Bycast Folder 1106 Lr

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Cast iron air-preheaters Engineering and Foundry

BY-CAST QUALITY

The recuperative cast iron air-preheater for boilers,incinerators and fired heaters

QUALITY STANDARDSNBN EN ISO 9001 : 1994/1997/2000

TRADEMARK OWNERS

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Kanaalweg 77B-3980 Tessenderlo

FLANDERS - BELGIUM

tel. 32-13-66 26 51fax 32-13-66 73 53e-mail: [email protected]: http://www.by-cast.com

A 5-pass « DEKA » Airpreheater serving the primary reformer on a 950 tons/day ammoniaplant. Fluegas flow is vertically upward with air in cross/counter. Heat transfer surface all castiron tubes.

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he DEKA air preheater is a static recuperative heat exchanger principally designed to recover heat from combustion processes by preheating the air supply to burners.

he DEKA trademark is owned by BY-CAST N.V. and the air preheaters are manufacturedin the BY-CAST plant at Tessenderlo, Belgium. The plant includes a foundry, devoted to casting the special finned heat transfer surface,

plus steel fabrication and assembly shops. The BY-CAST design and engineering office is also located at the same site. BY-CAST was awarded ISO-9001 certification since 1993/94.

he design was developed specifically to give trouble-free operation when handling dust-ladenor potentially corrosive fluegas. Heat transfer surface comprises banks of horizontal cast iron « tubes », (sometimes referredto as elements), usually stacked one above another with fluegas flowing vertically down-

ward, outside tubes.Air flows inside the tubes in cross/counterflow and the tube banks are separated to give a multi-pass arrangement.In cases where the fuel contains a significant amount of sulphur the first air pass, i.e. the « cold »end of the air preheater, is constructed with borosilicate glass tubes supported and sealed inPTFE tubesheets.This surface is completely resistant to corrosion by acidic condensation. The cold incoming airis heated in this bank before entering the cast iron banks thus protecting the cast iron tubes fromcondensation and attack.

Following are some of the key industries in which DEKA air preheaters have been repeatedlyinstalled for more than 60 years ;

• Fossil-fuelled power generation• Oil refining• Gas processing• Fertiliser manufacture• Steel and non-ferrous material manufacture• Petrochemicals

The air preheater is usually designed to operate with a new fired heater, boiler or incinerator.BY-CAST also frequently supplies a DEKA unit for retro-fitting to existing plant.The flexible BY-CAST design programmes and modular construction of the air preheater willalways provide a suitable solution for these retro-fits.

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SUPERIOR CORROSION RESISTANCEDEKA airpreheaters operate with all types of fuel from “clean” gas to high-sulphur coals andoil. The rugged construction is suitable for outdoor installation in all climates, from tropical toarctic !

• LEAK-TIGHT CONSTRUCTION

• CERAMIC SEAL BETWEEN TUBES

• EACH CAST IRON TUBE IS SEPARATELY

AIR PRESSURE TESTED

• METAL ANALYSIS BY AN INDEPENDENT

LABORATORY

Many DEKA units are still in serviceafter decades ofoperation with

minimum maintenance.

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The cast iron tubes are produced in the BY-CASTfoundry under strict quality control. Tubes arecast in a range of standard lenghts from 894 to3288mm.Standard wall thickness is 5 mm but may beincreased for special applications. Material ofconstruction normally grey unalloyed iron but forgas temperatures above 800 deg C and wall tem-perature below 450 deg C chromium-alloyed ironis used. The seal between adjacent tubes isformed by a continuous ceramic fibre roperetained in a groove around the edges of the rec-tangular end flanges. This rope absorbs any smalldifferential expansion between successive tuberows and maintains a completely gas-tight sealbetween the fluegas and air circuits.

THE DEKA AIR PREHEATER HAS NO MOVING PARTS OR WEARING SURFACES.NO MEASURABLE LEAKAGE FROM AIR TO FLUEGAS GIVING SAFE &

EFFICIENT OPERATION WITH MINIMUM MAINTENANCE.

