GAB neumann graphite presentation



Synthetic Graphite Manufacturing

Petroleum and pitch

green cokes

Homogenous KneadingExtrusion, vibro-molding

or isostatic pressing

Carbonization

at 900+°C

(1 month)

Pitch impregnation Graphitization

at 2700+°C

(2 months)

Synthetic graphite suitable

for process equipment

manufacturing

Coking

Coke silos

Grinding Screening



Transformation of carbon into graphite

Graphite is crystalline

Easily machinable

Very high electrical and thermal conductivities

Carbon is amorphous

Very difficult to machine

Low electrical and thermal conductivities

Energy

Time



Outstanding Thermal Conductivity (SI)

1

12

17

17

25

50

130

130

0 20 40 60 80 100 120 140

Glass

Hastelloy

Stainless steel

Titanium

Zirconium

Tantalum

Silicon Carbide

Graphite

W/m.K



Outstanding Thermal Conductivity (USCS)

7

80

120

120

170

410

900

900

0 200 400 600 800 1000

Glass

Hastelloy

Stainless steel

Titanium

Zirconium

Tantalum

Silicon Carbide

Graphite

BTU/hrft°F



Process Equipment Graphite Manufacturing

Synthetic graphite

Blocks contain

15 to 20% void

Pre-machining Drying

(>110°C)

Impregnation

(>10 bar)

Curing

(>165°C)

Phenolic

resin

Final CNC

machining

• Porous synthetic graphite

• Impregnation with phenolic resin

• Totally impervious graphite after impregnationImpervious graphite

parts and elements



Phenolic Resin Polymerization

OH

CH2

CH2

OH

H2C CH2OH

CH2

OH OH

H2C

CH2

CH2160°C

CH2 O CH2

CH2

H2O+

ether groups

OH OH

H2C CH2

CH2

CH2

H2O

CH2

+

methylen groups

180°C

2

+ 2

• At 160°C (320°F) polycondensation

occurs (elimination of H2O) and

ether groups are formed

• At about 180°C (356°F) another

polycondensation occurs resulting in

the formation of methylene groups

• Solid and hard polymer

• Three dimensional cross linked

structure resulting in a good

chemical resistance to most

common chemicals especially acids

OH

CH2

CH2

OH

H2C CH2OH

CH2

OH OH

H2C

CH2

CH2160°C

CH2 O CH2

CH2

H2O+

ether groups

OH OH

H2C CH2

CH2

CH2

H2O

CH2

+

methylen groups

180°C

2

+ 2



Quality criteria for impervious graphite

• Graphite:

• Compact grain structure

• Well distributed grain / pore size

• No structural irregularities (cracks, large

pores, impurities, etc…)

Micrograph GAB GX1 magnified x10

Micrograph GAB GX1 magnified x200

• Impregnation:

• Pores totally filled with phenolic resin

• Perfect bond between resin and graphite

• Polycondensation bubbles well distributed



Graphite Material Data (SI)

Material Characteristics Units Graphite

Density (20°C) kg/dm³ 1,9

Flexural strength (20°C) MPa 30

Compression strength (20°C) MPa 45

Elastic modulus (20°C) GPa 20

Thermal expansion coefficient (20°C/200°C) K-1 6 x 10-6

Thermal conductivity (20°C/200°C) W/mK 130

Open porosity % 0



Graphite Material Data (USCS)

Material Characteristics Units Graphite

Density (68°F) oz/gal 253.7

Flexural strength (68°F) ksi 4.35

Compression strength (68°F) ksi 6.53

Elastic modulus (68°F) msi 2.9

Thermal expansion coefficient (68°F/392°F) K-1 6 x 10-6

Thermal conductivity (68°F/392°F) BTU/hr.ft.°F 901.3

Open porosity % 0



Very low adhesion: excellent cleanability

37,3

36,6

36

35,7

31,6

29

25,3

20 25 30 35 40

Stainless steelsandblasted

Glass lined

Impregloncoating

Stainless steelelectropolished

Stainless steelbase grounded

Graphite

Perfluoroalkoxy

Degree



GAB GPX Graphite Qualities (SI)

GAB Neumann

GPX1 GPX1T GPX2

Density g/cm³ 1,9±0,02 1,9±0,02 1,9±0,02

Maximum grain size mm 0,80 0,8 0,8

Resin content(Equals to open porosity before impregnation) % 22 22 15

Permeability cm²/s 10-6 10-6 10-6

Tensile strength N/mm² ≥18 ≥18 ≥20

Bending strength N/mm² ≥32 ≥32 ≥35

Compression strength N/mm² 60-80 60-80 60-80

Labelling (acc. AD 2000 - N2) G18-0-180 G18-0-200 G20-0-200

GXX-…-… (tens. strength) N/mm² 18 18 20

G…-XX-… (decrease / +10K) ‰ 0 0 0

G…-…-XX (maximum T) °C 180 200 200

Thermal conductivity W/m.K ≥120 ≥120 ≥150



GAB GPX Graphite Qualities (USCS)

