[{"data":1,"prerenderedAt":528},["ShallowReactive",2],{"site-footer-common":3,"resources-blog:ljungstrom-air-preheater-fouling":45},{"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,"author":48,"body":49,"description":476,"extension":477,"meta":478,"navigation":479,"path":480,"primaryKeyword":70,"publishedAt":481,"secondaryKeywords":482,"seo":488,"sources":491,"stem":522,"summary":523,"updatedAt":481,"__hash__":527},"blog\u002Fresources\u002Fblog\u002Fljungstrom-air-preheater-fouling.md","Ljungström air preheater fouling: what the rising pressure-drop is really telling you","Sylio",{"type":50,"value":51,"toc":460},"minimark",[52,57,72,75,78,82,90,103,106,114,117,121,129,132,135,138,141,145,148,153,180,183,186,189,193,201,208,211,215,218,299,312,320,328,351,354,357,361,369,372,375,383,391,395,398,444,447,451,454,457],[53,54,56],"h2",{"id":55},"rising-pressure-drop-is-a-symptom","Rising pressure drop is a symptom",[58,59,60,61,66,67,71],"p",{},"On a ",[62,63,65],"a",{"href":64},"\u002Fglossary\u002Fljungstrom-air-preheater","Ljungström air preheater",", ",[68,69,70],"strong",{},"air preheater fouling"," usually announces itself as rising pressure drop, not as a deposit that operators can see. The forced-draught and induced-draught fans work harder, their margin disappears, and the unit eventually reaches a load it can no longer hold. High air preheater differential pressure is therefore a serious warning, but it is not yet a diagnosis.",[58,73,74],{},"That distinction decides whether cleaning will help. Dry fly ash packed into hot-end and intermediate baskets is a genuine online prevention opportunity. Sticky ammonium bisulphate in the cold end is a washing and temperature-management problem. Cold-end corrosion is a chemistry and metal-temperature problem. All three can narrow the gas path and raise pressure drop, but they do not respond to the same tool.",[58,76,77],{},"The useful question is not simply how to clean the air heater. It is what has increased the resistance, where it sits, and whether the deposit is still dry and movable. Match those three facts to the cleaning method and rising pressure drop becomes an early operating signal. Ignore them and the plant can spend more steam, air and outage time working the wrong mechanism.",[53,79,81],{"id":80},"what-air-preheater-high-differential-pressure-is-telling-you","What air preheater high differential pressure is telling you",[58,83,84,85,89],{},"Differential pressure is the pressure lost as combustion air and flue gas pass through the narrow channels in the heat-transfer baskets. A clean basket already has designed resistance. As ash bridges channels, coats plate edges or roughens the passages, the open flow area falls and drag rises. Flow then redistributes through the passages that remain open, increasing local velocity and encouraging further ",[62,86,88],{"href":87},"\u002Fglossary\u002Fheat-transfer-surface-fouling","heat-transfer surface fouling",".",[58,91,92,93,97,98,102],{},"The penalty is hydraulic before it is thermal. The FD, primary-air and ",[62,94,96],{"href":95},"\u002Fglossary\u002Fid-fan","ID fans"," must produce more head to hold the required air and gas flow. Fan power rises. If a fan reaches its motor-current, speed, damper or stall limit, the boiler cannot add more fuel safely because it cannot move enough air and flue gas. The operator has to reduce load, turning air heater pluggage into a ",[62,99,101],{"href":100},"\u002Fglossary\u002Fderate-capacity","capacity derate"," and lost generation.",[58,104,105],{},"The size of that loss is plant-specific. One published 600 MW case reported that cold-end plugging forced the unit below 470 MW, a reduction of more than 20 per cent. That is not a benchmark for another station, but it shows the mechanism clearly: basket resistance consumed the fan margin, and fan margin capped the boiler. In a separate 760 MW case involving fouled air-heater coils, specialist offline cleaning cut air-side pressure drop from 8 to 4 inches of water, although it did not restore the original 1.7-inch design value.",[58,107,108,109,113],{},"Raw differential pressure still needs context. Pressure drop changes with gas flow, density, temperature, excess air and leakage, so a low-load reading should not be compared directly with a full-load reading. Trend it at a consistent operating point, or correct it to a reference flow and temperature. Confirm the pressure transmitters and impulse lines as well. The same discipline used to interpret