Bloksma Box Cooler K-Type


Kelvion Machine Cooling B.V. (formerly GEA Bloksma B.V.) has signed a Distributor Agreement with Separator Spares & Equipment, LLC. We are the Authorized Kelvion Machine Cooling (GEA Bloksma) Distribution Center, for their products, in the United States.

Design & Function

The box cooler comprises a U-tube bundle that is fitted in the sea chest on the side of a vessel, saving space in the engine room. The sea chest is equipped with inlet and outlet grids. Cooling sea water enters through the inlet grid and flows along the U-tube bundle to the outlet grid, thus cooling the water inside the tubes. The cooling effect is achieved by the forced circulation of sea water when the vessel is moving or by natural convection when it is stationary.

Box coolers can be used for a wide variety of temperature-reducing duties on a vessel, from cooling the main engines, auxiliary engines and bow thrusters to air conditioning and hydraulic systems.

Kelvion Box Coolers are ideal for small and medium sized vessels, including for example: tugboats, barges, fishing boats, carriers, dredgers, supply vessels, ferries, ice breakers, cargo freighters, tankers and refers.



  • Eliminates on-board sea water system
  • Anti-corrosive materials
  • Less susceptible to corrosion and fouling
  • Can operate in icy conditions, silt, or polluted waters
  • Low maintenance
  • Space-saving in the machine room
  • Low operational costs
  • In-hull protection

Why are Kelvion (GEA Bloksma) externally coated tubes better than uncoated 90/10 Copper Nickel Tubes?

All of the materials of the Kelvion (GEA Bloksma) boxcooler, which are in contact with seawater, are from seawater resistance materials, and so corrosion of the boxcooler will not occur. However, a copper alloy boxcooler connected to a carbon steel hull increase the risk of an electrochemical attack of the weaker part of the two metals: the hull. This case is similar to a bronze propeller and a steel hull. In the case of Kelvion’s externally coated tube boxcoolers, the distance between the noble and less noble materials are very small.

The purpose of the coating by covering the materials of the bundle is to stop the galvanic current between boxcooler and sea chest. This also means that damage in the coating has no detrimental effect until a substantial part of the surface has been damaged. A extra advantage of coating is that it increases the corrosion resistance of the boxcooler. This makes it not sensitive for “under deposit corrosion” caused by to biological fouling.


Anti Fouling

To prevent the box cooler from biological fouling, we recommend the Kelvion ICAF (GEA Bloksma ICAF) (Impressed Current Anti Fouling). This system is reliable, effective under all circumstances, and virtually maintenance free.

Anodes of pure copper 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 create a continues toxic environment for biological growth, preventing the attachment and growth of marine organisms.

These anodes are to be mounted directly under the box cooler. Alternatively the anode system can be integrated into the box cooler. With these integrated anodes, 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.

Retrofitting an ICAF System

In case the thermal performance of a box cooler has deteriorated, due to marine growth, retrofitting an ICAF system is possible in most cases. Contact us in case retrofitting is considered.

The combination of a Kelvion boxcooler and ICAF system guarantees excellence thermal performance without corrosion and without fouling. This creates a problem-free cooling solution!


Air Conditioning System
Auxiliary Engines
Bow Thrusters

Deck Equipment
Hydraulic Systems
Generator Sets
Main Propulsion Engines

Reduction Gears
and more …


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