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Self Cleaning Heat Exchangers (Zero Fouling)

  • 1.  Self Cleaning Heat Exchangers (Zero Fouling)

    Posted 03-27-2019 10:37
    Recently I came across a site that claims they deal in production of self cleaning shell and tube heat exchangers that allow for zero fouling! Is Automatic Tube Cleaning a practical realisation and if so what seem to be its flaws since this idea involves mechanical cleaning.
    Also what are some techniques that are industrially applied on large scale that may approximate near zero fouling ;that's if it is realisable

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    Noah Tibasiima


    Kampala
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  • 2.  RE: Self Cleaning Heat Exchangers (Zero Fouling)

    SENIOR MEMBER
    Posted 06-26-2019 04:42
    We do have some Automatic Tube Cleaning System (ATCS) installed at a few facilities which works fine. Only thing is if these deposits are again getting dissolved which may increase TDS (or TSS as the case for these solids). I could not come up with any other downside. If you came across about any downside, please share it with me as well.

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    Ankush Jain
    Specialist
    ITC LIMITED
    Kolkata
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  • 3.  RE: Self Cleaning Heat Exchangers (Zero Fouling)

    SENIOR MEMBER
    Posted 06-27-2019 00:32
    We have large chillers for industrial cooling water.  They have two heat exchangers.  On the "evaporator" side, we cool down the "process cooling water return" fluid by evaporating a refrigerant.  On the "condenser" side, we condense the refrigerant by using supply water from cooling towers.

    The cooling tower water has a lot of hardness (we are in Arizona desert) and fouling in the condenser heat exchanger is very common.  We have automated cleaning systems that pass balls or brushes in the tubes to remove the build up.   They are effective as long as the build up is uniform in thickness (which is not the case during summer time here).  Otherwise, the ball or the brush may get stuck.

    So, if your cooling liquid does not have large particles or a lot of hardness, I suggest using the automatic cleaning system.  Otherwise, manual cleaning may be more effective.

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    Nader Shakerin
    Facilities Manager
    Intel Corporation
    Chandler AZ
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  • 4.  RE: Self Cleaning Heat Exchangers (Zero Fouling)

    SENIOR MEMBER
    Posted 07-02-2019 06:41
    I'm not certain of your application for self-cleaning heat exchanger technology, but spiral heat exchangers have about the best overall record for (near) zero fouling of any heat exchanger I've ever utilized.  Our service was difficult, liquid titanium tetrachloride, where any fouling could lead to significant corrosion and holing of the vessel.  Spiral heat exchangers remained 'clean' the longest, allowing for fewer turnarounds for cleaning and inspection.  And, they were relatively easy to clean as well.  The two main suppliers during my industrial tenure were Alfa-Laval and GEA-Canzler.  I'd recommend investigating those.

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    Lawrence Rentkiewicz PE,CSSA,GICSP
    Senior Lead Chemical Engineer
    Booz Allen Hamilton
    Ellicott City MD
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  • 5.  RE: Self Cleaning Heat Exchangers (Zero Fouling)

    SENIOR MEMBER
    Posted 07-02-2019 08:32
    I will echo other comment, with one addition. Automatic tubeside cleaning systems have been around for a while. They are some variation of brushes or abrasive sponge balls that randomly circulate through tubes, are recovered and recirculated. Mostly used in my experience to mitigate water fouling ( carbonate and biofouling). Other liquids would have to have brush/ball material compatible to fluid. So it depends on your application.

    They work but you have to be able to make the economic justification of reduced fouling/downtime, maintenance vs cost.

    These work on the tube side only.

    There is one product out there that bakes on a Teflon film (very thin to cut down thermal resistance. It has been tested in difficult crude oil applications.

    Spirals do have a self cleaning feature due to the spiral flow. However they are size limited so you might be buying multiple of those vs a large S&T

    Hope that helps

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    Don [McConnell PE, CEM, CEMI
    Principal Consultant, Energy Engineering
    DuPont/DuPont Engineering & Research Technology
    Charlotte North Carolina
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  • 6.  RE: Self Cleaning Heat Exchangers (Zero Fouling)

    SENIOR MEMBER
    Posted 08-08-2019 17:59
    Edited by Hussein Mushatti 08-08-2019 18:16
    Conventional shell and tube heat exchangers sometimes have to use two severely fouling process streams, one in the tubes and one in the shell. This paper presents the design of a self-cleaning heat exchanger that applies the self-cleaning mechanism in the tubes of two parallel bundles handling the fouling process streams. For the transfer of heat between both bundles, a small circulating flow of conditioned water is used as an intermediate fluid, a fraction of which evaporates on the outside of the tubes of the high-temperature bundle and condenses on the outside of the tubes of the low-temperature bundle. This novel design, which consists of two parallel bundles in one shell, experiences very high film coefficients at the outside surface of both tube bundles and does not suffer from any fouling. Therefore, it is referred to as a "zero fouling" self-cleaning heat exchanger. a conventional severely fouling crude oil preheater will be compared with a zero fouling self-cleaning heat exchanger for the same service.

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    Hussein Mushatti
    Regional Engineering & Field Services Manager.

    Muscat
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