Keel cooler
Bundled to perfection
The GRIDCOOLER® Keel Cooler is mounted externally on the hull below the waterline. The engine coolant is circulated through the GRIDCOOLER Keel Cooler, which transfers heat from the coolant before it returns to the engine. The keel cooler is in constant contact with seawater to efficiently transfer heat.
Technology
Engineered to cool
A keel cooler is a closed-circuit cooling system mounted externally on the vessel’s hull below the waterline. The concept of keel cooling is similar to the application of a radiator on a car. Engine coolant is circulated through the keel cooler, which transfers heat from the coolant before it returns to the engine. The keel cooler is in constant contact with seawater allowing the cooling system to efficiently transfer heat between the coolant and seawater.
ADVANTAGES
Compared to an open circuit cooling system (inboard heat exchanger), a closed-circuit cooling system provides several distinct advantages. A closed-circuit cooling system eliminates the need for an inboard heat exchanger, raw water pumps, strainers, seawater piping, and the high maintenance associated with open circuit cooling systems. It also eliminates silt and sand build-up in the cooling circuit and protects the system from saltwater corrosion.
The use of a keel cooler eliminates the need for seawater to enter the hull. From an environmentally friendly perspective, keel cooling provides a zero-discharge solution eliminating the possibility of contaminants entering the seawater.
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We are happy to assist you with your cooling challenges
Applications
Low in maintenance cost, durable and natural anti-fouling
The GRIDCOOLER® Keel Cooler is a custom-made cooling system engineered to meet the specific demands of the engine manufacturer and operating conditions of your vessel or industrial application. With over 60 years of experience in keel cooling, our sales and engineering team can help provide a reliable cooling solution to meet your specific needs.
Marine Applications
- ATB
- Barges
- Commercial Fishing
- Dredges
- Ferries
- Landing Craft
- Lifeboats
- OSV
- Passenger Vessels
- Patrol Boats
- Pilot Boats
- PSV
- Push Boats
- Recreational Boats
- Semi-Submersible (AUV & ROV)
- Tugboats
Stationary & Industrial Applications
- Buoys
- Drainage Systems
- Facilities’ Climate Control
- Hydroelectric Plants
- Irrigation Systems
- Lift Stations
- Offshore Wind Generators
- Storm Sewer Systems
- Wave & Tidal Generators
- Pump Station Installation
Heat sources
- Air Conditioning Units
- Bow Thrusters
- Compressors
- Electrical Equipment
- Generator Sets
- Hydraulics
- Land Based Applications
- Propulsion & Auxiliary Engines
- Pumps
- Reduction Gears
- Winches
Materials
The Selection of possible materials
The GRIDCOOLER® Keel Cooler is a completely assembled unit and is factory tested to ensure dependability. The rectangular shaped tubing used in its construction is structurally sound and provides a higher heat transfer rate than round tubing. We offer two types of surfaces on the interior of the copper nickel tubing Gridcooler Keel Cooler, smooth or enhanced and an aluminium Gridcooler Keel Cooler.
Copper-Nickel 90/10 – Smooth Surface
The copper-nickel – Smooth Interior Walled Tubing – GRIDCOOLER Keel Cooler is crafted using heavy walled rectangular 90/10 copper-nickel tubing. This alloy was selected based on its durability, heat exchange abilities, resistance to saltwater corrosion, and natural antifouling capabilities. Each copper-nickel keel cooler is torch brazed with 56% silver (content) braze wire to maximize the flexibility and durability of the unit.
Copper-Nickel 90/10 – Enhanced Surface
The Enhanced Interior Walled Tubing Copper-Nickel 90/10 Keel Cooler, a Fernstrum exclusive, is a truncated cone pattern on the interior of the tube generating greater heat transfer. Compared to a smooth walled tube, the enhanced tube increases the heat transfer capability by up to 30 percent. This is especially true in applications where glycol solutions are utilized. The improvement in efficiency may reduce the number or size of the units required for an application. Note: The interior surface of the tubing is determined based on your cooling requirements. Each copper-nickel keel cooler is torch brazed with 56% silver (content) braze wire to maximize the flexibility and durability of the unit.
Aluminium – 5000 Series
The aluminium GRIDCOOLER Keel Cooler is designed specifically for unpainted aluminium hull applications in fresh or cold seawater environments. 5000 series aluminium alloy was selected based on its compatibility with unpainted aluminium hulls and saltwater corrosion resistance. The alloy compatibility between the hull and keel cooler prevents pitting and avoids potential damage from interacting metals.
Copper-Nickel 90/10 Advantages
Amazing results after a 6 week feasibility study
Natural Anti-Fouling
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). It’s the result of a six weeks feasibility 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.
Eliminates raw water pumps, strainers, and filters
Virtually maintenance free
Cools engines up to 40,000 kw
In-hull protection
Installation & design options
Depending on your operating conditions and hull design.
Recessed
Recessing a GRIDCOOLER Keel Cooler streamlines the installation and provides significant protection from potential damage. Independent tests conducted at the Vienna Model Test Basin have shown that drag is negligible when the unit is recessed into a ship’s hull. The position of the recess can be located on the side or bottom of the hull. This type of installation is common in new projects and ideal for fast-moving vessels.
External
An external installation typically applies fairing and side plates for added protection and to improve streamlining. This mounting option is commonly used in retrofitting projects.
Side Mounted
Mounting the GRIDCOOLER Keel Cooler on the side of the hull prevents potential damage to the unit. It is ideal for situations where a keel cooler cannot be mounted to the bottom of the hull. Note: When recessing the unit into the side of the hull for generator sets and/or equipment operating at dockside, angle the top of the recess box to allow convection current over the cooler.
Industrial Installation
The GRIDCOOLER® Keel Cooler gives you the choice of being able to mount the units in several configurations. Typically mounted in the suction or discharge sump, the keel coolers can be supported by means of brackets (customer supplied) or the units can be supplied with mounting feet for mounting directly to the sump wall or floor. Flanged connections are available and are supplied with corresponding mating flanges.
Stacked GRIDCOOLER
Keel Cooler
When faced with limited space or larger cooling requirements, a stacked GRIDCOOLER® Keel Cooler reduces the footprint of the keel cooler while providing greater heat transfer. The design is ideal for cooling larger engines, reducing the number of units required, or fitting into an existing application in the case of repowering.
Angled Tube GRIDCOOLER Keel Cooler
An angled tube GRIDCOOLER Keel Cooler optimizes the heat transfer for side mounted zero knot or stationary applications. The design exploits the natural convection current created by the heat exchanger. The unique position and angle of the tubes are crafted to maximize the flow of raw water between the tubes. This configuration also resists the collection of silt and other debris from building up on the unit.
Aluminium – 5000 Series
The aluminium GRIDCOOLER Keel Cooler is designed specifically for unpainted aluminium hull applications in fresh or cold seawater environments. 5000 series aluminium alloy was selected based on its compatibility with unpainted aluminium hulls and saltwater corrosion resistance. The alloy compatibility between the hull and keel cooler prevents pitting and avoids potential damage from interacting metals.
Classification
Upon request the GRIDCOOLER Keelcooler can be supplied with a test certificate of one of the well-known classification societies. For example, ABS, Bureau Veritas, DNV-GL, Lloyds Register of Shipping, RINA, RMRS, RRR and various others upon request.