[{"data":1,"prerenderedAt":1035},["ShallowReactive",2],{"site-footer-common":3,"glossary:sound-pressure-level":45,"glossary-related:sound-pressure-level":258},{"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":234,"description":235,"extension":236,"meta":237,"navigation":238,"path":239,"relatedTerms":240,"seo":245,"sources":248,"stem":255,"term":256,"__hash__":257},"glossary\u002Fglossary\u002Fsound-pressure-level.md","Sound pressure level (SPL)",[49,50],"SPL","sound pressure level dB",{"type":52,"value":53,"toc":226},"minimark",[54,77,82,158,162,175,179,197,201],[55,56,57,60,61,66,67,71,72,76],"p",{},[58,59,47],"strong",{}," is the logarithmic measure of sound pressure relative to the 20 µPa human-hearing reference, expressed in ",[62,63,65],"a",{"href":64},"\u002Fglossary\u002Fdecibel","decibels",". It is the primary specification figure for any ",[62,68,70],{"href":69},"\u002Fglossary\u002Fsonic-horn","sonic horn"," or ",[62,73,75],{"href":74},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the metric used to size noise-exposure controls at the work area.",[78,79,81],"h2",{"id":80},"industrial-reference-values","Industrial reference values",[83,84,85,98],"table",{},[86,87,88],"thead",{},[89,90,91,95],"tr",{},[92,93,94],"th",{},"SPL (dB)",[92,96,97],{},"Reference",[99,100,101,110,118,126,134,142,150],"tbody",{},[89,102,103,107],{},[104,105,106],"td",{},"0",[104,108,109],{},"Threshold of human hearing",[89,111,112,115],{},[104,113,114],{},"60",[104,116,117],{},"Normal conversation",[89,119,120,123],{},[104,121,122],{},"120",[104,124,125],{},"Threshold of pain",[89,127,128,131],{},[104,129,130],{},"140",[104,132,133],{},"Industrial sonic horn (lower-output models)",[89,135,136,139],{},[104,137,138],{},"160",[104,140,141],{},"Typical cement \u002F ESP sonic horn",[89,143,144,147],{},[104,145,146],{},"180",[104,148,149],{},"Upper limit of pneumatic industrial sonic horns",[89,151,152,155],{},[104,153,154],{},"194",[104,156,157],{},"Theoretical maximum for an undistorted sine wave in air",[78,159,161],{"id":160},"spl-and-cleaning-effectiveness","SPL and cleaning effectiveness",[55,163,164,165,169,170,174],{},"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: ",[62,166,168],{"href":167},"\u002Fglossary\u002Ffrequency","frequency"," determines ",[62,171,173],{"href":172},"\u002Fglossary\u002Fwavelength","wavelength"," and therefore penetration. A 150 dB low-frequency horn typically out-cleans a 160 dB high-frequency horn in a large open vessel.",[78,176,178],{"id":177},"spl-and-exposure","SPL and exposure",[55,180,181,182,186,187,191,192,196],{},"Reported nameplate SPL is measured at 1 m on the bell axis. Real exposure at the work area falls with distance per the ",[62,183,185],{"href":184},"\u002Fglossary\u002Finverse-square-law","inverse-square law"," and through enclosure attenuation. Compliance with ",[62,188,190],{"href":189},"\u002Fglossary\u002Fosha-29-cfr-1910-95","OSHA 29 CFR 1910.95"," and ",[62,193,195],{"href":194},"\u002Fglossary\u002Feu-directive-2003-10-ec","EU Directive 2003\u002F10\u002FEC"," is calculated from exposure, not from nameplate SPL.",[78,198,200],{"id":199},"related-terms","Related terms",[202,203,204,210,215,221],"ul",{},[205,206,207],"li",{},[62,208,209],{"href":64},"Decibel",[205,211,212],{},[62,213,214],{"href":167},"Frequency",[205,216,217],{},[62,218,220],{"href":219},"\u002Fglossary\u002Fsound-power-vs-sound-pressure","Sound power vs sound pressure",[205,222,223],{},[62,224,225],{"href":184},"Inverse-square law",{"title":227,"searchDepth":228,"depth":228,"links":229},"",2,[230,231,232,233],{"id":80,"depth":228,"text":81},{"id":160,"depth":228,"text":161},{"id":177,"depth":228,"text":178},{"id":199,"depth":228,"text":200},"acoustics-physics","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.","md",{},true,"\u002Fglossary\u002Fsound-pressure-level",[241,168,242,243,244],"decibel","sound-power-vs-sound-pressure","inverse-square-law","sonic-horn",{"title":246,"description":247},"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.",[249,252],{"title":250,"url":251},"Wikipedia — Sound pressure","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSound_pressure",{"title":253,"url":254},"Acoustical Society of America — Sound Pressure Level","https:\u002F\u002Fasastandards.org\u002F","glossary\u002Fsound-pressure-level","Sound pressure level","ayEoQNuJweSv9WGpwDPcx5CMESsbiPd4QPUpIoyQA6M",[259,399,585,673,818],{"id":260,"title":261,"aliases":262,"body":264,"category":234,"description":385,"extension":236,"meta":386,"navigation":238,"path":64,"relatedTerms":387,"seo":390,"sources":393,"stem":397,"term":209,"__hash__":398},"glossary\u002Fglossary\u002Fdecibel.md","Decibel (dB)",[263,65],"dB",{"type":52,"value":265,"toc":379},[266,273,277,280,284,349,353,361,363],[55,267,268,269,272],{},"The ",[58,270,271],{},"decibel (dB)"," is a logarithmic unit used to express the ratio between two values of an acoustic quantity — most commonly sound pressure, sound intensity or sound power. A 10 dB increase represents a tenfold increase in intensity and a perceived roughly doubled loudness. A 3 dB increase represents a doubling of intensity.",[78,274,276],{"id":275},"why-a-logarithmic-scale","Why a logarithmic scale",[55,278,279],{},"Human hearing — and the practical range of industrial acoustic cleaning — spans more than ten orders of magnitude of sound pressure (20 µPa to several hundred Pa). A linear scale would be unwieldy. The logarithmic decibel compresses this into a tractable 0–180 dB band and aligns with how the ear actually responds to intensity changes.",[78,281,283],{"id":282},"reference-points","Reference points",[83,285,286,296],{},[86,287,288],{},[89,289,290,293],{},[92,291,292],{},"Value",[92,294,295],{},"Meaning",[99,297,298,306,314,322,330,341],{},[89,299,300,303],{},[104,301,302],{},"+3 dB",[104,304,305],{},"Sound intensity doubled",[89,307,308,311],{},[104,309,310],{},"+10 dB",[104,312,313],{},"Sound intensity ×10; perceived loudness roughly doubled",[89,315,316,319],{},[104,317,318],{},"+20 dB",[104,320,321],{},"Sound intensity ×100",[89,323,324,327],{},[104,325,326],{},"0 dB SPL",[104,328,329],{},"Reference threshold of hearing (20 µPa)",[89,331,332,335],{},[104,333,334],{},"140 dB SPL",[104,336,337,338,340],{},"Lower end of industrial ",[62,339,70],{"href":69}," output",[89,342,343,346],{},[104,344,345],{},"180 dB SPL",[104,347,348],{},"Upper end of pneumatic industrial cleaning horns",[78,350,352],{"id":351},"weighting","Weighting",[55,354,355,356,191,358,360],{},"For noise-exposure work, raw dB is often weighted to better reflect human hearing. A-weighting (dBA) is the standard for occupational-noise calculations under ",[62,357,190],{"href":189},[62,359,195],{"href":194},". C-weighting (dBC) is used for peak exposure to high-level impulsive sound.",[78,362,200],{"id":199},[202,364,365,369,373],{},[205,366,367],{},[62,368,256],{"href":239},[205,370,371],{},[62,372,214],{"href":167},[205,374,375],{},[62,376,378],{"href":377},"\u002Fglossary\u002Foctave-band","Octave band",{"title":227,"searchDepth":228,"depth":228,"links":380},[381,382,383,384],{"id":275,"depth":228,"text":276},{"id":282,"depth":228,"text":283},{"id":351,"depth":228,"text":352},{"id":199,"depth":228,"text":200},"The decibel (dB) is a logarithmic unit used to express the ratio between two values of an acoustic quantity — most commonly sound pressure, sound intensity or sound power. A 10 dB increase represents a tenfold increase in intensity and a perceived roughly doubled loudness. A 3 dB increase represents a doubling of intensity.",{},[388,168,243,389],"sound-pressure-level","octave-band",{"title":391,"description":392},"Decibel (dB) — logarithmic sound unit explained for industrial use","The decibel is a logarithmic ratio used to express sound pressure, sound intensity and sound power. A 10 dB rise represents a tenfold rise in intensity.",[394],{"title":395,"url":396},"Wikipedia — Decibel","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FDecibel","glossary\u002Fdecibel","RnO0-e6FXXcqpL2fccyibxKPWKiXzYwQXLsx0a4VvbA",{"id":400,"title":401,"aliases":402,"body":406,"category":234,"description":569,"extension":236,"meta":570,"navigation":238,"path":167,"relatedTerms":571,"seo":576,"sources":579,"stem":583,"term":214,"__hash__":584},"glossary\u002Fglossary\u002Ffrequency.md","Frequency (Hz)",[403,404,405],"Hz","acoustic frequency","sonic horn frequency",{"type":52,"value":407,"toc":564},[408,419,423,512,516,527,529],[55,409,410,412,413,415,416,418],{},[58,411,214],{}," 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 ",[62,414,49],{"href":239},": frequency determines ",[62,417,173],{"href":172},", which in turn governs how the sound wave penetrates the vessel.",[78,420,422],{"id":421},"industrial-cleaning-bands","Industrial cleaning bands",[83,424,425,441],{},[86,426,427],{},[89,428,429,432,435,438],{},[92,430,431],{},"Band",[92,433,434],{},"Range",[92,436,437],{},"Wavelength in air",[92,439,440],{},"Typical use",[99,442,443,466,491],{},[89,444,445,448,451,454],{},[104,446,447],{},"Infrasonic",[104,449,450],{},"12–30 Hz",[104,452,453],{},"11–28 m",[104,455,456,460,461,465],{},[62,457,459],{"href":458},"\u002Fglossary\u002Frecovery-boiler","Recovery boilers",", ",[62,462,464],{"href":463},"\u002Fglossary\u002Fwaste-to-energy","WtE"," flue paths",[89,467,468,471,474,477],{},[104,469,470],{},"Low frequency",[104,472,473],{},"60–250 Hz",[104,475,476],{},"1.4–5.7 m",[104,478,479,460,483,460,487],{},[62,480,482],{"href":481},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",[62,484,486],{"href":485},"\u002Fglossary\u002Fpreheater-cyclone","preheater cyclones",[62,488,490],{"href":489},"\u002Fglossary\u002Fsilo","silos",[89,492,493,496,499,502],{},[104,494,495],{},"High frequency",[104,497,498],{},"250–450 Hz",[104,500,501],{},"0.75–1.4 m",[104,503,504,460,508],{},[62,505,507],{"href":506},"\u002Fglossary\u002Ffabric-filter","Fabric filters",[62,509,511],{"href":510},"\u002Fglossary\u002Fselective-catalytic-reduction","SCR catalysts",[78,513,515],{"id":514},"trade-off","Trade-off",[55,517,518,519,191,523,526],{},"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 ",[520,521,522],"em",{},"reach",[520,524,525],{},"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.",[78,528,200],{"id":199},[202,530,531,536,540,546,552,558],{},[205,532,533],{},[62,534,535],{"href":172},"Wavelength",[205,537,538],{},[62,539,256],{"href":239},[205,541,542],{},[62,543,545],{"href":544},"\u002Fglossary\u002Ffundamental-frequency","Fundamental frequency",[205,547,548],{},[62,549,551],{"href":550},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","Low-frequency acoustic cleaner",[205,553,554],{},[62,555,557],{"href":556},"\u002Fglossary\u002Fhigh-frequency-acoustic-cleaner","High-frequency acoustic cleaner",[205,559,560],{},[62,561,563],{"href":562},"\u002Fglossary\u002Finfrasonic-cleaner","Infrasonic cleaner",{"title":227,"searchDepth":228,"depth":228,"links":565},[566,567,568],{"id":421,"depth":228,"text":422},{"id":514,"depth":228,"text":515},{"id":199,"depth":228,"text":200},"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.",{},[173,388,572,573,574,575],"fundamental-frequency","low-frequency-acoustic-cleaner","high-frequency-acoustic-cleaner","infrasonic-cleaner",{"title":577,"description":578},"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).",[580],{"title":581,"url":582},"Wikipedia — Frequency","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FFrequency","glossary\u002Ffrequency","7P2gkJzmA_x2ddonur2FhvOEPYFBCmPrnuK_ZNv8mqc",{"id":586,"title":220,"aliases":587,"body":591,"category":234,"description":657,"extension":236,"meta":658,"navigation":238,"path":219,"relatedTerms":659,"seo":661,"sources":664,"stem":671,"term":220,"__hash__":672},"glossary\u002Fglossary\u002Fsound-power-vs-sound-pressure.md",[588,589,590],"sound power","sound power level","PWL vs SPL",{"type":52,"value":592,"toc":652},[593,612,616,624,628,631,633],[55,594,595,598,599,602,603,605,606,608,609,611],{},[58,596,597],{},"Sound power"," is the total acoustic energy a source emits per unit time, measured in watts. It is an intrinsic property of the source and does not change with listener distance. ",[58,600,601],{},"Sound pressure"," is the local pressure fluctuation at a measurement point, measured in pascals (and reported in ",[62,604,65],{"href":64}," as ",[62,607,49],{"href":239},"). Pressure falls with distance per the ",[62,610,185],{"href":184},"; power does not.",[78,613,615],{"id":614},"why-both-matter-for-a-sonic-horn","Why both matter for a sonic horn",[55,617,618,619,623],{},"Vendor datasheets normally publish SPL at 1 m on the bell axis, because that is what specifiers compare. But two horns with identical 150 dB nameplate SPL can radiate different sound power if their directivity differs — a wider radiation pattern delivers more useful energy into the vessel. Sound power level (PWL) is the comparable metric when evaluating total cleaning energy, measured per ",[62,620,622],{"href":621},"\u002Fglossary\u002Fiso-9614-sound-power","ISO 9614",".",[78,625,627],{"id":626},"practical-rule-of-thumb","Practical rule of thumb",[55,629,630],{},"For noise-exposure work at the operator station, use SPL with distance corrections. For cleaning-coverage modelling inside the vessel, sound power and directivity are the more useful inputs.",[78,632,200],{"id":199},[202,634,635,639,643,647],{},[205,636,637],{},[62,638,256],{"href":239},[205,640,641],{},[62,642,209],{"href":64},[205,644,645],{},[62,646,225],{"href":184},[205,648,649],{},[62,650,651],{"href":621},"ISO 9614 (sound power)",{"title":227,"searchDepth":228,"depth":228,"links":653},[654,655,656],{"id":614,"depth":228,"text":615},{"id":626,"depth":228,"text":627},{"id":199,"depth":228,"text":200},"Sound power is the total acoustic energy a source emits per unit time, measured in watts. It is an intrinsic property of the source and does not change with listener distance. Sound pressure is the local pressure fluctuation at a measurement point, measured in pascals (and reported in decibels as SPL). Pressure falls with distance per the inverse-square law; power does not.",{},[388,241,243,660],"iso-9614-sound-power",{"title":662,"description":663},"Sound power vs sound pressure — what's the difference for sonic horns?","Sound power is the total acoustic energy a source emits per second and is a property of the source. Sound pressure is what a microphone measures at a point and falls with distance.",[665,668],{"title":666,"url":667},"Wikipedia — Sound power","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSound_power",{"title":669,"url":670},"ISO 9614 — Determination of sound power levels","https:\u002F\u002Fwww.iso.org\u002Fstandard\u002F24249.html","glossary\u002Fsound-power-vs-sound-pressure","s-f6ppBgdqiGjcmCwUO7MSFq5tucJMiULv_eua6axuw",{"id":674,"title":225,"aliases":675,"body":678,"category":234,"description":804,"extension":236,"meta":805,"navigation":238,"path":184,"relatedTerms":806,"seo":809,"sources":812,"stem":816,"term":225,"__hash__":817},"glossary\u002Fglossary\u002Finverse-square-law.md",[676,677],"1\u002Fr² law (acoustic)","geometric spreading",{"type":52,"value":679,"toc":798},[680,690,694,697,751,755,768,772,780,782],[55,681,268,682,684,685,460,687,689],{},[58,683,185],{}," states