Heat Exchanger Protection

Blygold Libya

What Is Corrosion?

The deterioration of a substance or it’s properties through a reaction with the environment.

Threatening Pollution In The Air

• Sulphur Dioxide and Nitrogen Dioxide –from fuel combustion (traffic, power plants, refineries), when mixed with rain will form sulphuric acid.

• Ammonia – from decomposition of fertilizers, maggots, cheese etc.

• Salt will cause an electrolitic reaction between the copper and the alluminium

Chemical corrosion due to the environment

Aluminium oxidation

Aluminium

Aluminiumoxide

Chemical corrosion due to the environment

Galvanic Corrosion

Moisture with an electrolyte

Me Men+ + ne

copper

aluminium

deterioration

Galvanic Corrosion

Corrosion Tests

mass loss during acetic saltspray

-20

-15

-10

-5

0

5

10

0 200 400 600 800 1000 1200 1400

Time (hours)

Varia

tion

of m

ass

(%)

Cu Al Sn/Cu

Corrosion Protection• Seals the metals from the environment; prevents

electrolytes causing reactions between the different metals and prevents a direct reaction between environment and metals

8heat conducting 8flexibility

8thin layers to maintain airflow 8chemical resistant

8adhesion to aluminum 8UV resistant

Precoat

• application before production process• thin layer• smooth finishing• poor UV resistance• layer between aluminium and copper (A)• cutting edges untreated

– filiform corrosion (B)– inpitting (C)

A

Filiform Corrosion B

Inpitting C

Postcoat• application process after production of coil• application

– dipping– spraying

• complete seal from environment• UV resistance is possible

Test Results

mass loss during acetic saltspray

-20

-15

-10

-5

0

5

10

0 200 400 600 800 1000 1200 1400

Time (hours)

Var

iatio

n of

mas

s (%

)

postcoat Cu Al Sn/Cu precoat

Results

• lifetime extension

• energy consumption control

Lifetime extension

• corrosion protection will increase lifetime of a heat exchanger

• important:

8 type of coating 8 application 8 pre-treatment 8 maintenance8 environment 8 coil geometry

Practical Calculationcondensing temperature increase of 1 º C

drop of cooling capacity of 1.1 %

raise of energy consumption of + 1.3 % (depending on compressor, refrigerant etc)

Blygold PoluAl

• Aluminum in pigmentation for heat conduction• 100 % penetration due to high spray pressures• UV resistance: excellent• very flexible• Excellent chemical resistance• hydrophobic• filling and sealing fin-tube spacing• Very high abrasion resistance

Blygold Tropic

• bronze in pigmentation for heat conduction• 100 % penetration due to special techniques• UV resistance• very flexible• hydrophobic• repairable• wax based coating

VM Energy Report – April 2009• Blygold treated 1 YCAJ76 York Chiller• Without impacting on building users• Achieved a reduction in condensing temperature• Reduced compressor running time, extending life cycle• The capacity of the chiller increased by 7.33%• 33.64 KW increase in cooling capacity • 149KW hours per day less running time• An Annual C02 saving of 23455KG@043kgC02/kg• A saving of £5455.00 per year• Payback in less than 6 months (£2200.00 to C&C)

Blygold Coatings

• Blygold coatings in effect will :- double the life time of your coils- reduce your energy bills- reduce wear and tear on rest of unit- reduce maintenance costs- reduce call outs of your HVAC contractor- reduce need for early replacement