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90/10 cupro-nickel tubing is resistant to waterflow erosion and serves as an antifoulant. Compact, one-piece design makes installation simple. Streamlined header design reduces pressure drop in water flowing through the cooler. External water travels more quickly to tubes increasing the heat transfer efficiency of the cooler. Custom-sized for your engine specifications and operational requirements. Available with through-hull type fittings or non-through-hull flanges. PATENT PENDING. Tube Cooler Success / Major Breakthrough Testing Results / Commitment to Design

Success of the Rectangular Tube Cooler In 1946, the first rectangular tube keel cooler came to the marine market. For nearly half a century, this design has enjoyed considerable success in the marine industry for keel cooling of heat sources on marine vessels. This type of cooler has been successful in the marine industry for three reasons: Large amounts of tubing surface area in a relatively small, compact footprint. This equates to a highly efficient heat exchange device. Durability of design: In many applications, the design has with stood more than twenty years of continuous use in severe marine environments. Ease of installation: Shipyard workers appreciate the ease of installation of the one piece keel cooler.   back to top

First Major Breakthrough in Keel Cooling Technology In 1997, Duramax® Marine LLC initiated a research and development program to identify opportunities to improve the operational efficiency of the square-headed outboard keel cooler. Finite element computer studies were conducted to determine internal and external flow patterns, pressure drop and heat transfer characteristics for different heat exchanger geometries. Flow pattern studies determined that the outside tubes, tubes number 1 and number 8, (the outside tubes) in the square-headed keel cooler tested were being used inefficiently despite the fact these tubes have the greatest potential heat rejection per linear foot. The design of the existing square header is the reason for this inefficiency. Duramax® Marine LLC immediately began to develop a more efficient header design. Duramax® Marine LLC engineered the new streamlined header design to further enhance interior and exterior flow patterns and, at the same time, reduce the overall pressure drop within the keel cooler unit. In initial testing, the design also increased coolant flow to the outside tubes that had been used less efficiently in the traditional keel cooler design. Coolant flow distribution in the outer tubes increased 35% after the geometry modifications. Heat rejection in the outer tubes jumped 45%. Overall heat transfer in the DuraCooler® SC-48-96 increased 17% over the square-headed unit of equal size in initial testing. The DuraCooler® design with increased coolant flow to the outside tubes will result in smaller units versus traditional square headers and lower costs. Overall footprint may be reduced as much as 42% in some units. (see graphs below) back to top

Testing Results

Traditional Design Tested	DuraCooler®
Computer modeling of the traditional design keel cooler tested showed poor coolant flow through tubes 1 & 8.	DuraCooler® header design change produced an increase of 35% in the outside tubes.
Traditional Design Tested	DuraCooler®
Computer modeling of the traditional design keel cooler tested indicated the outside tubes were being used least efficiently even though these tubes had the greatest potential heat rejection per linear foot.	DuraCooler® header design increased heat transfer in the outside tubes by 45%!

	Note: Study above conducted on a SC-48-96 and equivalent size square-head unit. Studies conducted by: Flow Simulations Inc. e-mail: info@flowsimulations.com
	Overall heat transfer in the DuraCooler SC-48-96 increased by 17% over the square-headed, traditional design keel cooler unit tested of equal size in initial testing.

Commitment to Design Improvements Duramax® Marine LLC, with promising results from the finite element testing proceeded to the next phase of testing, actual unit testing in its research pond. In 1998, Duramax® Marine LLC built an 800,000-gallon testing facility to better emulate marine conditions in a controlled environment. Testing facility can test keel coolers 20 feet long and weighing as much as two tons. Temperature drop, pressure drop and flow rates are monitored and recorded. Initial tests on the same size square-head keel cooler that was tested in the laboratory validated the computerized testing.

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Duramax® Marine LLC
17990 Great Lakes Parkway
Hiram, OH 44234 USA
Phone: 440.834.5400
Fax: 440.834.4950 or Fax: 800.497.9283 (US and Canada)
© 2002, Duramax® Marine LLC. All rights reserved.
DuraCooler is Patent Pending.