CAST IRON TUBE TYPE

� HT tube finned outside and inside.Maximum heat transfer surface.

� LT tube finned outside and ribbedinside to increase metal temperature.

� LTL tube finned outside smooth inside togive higher metal temperature whenapproaching dewpoint.

• In-line arrangement of vertical fins on outside (fluegas) surface.

• Entire surface is swept by gas flow.

No on-line cleaning required.

QUALITY CONTROL• Dimensionally

• Tightness• Visual Inspections

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FLANDERS - BELGIUM


A 4-pass DEKA air preheater being retro-fitted to the main atmospheric crude furnace in a largeoil refinery. This air preheater saves the equivalent of 8000 tons/year fuel oil thus reducingthe quantity of CO2 and SO2 discharged into the atmosphere.

The DEKA unit was delivered to site in 5 preassembled modules – 4 with cast iron tubes plusone with glass tubes.

A smaller 2-pass DEKA air preheater installed some years earlier can be seen on page 11 right-hand side.

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Cast iron exists as a metal matrix containing a proportion of free (uncombined) carbon.The matrix normally has a perlitic structure giving the material similar mechanical characteris-tics to steel containing +/- 0,9 % carbon.

The free carbon is present in the form of very thin plates or lamellae.This free carbon is inert to most compounds which attack metals.

The structure and composition outlined above give cast iron the following properties ;

1. Cast iron has an elasticity comparable with spring steel. Piston sealing rings in gasolineand diesel engines are normally made of cast iron.

2. The elasticity is stable against time and is retained up to relatively high temperatures.

3. Cast iron has no permanent deformation i.e. the material will crack if its elastic limit is exceeded (steel would retain a permanent deformation).

4. Cast iron has excellent resistance to corrosion over a wide range of operating environ-ments. Initially the surface will slightly rust but the rusting is then practically arrested at thecarbon lamellae.The corrosion resistance of cast iron is much better than that of steel, including most stain-less steels. Stoves and fire grates if made from carbon steel would be burned out in a frac-tion of the lifetime of cast iron. Uncoated cast iron pipelines for drinking water supply havean almost indefinite life.There are many other examples of the durability of cast iron in the chemical and processindustries.

5. The resistance of cast iron to erosion is well-known. In pneumatic handling and drying sys-tems for abrasive powders cast iron liners are frequently fitted inside ducts to protect thesteel duct from excessive wear.

In light of these properties it must be anticipated that an air preheater with cast iron elementswill have a much longer service life than one with steel elements operating under identical con-ditions, even if the cast iron and steel elements were initially of equal thickness.

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Kanaalweg 77B-3980 TessenderloFLANDERS - BELGIUM


BTW - VAT BE 429.268.451 - HRH 66179

BANKS : FORTIS IBAN BE11-2350 4731 0548 BIC GEBABEBB

DEXIA IBAN BE86-5513 3297 0050 BIC ARTEBEBB

ING IBAN BE46 3350 4311 5536 BIC BBRUBEBB

CAST IRON & GLASS AIRPREHEATERS

A Larsby Company

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By-Cast manufactures fuel-saving equipment for bulk consumers of fossil fuels.

A By-Cast airpreheater typically reduces fuel consumption in boilers and fired heaters from 10 to 25 %by recovering and recycling heat from the exhaust gas.The airpreheater can be used with all types of fuel including coal, gas, wood and oil.Major oil refineries and chemical plants around the world use the unique By-Cast equipment.

Production of the airpreheater is centred at the By-Cast plant in Tessenderlo.The facilities include design, engineering and casting of the special cast iron heattransfer elements. The elements are assembled at the plant into transportable modules, up to 60 tonsin weight. These modules are then shipped to the ultimate destination anywhere in the world. On arrival at site the modules are simply assembled together to form the complete airpreheater.

By-Cast’s average annual production of airpreheaters results in a worldwide saving equivalent to some247,000 tons of fuel oil. This corresponds to a reduction in emission to the atmosphere of 773,000 tons of CO2.