a ",[62,110,112],{"href":111},"\u002Fresources\u002Fblog\u002Fbaghouse-differential-pressure-rising","rising baghouse differential pressure"," applies here: watch the comparable baseline, not an isolated high number.",[58,115,116],{},"Even a well-corrected trend cannot identify the deposit by itself. It tells you that resistance has increased. Temperature history, SCR operation, cleaning response and inspection evidence tell you why.",[53,118,120],{"id":119},"where-a-ljungström-air-preheater-fouls","Where a Ljungström air preheater fouls",[58,122,123,124,128],{},"A rotary regenerative ",[62,125,127],{"href":126},"\u002Fglossary\u002Fair-heater","air heater"," contains a slow-turning rotor filled with corrugated steel heating elements held in baskets. Each sector passes alternately through hot flue gas and cooler combustion air. The metal absorbs heat from the gas, rotates into the air side and gives that heat to the incoming air. This cycling provides compact, effective heat recovery, but it also presents a deep matrix of narrow passages to an ash-bearing gas stream.",[58,130,131],{},"The temperature is not uniform through the rotor depth. The gas inlet is the hot end, followed by an intermediate layer and the cold end near the gas outlet. The baskets therefore see different deposit mechanisms.",[58,133,134],{},"At the hot end and through much of the intermediate layer, entrained fly ash is often still dry. Larger particles can lodge at element entrances or between corrugations. Finer ash settles on edges, catches behind existing particles and gradually packs the channel. Surface profile, ash loading, gas velocity, fuel changes and the reach of existing sootblowers all affect the rate.",[58,136,137],{},"Dry does not mean harmless. A friable layer can become denser as more particles arrive, and a small restriction can redirect flow into neighbouring channels. If oil, moisture or a reactive salt reaches the same zone, loose ash can become a much harder deposit. The important opportunity is timing: while the material remains dry and weakly held, it can be kept moving before consolidation turns prevention into recovery cleaning.",[58,139,140],{},"That is the genuine acoustic-cleaning zone. Distributed sound can reach plate gaps and shadowed spaces that a directed jet misses. It does not have to break a chemical bond. It only has to keep dry particles from staying long enough to pack the basket.",[53,142,144],{"id":143},"air-preheater-cold-end-fouling-abs-and-acid-are-different","Air preheater cold-end fouling: ABS and acid are different",[58,146,147],{},"The cold end needs a separate diagnosis because two chemistry-driven mechanisms can occur there, sometimes together. Calling both of them cold-end ash hides the reason ordinary cleaning struggles.",[149,150,152],"h3",{"id":151},"ammonium-bisulphate-air-heater-plugging","Ammonium bisulphate air heater plugging",[58,154,155,159,160,164,165,169,170,174,175,179],{},[62,156,158],{"href":157},"\u002Fglossary\u002Fammonium-bisulphate","Ammonium bisulphate",", or ABS, forms when unreacted ammonia meets sulphur trioxide or sulphuric acid in a cooling flue-gas stream. The ammonia commonly arrives as ",[62,161,163],{"href":162},"\u002Fglossary\u002Fammonia-slip","ammonia slip"," from an upstream ",[62,166,168],{"href":167},"\u002Fglossary\u002Fselective-catalytic-reduction","selective catalytic reduction"," system. The SO3 comes from the fuel and from ",[62,171,173],{"href":172},"\u002Fglossary\u002Fso2-so3-conversion","SO2 to SO3 conversion"," across the boiler and catalyst. The connection is why air-heater trends should be reviewed with the plant's ",[62,176,178],{"href":177},"\u002Fresources\u002Fblog\u002Fscr-catalyst-cleaning-sootblowers-vs-acoustic-horns","SCR catalyst-cleaning and ammonia-slip data",", not as an isolated auxiliary problem.",[58,181,182],{},"There is no universal ABS formation temperature. It shifts with the product of NH3 and SO3 concentrations, moisture, pressure and the way formation is measured. Reviews commonly place the relevant range around 190 to 240 degrees Celsius, while a bench-scale air-preheater channel found onset around 227 to 247 degrees Celsius at representative concentrations. Field deposition can be heaviest at lower metal temperatures, which is why a practical investigation may treat roughly 190 to 250 degrees Celsius as a working formation window but map the actual basket temperatures rather than rely on one threshold.",[58,184,185],{},"Once formed, ABS is