Shell and Tube Heat Exchangers

Process Technology

DIABON®

Broad Base. Best Solutions.

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SGL Group – The Carbon Company

SGL Group – The Carbon Company – is one of the world’s leading manufacturers of carbon-based products. We have a comprehensiveportfolio ranging from carbon and graphite products to carbon fibersand composites.

Our core competencies include a wide knowledge of raw materials, specialized production expertise and in-depth application andengineer ing know-how. As a result, we have built up a comprehensivetechnology and product portfolio. We operate on a global scale and are close to our customers anywhere at any time. Supported by this broad base, we offer our customers the best solutions. That is what SGL Excellence stands for.

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Our Business Line Process Technology is focused on supporting the technical processes of our globally operating customers in the chemical industry, metal manufacturing and environmental protectiontechnology. A maximum degree of know-how and expertise in corrosionprotection, a global presence and full-package systems from a singlesource: that’s what our customers need – and get from us:

Process TechnologyPerfection in Graphite and PTFE

� Long-standing experience and a high level of expertise in process technology

� Comprehensive process, material and design know-how on graphite and PTFE

� Closeness to customers: cost-effective manufacturing to internationaland local standards at our production sites in Europe, America andAsia and worldwide customer service

� A consistently high standard of quality

Our comprehensive range of products and services extends from process equipment and components made from DIABON® graphiteand POLYFLURON® virginal, paste-extruded PTFE, through LICUFLON® skived PTFE sheet-lined steel equipment, FLURO-FLEX® bellows, FLUROPIPE® pipe systems, FLUROSIC® siliconcarbide heat exchangers and DIABON® graphite or exotic metalpumps, to the planning and assembly of complex systems.

Contents

DIABON Shell and Tube Heat Exchangers 4

Technical Information 6

Design Options 7

Properties and Applications 8

Carbon Fiber-Reinforced DIABON Components 9

Multi-Tube Bundle Heat Exchangers 10

Customer Service 14

Quality Management 15

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DIABON® Shell and Tube Heat Exchangers at a Glance

Advantages of our shell and tube heat exchangers in DIABON processequipment graphite

� High efficiency� Large heat exchange areas possible

(over 2,000 m2)� Price advantage for medium and large

heat exchange areas� High heat transfer capacity� Abrasive wear protection minimizes erosion� Low pressure drops� All seals are external for ease of inspection� Ease of repair� Excellent drainage of condensate in steam

applications� Complete drainage of product and service side� Wide range of material combinations for shell

and header (FRP, rubber-lined steel, enamel,steel/PTFE)

DIABON® tube bundle

On this basis, DIABON shell and tube heat exchang-ers are used as heaters, coolers, condensers andfalling-film evaporators and absorbers, especiallyin the treatment of:� Hydrochloric acid� Sulfuric acid� Hydrofluoric acid� Phosphoric acid� Chlorinated hydrocarbons� Organic and inorganic media� Waste acids� Combustion gases

Pressures and temperaturesA maximum permissible materialtemperature of 200 °C has beencertified for DIABON NS1 andNS2 tubes by the South GermanTechnical Supervisory Board(TÜV). Moreover, strength certifi-cation up to G32-0-200 (32N/mm2 with 0 ‰ strength de-crease up to 200 °C) can be givenfor the tubes. The standard designallows for optional pressures of upto 6 bar gauge for both serviceand product sides. Special designsfor higher pressures up to 16 bargauge on the service side and upto 12 bar gauge on the productside can be supplied on request.

TrainingServicing of our DIABON shelland tube heat exchangers is sim-ple and can be carried out on siteby your own personnel. On re-quest, we put your technical per-sonnel through our training cour-ses. This enables repairs andoverhauls to be carried out evenmore quickly and economically.In addition, our specialists arealways at your service – whateveryour problem. We also supplyspare parts quickly and easily.

