a McDermott company

Dry Flue GasDesulfurization (FGD)Systems

Proven spray dry absorber (SDA) process reliably meets low

SO2 emission limits

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SWEPCO-MU-Ex. 70

Typical B&W/Niro SDA system installationsoperate at 90 to 95 percent SO2 removalefficiency, with someplants running as highas 98 percent. SO3 andHCl removal efficienciesare normally greaterthan 95 percent.

The Babcock & Wilcox Company

(B&W) has been at the technological

forefront in providing cost-effective

solutions to tough emission control

problems for more than 30 years. Our

continued research and commercial

efforts in NOx, SO2, particulate and

mercury emissions reduction have led

to many advancements in air pollution

control technology.

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SWEPCO-MU-Ex. 70

B&W Spray Dry FGD Systems –Emission reduction with highavailability and reliability

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B&W’s commitment to pro-viding the best in emissionreduction technology forfossil fuel-fired power gen-eration continues with ourspray dry flue gas desulfur-ization (FGD) systems forcontrolling SO2 emissions.

B&W is the exclusive North American licensee of Niro A/S, Denmark, forits spray drying absorption(SDA) process. The twocompanies also worktogether worldwide on spe-cific project opportunities.The Niro process is globallyrecognized by the industryas the dry FGD technologyof choice and has the major-ity market share for all dryFGD processes. Since 1980,B&W/Niro’s continualrecord of utility, industrialand cogeneration dry FGDprojects has achieved asteady, long-term marketdominance.

SDA Features■ Rotary atomizer– Highest slurry capacity

atomizers in the industry– Low maintenance/high

availability– Abrasion-resistant

components■ Unique flue gas dispersion system– No damper/vane

adjustments needed to follow boiler load

■ Performance maintainedover complete load range– Slurry flow control

■ Large SDA chambers

SDA Benefits■ High SO2 removal efficiency

■ Integral SO3, HCl, HF and PM2.5 emissionsreduction

■ Low capital cost■ Low auxiliary power use■ High system availability■ Low operation and maintenance costs

■ Low water consumption■ Inherent oxidized mercuryemissions reduction

■ No waste-water stream

Worldwide, the Niro dry scrubbing technology has provensuccessful on more than10,000 MW of utility and industrial coal-firedboilers, as well as morethan 50 waste-to-energyinstallations. B&W/Niroinstallations dominate the large (350 to 900 MW)utility boiler market segment.

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The B&W/Niro SDA provides significant turn-down to accommodateboiler load variationswhile maintaining optimal performance.

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Dry FlueGas DesulfurizationSWEPCO-MU-Ex. 70

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The heart of the SDA systemis the rotary atomizer. A Nirorotary atomizer is used toatomize a mixture of limeand recycle slurry into a finespray. Hot untreated fluegas is brought into contactwith the slurry spray. Achemical reaction results in the removal of SO2, SO3,HC1, and HF, and the sim-ultaneous evaporation of the water. A single, centralatomizer promotes an evendistribution of the fine spraywhile minimizing any poten-tial for wall wetting anddeposition. The alkalineslurry is converted into a dry, free-flowing powder ofcalcium/sulfur compounds.

For large utility boiler applications, flue gas entersthe spray dry absorber attwo locations: the roof gasdisperser and the central gas disperser. Smallerinstallations require onlya roof gas disperser.

The ratio of fresh lime slurryto recycle slurry is controlledto maintain the requiredlevel of alkalinity in thefeed slurry to achieve thedesired level of SO2 removal.The total amount of slurryfed to the atomizer is con-trolled to maintain the

desired outlet temperature.This process reduces theconsumption of fresh reagent.

The cooled and treated flue gas exits the SDA andis directed to a particulatecollector, which is typi-cally a fabric filter. The

Process Features PromoteEfficiency and Reliability

RotaryAtomizer

AtomizedSpray

Central Gas Disperser

InletFlue Gas

InletFlue Gas

InletFlue Gas

To ParticulateCollection

The unique flue gas dispersion system used in theB&W/Niro SDA, coupled with the rotary atomizer,ensures a uniform distribution of slurry and provides for intimate contact with the flue gas to optimize absorption efficiency in the spray drying chamber.

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particulate collector is an integral part of the SO2

removal process as thesolids continue to reactwith the SO2 in the fluegas. SO3 removal also takes place in the particulatecollector.

Ash Market

InletFlue Gas Spray Dry

Absorber

Water

Lime

ProcessWater

RecycleSolids

Disposal

Lime Feed Recycle Feed

Head Tank

Optional Fly AshPre-Collection

Optional Solids Recycle

A reagent recycle sys-tem (optional) reduceslime consumption. Alsoshown is optional flyash pre-collection.

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Detail of roof gas disperser

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SWEPCO-MU-Ex. 70

Dry FlueGas Desulfurization

The single, centrallylocated rotary atomizerminimizes the potentialfor wall wetting anddeposition which pro-vides optimum reagentutilization. Its abrasion-resistant construction isdesigned for reliable,continuous operationwith a minimal amount of maintenance.

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■ Reagent slurry– Recycle or lime only

■ Fly ash pre-collection– Can preserve existing

plant fly ash sales forretrofit applications

■ Particulate collector integration– Baghouse or electro-

static precipitator

Integrated ParticulateControl Particulate and scrubberreaction by-products down-stream of the spray dryabsorber can be collectedby either an electrostaticprecipitator (ESP) or a fabric filter dust collector“baghouse.” The preferredmethod is typically a fabricfilter because it serves as an

efficient secondary SO2

reactor and provides excel-lent particulate removal.

