Effective and reliable marine cooling system
A Box Cooler is a water cooling system which finds a growing market share in both inland and sea going ships. Fresh on-board cooling water is forced through a U-tube-bundle, which is placed in a sea-chest having inlet- and outlet-grids. The cooling effect is reached by natural circulation of the outboard water in the sea-chest or by a circulation due to the speed of the vessel.
The Bloksma Box cooler cooling system, widely used on smaller and medium-sized vessels, is well-known for its high quality standard which resulted in a major market share in water cooling systems. Bloksma Box coolers are available in a wide variety of sizes and execution therefore complying with almost each seachest design. Due to its unique principal the complexity of the entire cooling system is reduced and leads to a reduction of investment by the shipyard and shipowner. Moreover the Bloksma Box coolers are virtually maintenance free which reduces operational costs compared to any other cooling system.
- Elimination of complete outboard secondary cooling water circuit. Eliminating (seawater) pump, filters, valves, and expensive seawater piping etc.
- Flexibile solutions and sizes available, i.e. Bottom Pull, Top pull, stepped bundles, double circuit, Integrated ICAF and more
- Box coolers are much less susceptible to corrosion and fouling compared with any other solution
- Box coolers are ideally suited for operation in icy, sandy shallow and silt polluted water
- Energy saving (elimination of secondary pump)
Plug & Run Cooling Solutions
The Bloksma FlowBox combines the valued features of box coolers and plate heat exchangers while adding ease of maintenance and installation. In addition, the Bloksma FlowBox is a worry-free fit-and-forget installation with delivery including the seawater box. Truly a plug & run solution.
When compared with other cooling systems such as plate heat exchangers or conventional shell & tube coolers, the FlowBox provides the following advantages valued by ship owners, designers and yards alike:
All Bloksma box cooler materials, which are in contact with seawater, are from seawater resistance materials and are carefully selected. Corrosion on the box cooler unit itself will therefore not occur. However, a copper alloy box cooler connected to a carbon steel hull increases the risk of an electrochemical (galvanic corrosion) attack on the weakest material, the hull. Therefore Bloksma Box coolers are applied with a special selected hot-cured phenolic resin based coating to eliminate any material contact that could lead to galvanic corrosion. A long lasting and reliable insulating effect with the phenolic coating is ensured, because local damage to the coating results in a small galvanic drain only. Furthermore the Bloksma coated box coolers system is not sensitive or is influenced by other systems, like ICCP (Impressed Current Cathodic Protecting) and ICAF (Impressed Current Anti Fouling).
In general the box cooler system is a maintenance free system. However depending on the area of sailing and on several operational conditions biological fouling can occur. The type of organism most responsible for biological fouling on box coolers is mussels. Biological fouling can appear either on coated as well as un-coated box coolers. In case of severe biological fouling the thermal performance of the box cooler is deteriorated by blockage of the heat transfer surface. To avoid this biological fouling an anti-fouling system is recommended.
To prevent the box cooler from biological grown (fouling) more systems are available in the market, the most common is ICAF (Impressed Current Anti Fouling). This system is reliable, effective under all circumstances and maintenance free between docking periods. Pure copper anodes are mounted under the box cooler in the sea chest. A constant current is applied between the anodes and the sea chest, which causes copper to dissolve in the sea-water. These CU ions creates locally a continues toxic environment, preventing attachment and growth of marine organisms.
These anodes are to be mounted directly under the box cooler. In case of separate anodes the supports for the anodes are welded into the sea chest. Alternatively the anode system can be integrated to the Bloksma box cooler system. With these integrated anodes - see figure - the cabling is fed through the box cooler to ease installation. The extra weight of the anode-rack does not influence the mechanical stability of the cooler, even under heavy seagoing conditions.