":676},"Wikipedia — Fundamental frequency","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FFundamental_frequency","glossary\u002Ffundamental-frequency","yoqzKueqavnquJYq4CSlQR5iTTxQstFLlnjbndf-AD4",{"id":680,"title":219,"aliases":681,"body":685,"category":860,"description":861,"extension":241,"meta":862,"navigation":243,"path":218,"relatedTerms":863,"seo":866,"sources":869,"stem":876,"term":219,"__hash__":877},"glossary\u002Fglossary\u002Flow-frequency-acoustic-cleaner.md",[682,683,684],"low frequency sonic horn","low-frequency horn","LF acoustic cleaner",{"type":53,"value":686,"toc":854},[687,702,706,713,717,773,777,827,829],[56,688,689,690,693,694,696,697,701],{},"A ",[59,691,692],{},"low-frequency acoustic cleaner"," is an industrial ",[64,695,432],{"href":431}," whose fundamental frequency sits in the 60–250 Hz band. The long acoustic wavelength — between 1.4 and 5.7 metres in air — projects further from the ",[64,698,700],{"href":699},"\u002Fglossary\u002Fbell-horn","bell horn"," than higher-frequency designs, fills large open vessels more uniformly and is the default choice for cleaning bulky industrial equipment.",[75,703,705],{"id":704},"why-frequency-choice-matters","Why frequency choice matters",[56,707,708,709,712],{},"Acoustic energy at long wavelengths diffracts around obstructions (tube banks, electrode rows, baffles) instead of being absorbed or scattered. That makes low-frequency horns the appropriate selection where the cleaning target is several metres deep and partly obstructed — most large industrial vessels fall into this category. Higher-frequency horns concentrate more energy per unit volume but lose effectiveness in deep cavities; see ",[64,710,711],{"href":224},"high-frequency acoustic cleaner"," for the complementary case.",[75,714,716],{"id":715},"typical-applications","Typical applications",[195,718,719,725,735,746,753,766],{},[198,720,721,724],{},[64,722,723],{"href":143},"Electrostatic precipitators"," — collecting-plate cleaning, hopper de-bridging",[198,726,727,185,730,734],{},[64,728,729],{"href":147},"Preheater cyclones",[64,731,733],{"href":732},"\u002Fglossary\u002Fcalciner","calciners"," in cement plants",[198,736,737,740,741,745],{},[64,738,739],{"href":120},"Kraft recovery boilers"," — superheaters, ",[64,742,744],{"href":743},"\u002Fglossary\u002Fgenerating-bank","generating banks",", economisers",[198,747,748,752],{},[64,749,751],{"href":750},"\u002Fglossary\u002Fair-heater","Air heater"," cold-end basket cleaning",[198,754,755,756,122,760,185,762],{},"Large ",[64,757,759],{"href":758},"\u002Fglossary\u002Ffly-ash-hopper","fly-ash hoppers",[64,761,152],{"href":151},[64,763,765],{"href":764},"\u002Fglossary\u002Fbunker-coal-bunker","bunkers",[198,767,768,772],{},[64,769,771],{"href":770},"\u002Fglossary\u002Fheat-recovery-steam-generator","HRSG harp-tube banks"," in combined-cycle plants",[75,774,776],{"id":775},"indicative-selection-bands","Indicative selection bands",[80,778,779,789],{},[83,780,781],{},[86,782,783,785,787],{},[89,784,91],{},[89,786,291],{},[89,788,100],{},[102,790,791,800,809,818],{},[86,792,793,795,797],{},[107,794,314],{},[107,796,317],{},[107,798,799],{},"Very large ESPs, recovery boilers, deep silos",[86,801,802,804,806],{},[107,803,322],{},[107,805,325],{},[107,807,808],{},"ESPs, preheater cyclones, large hoppers",[86,810,811,813,815],{},[107,812,330],{},[107,814,333],{},[107,816,817],{},"Mid-size ESPs, baghouse compartments, calciners",[86,819,820,822,824],{},[107,821,338],{},[107,823,341],{},[107,825,826],{},"Boiler convective passes, smaller hoppers, baghouses",[75,828,193],{"id":192},[195,830,831,836,841,845,849],{},[198,832,833],{},[64,834,835],{"href":431},"Sonic horn",[198,837,838],{},[64,839,840],{"href":436},"Acoustic cleaner",[198,842,843],{},[64,844,225],{"href":224},[198,846,847],{},[64,848,231],{"href":230},[198,850,851],{},[64,852,853],{"href":699},"Bell