sticky and acidic. It coats the plate surface and captures fly ash from the gas. The resulting salt-and-ash mass fills the narrow channels, often around the cold-to-intermediate transition where the deposit is hard for an end-mounted jet to reach. More ammonia slip or SO3 raises the formation potential, while low-load and cold-weather operation can move more basket metal into the deposition range.",[58,187,188],{},"This is not dry-ash fouling. Steam or air sootblowers are seldom effective once sticky ABS has accumulated deep in the layer, and acoustic horns are weaker still because sound does not dissolve a salt or supply high surface shear. Water washing is the established corrective method. The lasting controls are to reduce ammonia slip and SO3 where practicable, improve distribution, and, where the unit design permits, keep cold-end metal above the unit-specific ABS formation temperature.",[149,190,192],{"id":191},"acid-dew-point-corrosion","Acid dew-point corrosion",[58,194,195,196,200],{},"Sulphuric acid condensation is related but distinct. When element metal falls below the ",[62,197,199],{"href":198},"\u002Fglossary\u002Facid-dew-point","acid dew point",", acid condenses on the cold surface. It attacks the steel, creates iron sulphate corrosion products and leaves a rough, wet surface that captures more ash. The result can be both metal loss and blockage.",[58,202,203,207],{},[62,204,206],{"href":205},"\u002Fglossary\u002Fcold-end-corrosion-dew-point-corrosion","Cold-end corrosion"," is not cured by removing one deposit. Washing may expose the surface and clear soluble material, but if the same temperature and chemistry return, condensation returns too. Inlet-air preheating, hot-air recirculation, cold-air bypass, SO3 management, corrosion-resistant or enamelled elements, and revised basket depth can all be relevant. Each carries design, efficiency or operating trade-offs that should be evaluated for the unit.",[58,209,210],{},"ABS plugging and acid corrosion can reinforce each other, but they should not be merged into one cleaning claim. ABS begins with ammonia and sulphur chemistry. Acid corrosion begins with metal below the acid dew point. Both are temperature problems before they are cleaning problems.",[53,212,214],{"id":213},"air-preheater-sootblower-vs-water-wash-vs-acoustic-cleaning","Air preheater sootblower vs water wash vs acoustic cleaning",[58,216,217],{},"The cleaning options become clearer when they are compared by deposit state rather than by purchase price.",[219,220,221,240],"table",{},[222,223,224],"thead",{},[225,226,227,231,234,237],"tr",{},[228,229,230],"th",{},"Method",[228,232,233],{},"Best fit",[228,235,236],{},"Main limitation",[228,238,239],{},"Typical availability",[241,242,243,258,272,285],"tbody",{},[225,244,245,249,252,255],{},[246,247,248],"td",{},"Steam or air sootblower",[246,250,251],{},"Loose to moderately held ash within jet reach",[246,253,254],{},"Limited penetration into deep, sticky ABS; moisture and erosion risk",[246,256,257],{},"Online",[225,259,260,263,266,269],{},[246,261,262],{},"Water wash or hydroblasting",[246,264,265],{},"ABS, soluble salts and heavy cold-end plugging",[246,267,268],{},"Isolation, drainage, effluent, drying and corrosion control",[246,270,271],{},"Usually offline",[225,273,274,277,280,283],{},[246,275,276],{},"Acoustic horn",[246,278,279],{},"Dry, friable fly ash before it packs or bonds",[246,281,282],{},"Not a rescue method for sticky, molten or hardened deposits",[246,284,257],{},[225,286,287,290,293,296],{},[246,288,289],{},"Pressurised liquid nitrogen",[246,291,292],{},"Specialist removal of tenacious offline deposits",[246,294,295],{},"Access, contractor logistics and no ongoing prevention",[246,297,298],{},"Offline",[58,300,301,302,306,307,311],{},"A ",[62,303,305],{"href":304},"\u002Fglossary\u002Fsteam-sootblower","steam sootblower"," or compressed-air blower sends a directed jet at the basket face. It can remove loose ash and some consolidated material when the nozzle pattern, pressure and dwell are correct. Hot-end and cold-end blowers may complement each other. The limitations are reach and deposit behaviour. A jet loses energy with distance, can push material deeper into a layer and can deform or fatigue thin element plates if used too aggressively. Wet steam adds moisture to exactly the place where ash adhesion is already a risk. The broader ",[62,308,310],{"href":309},"\u002Fresources\u002Fblog\u002Fsonic-horn-vs-steam-sootblower","sonic-horn versus