1 Corporate presentation - june 2014

FULL POLYMER

HEAT-EXCHANGER TUBES

2

THERMAL PROPERTIES

Traditionally plastic profiles have only been known as excellent

thermal insulating parts, mostly in the construction industry.

But things have changed lately. The usage of highly conductive

graphite as a filler is now offering new dimensions in heat

conduction applications such as heat exchangers.

With the Technoform process it is possible to combine a high

degree of filler and an optimized orientation of the particles with

a smooth surface.

This polymer compound combination is able to achieve

similar heat conductivity values as stainless steel or

titanium.

* calculated out of practical heat transfer coefficient measurement, no direct measurement possible

** Measured on test rig under follwing conditions: Salinity 65g/kg, mass flow water 0,1kg/(s*m),

Temperature heating vapour 80°C, Temperature evaporation: 75,8 °C

THERMAL PROPERTIES OF PP-GRAPHITE

Heat resistance long term 90 °C

Specific heat capacity cp 1.21 J/(g*K)

Thermal elongation 29 x 10-6 1/K

Thermal conductivity in plane (injection moulding) 26.6 W/(m*K)

Thermal conductivity through plane (injection moulding) 4.5 W/(m*K)

Thermal conductivity through plane (extruded tube)* 10-15 W/(m*K)

Heat transfer coefficient on tube ** 2316 W/(m²*K)

3

MECHANICAL PROPERTIES

of PP-Graphite

In general plastics have a wide range of properties and can be

adjusted to different requirements. The young's-modulus can

be adapted (depending on base polymer and reinforcement

fibers) in a range from 500 to 45000 MPa. A maximum tensile

strength of 330 MPa is possible. The softening-temperature

may be as high as 350°C (under 1.8MPa load).

TECHNICAL DATA

Density 1.56 g/cm³

Flexural-modulus 10400 MPa

Flexural strength (no yield) 49.5 MPa

Elongation 0.63 %

Roughness Rz (extruded tube) < 3 µm

Roughness Ra (extruded tube) <0.5 µm

Burst strength (1.5 mm wall extruded PP-GR tube) >5 bar

δ

X(t)

X0

t

T

PP has the advantage of having a high mechanical damping

factor: tanδ of 0.07-0.01 compared to 0.00002 for steel or

0.002 for copper.

This means system vibrations can be reduced by good

damping behaviour.

4

INFLUENCE OF SURFACE ACTIVATION

on wetting behaviour

The polymer solution can be influenced

in its wetting behaviour. In their natural

state the tubes show hydrophobic

properties (see upper sample, right). But

with a special surface activation the

wetting can be increased to values

similar to Al-brass, thus ensuring equal

wetting on the outside.

Material Contact angle Θ

PP (untreated) 93.1°

PP (treated) 68.7°

Al-brass 63.3°

Θ In MED-plants this provides the option to

retain water repellent properties inside

the tube to initialize droplet conden-

sation, which leads to a massive

increase in the partial-heat-transfer

coefficient inside. In contrast, activation

enhances the wetting properties on the

outside.

5

FOULING / SCALING BEHAVIOUR

Tests were carried out in a tank with a

spray nozzle system. Artificial seawater

(composition according to Kester et al.

with salinity of 65 g/kg) was used for the

test.

Test conditions: 4 weeks at system-

temperature 72°C (80°C water heating

inside); 4 tubes of each material stacked

in the tester; wetting of all tubes was

ensured.

The result show a much better fouling

behaviour with polymer tubes. The

deposition on polymer tubes can be

removed much easier by wiping. They do

not show the usual encrustation, which

leads us to the assumption that scaling

does not take place.

Reduced fouling/scaling leads to

lower costs due to fewer shut-downs

for cleaning processes as well as the

advantage of using less anti-scalants.

0,0 g/m

0,2 g/m

0,4 g/m

0,6 g/m

0,8 g/m

1,0 g/m

Al-Brass PA6-GR70PA12-GR70

PP-GR70

0.94 g/m

0.59 g/m 0.52 g/m 0.51 g/m

DEPOSITS ON TUBESURFACE [g/m]

Al-brass PP-Graphite

46% less fouling

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PARTICLE ORIENTATION is key to thermal conductivity

The special processing technology of Technoform allows the

alignment of particles relative to the extrusion direction. This

gives the heat transfer across the wall a remarkable boost.

The highest conductivity is achieved with an orientation-angle

of particles between 45° and 90°. We measured over 60% of

particles with an angle like this in our PP-Graphite tubes.

Over 60% with an angle

more than 45°

7

THERMAL PROPERTIES in terms of fouling / scaling

Because of its fouling/scaling behaviour,

PP-Graphite tubes show their biggest

benefits after a certain time of usage.

After just 1000 hours of operation,

their heat transmission coefficient

equals tubes made of metal.