Terms of referenceTo be able to offer the same standards of qualityanywhere in the world, our shell and tube heatexchangers are designed to meet the following in-ternational standards:AD specification GermanyAPAVE FranceASME USABS United KingdomChinese Requirements ChinaISPESL ItalyJIS JapanStoomwezen HollandSVTI Switzerland UDT Poland

Corrosion resistanceThe basic materials for our shelland tube heat exchangers, DIA-BON NS1 and DIABON NS2process equipment graphite, areresistant to virtually all organicand inorganic media. For heatexchange between two corrosivemedia, we supply special designson request with a suitable anti-corrosion lining or coating of thesteel shell (rubber, PTFE, enamel,etc.)

O-ring sealOur long experience has shownthat O-ring seals offer substantialadvantages over stuffing boxpackings:

� Extremely low coefficients of friction

� Low sealing forces required� Universal resistance of

O-ring seals� Ease of adjustment� Ease of replacement� Long service life� Low servicing cost

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Shell and tube heat exchanger with DIABON® NS1 tubes

Tube type 0

Tube type 1

Tube type 2

Tube type 3

Tube length

Tube bundles and headers

Shell and flanges

Acceptance inspection

Design pressure

Design temperature

Tubes

Material

Others

1 bis 9 meter (standard)

DIABON NS1 / NS2 / HF1 / HF2

DIN standard steel, P 265 GH

CE, TÜV and other authorized test institutes

-1 / 6 bar gauge (standard)

180 °C (standard)

15

22

25

37

26

32

37

50

33

39

44

57

t [mm]d1 [mm] d2 [mm]

DIABON shell and tube heat exchangersare constructed from the following com-ponents:

� Two tube sheets with or without carbon fiber reinforcement – one fixed and the other floating, relative to the shell

� Baffle cages with DIABON baffles � Headers made from DIABON NS1/ NS2

graphite or other materials. Depending on theapplication, the header in contact with thefloating tube sheet is braced against the tubesheet by a dual clamping tie rod system

� Shell made from steel, with anti-corrosion lining on request, or from other materials

� Partition plates in the headers allow several passes through the tube bundle, when required in the process

Technical InformationDIABON® Shell and Tube Heat Exchangers

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Technical specification

DIABON® tube sheet with wear sleeves

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Options for Various Designs

Cooled DIABON®

header for high gas inlet temperatures

Falling-filmDIABON® header

Top header with laterial nozzle and

removable top cover

Extended DIABON®

bottom header for separating gases

and liquids

Conical steel bottom header withcorrosion-resistant

lining

Steel shell with 360° steam distributor

Steel shell with conical steam inlet nozzle

Steel shell withsteam inlet distributor

Standard steel shell

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Properties and Applications of DIABON® Graphite Brands

DIABON® NS1

PropertiesStandard material for a widerange of applications in chemi-cal technology, environmentalprotection and similar industries.DIABON NS1 is an impervious,synthetic resin-impregnated pro-cess equipment graphite with ahighly homogeneous materialstructure. This results in excellentcorrosion resistance and thermalstability. The maximum permissi-ble material temperature underpermanent load is 200 °C.

ApplicationsStandard material for the pro-duction of heat exchangers andfor all pressure- and temperature-stressed components.

DIABON® NS2

PropertiesGraphite material for superiordemands. This graphite brandis distinguished by its lower porevolume combined with reducedpore size and greater mechani-cal strength. The maximum per-missible material temperature is200 °C.

ApplicationsDIABON NS2 is suitable forheat exchanger tube sheets andtubes, if these are subjected toelevated mechanical stressand/or extremely corrosivemedia and solvents.

Micrograph of DIABON® NS1 Micrograph of DIABON® NS2

Properties of graphite tubes with carbon fiber reinforcement

� Increased bursting pressureThe tube becomes more resistant to steam hammerand service pressures above the permitted limit, itsbursting pressure at room temperature being raisedto 130 to 140 % of that of a non-reinforced tube,depending on the tube dimensions.

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Carbon Fiber-Reinforced Components for Increased Safety

In developing the carbon fiber reinforcement of components (DIA-BON HF), SGL Group has found a way to increase the operationalreliability of DIABON graphite components appreciably and expandtheir range of application under high-stress conditions. The fiber rein-forcement is used for tube sheets, headers and column sections andespecially for tubes.