horn",{"title":233,"searchDepth":234,"depth":234,"links":855},[856,857,858,859],{"id":704,"depth":234,"text":705},{"id":715,"depth":234,"text":716},{"id":775,"depth":234,"text":776},{"id":192,"depth":234,"text":193},"core-technology","A low-frequency acoustic cleaner is an industrial sonic horn whose fundamental frequency sits in the 60–250 Hz band. The long acoustic wavelength — between 1.4 and 5.7 metres in air — projects further from the bell horn than higher-frequency designs, fills large open vessels more uniformly and is the default choice for cleaning bulky industrial equipment.",{},[864,583,249,250,865],"acoustic-cleaner","bell-horn",{"title":867,"description":868},"Low-frequency acoustic cleaner — 60–250 Hz horn selection guide","Low-frequency acoustic cleaners operate at 60–250 Hz. The long wavelength penetrates deep into large open vessels such as ESPs, recovery boilers and cement preheater cyclones.",[870,873],{"title":871,"url":872},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":874,"url":875},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F","glossary\u002Flow-frequency-acoustic-cleaner","m6cj771ScgiY0798OZ0cdR03A65ardaL1YsF3e8jwFM",{"id":879,"title":225,"aliases":880,"body":884,"category":860,"description":1032,"extension":241,"meta":1033,"navigation":243,"path":224,"relatedTerms":1034,"seo":1036,"sources":1039,"stem":1044,"term":225,"__hash__":1045},"glossary\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner.md",[881,882,883],"high frequency sonic horn","HF acoustic cleaner","high-frequency horn",{"type":53,"value":885,"toc":1025},[886,898,902,923,927,964,968,979,983,999,1001],[56,887,689,888,890,891,893,894,897],{},[59,889,711],{}," is a ",[64,892,432],{"href":431}," operating in the upper end of the audible industrial-cleaning band, typically 250 to 450 Hz. The shorter wavelength — 0.75 to 1.4 metres in air — couples more energy into smaller geometries and finer dust loads than long-wavelength ",[64,895,896],{"href":218},"low-frequency horns"," can deliver.",[75,899,901],{"id":900},"where-high-frequency-horns-earn-their-place","Where high-frequency horns earn their place",[56,903,904,905,908,909,913,914,918,919,922],{},"The cleaning target dictates the choice. Where deposits are fine and surfaces are densely packed — ",[64,906,907],{"href":168},"fabric-filter"," bag rows, ",[64,910,912],{"href":911},"\u002Fglossary\u002Fhoneycomb-catalyst","honeycomb SCR catalyst"," cell faces, small ",[64,915,917],{"href":916},"\u002Fglossary\u002Fcyclone-separator","cyclone separators",", tight ",[64,920,921],{"href":750},"air-heater"," basket geometries — the higher energy density of a 250–450 Hz horn lifts particulate more reliably than a long wave that would diffract past it.",[75,924,926],{"id":925},"selection-guide","Selection guide",[80,928,929,938],{},[83,930,931],{},[86,932,933,935],{},[89,934,61],{},[89,936,937],{},"Best for",[102,939,940,948,956],{},[86,941,942,945],{},[107,943,944],{},"250 Hz",[107,946,947],{},"Mid-size baghouse compartments, smaller boiler convective passes",[86,949,950,953],{},[107,951,952],{},"350 Hz",[107,954,955],{},"SCR catalyst layers, fine-particulate fabric filters",[86,957,958,961],{},[107,959,960],{},"400–450 Hz",[107,962,963],{},"Compact hoppers, fine-cell honeycomb catalysts, small ducting",[75,965,967],{"id":966},"construction-differences-from-low-frequency-horns","Construction differences from low-frequency horns",[56,969,970,971,973,974,978],{},"A higher fundamental frequency means a smaller ",[64,972,700],{"href":699}," cut-off and therefore a physically smaller, lighter unit — useful where mounting clearance is tight or where a large array of horns must be distributed across a baghouse roof. High-frequency designs are often ",[64,975,977],{"href":976},"\u002Fglossary\u002Fpiston-whistle-horn","piston-whistle"," rather than