0

500

1000

1500

2000

2500

3000

3500

4000

PP-Gaphit Al Brass Alu Alloy 5052 Titanium

2316

2957 2998 2878

2.106 2.161 2.157 2.094

Ove

rall

he

at tr

an

sfe

r co

eff

icie

nt U

[W

/m²K

]

COMPARISON OF HEAT TRANSMISSION PERFORMANCE

heat transmission in fresh state estimated heat transmission after 1000h

8

CHEMICAL RESISTANCE

Stainless steel Al-brass Al-alloy Titanium PP-Graphite

critical in dead

water (crevice

corrosion), temp

>45-85° and high

chloride

concentration

critical at temp

>70°

critical at temp

>50°, sensitive to

aerated water,

electrolytic

corrosion

Resistant to

seawater

Resistant to

seawater

Stainless Steel Al-brass Al-alloy Titanium PP-Graphite

Resistant to most

diluted acids

Resistant to most

diluted acids

Sensitive to acids Acid cleaning

unproblematic,

only hot acids may

attack material

Acid contact

unproblematic

pH-value of media

from 0-14 is

possible

Phosphoric acid

95%, Sulfuric Acid

90%, Hypochloric

acid >38%, Sodium

hydroxide >60%

Polymer-graphite compounds have no corrosion problems with high saline water even at

temperatures above 90°.

PP or PPS -Graphite compounds have outstanding chemical resistance against even

highly concentrated acids and bases.

SALT RESISTANCE / CORROSION

CHEMICAL (ACID-) RESISTANCE

9

0 0,5 1 1,5 2 2,5 3

PP-Graphite

Al-brass 2.99 kg CO2 per kg tube

0.78 kg CO2 per kg tube 74% less

CARBON FOOTPRINT

Adding all emissions of CO2, from mining and smelting/refining to

the final tube production, it becomes apparent that heat-

exchanger tubes made of PP-Graphite generate a 74% smaller

footprint than tubes made of Al-brass.

10

COMPLIANCE

The polymer has a FDA certification and

all components have been confirmed not

to contain any substance with health

concerns related to drinking water.

Specific tests of the manufactured tubes

are under examination:

• Change of odour and flavour of water

• Change of the appearance of water

• Extraction of substances

11

CONNECTING the heat-exchanger tubes For mounting a optimized connection

system should be considered. Possible

ways for a fitting could be

• Thermoforming (by heated

thorn)

• End-connectors with O-Ring

and fitting

• Insert in a Rubber gasket

(like in a drainpipe)

• Welding or bonding

THERMOFORMING

This technology can be used

for non-detachable

connections by beading the

end of the tube with a heated

or ultrasonic driven thorn.

END-CONNECTORS WITH

FITTING AND SEALING

The connector can be formed

with a thread or a self-locking

cone to press on a

rubber O-ring seal. It

combines good pressure

resistance and flexible tube

exchange.

INSERT IN A RUBBER

GASKET

The gasket connection offers

fast and simple connection

like in a drain pipe suitable

for applications with low

pressure difference .

WELDING OR BONDING

For compatible plastic plates

a welding connection with the

tube is possible.

For all other combinations we

recommend bonding. This

enables the safe connection

of different materials and also

provides sealing properties.

A proper bonding system

depending on materials,

temperatures and media has

to be chosen.

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SUMMARY & CONCLUSION

Plastics for the use in seawater-desalination plants form a

whole new material class.

They enable companies not only to realize a cost effective

system, but also to develop individual solutions, matching the

technical demands of the customers.

The freedom in design (of the geometry) in combination with

an outstanding corrosion behaviour and chemical resistance

provides a highly effective system.

Examples of possible geometries

A significant reduction in the use of process-chemicals (such as

anti-scalants and corrosion inhibitors) can be achieved by

utilizing polymer tubes. Furthermore, the wash out of heavy

metals (like copper), that may be harmful to the environment, is

eliminated. This might be of value for possible future regulations.

These properties in combination with the heat-transfer

technology developed by Technoform Kunststoffprofile

extends the possibilities for all heat-exchangers in the

future.

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MARKET LEADER

in extrusion of reinforced technical plastics

Technoform was founded in 1969

by Karl-Hans Caprano and Erwin

Brunnhofer as a family owned

business. Until today the company

has been directed by the families.

High degree of expertise in main

industrial sectors

Electro technology, mechanical

construction, automotive, aviation,

shipping, construction

Pushing the limits of possible

applications

Research and developement as key to

success e.g. thermal conductive

profiles, electrical conductive profiles,

high strength profiles, profiles for metal

substitution.

Continous growth over the past 40 years:

from 2 → 1500 Employees

from 1 → 40 countries (production and sales sites)

from 0 → 300.000.0000 € turnover p.a.

from 0 → 30.000.000 kg processed polyamide p.a.

Sebastian Ossadnik,

R&D engineer

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DRIVEN BY INNOVATION

Technoform Kunststoffprofile GmbH

Otto-Hahn-Str 34 | 34253 Lohfelden

www.tkp.biz | info@tkp.biz