that the intensity of a point-source sound wave falls as 1\u002Fr² with distance. Expressed in ",[62,686,65],{"href":64},[62,688,49],{"href":239}," decreases by approximately 6 dB for every doubling of distance from the source in a free field.",[78,691,693],{"id":692},"worked-example-for-a-sonic-horn","Worked example for a sonic horn",[55,695,696],{},"A horn rated at 150 dB SPL at 1 m on the bell axis will produce, in free-field conditions:",[83,698,699,709],{},[86,700,701],{},[89,702,703,706],{},[92,704,705],{},"Distance",[92,707,708],{},"Approximate SPL",[99,710,711,719,727,735,743],{},[89,712,713,716],{},[104,714,715],{},"1 m",[104,717,718],{},"150 dB",[89,720,721,724],{},[104,722,723],{},"2 m",[104,725,726],{},"144 dB",[89,728,729,732],{},[104,730,731],{},"4 m",[104,733,734],{},"138 dB",[89,736,737,740],{},[104,738,739],{},"8 m",[104,741,742],{},"132 dB",[89,744,745,748],{},[104,746,747],{},"16 m",[104,749,750],{},"126 dB",[78,752,754],{"id":753},"where-the-rule-breaks-down","Where the rule breaks down",[55,756,757,758,762,763,767],{},"Three real conditions modify the textbook result. Inside a vessel, reflections from walls and tube banks reinforce the sound field and slow the fall-off; geometry no longer behaves as a free field. In the ",[62,759,761],{"href":760},"\u002Fglossary\u002Fnear-field-far-field","near field"," of the bell, the simple 1\u002Fr² rule does not apply. And at long distances and high frequencies, ",[62,764,766],{"href":765},"\u002Fglossary\u002Fattenuation-acoustic","attenuation"," absorbs additional energy beyond geometric spreading.",[78,769,771],{"id":770},"why-it-matters-for-noise-exposure","Why it matters for noise exposure",[55,773,774,775,71,777,779],{},"Worker exposure assessments work backwards from the inverse-square law: knowing the nameplate SPL and the operator-station distance, the predicted exposure can be compared with ",[62,776,190],{"href":189},[62,778,195],{"href":194}," action levels.",[78,781,200],{"id":199},[202,783,784,788,793],{},[205,785,786],{},[62,787,256],{"href":239},[205,789,790],{},[62,791,792],{"href":765},"Attenuation (acoustic)",[205,794,795],{},[62,796,797],{"href":760},"Near field \u002F far field",{"title":227,"searchDepth":228,"depth":228,"links":799},[800,801,802,803],{"id":692,"depth":228,"text":693},{"id":753,"depth":228,"text":754},{"id":770,"depth":228,"text":771},{"id":199,"depth":228,"text":200},"The inverse-square law states that the intensity of a point-source sound wave falls as 1\u002Fr² with distance. Expressed in decibels, SPL decreases by approximately 6 dB for every doubling of distance from the source in a free field.",{},[388,807,808],"attenuation-acoustic","near-field-far-field",{"title":810,"description":811},"Inverse-square law — sound pressure halves every doubling of distance","In free-field conditions sound intensity falls as 1\u002Fr². Sound pressure level drops by approximately 6 dB for each doubling of distance from the source.",[813],{"title":814,"url":815},"Wikipedia — Inverse-square law","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FInverse-square_law","glossary\u002Finverse-square-law","EYJdDFIbE5CXCp0ONbKYLs6jeZE8zRgWkX6myn6g82k",{"id":819,"title":820,"aliases":821,"body":825,"category":1011,"description":1012,"extension":236,"meta":1013,"navigation":238,"path":69,"relatedTerms":1014,"seo":1020,"sources":1023,"stem":1033,"term":820,"__hash__":1034},"glossary\u002Fglossary\u002Fsonic-horn.md","Sonic horn",[822,823,824],"sonic horns","sonic cleaning horn","industrial sonic horn",{"type":52,"value":826,"toc":1004},[827,851,855,863,867,927,931,961,965,973,975],[55,828,829,830,832,833,835,836,460,838,460,841,460,843,191,847,623],{},"A ",[58,831,70],{}," 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 ",[62,834,75],{"href":74}," and the