High Corrosion in a Closed Loop Cooling System

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How do I prevent and treat high corrosion in a closed loop cooling system? 

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17 Answers

  1. 1. Please arrange the linear velocity in HE in 3-5 feet/second. 

    2. Check material construction of the sysrtem.

    3. Check it the minimum temperatures in the cooler/chiller.

    4. You use Nitrite Program add with Borate as for pH buffering  with control 1500-2500 ppm. And pH in 9 - 10 in range. If the Material Construction has aluminum alloy the PH control in 7.5-8.5.

    5. The superior is with Molybdenum the control MoO4 will in range 150-250 ppm as MoO4.

    If the system has copper alloy the program must add with Azole compound. 

    Usually the program provided with anti scalant, especially for high temperature in close  loop syste.

    Usually the corrosion rate mild steel, with Nitrite: 3.5-4.1 mpy.

    For MoO4, the corrosion rate will

  2. 1. Please arrange the linear velocity in HE in 3-5 feet/second. 

    2. Check material construction of the sysrtem.

    3. Check it the minimum temperatures in the cooler/chiller.

    4. You use Nitrite Program add with Borate as for pH buffering  with control 1500-2500 ppm. And pH in 9 - 10 in range. If the Material Construction has aluminum alloy the PH control in 7.5-8.5.

    5. The superior is with Molybdenum the control MoO4 will in range 150-250 ppm as MoO4.

    If the system has copper alloy the program must add with Azole compound. 

    Usually the program provided with anti scalant, especially for high temperature in close  loop syste.

    Usually the corrosion rate mild steel, with Nitrite: 3.5-4.1 mpy.

    For MoO4, the corrosion rate will

  5. Hi Oswell,

    never use oxidizing biocides in a closed loop, that will cause high corrosion rates.

    If the corrosion is MIC than use chemicalfree disinfection system #HOD-UV from Atlantium. 

    Further questions - do not hesitate to contact me. jorge@atlantium.com

  6. I'm afraid there is insufficient information to be able to advise you.  What temperature is the cooling medium?  What metals are involved in the system?  What is the water quality involved supplying it. 

    Having been involved with issues over the last 45 years the questions come first.  Somewhere between 10-15 % of closed loop systems have biological issues.  Some of these can be iron bacteria which are very difficult to grow on artificial media and take longer incubation times and only respond to very few biocides.

    The first principle is to make sure that the system is pre-cleaned to remove suspended matter. If a system is new, it still needs to be cleaned to remove material present, which varies from oils or grease, corrosion products to bacteria to weld or solder.  Water flushing is not sufficient.

    The choice of corrosion inhibitor will depend on the metals involved, the amount of water make-up, it will be restricted to ones approved in the food industry.  Certain systems may be limited in what they use, because there is a limit on the conductivity used in the water system because it will impact the process.

    It really is a specialised area, that needs to be looked at professionally.  

     

    Answered on by

  7.  

    A water loop is defined to be “closed”, for water treatment purposes, if the make-up rate is less than 10% of the system capacity per year. In a true closed loop, the chemical treatment is added initially, and is expected to remain in the loop for a long period of time - until the loop is drained either fully or partially.

    One of the most important goals in closed loop is to minimize make-up consumption. Closed loop water treatment would generally consist of,

    [1] pH adjustment additive (PH booster) 

    [2] Film-forming amine, corrosion inhibitor by coating all internal surfaces of the piping and equipments with a protective thin layer (Preferable anodic corrosion inhibitor rather than cathodic inhibitor which anodic inhibitor can provide passivation to the surface of the metal), monomolecular film. Corrosion inhibitors, like molybdate, nitrite and azole are very common passivator to prevent attack of oxygen

    [3] Azoles are added if there is copper in the system (Cathodic corrosion inhibitor)

    [4] Ethylene glycol or propylene glycol to freeze-proof the system

    [5] Oxidizing or non-oxidizing biocide, (should not react with corrosion inhibitor) – in hot water system biocides may not be necessary. 

    Finally, the choice of treatment regime is based on the metallurgy of the operating system.

  10. You need to check the materials used in the system, the water chemistry and preferably as well the composition of the corrossion products you probably see. With that information the cause of the corrossion can be identified and an adequated solution can be found.

  11. You can dose corrosion inhibitors, oxygen scavangers , adjust pH, but as previously mentionned, it depends on many factors such as: metallurgy of the heat exchangers, water quality, flow/frequency for the blow-down and the water make-up, etc. The most convenient solution is to get and advice from 2 or 3 chemicals suppliers...

  13. The solution will depend on the water characteristics, operating conditions and the metallurgy in the system. Once that is established then a solution can be determined.

    Answered on by

  14. Dear Oswald, Is your system properly grounded?  Is there a possibility that your cooling water is at a different potential than your cooling circuit?

  15. It will depend on the quality of heat transfer fluid you will be using and you working temperatures so as to give a specific recommendation to your problem. You may contact me with the following details to my email 1) water quality 2) Type of heat transfer fluid mixture and current ratio of mixture  3) Temperature which u need to attain so that i will give you optimum mixture 4) Type of transmission pie network with reference to materials and coats of the internal my email is musaope@sutsol.solutions

  16. Oswald

    to review corrosion in a cooling tower, a competent water treatment consultant would review the water chemistry, the type of chemicals used for disinfection and the materials of fabrication for both the cooling tower and the interconnecting piping.

    Please contact myself if you wish to save money via the use of a competent water treatment consultant.

    stewart@slswaterfilters.com.au