[{"data":1,"prerenderedAt":601},["ShallowReactive",2],{"site-footer-common":3,"glossary:direct-reduced-iron":45,"glossary-related:direct-reduced-iron":153},{"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":53,"category":134,"description":135,"extension":136,"meta":137,"navigation":138,"path":139,"relatedTerms":140,"seo":143,"sources":146,"stem":150,"term":151,"__hash__":152},"glossary\u002Fglossary\u002Fdirect-reduced-iron.md","Direct reduced iron (DRI)",[49,50,51,52],"DRI","sponge iron","HBI","hot-briquetted iron",{"type":54,"value":55,"toc":128},"minimark",[56,69,74,77,93,106,110],[57,58,59,62,63,68],"p",{},[60,61,47],"strong",{}," is iron produced from iron-ore pellets by reducing the ore in the solid state, using natural gas, hydrogen or coal as the reducing agent. DRI feeds ",[64,65,67],"a",{"href":66},"\u002Fglossary\u002Felectric-arc-furnace","electric arc furnaces"," and is the leading candidate for low-carbon iron-making, particularly with hydrogen as the reducer.",[70,71,73],"h2",{"id":72},"dri-dust-handling-issues","DRI dust-handling issues",[57,75,76],{},"DRI processes generate fine iron-bearing dust at multiple points:",[78,79,80,84,87,90],"ul",{},[81,82,83],"li",{},"DRI plant baghouse hoppers",[81,85,86],{},"DRI cooler dust extraction",[81,88,89],{},"HBI (hot-briquetted iron) hot screening dust",[81,91,92],{},"Storage-silo discharge points",[57,94,95,96,100,101,105],{},"The dust is fine, dense, and prone to ",[64,97,99],{"href":98},"\u002Fglossary\u002Fbridging","bridging"," under self-weight in tall silos. ",[64,102,104],{"href":103},"\u002Fglossary\u002Fsonic-horn","Sonic horns"," on DRI dust hoppers prevent the discharge interruptions that would otherwise force operator intervention.",[70,107,109],{"id":108},"related-terms","Related terms",[78,111,112,117,123],{},[81,113,114],{},[64,115,116],{"href":66},"Electric arc furnace (EAF)",[81,118,119],{},[64,120,122],{"href":121},"\u002Fglossary\u002Fhopper","Hopper",[81,124,125],{},[64,126,127],{"href":98},"Bridging",{"title":129,"searchDepth":130,"depth":130,"links":131},"",2,[132,133],{"id":72,"depth":130,"text":73},{"id":108,"depth":130,"text":109},"steel-refining","Direct reduced iron (DRI) is iron produced from iron-ore pellets by reducing the ore in the solid state, using natural gas, hydrogen or coal as the reducing agent. DRI feeds electric arc furnaces and is the leading candidate for low-carbon iron-making, particularly with hydrogen as the reducer.","md",{},true,"\u002Fglossary\u002Fdirect-reduced-iron",[141,142,99],"electric-arc-furnace","hopper",{"title":144,"description":145},"Direct reduced iron (DRI) — low-carbon iron-making route gaining ground","DRI reduces iron-ore pellets to metallic iron in solid state using gas or coal. Hopper bridging in DRI dust handling is a recurring operational issue.",[147],{"title":148,"url":149},"Wikipedia — Direct reduced iron","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FDirect_reduced_iron","glossary\u002Fdirect-reduced-iron","Direct reduced iron","S4IYmePoRAKzMuBxU7QP5kti_BJsw31XihNBmP9RtZ4",[154,239,400],{"id":155,"title":116,"aliases":156,"body":160,"category":134,"description":223,"extension":136,"meta":224,"navigation":138,"path":66,"relatedTerms":225,"seo":229,"sources":232,"stem":236,"term":237,"__hash__":238},"glossary\u002Fglossary\u002Felectric-arc-furnace.md",[157,158,159],"EAF","arc furnace","DC arc furnace",{"type":54,"value":161,"toc":218},[162,173,177,185,189,194,196],[57,163,164,165,168,169,172],{},"An ",[60,166,167],{},"electric arc furnace (EAF)"," melts steel scrap and ",[64,170,171],{"href":139},"direct reduced iron (DRI)"," in a refractory-lined vessel using a high-current electric arc between graphite electrodes and the metal bath. EAF steelmaking is the dominant