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Chlorination for MIC

  • 1.  Chlorination for MIC

    Posted 16 days ago
    ​Hello All,

    Greetings for the day!

    One of our customer are facing MIC induced pitting corrosion in sea water cooler (shell and tube heat exchanger). They want to avoid it by some biocides or through chlorination.

    Request to give your input on waht is the ppm of Cl allowed or safe if they want to go for Chlorination. Or if they go for biocide then please suggest type, brand etc.

    Your valuable inputs will be appretiated.

    Thanks & Regards

    Sudhindra
    Business Development Manager
    Sandvik Asia P Ltd
    India

    ------------------------------
    Sudhindra Hathwar
    Business Development Manager
    Sandvik Materials Technology
    Pune MA
    9590344999
    ------------------------------


  • 2.  RE: Chlorination for MIC

    Posted 15 days ago
    ​There are many ways to deal with MIC. Are they anchored only on chlorination as the only solution? Are they also experiencing fouling in addition to MIC?

    Possible solutions;
    1) metallurgy - duplex stainless steel is a common upgrade for cooling water fouling and corrosion protection. This is likely the cheapest long term solution
    2) Biocide chemistry - more complex because it requires an injection, monitoring and control. Chlorine can be used but has a toxicity hazard of gas so a safer option is sodium hypochlorite or bleach vs. Cl-. This may be cheaper in the short term vs. metallurgy but takes much more resources to manage safely
    3) Coatings - why not coat the inside of the exchanger with electroless nickel and Teflon (PTFE) plating? This is much cheaper than duplex stainless, won't corrode and the Teflon will shed hard water scale.

    ------------------------------
    Kerry Barbetti
    System Reliability Engineer
    Koch Industries, Inc.
    rosemount MN
    651-437-0894
    ------------------------------



  • 3.  RE: Chlorination for MIC

    Posted 15 days ago
    ​Hi

    Thanks for your valued input. Material upgradation has been considered to super duplex. Temperature here is tube inlet 35 C and outlet 45 C.
    Ti can not be used as shell side H is there.

    Chlorination and Biocide are the additional action been considered to mitigate the MIC.

    Thanks

    Regards,

    Sudhindra

    ------------------------------
    Sudhindra Hathwar
    Business Development Manager
    Sandvik Materials Technology
    Pune MA
    9590344999
    ------------------------------



  • 4.  RE: Chlorination for MIC

    Posted 15 days ago
    Kerry,
    Be aware that duplex Stainless Steel may not be an answer to MIC Corrosion. I know of at least one example where duplex was used to replace 300 series SS but then also suffered from severe MIC Corrosion​ and had to be again replaced by either copper nickel or titanium - both of which offered a final solution to the problem.

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    Charles Young
    Business Development Manager
    Tricor Industrial Inc.
    Virginia Beach VA
    330-264-3299
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  • 5.  RE: Chlorination for MIC

    Posted 15 days ago
    ​Thanks Charles. Of course, none of these solutions are absolute and the end user will have to determine which is the right one for their specific application based upon cost, chemistry or other risk.

    we've started to evaluate plating out nickel / Teflon on cooling water exchangers and it seems to be working well thus far. It's cheap to apply, thin and makes cleaning easy as well.

    From an overall water chemistry perspective, don't most companies use bleach or a phosphorus based chemistry to manage biologicals? Of the choices available, using chlorine directly is not the safest alternative because of the toxic gas consideration; bleach is much safer.

    ------------------------------
    Kerry Barbetti
    System Reliability Engineer
    Koch Industries, Inc.
    rosemount MN
    651-437-0894
    ------------------------------