Comparison of tube properties

Flexural strength, longitudinal

Bursting pressure at 20 °C

Bursting pressure at 50 °C

Resistance to pressure surges

Leakage pressure2) 5)

Thermal conductivity

Maximum material temperature4)

N/mm2

bar

bar

relative %

bar gauge

W/(K·m)

°C

>52

110

120

250

2-5

50 3)

200

>52

80

75

100

0

>60

200

1) DIABON® tube reinforcedwith SIGRAFIL® HF fibers

2) on a cracked tube underinternal pressure from water

3) effective value, calculated from the tube’sheat transfer capacity

4) depends on service medium

5) pressure up to which no appreciable loss of medium occurs from the cracked tube under brief pressure surges

DIABON NS1Unit DIABON HF1 1)

� Resistance of a cracked tube to leakageShould a longitudinal crack occur in a DIABON HFtube as a result of overstressing, the tube will notallow any major leakage up to a differential pres-sure of some 2 to 5 bar. In all instances, the rein-forcement prevents any spalling from the tube anda consequent escape of product in large quantities. Usually theequipment can continue in operation without interruption until the nextplanned shutdown.

DIABON® HF tubes

Carbon fiber-reinforced tube sheet

Multi-Tube Bundle Heat Exchangers made from DIABON® Process Equipment Graphite

A new generation of heat exchangersUnlike conventional products, our DIABON multi-tube bundle heat exchangers feature an exchangesurface area distributed over several identical smalltube bundles instead of a single large bundle.

Separate graphite tube bundles are incorporatedin a shell made from carbon steel. One or more ofthese elements can be integrated in a frame of sup-port plates. The tube bundles are sealed againstboth the steel flanges and headers with O-ring sealsmade from a high-quality sealing material.

The special design features make for a whole range of advantages:

Technical� High performance combined with small heat

exchange area� Savings in heat exchange area of up to 40 %� Modular design� Multi-mode operation in a single unit� Flexibility in use� Connection scheme adjustable to requirements� Stress-free installation of tube bundles

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DIABON® bundles of a multi-tube bundle heat exchanger

The special design of multi-tube bundle heatexchangers allows single or multiple counter-currentflow, or several different applications in a singleunit, e.g. in

� condensation� residual gas and condensate sub-cooling

using different cooling media for the purpose

Design advantages� Design ideally matched to graphite material

– sliding seal to compensate for thermal expansion

– minimal axial and radial movement– short tightening distances

� Identical and standardized assemblies(tube bundles, modules, headers, etc.)

� Practical sealing system with reliable O-ringsand sealing cords in high-quality materials

� Flexible design allowing– co-current-flow operation– multi-mode operations

Operational advantages� Vertical and horizontal installation� Antifouling properties� Optimum design for CIP procedures

(Cleaning in Place)

� Meets cGMP requirements (current Good Manufacturing Practices)

� Automatic ventilation and emptying possible

� Long servicing intervals� Ease of handling� Ease of servicing� Maximum operational reliability� Optional inspection glass allows

process control

Cost advantages� Low space requirements due to

compact design� Low capital expenditure� Up to 80 % savings on servicing

and repairs

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DIABON® multi-tube bundle heat exchangers (2 bundles)

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DIABON® multi-tube bundle heat exchanger (5 bundles)

Another special advantage of this design is that itallows pure counter-current flow. Compared withstandard equipment, the temperature differentialcan be used to full advantage. Moreover, the de-sign can be individually adapted and optimized foreach application. The resulting savings in heatexchange area can be as much as 40 %.

The equipment design is optimized to allow an idealinlet flow profile for the cylindrical tube sections. Asa result, flow conditions for each tube bundle areidentical, without dead spaces or areas exposed toundercurrents and turbulence. This is why our equip-ment displays excellent antifouling behavior whenused for media with an inherent fouling tendency.

Multi-Tube Bundle Heat Exchangers made from DIABON® Process Equipment Graphite

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DIABON® multi-tube bundle heat exchanger (3 bundles)

A further advantage of this design is its ease ofhandling. Since the heat exchanger has only a fewcomponents, dismantling is just a short sequenceof operations that can be easily performed by theoperators themselves.

The availability of the equipment can be increasedsignificantly by keeping spare bundles in stock.During heat exchanger cleaning operations, tubebundles can be replaced as required in a minimumof time. This ensures nearly 100 % availability of the

equipment and associated plants.Damaged tube bundles can be re-paired at any time and even repeat-edly, thereby minimizing the cost ofservicing.