steam-sootblower comparison"," explains why the two methods should not be treated as interchangeable.",[58,313,314,315,319],{},"Water washing dissolves ABS and flushes salt, ash and corrosion products out of the channels. Offline ",[62,316,318],{"href":317},"\u002Fglossary\u002Fhydroblasting-offline","hydroblasting"," adds impact for harder residual deposits. This is why washing is the honest answer to severe ammonium bisulphate air heater plugging. It is also a significant maintenance event. Published utility experience puts the wash itself at roughly 6 to 14 hours, with shutdown, cooling, isolation and drying taking the total outage to around 30 hours or more. The plant needs drainage, effluent treatment, protection of downstream equipment and enough drying time to stop fresh ash sticking to wet metal. Repeated washing can also accelerate corrosion if deposits are not removed and the unit dried correctly.",[58,321,322,323,327],{},"Some twin-air-heater arrangements can isolate and wash one unit at reduced boiler load, but that does not make washing an ordinary online clean. The distinction between ",[62,324,326],{"href":325},"\u002Fglossary\u002Fonline-vs-offline-cleaning","online and offline cleaning"," still matters: isolation, water management and reduced output remain part of the intervention.",[58,329,330,331,335,336,340,341,345,346,350],{},"An ",[62,332,334],{"href":333},"\u002Fglossary\u002Facoustic-cleaning-system","acoustic cleaning system"," uses short bursts of low-frequency sound to disturb particles throughout a gas volume. Typical industrial ",[62,337,339],{"href":338},"\u002Fglossary\u002Fsonic-horn","sonic horns"," operate around 125 to 250 hertz and produce about 140 to 150 decibels near the bell. ",[62,342,344],{"href":343},"\u002Fglossary\u002Fcompressed-air","Compressed air"," drives a diaphragm, and the horn geometry couples the pressure wave into the casing. The method is non-contact and reaches around many obstructions, which makes it attractive for dry ash in deep, complex passages. The full ",[62,347,349],{"href":348},"\u002Fresources\u002Fblog\u002Facoustic-cleaning-system","acoustic-cleaning system guide"," covers air supply, controls, placement and commissioning.",[58,352,353],{},"Its low surface force is both the advantage and the limit. Sound can keep loose particles oscillating and stop a weak deposit from consolidating. It cannot peel off a sticky ABS layer, reverse acid attack or break a hard shell reliably. A horn should normally start from a clean or recoverable surface and fire often enough that dry ash never gets the residence time to pack.",[58,355,356],{},"Pressurised liquid nitrogen is a specialist outage method rather than a routine competitor. Rapid cooling can fracture tenacious contamination with little average temperature change in the base metal. The published 760 MW case achieved a large pressure-drop improvement on finned air-heater coils, and sample Ljungström baskets were also cleaned successfully. It may be useful where water, detergents or ordinary blasting have failed, but it requires access, trained contractors and a shutdown. It does not provide continuing fouling control after the unit returns to service.",[53,358,360],{"id":359},"where-acoustic-cleaning-fits-and-where-it-does-not","Where acoustic cleaning fits, and where it does not",[58,362,363,364,368],{},"The strongest case for ",[62,365,367],{"href":366},"\u002Fglossary\u002Flow-frequency-acoustic-cleaner","low-frequency acoustic cleaning"," is dry fly ash on hot-end and intermediate baskets. The horn supplies frequent, distributed disturbance across the rotor face and between element passages. Ash that would otherwise settle at a ledge or bridge a corrugation stays mobile and leaves with the gas stream. Pressure-drop creep slows because the deposit is prevented, not because a mature blockage is attacked harder.",[58,370,371],{},"That role makes horns complementary to sootblowers. After an offline clean or recovery blow establishes a clean baseline, acoustic cleaning can carry the frequent prevention duty. Sootblowers remain available for material that needs a directed jet. If the dry-ash rate falls, the plant may be able to reduce sootblower frequency, steam use and plate wear, but any change should follow trend evidence rather than a promised percentage.",[58,373,374],{},"Placement and operation matter. A convenient nozzle is not necessarily an effective acoustic location. The design should account for rotor diameter, basket