WEKA has been manufacturing marine products since 1957. The core business is boxcoolers which are used for inland waterways and sea-going vessels. Weka offers a range of materials for different applications.
Protection against biological marine growth is necessary. This image illustrates a comparison between traditional aluminum brass tubes with hard baked coating (left side) and uncoated 90/10 copper-nickel tubes (right side). The image shows the result of a six week test. The high copper content of the tubing provides natural anti-fouling capabilities, offering protection against marine growth. Copper alloys possess an inherent natural resistance to biofouling. Clearly, the 90/10 Cu-Ni alloy is resisting fouling from algae mussels and other marine growth. For clarification, the biofouling resistance of copper alloys is due to the copper in the protective oxide film; it is not from the leaching of copper ions.
Virtually maintenance free
The box cooler requires less maintenance since it has fewer components. Operational costs therefore are much lower than for any other cooling system. In harsh conditions when travelling in icy water the risk of clogging the system with ice is significantly reduced in a boxcooler, since it melts the ice and cool the system in that way.Elimination of an outboard circuitThe box cooler does not require a secondary raw water cooling circuit on board, which eliminates the need to bring raw water into the vessel.This reduces the chance of raw water leakages and cuts back the risks subjected to breakdown due to wear and tear.
Boxcoolers require no electrical energy for sea water pumps. Based on overall performance the box cooler design is the most favourable cooling system solution.
The boxcooler system consists of less parts than a central sea water cooling system. The box cooler system requires less pumps & valves, the pipeline length is reduced and there is no need for a mud box or heat exchanger. The system requires less auxiliary power, which saves fuel and results in lower installation costs. The box cooler requires fewer parts which require nautical certification, resulting in a shortened certification process and a cost effective system.
Less susceptible to corrosion
The boxcooler is much less susceptible to corrosion and fouling than any other solutions. The corrosion resistance of the Copper-Nickel 90/10 alloy depends upon the formation of a protective oxide film. Alloying elements such as zinc, nickel, or tin affect the tenacity and adherence of the protective films that form, and thus the relative corrosion resistance of the individual alloys. The general corrosion rate of the Cuni 90/10 alloy in seawater is very low and decreases quickly over time as the protective oxide films form. For this reason, premature failure from general corrosion is rarely experienced. In this respect Copper-Nickel90/10 is clearly a superior alloy with regard to corrosion resistance.
Copper-nickel alloys also have a high inherent resistance to macrofouling. This reduces the frequency of cleaning of piping systems and condensers, and decreases fouling removal costs for boxcoolers. Fouling that does form is poorly adherent and thus easily removed. The biofouling resistance of copper-nickel tubing allows shipboard condensers to maintain good heat transfer capability for several years.
An ICAF (Impressed Current Anti Fouling System) actively releases copper into the sea. One ship equipped with such a system may release 500 kg of copper ions per year. Because of the natural anti-fouling of the Weka box coolers, no extra coating and ICAF system are needed