The average life of a By-Cast airpreheater is 15 years. This means that the cumulative annual savingworldwide amounts to 3.7 million tons of fuel oil equivalent – sufficient to provide heating for 1.6 millionfamilies in Western Europe.

This annual saving in fuel consumption also corresponds to a reduction inCO2 emission of 11.5 million tons per year.

We are proud to be making this contribution to the preservation of the globalenvironment.

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Kanaalweg 77B-3980 TessenderloFLANDERS - BELGIUM


CAST IRON & GLASS AIRPREHEATERS

A Larsby Company

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BTW - VAT BE 0 429.268.451 - HRH 66179

BANKS : FORTIS IBAN BE11-2350 4731 0548 BIC GEBABEBB

DEXIA IBAN BE86-5513 3297 0050 BIC ARTEBEBB

ING IBAN BE46 3350 4311 5536 BIC BBRUBEBB

In the design of any fluegas-to-airpreheater (APH) it is essential that the metal surfaces in contact withthe flue gas are maintained above the dewpoint temperature to avoid acidic condensation and corrosion.For security the temperature is best kept at least 10°C above the dewpoint.

In some cases this means that before the cold ambient air enters the metal sections of the APH it mustbe first be warmed up. There are two solutions :

First solution :The incoming air is first passed through a bank of borosilicate glass tubes over which flows the fluegasleaving the metal sections. The air is thus warmed up and can than be safely passed into the metal sections. The glass tubes are impervious to corrosion and the fluegas can therefore be cooled to a lowertemperature in this bank.This solution allows maximum recovery of heat from the fluegas and is the most economical one. The size and cost of the metal APH are reduced since +/- 25% of the available fluegas heat is recovered in the glass-tubes section.

Second solution :The incoming air is warmed up in an external steam-to-air heat exchanger and is then fed directly intothe metal APH. The steam heat is supplied from a outside source.This solution requires a bigger metal APH because the temperature difference (LMTD) between fluegasand air is lower. The APH is consequently more expensive and requires a higher pressure drop on theair side.

By-Cast is always willing to examine the relative merits of each system and to offer the most suitablesolution.

Opgeslagen onder : word97/algemeen/steam versus glass.TS

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BY-CAST uses special borosilicateglass tubes in corrosion proof heatexchanger sections.

Special lining material for Equipment operating at flue gasdewpoint temperatures.

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FLANDERS - BELGIUM


R E S E A R C H

RESEARCH DEPARTMENT helps By-Cast in continuously improving quality and efficiency

BY-CAST NV FLANDERS

BY-CAST FOUNDRYOPERATES WITHRESPECT FOR:

ECOLOGY&

SAFETY

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FLANDERS - BELGIUM


EXTERNAL LOADSFROM FLUE

GAS AND AIR DUCTING ARE

CARRIED DIRECTLY ON THEROBUST DEKA AIR

PREHEATER FRAME

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FLANDERS - BELGIUM


3.25 MW AirpreheaterFractionator Feed Heater Equipment

installed in Mexico.

HHIIGGHH EEFFFFIICCIIEENNCCYY FFUURRNNAACCEEin a Californian Refinery• Lower emission• Preheated air in a DEKA Airpreheater 4.7MW

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FLANDERS - BELGIUM


THERE ARE NOWOVER A THOUSAND

DEKAAIRPREHEATERSIN OPERATIONWORLDWIDE.

3 EDC Pyrolysis Furnaces.These are equipped with a P3 high efficiency cast ironairpreheater of 6,45 MW

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BELGIUM

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Orders per continent

B Y- C A S T N V F L A N D E R S

Australia0,0% Europe

23,3%America14,9%

Africa4,8%

Asia57,0%

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FLANDERS - BELGIUM


A Larsby Company

KANAALWEG 77B-3980 TESSENDERLOFLANDERS - BELGIUM

TEL. (32) 13.662651FAX. (32) 13.667353E-MAIL : [email protected] : http://www.by-cast.com

Bycast Folder 1106 Lr

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