default specification for cleaning ",[62,837,482],{"href":481},[62,839,840],{"href":506},"baghouses",[62,842,511],{"href":510},[62,844,846],{"href":845},"\u002Fglossary\u002Fsuperheater","boiler heat-transfer surfaces",[62,848,850],{"href":849},"\u002Fglossary\u002Fhopper","hoppers and silos",[78,852,854],{"id":853},"how-a-sonic-horn-works","How a sonic horn works",[55,856,857,858,862],{},"Compressed plant air admitted through a ",[62,859,861],{"href":860},"\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.",[78,864,866],{"id":865},"key-parameters","Key parameters",[83,868,869,879],{},[86,870,871],{},[89,872,873,876],{},[92,874,875],{},"Parameter",[92,877,878],{},"Typical range",[99,880,881,888,895,903,911,919],{},[89,882,883,885],{},[104,884,545],{},[104,886,887],{},"60–400 Hz",[89,889,890,892],{},[104,891,256],{},[104,893,894],{},"140–180 dB",[89,896,897,900],{},[104,898,899],{},"Compressed-air consumption",[104,901,902],{},"8–14 Nm³\u002Fmin at 4–7 bar",[89,904,905,908],{},[104,906,907],{},"Operating temperature (with appropriate materials)",[104,909,910],{},"−40 °C to +500 °C",[89,912,913,916],{},[104,914,915],{},"Firing cycle",[104,917,918],{},"5–15 s burst, repeated every 3–15 minutes",[89,920,921,924],{},[104,922,923],{},"Mass",[104,925,926],{},"15–60 kg depending on horn size",[78,928,930],{"id":929},"frequency-selection","Frequency selection",[55,932,933,934,460,936,939,940,460,944,946,947,460,950,954,955,191,958,623],{},"Lower frequencies (60–125 Hz) project longer wavelengths and penetrate further into large open vessels — ",[62,935,486],{"href":485},[62,937,938],{"href":458},"recovery-boiler superheaters",", large ",[62,941,943],{"href":942},"\u002Fglossary\u002Fesp-field-bus-section","ESP fields",[62,945,490],{"href":489},". Higher frequencies (230–400 Hz) carry more energy per unit volume and suit finer dust loads in ",[62,948,949],{"href":506},"fabric-filter compartments",[62,951,953],{"href":952},"\u002Fglossary\u002Fhoneycomb-catalyst","catalyst layers"," and smaller hopper geometries. See ",[62,956,957],{"href":550},"low-frequency acoustic cleaner",[62,959,960],{"href":556},"high-frequency acoustic cleaner",[78,962,964],{"id":963},"sonic-horn-vs-steam-sootblower","Sonic horn vs steam sootblower",[55,966,967,968,972],{},"Sonic horns are increasingly specified alongside or in place of ",[62,969,971],{"href":970},"\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.",[78,974,200],{"id":199},[202,976,977,982,988,994,1000],{},[205,978,979],{},[62,980,981],{"href":74},"Acoustic cleaner",[205,983,984],{},[62,985,987],{"href":986},"\u002Fglossary\u002Fsonic-sootblower","Sonic sootblower",[205,989,990],{},[62,991,993],{"href":992},"\u002Fglossary\u002Fbell-horn","Bell horn",[205,995,996],{},[62,997,999],{"href":998},"\u002Fglossary\u002Fdiaphragm-horn","Diaphragm horn",[205,1001,1002],{},[62,1003,551],{"href":550},{"title":227,"searchDepth":228,"depth":228,"links":1005},[1006,1007,1008,1009,1010],{"id":853,"depth":228,"text":854},{"id":865,"depth":228,"text":866},{"id":929,"depth":228,"text":930},{"id":963,"depth":228,"text":964},{"id":199,"depth":228,"text":200},"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.",{},[1015,1016,1017,1018,1019,573],"acoustic-cleaner","acoustic-cleaning-system","sonic-sootblower","bell-horn","diaphragm-horn",{"title":1021,"description":1022},"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.",[1024,1027,1030],{"title":1025,"url":1026},"Power Engineering — Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":1028,"url":1029},"Power Engineering — Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":1031,"url":1032},"Wikipedia — Sonic soot blowers","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSonic_soot_blowers","glossary\u002Fsonic-horn","YzrhN0kKzqSaQo0wfn0rueNZ-V43mcg5zahqeWi3lnU",1782613716067]