depth, casing geometry, gas velocity, ash loading, background temperature, sound propagation, access and the route by which loosened ash leaves. Firing intervals should be short enough to prevent consolidation and should be tuned against corrected pressure drop and inspection findings.",[58,376,377,378,382],{},"The boundary is just as important. Do not specify horns as an ABS-removal system. Do not ask them to repair acid corrosion. Do not expect a first firing to clear years of bonded material. Moisture, oil, salts and low-melting ash can turn a good acoustic duty into the kind of ",[62,379,381],{"href":380},"\u002Fresources\u002Fblog\u002Fsticky-ash-biomass-waste-to-energy-boilers","sticky-ash problem"," that needs a different recovery method.",[58,384,385,386,390],{},"The honest commercial case is therefore narrow and measurable: acoustic cleaning is an online prevention system for dry, friable ash in the zones where sound can couple effectively. Its value comes from holding pressure drop, reducing the cleaning burden and extending the interval between offline interventions. The plant-specific ",[62,387,389],{"href":388},"\u002Fresources\u002Fblog\u002Facoustic-cleaning-roi-payback","acoustic-cleaning ROI"," should be based on those avoided costs, not on a claim that one horn cures every form of air heater pluggage.",[53,392,394],{"id":393},"how-to-reduce-air-preheater-pressure-drop","How to reduce air preheater pressure drop",[58,396,397],{},"Start with the trend, but do not stop there. A useful response sequence separates measurement, location, deposit and remedy.",[399,400,401,408,414,420,426,432,438],"ol",{},[402,403,404,407],"li",{},[68,405,406],{},"Validate the signal."," Compare differential pressure at the same load, gas flow, temperature and excess-air condition. Check transmitter calibration and impulse lines. Trend gas, primary-air and secondary-air sides separately where the instrumentation allows it.",[402,409,410,413],{},[68,411,412],{},"Look for fan limitation."," Record fan current, speed or damper position, flow and control margin. This shows whether rising resistance is only an efficiency penalty or is already limiting boiler load.",[402,415,416,419],{},[68,417,418],{},"Map the temperature exposure."," Review cold-end average temperature, inlet-air temperature, ambient conditions and low-load periods. Average gas temperature is not the same as the minimum rotating metal temperature, so use an OEM or engineering model where the risk justifies it.",[402,421,422,425],{},[68,423,424],{},"Review upstream chemistry."," Trend ammonia slip, NOx distribution, coal sulphur, SO3 controls and catalyst condition. A pressure rise that follows SCR tuning or prolonged low-load operation points towards ABS more strongly than dry ash alone.",[402,427,428,431],{},[68,429,430],{},"Use cleaning response as evidence."," A repeatable fall after sootblowing suggests material within jet reach. A trend that barely responds to blowing but resets after washing points towards sticky salt or deep cold-end deposits. A horn trial should be judged by a slower rate of increase over a comparable operating campaign, not by an immediate dramatic drop.",[402,433,434,437],{},[68,435,436],{},"Inspect by zone."," Outage photographs, basket samples and deposit analysis should distinguish loose fly ash, sticky ABS, corrosion products and mixed deposits. The appearance and solubility of the deposit matter more than the generic label fouling.",[402,439,440,443],{},[68,441,442],{},"Match the intervention."," Use acoustic cleaning to prevent dry ash, sootblowers for reachable deposits needing more local force, water washing for ABS and soluble cold-end plugging, and temperature or chemistry changes for the mechanisms that cleaning cannot remove permanently.",[58,445,446],{},"This turns differential pressure into a maintenance decision rather than an alarm threshold. The goal is not merely to bring the number down once. It is to identify which condition makes it rise, remove the established deposit safely, and prevent the same mechanism from rebuilding it.",[53,448,450],{"id":449},"the-bottom-line","The bottom line",[58,452,453],{},"Rising pressure drop across a Ljungström air preheater means the flow path is becoming more resistant, but the gauge cannot tell you whether the cause is dry ash, sticky ammonium bisulphate or corrosion products. That diagnosis comes from zone temperature, upstream chemistry, cleaning response and inspection evidence. Until those