route in scrap-rich economies (US, Italy, Türkiye, parts of South-East Asia) and is the primary growth path for low-carbon steel via \"mini-mill\" production.",[70,174,176],{"id":175},"fume-capture-and-cleaning","Fume capture and cleaning",[57,178,179,180,184],{},"EAF off-gas leaves the furnace through a fourth-hole evacuation duct, is combined with secondary canopy hood emissions, and is collected at a large ",[64,181,183],{"href":182},"\u002Fglossary\u002Fbaghouse","baghouse"," — typical capacity 1,000–3,000 m³\u002Fs. The baghouse compartments handle fine ferrous and non-ferrous oxide dust at temperatures of 80–150 °C.",[70,186,188],{"id":187},"sonic-horn-duty","Sonic-horn duty",[57,190,191,193],{},[64,192,104],{"href":103}," on EAF baghouse compartment roofs and hoppers prevent fine-dust bridging. The hopper duty is particularly demanding because EAF dust contains zinc oxide (from galvanised scrap), which is hygroscopic and sticky.",[70,195,109],{"id":108},[78,197,198,204,208,213],{},[81,199,200],{},[64,201,203],{"href":202},"\u002Fglossary\u002Fbasic-oxygen-furnace","Basic oxygen furnace (BOF)",[81,205,206],{},[64,207,47],{"href":139},[81,209,210],{},[64,211,212],{"href":182},"Baghouse",[81,214,215],{},[64,216,217],{"href":103},"Sonic horn",{"title":129,"searchDepth":130,"depth":130,"links":219},[220,221,222],{"id":175,"depth":130,"text":176},{"id":187,"depth":130,"text":188},{"id":108,"depth":130,"text":109},"An electric arc furnace (EAF) melts steel scrap and direct reduced iron (DRI) in a refractory-lined vessel using a high-current electric arc between graphite electrodes and the metal bath. EAF steelmaking is the dominant route in scrap-rich economies (US, Italy, Türkiye, parts of South-East Asia) and is the primary growth path for low-carbon steel via \"mini-mill\" production.",{},[226,227,183,228],"basic-oxygen-furnace","direct-reduced-iron","sonic-horn",{"title":230,"description":231},"Electric arc furnace (EAF) — scrap-based steelmaking with electric heating","An EAF melts steel scrap and DRI in a refractory-lined vessel using an electric arc. Dust collection is via a roof-evacuation duct to a large baghouse, prone to compartment fouling.",[233],{"title":234,"url":235},"Wikipedia — Electric arc furnace","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FElectric_arc_furnace","glossary\u002Felectric-arc-furnace","Electric arc furnace","IGVrtjmWxkk0gPKwQd8c2UxW2mHpRPsPMkuofdUYDHI",{"id":240,"title":122,"aliases":241,"body":245,"category":382,"description":383,"extension":136,"meta":384,"navigation":138,"path":121,"relatedTerms":385,"seo":391,"sources":394,"stem":398,"term":122,"__hash__":399},"glossary\u002Fglossary\u002Fhopper.md",[242,243,244],"hoppers","storage hopper","process hopper",{"type":54,"value":246,"toc":377},[247,278,282,316,320,338,340],[57,248,249,250,252,253,257,258,257,261,257,265,269,270,257,274,277],{},"A ",[60,251,142],{}," is an inverted-pyramid or conical vessel designed to store bulk solids and discharge them through a converging outlet. Hoppers appear under ",[64,254,256],{"href":255},"\u002Fglossary\u002Felectrostatic-precipitator","ESPs",", ",[64,259,260],{"href":182},"baghouses",[64,262,264],{"href":263},"\u002Fglossary\u002Feconomiser","economisers",[64,266,268],{"href":267},"\u002Fglossary\u002Fair-heater","air heaters"," and process equipment of every kind across cement, power, ",[64,271,273],{"href":272},"\u002Fglossary\u002Fwaste-to-energy","WtE",[64,275,276],{"href":272},"biomass",", refining, pharma, food and mining.",[70,279,281],{"id":280},"universal-failure-modes","Universal failure modes",[78,283,284,291,300,306],{},[81,285,286,290],{},[60,287,288],{},[64,289,127],{"href":98}," — stable arch forms above the