B&W’s fabric filter tech-nology includes nearly 35 years of experience insupplying over 100 installa-tions with reverse gas cleaning

Total-Project Scope Ensures Effective System Performance

Variety of Applicationsand Options to Fit Your NeedsB&W’s dry FGD systemsare ideal for new fossil fuel-fired power generation projects or retrofits to existing plants. Becausethey require less space thanother FGD processes, dryFGDs can be used at siteswith limited space. The systems can typically beconnected and brought on-line during scheduledmaintenance outages, thusminimizing disruption topower generation.

■ Wide variety of fuels– B&W/Niro have more

than 3,000 MW of PRBcoal experience

or pulse jet fabric cleaningsystems. On electric utilitycoal-fired boilers alone, our fabric filter experienceincludes more than 8,000 MW of generationcapacity in more than 50 installations. B&W’sfabric filter technology hasbeen installed on all types of coal-fired boilers and ona wide range of industrialprocesses. Our installationsinclude some of the largestSDAs in the world and alsoone of the world’s largestutility pulse jet baghouses.

Count on B&W’sExperienceThe B&W/Niro dry FGDprocess effectively reducesemissions, meeting andexceeding federal and stateair quality regulations. TheNiro FGD technology hasproven successful on utilityand industrial coal-firedboilers with more than10,000 MW of installedcapacity worldwide in

B&W’s SDAs and fabricfilter provide an inte-grated SO2 and particu-late removal process.

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As part of a major utility boiler and environmentalequipment rebuild, this fabric filter baghouse is thelargest of its type in the U.S.

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B&W’s total-project scopeincludes design, procure-ment, construction andstart-up activities tofacilitate the effectiveperformance of theentire system and inte-gration with existing ornew NOx and particulatecontrol equipment.

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power generation applica-tions. Many additionalinstallations are controllingemissions from industrialprocesses and waste-to-energy applications.

B&W coordinates an annualUsers Group meeting, whichrotates among host dry FGDinstallations to provide aforum for sharing operatingexperiences and discussingnew developments. Thisreflects our continuing com-mitment to customer serviceand product innovation.

Research for FutureTechnologyDevelopmentTo help our customers prepare for future compli-ance regulations (mercuryemissions, for example) and to improve our existingtechnologies, research isconducted at our CleanEnvironment DevelopmentFacility (CEDF). TheCEDF is a state-of-the-art 100 million Btu/hr pilot plant with a dry FGD system

that allows the combustionof various fuels and the testing of technologies tocontrol pollution. Its largesize enables effective scale-up to commercial operation.

From Concept to Start-Up, B&W DeliversB&W takes pride in ourtotal-scope capabilities.Working with us is easy.Our dedicated team of engineers will meet withyou to offer the best solution to your emission control needs.

B&W carries out the com-plete process evaluation,conceptual design, detailengineering, equipment supply, construction, start-up and operational checkout of the system to ensure

successful execution. B&Whas supplied dry FGD sys-tems in a variety of contract-ing arrangements, includingpartnerships, open-book supply, and engineer-procure-construct (EPC). Expert project managers overseeproject execution.

As air emission regulationsbecome tougher, B&W iscommitted to provide thebest available technology to enhance the longevity and competitiveness ofcoal-fired power plants for many years to come.

Count on B&W to providethe total-scope solution for your next emissions control project.

Dry FGD systems can be effectively retrofittedinto sites with limitedspace.

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Adjacent SDAs share acommon spare atomizer.

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Dry FlueGas DesulfurizationSWEPCO-MU-Ex. 70

SWEPCO-MU-Ex. 70

While others may use the Babcock name, we are the original Babcock & Wilcox with more than 135 years of experience in engineering, constructingand servicing steam generating systems. Insist on us by name.

For more information, or a complete listing of our sales and service offices worldwide, call 1-800-BABCOCK (222-2625) in North America. Outside North America, call (330) 753-4511 or fax (330) 860-1886 (Barberton, Ohio, USA). Oraccess our Web site at www.babcock.com.

Canada:Cambridge, OntarioEdmonton, AlbertaMontreal, QuebecSaint John, New BrunswickVancouver (Richmond), British Columbia

Denmark: EsbjergIndia: PuneIndonesia: JakartaPeople’s Republic of China: BeijingSingapore: SingaporeUnited States of America:

Atlanta, GeorgiaBarberton, OhioCharlotte, North CarolinaChicago (Downers Grove), IllinoisCincinnati, OhioDallas, TexasDenver (Sheridan), ColoradoFairfield, New JerseyHouston, TexasKansas City, MissouriMt. Holly, New JerseySan Francisco (Napa), CaliforniaSt. Petersburg, Florida

Powering the World Through Teamwork and Innovation®

The information contained herein is provided for general information purposes only and is notintended or to be construed as a warranty, an offer, or any representation of contractual or otherlegal responsibility.

Powering the World Through Teamwork and Innovation is a trademark of The Babcock & Wilcox Company.

© 2002 The Babcock & Wilcox Company. All rights reserved.

E101-3178 5MR2G

a McDermott company

B&W’s FGD system provides cost-effective emissions reduction to enhance the longevity and competitiveness of coal-fired power plants.

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SWEPCO-MU-Ex. 70

SWEPCO-MU-Ex. 70