Building stainless heat exchanger

Discussion in 'Powerboats' started by guest, Jul 25, 2004.

  1. guest

    guest Guest

    Hi

    I have a 283 chevy marine engine and am looking at building a heat exchanger to go on this. Does anyone have any info on sizes that I would need and how they actualy work.
    Thanks
     
  2. hmattos
    Joined: Jun 2004
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    Location: Devon UK

    hmattos Senior Member

    Stainless steel is a very poor conductor of heat and is thus not my first choice for heat exchanger tubes. The copper / bronze alloys are usually used. Personally I would speak to Bowman - in the UK - or your local equivalent supplier, since a purchased unit will be much cheaper and more reliable than any hand built project
     
  3. Corpus Skipper
    Joined: Oct 2003
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    Location: Corpus Christi TX

    Corpus Skipper Hopeless Boataholic

    Stainless will corrode quickly when used for heat exchangers or saltwater piping.
     
  4. TheFisher
    Joined: Oct 2003
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    Location: Middleburg, FL

    TheFisher Junior Member

    Use Monel, Copper/Nickel, or Bronze.
     

  5. theodk
    Joined: Aug 2004
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    Location: Philadelphia, PA USA

    theodk New Member

    Heat Exchanger Configuration & Material Composition

    I would recommend either T316 or T321 SS construction for continuous salt-water or fresh water applications. While it is true that the thermal conductivity of brass/copper is better than SS, the performance of a identically-sized and designed exchanger will be impacted by 5-6%.

    Keep in mind however, that most heat exchangers sized for jacketwater cooling should be padded for the heatload tolerance specified by the dealer - for GM it is +/- 5%, for CAT is is +/- 8-10% depending on the engine model number.

    So, I would not worry about thermal performance comparisons between a SS and brass exchanger. I would design around life cycle of the unit. In either case, the use of a zinc anode would help extend the life of either SS or brass exchanger.

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    Regarding configuration..
    If engine room is plentyfull, a shell & tube design is prefereable. I would run the JW circuit through the shell side (treated 50/50 prop/glycol mix) and run the raw untreated water through the tubes. Try to size the unit into a single-pass design so that the tubes can be cleaned with a pipe cleaner without removing the end bonnets.

    If engine room is limited, a plate & frame exchanger is the way to go. They offer 45% more exchanging surface area than a comperable-footprint S&T (thus making the exchanger footprint much smaller), however are more costly and do offer a easy cleaning solution (if the internals get fouled by the raw cooling water).

    I hope this helps..

    Ted K.
    Philadelphia, PA
     
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