diaphragm-driven, with a different wear profile and shorter individual firing bursts.",[75,980,982],{"id":981},"when-to-step-down-to-low-frequency","When to step down to low frequency",[56,984,985,986,122,988,122,990,122,992,995,996,998],{},"For deep, open vessels and bulk-solids storage — ",[64,987,144],{"href":143},[64,989,148],{"href":147},[64,991,152],{"href":151},[64,993,994],{"href":120},"recovery-boiler superheaters"," — a ",[64,997,683],{"href":218}," projects further and is normally specified instead. Many real installations combine both bands: low-frequency horns clean the bulk volume; high-frequency horns clean the dense bag rows or catalyst faces nearby.",[75,1000,193],{"id":192},[195,1002,1003,1007,1011,1015,1020],{},[198,1004,1005],{},[64,1006,835],{"href":431},[198,1008,1009],{},[64,1010,840],{"href":436},[198,1012,1013],{},[64,1014,219],{"href":218},[198,1016,1017],{},[64,1018,1019],{"href":976},"Piston-whistle horn",[198,1021,1022],{},[64,1023,1024],{"href":168},"Fabric filter",{"title":233,"searchDepth":234,"depth":234,"links":1026},[1027,1028,1029,1030,1031],{"id":900,"depth":234,"text":901},{"id":925,"depth":234,"text":926},{"id":966,"depth":234,"text":967},{"id":981,"depth":234,"text":982},{"id":192,"depth":234,"text":193},"A high-frequency acoustic cleaner is a sonic horn operating in the upper end of the audible industrial-cleaning band, typically 250 to 450 Hz. The shorter wavelength — 0.75 to 1.4 metres in air — couples more energy into smaller geometries and finer dust loads than long-wavelength low-frequency horns can deliver.",{},[864,583,248,1035,907],"piston-whistle-horn",{"title":1037,"description":1038},"High-frequency acoustic cleaner — 250–450 Hz horns for fine dust","High-frequency acoustic cleaners operate at 250–450 Hz. The shorter wavelength carries more energy per unit volume and suits fabric filters, SCR catalysts and small hopper geometries.",[1040,1041],{"title":871,"url":872},{"title":1042,"url":1043},"Micronics — Sonic Horns for Baghouses","https:\u002F\u002Fwww.micronicsinc.com\u002Fdry-baghouse-filtration\u002Fparts\u002Fbaghouse-accessories\u002Fsonic-horns\u002F","glossary\u002Fhigh-frequency-acoustic-cleaner","lNIvkPALQGjCAhpfwsyKTlK4g-5X34MBQgtefiuEWTM",{"id":1047,"title":231,"aliases":1048,"body":1052,"category":860,"description":1227,"extension":241,"meta":1228,"navigation":243,"path":230,"relatedTerms":1229,"seo":1232,"sources":1235,"stem":1242,"term":231,"__hash__":1243},"glossary\u002Fglossary\u002Finfrasonic-cleaner.md",[1049,1050,1051],"infrasound cleaner","infrasonic cleaning system","sub-audible acoustic cleaner",{"type":53,"value":1053,"toc":1221},[1054,1070,1074,1160,1164,1184,1188,1195,1197],[56,1055,1056,1057,1060,1061,1063,1064,1066,1067,1069],{},"An ",[59,1058,1059],{},"infrasonic cleaner"," (also written ",[182,1062,1049],{},") is an ",[64,1065,437],{"href":436}," that operates below the threshold of human hearing — typically 12 to 30 Hz, against the 60–400 Hz range of a conventional ",[64,1068,432],{"href":431},". The very long wavelength of an infrasonic wave (above 10 metres at 30 Hz) fills a large vessel almost uniformly and penetrates further into deep, baffled or obstructed cavities than higher-frequency horns can reach.",[75,1071,1073],{"id":1072},"how-it-differs-from-a-sonic-horn","How it differs from a sonic horn",[80,1075,1076,1087],{},[83,1077,1078],{},[86,1079,1080,1083,1085],{},[89,1081,1082],{},"Attribute",[89,1084,231],{},[89,1086,835],{},[102,1088,1089,1099,1109,1120,1131,1142],{},[86,1090,1091,1093,1096],{},[107,1092,61],{},[107,1094,1095],{},"12–30 Hz (sub-audible)",[107,1097,1098],{},"60–400 Hz (audible)",[86,1100,1101,1103,1106],{},[107,1102,202],{},[107,1104,1105],{},"10–28 m",[107,1107,1108],{},"0.85–5.7 m",[86,1110,1111,1114,1117],{},[107,1112,1113],{},"Penetration",[107,1115,1116],{},"Excellent, fills the whole vessel",[107,1118,1119],{},"Directional, projected