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Thread: Uh Oh...Heat Exchanger Contamination?

  1. #1
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    Uh Oh...Heat Exchanger Contamination?

    Recently started brewing for a fairly young brewery. I don't know what the cleaning regimen for the heat-x was before I started, as the brewer was already gone, but I suspect it only saw chemical during BH CIPs and was probably just flushed w hot water pre/post brewing. It's possibly been clogged before, or at least had large amounts of material run through it (think NEIPAs). I've been giving it isolated caustic/acid fwd/rev, packing overnight, etc. The first few runs were shockingly soiled. Its gotten much better but still a decent amount of crap comes out.

    So then our HLT goes down and creates havoc. Gave the heat-x a cool/warm caustic run but then it sat (unintentionally long) with only water in it for about a week while other fires were being put out. When we're back online I run hot h2O to flush in preparation for chemical and the water came out cloudy and smelled FOUL. Very much of sulphur mixed with gross. Gave it chemical every which way and once we get an extra set of plate gaskets it'll be getting opened up.

    Anyone familiar with what could have caused this? No lab capabilities here yet but I intend to drop off a h2O sample at another local brewery that can plate it for us. I'll know for sure then, but because I'm impatient and in the event the chemical did its job and samples are clean I'd still like an idea of what we were/are dealing with.

    On another note, I plan to start packing the heat-x packed with iodophor instead of caustic or PAA, as I've read this is more gentle on the gaskets. Anyone care to dispute, or is this generally considered best practice?

  2. #2
    Join Date
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    The sulphury stench is infection growing on residual organic material left in the PHE. Simple as that. It needs cleaning properly. Start off back rinsing and then cleaning at 150%, or possibly even slightly higher using 2 to 3 % hot - 80 deg C caustic, and once up to temperature add some hydrogen peroxide. Rinse and repeat until the caustic is clear even after about 20 minutes. Hot liquor flush - 85 deg C or higher for 20 minutes. If you want to once cooled down, soak with 200 ppm PAA. If it still doesn't flow properly, you may end up stripping the plate pack down and manually cleaning it.

    Do NOT use iodophor, unless you want to risk developing holes in your plates and possibly failure due to stress corrosion cracking between the corrosion pits caused by the iodophor - which are most likely to be on the edges of the gaskets or any plate separation nipples. Bass as they were known at that time had to recall huge amounts (I have heard up to 15% volume but obviously don't know how true that % is) of production in final pack after glycol got into beer due to corrosion around the plate separation nipples.
    dick

  3. #3
    Join Date
    Aug 2010
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    It sure sounds to me like you're looking at a tear-down.

    This is one of my most dreaded jobs. First, paint diagonal lines down one of the long edges of the HX plates. This will make it immediately obvious if you get a plate out of order/orientation. Be sure you have a diagram from the manufacturer showing how the plates go, just in case. These diagrams are usually somewhat cryptic, so communicate with a tech to be sure you understand.

    I use two large, open grants (tubs, really), so I can keep the plates in order as I clean them. I like to do this when no one else is in the brewery to help keep me focused.

    Best of luck, and, yeah, no iodophor! PAA is perfectly safe if you're using Viton or Buna-N gaskets.
    Timm Turrentine

    Brewerywright,
    Terminal Gravity Brewing,
    Enterprise. Oregon.

  4. #4
    Join Date
    Nov 2009
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    Moab, Utah
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    For Sure Timm

    Quote Originally Posted by TGTimm View Post
    It sure sounds to me like you're looking at a tear-down.

    This is one of my most dreaded jobs. First, paint diagonal lines down one of the long edges of the HX plates. This will make it immediately obvious if you get a plate out of order/orientation. Be sure you have a diagram from the manufacturer showing how the plates go, just in case. These diagrams are usually somewhat cryptic, so communicate with a tech to be sure you understand.

    I use two large, open grants (tubs, really), so I can keep the plates in order as I clean them. I like to do this when no one else is in the brewery to help keep me focused.

    Best of luck, and, yeah, no iodophor! PAA is perfectly safe if you're using Viton or Buna-N gaskets.
    To say its dreaded might be a Colossal Understatement. I would advise getting a NEW plate pack from the OEM to cover all unforseen bases.
    It is helpful to cut some wooden dowels, to gauge the closure. Also knowing the OEM max closure for your HX is key. A power driven impact driver is helpful.

    Star
    Warren Turner
    Industrial Engineering Technician
    HVACR-Electrical Systems Specialist
    Moab Brewery
    " No Cell Phone Zone."

  5. #5
    Join Date
    Jun 2019
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    East Coast
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    Thanks for the replies. Good to know about iodophor, I'll continue with PAA/caustic.

    Definitely not looking forward to opening up the heatx. I sort of did it once at my last brewery, except in that case it was hard-piped to the BH and we didn't want to cut the copper, so all I could do was separate the plates by and inch or two, poke at it, and spray out the buildup with a hose. There the issue was restricted flow, and it did the trick, but even that was a huge pain in the ass. The tips and tricks should help, thanks for those.

    Side note - is there an optimal water pressure to have the main set at for brewery processing (specifically for the heatx)? Ours is really high and I'm planning on dropping it to 40-50psi based on some posts I've seen on here.

  6. #6
    Join Date
    Nov 2009
    Location
    Moab, Utah
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    598

    h20 Pressure

    Quote Originally Posted by Peters View Post
    Thanks for the replies. Good to know about iodophor, I'll continue with PAA/caustic.

    Definitely not looking forward to opening up the heatx. I sort of did it once at my last brewery, except in that case it was hard-piped to the BH and we didn't want to cut the copper, so all I could do was separate the plates by and inch or two, poke at it, and spray out the buildup with a hose. There the issue was restricted flow, and it did the trick, but even that was a huge pain in the ass. The tips and tricks should help, thanks for those.

    Side note - is there an optimal water pressure to have the main set at for brewery processing (specifically for the heatx)? Ours is really high and I'm planning on dropping it to 40-50psi based on some posts I've seen on here.
    Water pressure limits are based on the OEM spec. as given by the model number on your device.
    Warren Turner
    Industrial Engineering Technician
    HVACR-Electrical Systems Specialist
    Moab Brewery
    " No Cell Phone Zone."

  7. #7
    Join Date
    Jun 2019
    Location
    East Coast
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    8
    Quote Originally Posted by Starcat View Post
    Water pressure limits are based on the OEM spec. as given by the model number on your device.
    Great, thanks

  8. #8
    Join Date
    Aug 2010
    Location
    Enterprise, Oregon
    Posts
    1,988
    You should have a water pressure reducing regulator/anti-backflow valve set up where the water enters the brewery. 40-50 psi is pretty standard.

    If you have a pumped hot water system, you'll need to balance the pressure from the pump to match your pressure-reducer. Mixing water for brewing is almost impossible if the two pressures aren't close.
    Timm Turrentine

    Brewerywright,
    Terminal Gravity Brewing,
    Enterprise. Oregon.

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