The corrosion subject is an important part of the planning of your system. There are hardly any applications where there is no corrosive influence on the refrigeration components. In cold rooms alone, heat exchangers are often exposed to a variety of different substances that influence their lifetime. Be it salts, vinegar, smoke or even cleaning substances - it is important to know the effect of these influences on corrosion. Roller offers you effective corrosion protection for all applications with which you can operate the heat exchangers safely and, above all, tightly over their entire life cycle.
The corrosion protection variant "C" consists of a combination of copper core tube and coated fin package.
The block, which is completely coated with 2-component lacquer, offers reliable corrosion protection against aggressive substances such as organic acids, amines, and cleaning chemicals. With its food-compatible coating, it is particularly suitable for applications in the food industry. The coating has a slightly reduced heat transfer, which slightly reduces the cooling capacity of the air cooler.
The Roller selection software takes this into account when this option is selected. For CO2 evaporators, the corrosion protection variant C is available as an option.
For applications in a more aggressive atmosphere, where the copper tube must also be additionally protected, the corrosion protection variant "D" is recommended. It consists of a copper core tube with additional tin coating and a fin package coated with 2-component lacquer. This combination offers protection against aggressive substances such as: acids, salts, ammonia, sulphur compounds, organic acids and is particularly suitable for use in food processing.
The coating has a slightly reduced heat transfer, which reduces the cooling capacity of the air cooler somewhat. The Roller selection software takes this into account when configuring this option. The corrosion protection type D cannot be carried out on CO2 evaporators.
Epoxy resin coated fins are used wherever corrosion protection against atmospheres containing ammonia or acetic acid and cleaning chemicals must be guaranteed. The corrosion protection variant "F" forms a combination of copper core tube and expoxy resin phenol coated aluminium fin.
The variant can be used as increased protection in all food areas to be cooled.
The corrosion protection variant "G" combines the properties of variant "F" and is supplemented by additional protection of the copper tube. Here, the copper core tube is additionally equipped with a tin coating and offers itself as a sacrificial anode, so to speak, before the corrosion reaches the copper tube. This increases the protection against leakage enormously. The tin-plated core tube offers additional protection against aerosols and acids.
In order to provide complete protection against corrosion, the two exposed bend sides and the connections, as well as the end plates, are also coated with 2-component lacquer in the case of the "C and D" and "G" corrosion protection variants.
Heat exchangers consisting of a copper core tube and copper fins are used in particularly humid or chloride-containing atmospheres. Here, the corrosion protection variant "E" offers reliable corrosion protection. This variant is therefore used in applications near the sea, swimming pools or where the fin package is exposed to increased mechanical strain. This corrosion protection variant offers an approx. 8% increase in unit performance compared to copper-aluminium heat exchanger and is possible from blade spacings of up to 6 mm.
The coating "H" (H=hydrophilic, "moisture absorbent") is characterised by its ability to form a film of water with condensation, which makes natural oxidation more difficult. The water pearls off more easily, improving condensate drainage and reducing air pressure losses, which in turn results in less dirt adhering to the louvres. This means that less cleaning is required. It offers good protection in humid atmospheres and can be used very well for hybrid, i.e. sprayed, heat exchangers.
When it comes to increased corrosion protection in climatic weather conditions and especially near the sea, then the high resistance of an aluminium-magnesium fin alloy (AlMg3) is recommended. In sprayed systems, e.g. in hybrid drycoolers, the use of the resistant AlMg3 fins can make sense. Also available in combination with tinned copper core tubes.
Aluminium in itself offers good protection against corrosion. But there are also different alloys for aluminium. Roller uses the more robust AlFe1.5Mn alloy with a fin thickness of 0.3mm as standard, which also provides high stability during cleaning processes.
The housings of the air coolers are always made of corrosion-resistant aluminium. The aluminium housing is protected by a proven scratch-resistant, edge-enclosing, outer powder coating.
Some applications require an additional inner full-surface coating. ( Enclosure variant AL+I )
For particularly aggressive environmental atmospheres, the enclosure can also be manufactured in stainless steel (V2A).