outlet",[81,292,293,299],{},[60,294,295],{},[64,296,298],{"href":297},"\u002Fglossary\u002Frat-holing","Rat-holing"," — narrow channel above the outlet; surrounding material packs and hardens",[81,301,302,305],{},[60,303,304],{},"Pluggage"," — total blockage that stops discharge",[81,307,308,315],{},[60,309,310,311],{},"Funnel flow vs ",[64,312,314],{"href":313},"\u002Fglossary\u002Fmass-flow-vs-funnel-flow","mass flow"," — first-in, last-out behaviour leading to ageing material remaining indefinitely",[70,317,319],{"id":318},"why-acoustic-cleaning-works-on-hoppers","Why acoustic cleaning works on hoppers",[57,321,322,324,325,257,329,257,333,337],{},[64,323,104],{"href":103}," excel on hoppers because the geometry is small enough for the sound wave to fill the whole vessel and the dust is dry and friable. Compared with mechanical alternatives — ",[64,326,328],{"href":327},"\u002Fglossary\u002Fbin-vibrator","bin vibrators",[64,330,332],{"href":331},"\u002Fglossary\u002Fair-cannon-air-blaster","air cannons",[64,334,336],{"href":335},"\u002Fglossary\u002Fwhip-hammer","whip hammers"," — they cause no structural stress, no fatigue, and no impact damage to the hopper itself.",[70,339,109],{"id":108},[78,341,342,348,354,360,364,368,373],{},[81,343,344],{},[64,345,347],{"href":346},"\u002Fglossary\u002Fsilo","Silo",[81,349,350],{},[64,351,353],{"href":352},"\u002Fglossary\u002Fbunker-coal-bunker","Bunker \u002F coal bunker",[81,355,356],{},[64,357,359],{"href":358},"\u002Fglossary\u002Fbin","Bin",[81,361,362],{},[64,363,127],{"href":98},[81,365,366],{},[64,367,298],{"href":297},[81,369,370],{},[64,371,372],{"href":313},"Mass flow vs funnel flow",[81,374,375],{},[64,376,217],{"href":103},{"title":129,"searchDepth":130,"depth":130,"links":378},[379,380,381],{"id":280,"depth":130,"text":281},{"id":318,"depth":130,"text":319},{"id":108,"depth":130,"text":109},"hoppers-silos","A hopper is an inverted-pyramid or conical vessel designed to store bulk solids and discharge them through a converging outlet. Hoppers appear under ESPs, baghouses, economisers, air heaters and process equipment of every kind across cement, power, WtE, biomass, refining, pharma, food and mining.",{},[386,387,388,99,389,390,228],"silo","bunker-coal-bunker","bin","rat-holing","mass-flow-vs-funnel-flow",{"title":392,"description":393},"Hopper — converging vessel for storing and discharging bulk solids","A hopper is an inverted-pyramid or conical vessel for storing and discharging bulk solids. Bridging and rat-holing are the universal failure modes; sonic horns are a clean, low-maintenance remedy.",[395],{"title":396,"url":397},"Wikipedia — Hopper (particulate collection container)","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FHopper_(particulate_collection_container)","glossary\u002Fhopper","yaS0yQSinQlli40xEUR0l9zzxphPNmE4Pi2XHYeAc4k",{"id":401,"title":127,"aliases":402,"body":407,"category":382,"description":585,"extension":136,"meta":586,"navigation":138,"path":98,"relatedTerms":587,"seo":588,"sources":591,"stem":598,"term":599,"__hash__":600},"glossary\u002Fglossary\u002Fbridging.md",[403,404,405,406],"arching","arch formation","hopper bridging","silo bridging",{"type":54,"value":408,"toc":579},[409,426,430,433,455,459,473,477,555,557],[57,410,411,413,414,417,418,420,421,417,423,425],{},[60,412,127],{}," (also ",[415,416,403],"em",{}," or ",[415,419,404],{},") is the formation of a stable mechanical arch of bulk-solid material above the discharge outlet of a ",[64,422,142],{"href":121},[64,424,386],{"href":346},". Once a bridge forms, no material flows out of the outlet even though the vessel above is full. Bridging is the universal failure mode of bulk-solids storage.",[70,427,429],{"id":428},"how-a-bridge-forms","How a bridge forms",[57,431,432],{},"Cohesive forces between particles — moisture