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DE Filtration Nightmares

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  • DE Filtration Nightmares

    This is going out to all of you that had those late night filter runs. I have been using DE filters, in various sizes, for many years but I have never encountered one that has given me as much trouble as the current one I am using. A 4 square meter, horizontal screen, DE filter should have no problem doing 80 bbl/8 hour shift. I am lucky if I can get that done in a staggered split shift. My methods have not changed for the breweries I have worked for in the past so I use them at present and they seem to do me no good. I am at my wits end so advice in this matter would be appreciated.

    Filter SOP is as follows:
    Bring in beer from the FV (I am aware of the difference of opinion on whether water or beer for the precoat. Collectively we all can go round and round on this one and it comes down to personal preference, so leave it at that)

    Precoat with: 6lbs. hiflow
    6lbs. standard
    Body feed: 4lbs. Standard

    Prefilter analysis finds there are over 4 million cells. Our Lagers filter wonderfully and they have less than 2. Tank space is a problem and we move beer at the soonest we can without compromising the beer or our integrity. I am wondering if we were to improve clarity would that be the shot in the arm we need to get filtrations moving again. We do not have a centrifuge, however I willing to bet there is more than 1% solids in the beer prior to filtration. That would cause a big problem. What does a brewer do when the demand is there but the tank space to warrant longer lagering periods is not?

  • #2
    Your description of your precoat:
    Do you first coat with hiflo and then with standard? BTW I would use water every time for this purpose.

    Body feed of standard only? Given a good tight second precoat, you could probably body feed with about 70% hiflo and 30 % standard.

    Amount of body feed:
    Assuming standard DE dosing of 80-100 g/hL, 80 bbl (~94 hL), you are way light on body feed.

    Do you use any clarifying agents (hydro/xerogel)?

    Good luck,


    Liam McKenna


    • #3
      I agree with Liam, I would start by significantly increasing the amount of DE you are using in the body feed.

      My filter manual states

      For Precoating: "1 kg. of DE per square meter of filter surface"

      For Filtration: "The principle of amount of body feed ususally consists in the use of the same amound of DE as the solid substances to separate.

      by decreasing the amount of DE, the filter's pressure increases more rapidly and so filtration quantity decreases."

      So in essance if you are trying to seperate a lot of yeast and solids, you need an equivalent amount of DE in the body feed (i.e. more solids = more DE needed).

      Another procedure you may want to try is varying the ratios of DE in both the precoat and the body feed. I've found over numerous trials that using Celite 512 (5 micron), both precoat and body feed in my filter works the best for both acceptable clarity and filter time (1 - 1.5 hours for 30 BBL).


      • #4
        More DE in the bodyfeed.

        Hey Lewis,

        Undoubtedly you've claculated your pre-coat amounts properly; however, you should certainly increase the amount of DE you are using in the first bit of body feed. Since you're drawing beer from the bottom of the fermenter at the beginning of you run, the percentage of solids in the beer is going to be significantly higher than what you'll encounter further into your filtration.

        As you start your run, dose it a bit heavier with a denser slurry and ease back on both dosing rate and the percentage of DE in your body feed slurry as you get a handle on how the rest of the run will proceed. Try 9 pounds and adjust from there. Also, start your run at about 60% of your normal flowrate. Be aware that excessive dosing can also cause D.P. to increase.

        I cannot recommend blending DE grades for your body feed as it will compromise the integrity of your filter bed as the matrix relies on consistant particles.

        I hope your filtrations improve!


        Last edited by DFHBrewery; 10-10-2007, 01:01 PM.


        • #5
          "What does a brewer do when the demand is there but the tank space to warrant longer lagering periods is not?"

          Tried finings ? Otherwise the only option is to grossly dose the beer into the filter. You can probably, may even need to use a coarserpowder to cope, and just have to suffer filling the filter rapidly - 2 psi increase / hr at the inlet is about right