GAB Neumann

GPX1 GPX1T GPX2

Density oz/gal 254±2.7 254±2.7 254±2.7

Maximum grain size in 0.03 0.03 0.03

Resin content(Equals to open porosity before impregnation) % 22 22 15

Permeability cm²/s 10-6 10-6 10-6

Tensile strength ksi ≥2.61 ≥2.61 ≥2.9

Bending strength ksi ≥4.64 ≥4.64 ≥5.08

Compression strength ksi 8.7-11.6 8.7-11.6 8.7-11.6

Labelling (acc. AD 2000 - N2) G18-0-180 G18-0-200 G20-0-200

GXX-…-… (tens. strength) N/mm² 18 18 20

G…-XX-… (decrease / +10K) ‰ 0 0 0

G…-…-XX (maximum T) °C 180 200 200

Thermal conductivity BTU/hr.ft.°F ≥830 ≥830 ≥1,040



Equipment Manufacturing Process

Impervious graphite

CNC

machining

(Inspection)

Impervious graphite

parts and elements

(Individual pressure testing)

Steel parts

(plates, tie rods, springs, nuts, lugs)

Expansion bellows and other suppliers

Carbon fiber reinforcement

Final assembly

(Inspection)

Hydraulic testing

(Leak test, pressure test,

pressure drop, dimensions)

Packaging and shipmentCement

• Quality controls at each stage

• ISO 9001: full traceability

• Final testing guaranties performances

Impervious

graphite

(Inspection)



Equipment Manufacturing Process

• Small tolerances

• Repetitious accuracy

• High quality

• Cost efficiency

Latest CNC Machining Technology

Leakage testing of each elements

• 100% testing

• Hydraulic final testing

(Pressure vessel code)

• Only meaningful when impregnation is

made before machining



Annular-groove Design

Block or Shell & Tube Design

• Established flow shortly after

disruption (tube or block inlet)

• Laminar flow conditions

• Tendency to fouling / scaling

• Cross flow

> Lower heat transfer

Annular Groove Design

• Always turbulent flow

• Permanent disruption of the flow

• No fouling, no scaling

• Full counter flow

> Excellent heat transfer



Annular Groove Design

• Highly turbulent flow

• Thick graphite walls

• Adjustable cross-section

• Self-cleaning design

• Minimized fouling

• Highest heat transfer

• No gaskets

(cemented discs)

• Best thermal

performance

• No leakage

• No cross

contamination

• Lowest

maintenance need

• High reliability and

plant availability



Overall heat transfer coefficients (SI)

U ValueBlock or

Shell & Tubes

Annular

GrooveΔ

[W/m².K] [W/m².K] %

Two aqueous liquids 500 – 1000 1100 – 1600 +60 - 120%

Water and organic solvents 400 – 700 600 – 1200 +50 - 70%

Water and acid 400 – 700 600 – 1400 +50 - 100%

Water and condensing steam 600 – 1100 1300 – 1800 +60 - 130%

Water and condensing solvents 400 – 700 700 – 1300 +75 - 90%

Heating steam and boiling water 800 – 1100 1400 – 1800 +65 - 75%

Heating steam and organic solvent 600 – 900 800 – 1400 +35 - 55%

Heating steam and acid 500 – 900 700 – 1400 +40 - 55%



Overall heat transfer coefficients (USCS)

U ValueBlock or

Shell & Tubes

Annular

GrooveΔ

[Btu/(ft2h°F)] [Btu/(ft2h°F)] %

Two aqueous liquids 90 – 180 190 – 280 +60 - 120%

Water and organic solvents 70 – 120 100 – 210 +50 - 70%

Water and acid 70 – 120 100 – 250 +50 - 100%

Water and condensing steam 100 – 190 230 – 320 +60 - 130%

Water and condensing solvents 70 – 120 120 – 230 +75 - 90%

Heating steam and boiling water 140 – 190 260 – 320 +65 - 75%

Heating steam and organic solvent 100 – 160 140 – 260 +35 - 55%

Heating steam and acid 90 – 160 120 – 260 +40 - 55%



Better Heat Transfer

• Case study: acid heated with steam

• Block design:

18.8 m2 (202 ft2)

• Annular Groove design:

13.2 m2 (142 ft2)