Multi-tube bundle heat exchangers are suitablefor a wide range of chemical processes whenused as� Coolers� Heaters� Condensers� Evaporators (forced and natural circulation)� Falling-film evaporators� Integrated equipment for condensing

with simultaneous residual gas cleaning (cold trap)

� Heating and cooling of pickling lines

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Individual tube testing on a shell and tube heat exchanger

Customer Servicewith a Full Package of Benefits

Our continuing partnership with customers is based on the excellentservices and system solutions we provide. These are a key part of ourcommitment.All items of SGL Group’s DIABON process equipment are qualityproducts manufactured in our own plants from high-grade materialsusing the latest technologies. If a product still failsto meet your requirements, SGL Group’s world -wide network of service centers will be on handto help. We see every problem as a fresh oppor-tunity. Give us the chance to prove it.

Spare parts and repairsSGL Group’s responsibility for its products doesn't end when customerstake delivery of DIABON equipment. In fact, we give our customerssystematic support all the time it's in use. This support is a key part ofour customer service. The long service life of our graphite equipment depends crucially onits high quality and the servicing and/or cleaning it gets when incontact with highly corrosive and contaminated media.

Visual inspection of a tube sheet

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Heat exchanger during pressure testing

As a manufacturer of carbon and graphite products, process equipmentand systems for the chemical industry and environmental protection tech-nology, SGL Group maintains a targeted quality management systemdesigned to attain and meet the product quality standards demandedby customers. Our quality management system meets the require-ments of DIN EN ISO 9001:2000 and Pressure Equipment Directive97/23/EC Annex III, Module H/H1 and has been certified by the ap-proved associations of DQS and TÜV SÜD. In process equipment con-struction, Quality Management is responsible for the testing andapproval of semi-finished graphite products, impregnating resin, cementcomponents, outsourced parts, process equipment and components.

Quality Management by Process Technology

Synthetic resin impregnation, cementing and assemblyare all subject to continuous monitoring.

Appropriate marking of the semi-finished graphite prod-ucts before and after synthetic resin impregnation, during

machining and thereafter until assembly of the completeequipment or plant provides comprehensive evidence of the

semi-finished products employed. Consequently, they meetthe traceability requirement of specification AD 2000-Merk-

blatt N2 for pressure vessels made from electrographite andhard burned carbon. The conditions for synthetic resin im-pregnation of the semi-finished graphite products and those forcementing of the components are stipulated, monitored andchecked.

Evidence of the quality characteristics of the material gradesemployed, as required by specification AD 2000-MerkblattN2, is provided in a report issued by the testing laboratoryof TÜV SÜD Industrie Service GmbH.

Process Technology

SGL CARBON GmbH

Werner-von-Siemens-Straße 1886405 Meitingen/GermanyPhone +49 8271 83-1564Fax +49 8271 83-2101pt@sglcarbon.de

www.sglcarbon.com

Process Technology Brochures

� Process Technology – We Combat Corrosion – from Process Equipment and Components to Complex Systems

� DIABON® Graphite for Engineered Process Equipment

� DIABON® Shell and Tube Heat Exchangers

� DIABON® Block Heat Exchangers

� DIABON® Plate Heat Exchangers

� DIABON® Economizers for Heat Recovery

� DIABON® and LICUFLON® Columns and Column Internals

� DIABON® Hydrogen Chloride Synthesis Plants

� DIABON® and Exotic Metal Pumps

� DIABON® Safety Disks

� Systems – Solutions for Corrosive Processes

� ECOPOR® Porous Reactors

® registered trademark of SGL Group companies 03 2008/1 2NÄ Printed in Germany

The data contained herein represent the current state of our product knowledge and are intended to provide general information on our productsand their application spectra. In view of the variety and large number of application possibilities, these data should be regarded merely as generalinformation that gives no guarantee of any specific properties and/or suitability of those products for any particular application. Consequently,when ordering a product, please contact us for specific information on the properties required for the application concerned. On request, ourtechnical service will supply a profile of characteristics for your specific application requirements without delay.