agree, turning up any cleaner is guesswork.",[58,455,456],{},"Match the method to the mechanism. Acoustic horns are well suited to preventing dry fly ash from packing hot-end and intermediate baskets, especially after a clean baseline has been restored. Sootblowers provide more local force for deposits within their reach. Water washing remains the corrective answer for severe cold-end ABS plugging, while temperature and chemistry controls address why ABS and acid condensation formed in the first place.",[58,458,459],{},"That split is the practical meaning of the pressure-drop trend. It is not asking for one stronger cleaning device. It is asking the plant to separate a dry-particle problem from a sticky-salt problem and a corrosion problem, then act before fan margin becomes lost generation.",{"title":461,"searchDepth":462,"depth":462,"links":463},"",2,[464,465,466,467,472,473,474,475],{"id":55,"depth":462,"text":56},{"id":80,"depth":462,"text":81},{"id":119,"depth":462,"text":120},{"id":143,"depth":462,"text":144,"children":468},[469,471],{"id":151,"depth":470,"text":152},3,{"id":191,"depth":470,"text":192},{"id":213,"depth":462,"text":214},{"id":359,"depth":462,"text":360},{"id":393,"depth":462,"text":394},{"id":449,"depth":462,"text":450},"Learn what high air preheater differential pressure reveals, how dry ash differs from cold-end ABS, and which cleaning method fits each deposit.","md",{},true,"\u002Fresources\u002Fblog\u002Fljungstrom-air-preheater-fouling","2026-07-13",[483,484,485,486,487],"air preheater high differential pressure","air heater pluggage","air preheater cold end fouling","ammonium bisulphate air heater plugging","reduce air preheater pressure drop",{"title":489,"description":490},"Air preheater fouling and high differential pressure","Diagnose air preheater fouling from pressure-drop trends, separate dry ash from cold-end ABS, and choose acoustic cleaning, sootblowing or washing.",[492,495,498,501,504,507,510,513,516,519],{"title":493,"url":494},"LJUNGSTRÖM - Heat Transfer Solutions","https:\u002F\u002Fwww.ljungstrom.com\u002Fheat-transfer-solutions",{"title":496,"url":497},"Lehigh Energy Update - SCR and SNCR Processes Increase Risk of Air Preheater Fouling","https:\u002F\u002Fwww.lehigh.edu\u002F~inenr\u002Fleu\u002Fleu_27.pdf",{"title":499,"url":500},"Fuel - Ammonium Bisulfate Formation Temperature in a Bench-Scale Single-Channel Air Preheater","https:\u002F\u002Fdoi.org\u002F10.1016\u002Fj.fuel.2011.03.006",{"title":502,"url":503},"Environmental Science and Pollution Research - Status and Development for Detection and Control of Ammonium Bisulfate","https:\u002F\u002Fpmc.ncbi.nlm.nih.gov\u002Farticles\u002FPMC8129103\u002F",{"title":505,"url":506},"POWER Magazine - Power 101: Improving the Performance of Boiler Auxiliaries, Part II","https:\u002F\u002Fwww.powermag.com\u002Fpower-101-improving-the-performance-of-boiler-auxiliaries-part-ii\u002F",{"title":508,"url":509},"Babcock & Wilcox - Sootblower and Boiler Cleaning: Terminology, Principles and Applications","https:\u002F\u002Fwww.babcock.com\u002Fhome\u002Fabout\u002Fresources\u002Flearning-center\u002Fsootblower-and-boiler-cleaning-terminology-principles-and-applications",{"title":511,"url":512},"Power Engineering - Tuning in to Acoustic Cleaning","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Ftuning-in-to-acoustic-cleaning\u002F",{"title":514,"url":515},"Power Engineering - Sonic Horns: A User's Introduction","https:\u002F\u002Fwww.power-eng.com\u002Fcoal\u002Fsonic-horns-a-userrsquos-introduction\u002F",{"title":517,"url":518},"POWER Magazine - Innovative Cleaning of Air Preheater Coils with Pressurized Liquid Nitrogen","https:\u002F\u002Fwww.powermag.com\u002Finnovative-cleaning-of-air-preheater-coils-with-pressurized-liquid-nitrogen\u002F",{"title":520,"url":521},"Inner Mongolia Electric Power - Cause Analysis of Air Ducts Blocking on Air Preheater in 600 MW Unit and Its Treatment","https:\u002F\u002Fhtml.rhhz.net\u002Fnmgdljs\u002F20180113.htm","resources\u002Fblog\u002Fljungstrom-air-preheater-fouling",[524,525,526],"Rising differential pressure means basket resistance is increasing, but it does not identify the deposit or fouling zone.","Acoustic cleaning can prevent dry fly ash from packing hot-end and intermediate baskets after a clean baseline is restored.","Sticky cold-end ABS needs water washing and temperature or chemistry control; corrosion needs the same root-cause discipline.","555yCLlB4e8scsUMhizYDVudL72C8sE7Moo1qvFI9fA",1783975188198]