• Same duty

• Same fouling factors

• Much smaller heat transfer areaReplacement of a block heat

exchanger by an annular

groove heat exchanger



Better design against stress cracking

• Thick uniform cylindrical walls

(minimum 15 mm, 0.6 inch)

• Well distributed mechanical

constraints

• No crack

• No leakage / permeation

> Excellent reliability

• Uneven wall thickness

(3 to 5 mm, 0.1 to 0.15 inch)

• Mechanical stresses might exceed

material resistance locally

• Risk of cracks

• High risk of leakage / permeation

> Much lower reliability

Annular Groove Design Block Design



Stress cracking due to swelling

• Block cracked by swelling

stress effect

• Some organic solvents

might create physical

expansion of polymer resin

• Reversible effect

• Inhomogeneous structure

and thin walls create stress

peaks

• Common failure in

processes with organic

solvents

Swelling stress crack

(2 days after failure)

Gap width 0.8 to1.2 mm

(0.03 to 0.05 inch)

Same crack

(3 days later)

Gap width 0.2 mm

(0.007 inch)



Product Contamination / Black Particles

• More than 95% of black particles

result from resin film

• Film building is side effect of

impregnation

• Manufacturing sequence

(impregnation / machining)

matters

• GAB manufacturing sequence

(machining after impregnation)

completely avoids any product

side resin film in final components

Competitor blocks with

resin film at the surface

(impregnation after

machining)

GAB Neumann annular

groove design totally free

of resin film (machining

after impregnation)



Product Contamination / Black Particles

• Batch processes create thermal

stresses that might result in chip-

off of the resin film

• Special situation in fine

chemistry: non-contamination

requirement versus thermal

stress caused by batch

production

Competitor’ block design

with resin film: black

particle chip off after

thermal cycling

GAB Neumann Annular

Groove design without

resin film: no risk of

contamination

Time

Tem

pera

ture



GAB Graphite Equipment Portfolio

Columns and column

internals

Special process

equipment

• Quenches

• Absorbers

• Continuous reactors

• …

Machined componentsHeat exchangers

Unique: Annular

groove design



GAB Graphite Heat Exchangers

Annular-groove

Condenser

(GMP compliant)

Annular-groove

Cooler

Block HXAnnular-groove

Condenser

(GMP compliant)



GAB Graphite Heat Exchangers

Annular Groove Heat Exchanger

• Transfer area

0,6 to 68 m²

(6.4 to 730 ft²)

• Temperature range

-60 / +200°C

(-76 / +392°F)

• Pressure range

-1 / +10 bar

(Full Vacuum / 145 psig)

Block Heat Exchanger

• Transfer area

0,9 to 163 m²

(10 to 1,755 ft²)

• Temperature range

-60 / +200°C

(-76 / +392°F)

• Pressure range

-1 / +10 bar

(Full Vacuum / 145 psig)



Smooth operations

• Never exceed maximum torques indicated

on the drawing. Cross tightening

procedures should be carefully respected

• Avoid thermal shocks: smooth start up and

shut down. Allow sufficient time for the unit

to warm up. Implement automatic start up

and shut down procedures to eliminate the

human factor

• Avoid mechanical stress : ensure

appropriate installation and supporting.

Protect nozzles with expansion bellows.

Avoid pressure surges / water or steam

hammering: turn valves slowly and avoid

butterfly valves, drain condensates lines

Properly operated annular groove graphite

heat exchangers can work properly for more

than 20 years



Nozzle protection with expansion bellows

• Nozzles should be protected with expansion

bellows both on service and on process sides

• Expansion bellows protect graphite nozzles

from mechanical stresses due to piping

misalignment / inappropriate supporting

• GAB Neumann offers a complete range of

PTFE expansion bellows perfectly adapted to

ultra-corrosive applications

• We deliver our PTFE expansion bellows

mounted on the graphite nozzlesLarge antistatic PTFE

expansion bellow at vapors

inlet



Graphite Equipment Customers Worldwide

Extract of GAB Neumann

worldwide customer base



Applications

Steel Pickling Copper Electrolysis Contract Manufacturing Basic Chemicals

Crop Protection Active Ingredients Vitamins Flavors & Fragrances

Titanium Dioxide Synthetic Fibers Fine Chemicals Minerals Refining

Liquid Crystals Pharmaceuticals Electronic Chemicals Accumulator Acid

Extract of applications of

GAB Neumann products



GAB Neumann GmbH

Alemannenstrasse 29

79689 Maulburg

Germany

Phone +49 7622 6751 0

Fax +49 7622 6751 20

www.gab-neumann.de

[email protected]

GAB neumann graphite presentation

Technology

Transcript of GAB neumann graphite presentation