from the bell",[86,1121,1122,1125,1128],{},[107,1123,1124],{},"Audible noise at the work area",[107,1126,1127],{},"Very low (mostly inaudible)",[107,1129,1130],{},"Significant, often requires hearing protection",[86,1132,1133,1136,1139],{},[107,1134,1135],{},"Bell size",[107,1137,1138],{},"Large (low cut-off frequency demands physical bulk)",[107,1140,1141],{},"Compact",[86,1143,1144,1146,1157],{},[107,1145,716],{},[107,1147,1148,122,1150,1152,1153,1156],{},[64,1149,121],{"href":120},[64,1151,126],{"href":125}," flue paths, ",[64,1154,1155],{"href":770},"HRSGs",", marine boilers",[107,1158,1159],{},"Cross-application; default specification",[75,1161,1163],{"id":1162},"where-infrasonic-cleaners-are-preferred","Where infrasonic cleaners are preferred",[56,1165,1166,1167,1170,1171,1175,1176,1179,1180,1183],{},"Infrasonic technology was popularised by Swedish suppliers (Infrafone \u002F Heat Management) on pulp-and-paper ",[64,1168,1169],{"href":120},"kraft recovery boilers",", where the combination of deep superheater cavities and the strict need to extend the interval between ",[64,1172,1174],{"href":1173},"\u002Fglossary\u002Fchill-and-blow","chill-and-blow"," wash cycles rewards the deeper penetration of long waves. The same logic carries over to large ",[64,1177,1178],{"href":125},"WtE boilers"," with sticky chloride-laden ash, to ",[64,1181,1182],{"href":770},"HRSG harp tube banks"," and to large marine boilers where work-area noise must be kept low.",[75,1185,1187],{"id":1186},"when-to-choose-a-sonic-horn-instead","When to choose a sonic horn instead",[56,1189,1190,1191,1194],{},"For most baghouse, ESP, hopper and silo applications, a 60–250 Hz ",[64,1192,1193],{"href":218},"low-frequency sonic horn"," projects enough penetration with a smaller bell, lower capital cost, lower air consumption and simpler integration. Infrasonic cleaners earn their cost where vessel geometry, deposit depth or noise-exposure limits make the long wavelength specifically valuable.",[75,1196,193],{"id":192},[195,1198,1199,1203,1207,1211,1216],{},[198,1200,1201],{},[64,1202,840],{"href":436},[198,1204,1205],{},[64,1206,835],{"href":431},[198,1208,1209],{},[64,1210,219],{"href":218},[198,1212,1213],{},[64,1214,1215],{"href":120},"Recovery boiler",[198,1217,1218],{},[64,1219,1220],{"href":125},"Waste-to-energy",{"title":233,"searchDepth":234,"depth":234,"links":1222},[1223,1224,1225,1226],{"id":1072,"depth":234,"text":1073},{"id":1162,"depth":234,"text":1163},{"id":1186,"depth":234,"text":1187},{"id":192,"depth":234,"text":193},"An infrasonic cleaner (also written infrasound cleaner) is an acoustic cleaner that operates below the threshold of human hearing — typically 12 to 30 Hz, against the 60–400 Hz range of a conventional sonic horn. The very long wavelength of an infrasonic wave (above 10 metres at 30 Hz) fills a large vessel almost uniformly and penetrates further into deep, baffled or obstructed cavities than higher-frequency horns can reach.",{},[864,583,248,1230,1231],"recovery-boiler","waste-to-energy",{"title":1233,"description":1234},"Infrasonic cleaner — sub-20 Hz acoustic cleaning for deep penetration","An infrasonic cleaner operates below the audible threshold (typically 12–30 Hz). The very long wavelength penetrates further than a conventional sonic horn and is preferred on recovery boilers and WtE flue paths.",[1236,1239],{"title":1237,"url":1238},"Heat Management — Infrasound Cleaning for Boiler Efficiency","https:\u002F\u002Fheatmanage.com\u002Fknowledge\u002Funlocking-infrasound-cleaning-data-for-boiler-efficiency\u002F",{"title":1240,"url":1241},"Power Magazine — The Theory and Application of Acoustic Cleaners","https:\u002F\u002Fwww.powermag.com\u002Fthe-theory-and-application-of-acoustic-cleaners\u002F","glossary\u002Finfrasonic-cleaner","Oqfo1uKF8ioWxXKH687wPi188BqvEoa3EWC_w2jXmG4",1782613716034]