films, electrostatic charge, chemical bonding — combine with the converging-flow geometry to lock particles into an arch shape. The arch is self-supporting against the load above. Cohesion increases with:",[78,434,435,443,446,449,452],{},[81,436,437,438,442],{},"Fine particle size (especially Geldart-C powders — see ",[64,439,441],{"href":440},"\u002Fglossary\u002Fgeldart-classification","Geldart classification",")",[81,444,445],{},"Moisture",[81,447,448],{},"Hygroscopic chemistry (urea, ammonium nitrate, lime)",[81,450,451],{},"Long residence time (consolidation under sustained load)",[81,453,454],{},"Temperature cycling",[70,456,458],{"id":457},"diagnosing-a-bridge","Diagnosing a bridge",[78,460,461,464,467,470],{},[81,462,463],{},"Outlet flow stops while the level above remains high",[81,465,466],{},"Mass-flow indicators report no movement",[81,468,469],{},"A simple tap on the hopper outside the discharge cone produces a hollow sound",[81,471,472],{},"Borescope inspection from the inlet shows the arch directly",[70,474,476],{"id":475},"remedies","Remedies",[478,479,480,493],"table",{},[481,482,483],"thead",{},[484,485,486,490],"tr",{},[487,488,489],"th",{},"Technique",[487,491,492],{},"Notes",[494,495,496,506,516,526,536,547],"tbody",{},[484,497,498,503],{},[499,500,501],"td",{},[64,502,217],{"href":103},[499,504,505],{},"Continuous prevention; non-contact; minimal infrastructure",[484,507,508,513],{},[499,509,510],{},[64,511,512],{"href":331},"Air cannon",[499,514,515],{},"High-intensity periodic; effective on hard bridges; structural stress",[484,517,518,523],{},[499,519,520],{},[64,521,522],{"href":327},"Bin vibrator",[499,524,525],{},"Continuous vibration; can compact powder further if poorly sized",[484,527,528,533],{},[499,529,530],{},[64,531,532],{"href":335},"Whip hammer",[499,534,535],{},"Manual; legacy; HSE concerns",[484,537,538,544],{},[499,539,540],{},[64,541,543],{"href":542},"\u002Fglossary\u002Ffluidisation-pad-aeration-pad","Fluidisation pad",[499,545,546],{},"Aerates the lower vessel; not suitable for wet material",[484,548,549,552],{},[499,550,551],{},"Mechanical screw extractor",[499,553,554],{},"Bypasses the bridge entirely; high capex",[70,556,109],{"id":108},[78,558,559,563,567,571,575],{},[81,560,561],{},[64,562,122],{"href":121},[81,564,565],{},[64,566,347],{"href":346},[81,568,569],{},[64,570,298],{"href":297},[81,572,573],{},[64,574,372],{"href":313},[81,576,577],{},[64,578,217],{"href":103},{"title":129,"searchDepth":130,"depth":130,"links":580},[581,582,583,584],{"id":428,"depth":130,"text":429},{"id":457,"depth":130,"text":458},{"id":475,"depth":130,"text":476},{"id":108,"depth":130,"text":109},"Bridging (also arching or arch formation) is the formation of a stable mechanical arch of bulk-solid material above the discharge outlet of a hopper or silo. Once a bridge forms, no material flows out of the outlet even though the vessel above is full. Bridging is the universal failure mode of bulk-solids storage.",{},[142,386,389,390,228],{"title":589,"description":590},"Bridging — stable arch above the discharge of a hopper or silo","Bridging (also arching) is the formation of a stable arch of bulk solids above the discharge outlet of a hopper or silo, stopping material flow. The universal failure mode of bulk-solids storage.",[592,595],{"title":593,"url":594},"Powder & Bulk Solids — Preventing Rat-Holing and Bridging in Powder Silos","https:\u002F\u002Fsgsystemsglobal.com\u002Fglossary\u002Fsilo-rat-holing-and-bridging\u002F",{"title":596,"url":597},"Accendo Reliability — Bridging in Silos and Hoppers","https:\u002F\u002Faccendoreliability.com\u002Fbridging-silos-hoppers\u002F","glossary\u002Fbridging","Bridging (bulk-solids)","qG-iJwvR3z5_NliCxfeui3lEL9wxjVY3kU3rO9JWn8g",1782613756576]