Announcement

Collapse
No announcement yet.

Design of Lauter Tun Agitator

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Design of Lauter Tun Agitator

    Hi.

    I am going to settle 2000L Brew House. (Mash, Lauter, Kettle/WP)

    I am wondering which Lauter tun agitator will be more effective.
    (for efficiency and for cleaning work)

    A & B is not much different.

    But C, it has a BAR in the bottom.
    I think it will help for cleaning spent grain.
    But I am worried about grain filtering.
    I think the BAR can disturb filtering of grain bed.

    Anyone has experience of it?

    Lino Kim from Colombia, Bogota
    Attached Files

  • #2
    You're correct; the "BAR" is a plow for removing spent grain after lautering. But don't worry... it lifts out of the way until you need it. The plow (BAR) will be mounted on two swinging arms, and is held up, out of the way, by a chain or hook which you can release to "drop the plow" when you're ready to eject the spent grain.

    In some designs there are small folding paddles, like in your second photo, that trail behind each agitator. This is often called an "automatic grain plow" or similar name. When you're ready to eject the spent grain, the agitator rotation is reversed which forces each paddle to flip 90 degrees, and then they are lined up to form a continuous plow bar. In their normal trailing rotation they may slightly disturb the grain bed (compared to a "drop plow" that's completely out of the mash) but this doesn't seem to be a major problem since many breweries use this system.

    The top photo does not seem to have any sort of plow.

    The two different types of agitators (or "rakes") either designed for cutting (the wavy agitators) or lifting (the straight agitators with little horizontal fins) and you will find many differing opinions on which is best!

    Personally, I prefer more rakes spaced closely together (as in your third photo) and I also prefer lifting rakes in which the "horizontal fin" points are angled slightly downward so they lift and break the mash. This is a greater disturbance but I don't tend to agitate unless I *want* to break up the mash. Depending on your brewing style other types may be better suited.

    Very nice brewhouses can be designed with the ability to raise or lower the entire rake assembly, allowing you to leave the bottom few inches of the mash undisturbed while vigorously breaking up the top portion.
    Last edited by Yellowbeard; 08-28-2017, 12:29 AM.

    Comment


    • #3
      I like B!

      Having used all of these designs, I prefer design B

      As mentioned above, the "BAR" on "C" will raise up manually by way of the attached pivot point on top of the rakes. It is usually held by a chain that you drape over a hook. You turn the rakes, removing some of the spent grain, then you drop the "BAR" to push the rest out. It is a pretty effective way, but requires using your hands to drop the plow. You then have to lift the plow back up and lock it with the chain when done. Not very labor intensive, but you do have to reach in the tun. Premier likes this system.

      Design "B" has "automatic" rakes that flip outwards when you run your motor in reverse. It is very important to remove a good portion of grain in the FORWARD position before turning the motor in reverse to prevent breaking off the bottom rakes. It is just about as effective at removing grains, but only requires you to change the motor speed/direction. Virtually no labor, which is my preference. DME likes this system.

      Design "A" should be avoided unless there is a SIGNIFICANT cost reduction, as you will spend much more time graining out manually. If you have cheap labor (like here in India) it may not be a problem. Then the only labor is your voice, which is technically less that your finger on the motor button (depending on your labor I suppose). But time is money. Generally used only in 10BBL or less. The 30BBL I used this on was a PITA!

      I tend to prefer lifting fins as well, although a combination has shown to be very effective for me. Lifting fins are very nice if you make beers prone to sticky mashes.

      The bigger question is, do any of your options offer under-screen spray nozzles? That would be my preference over removing the screen plates each time.

      Comment


      • #4
        under-screen spray nozzles

        Thank you for your advise.

        No one offered me under-screen spray nozzles.
        Do you have experience with this function?

        I think the hole of falesbottom is very small so that the spaying cannot pass through the screen up.

        If it helps, I would add this function.

        Lino Kim in Bogota, Colombia.

        Originally posted by UnFermentable View Post
        Having used all of these designs, I prefer design B

        As mentioned above, the "BAR" on "C" will raise up manually by way of the attached pivot point on top of the rakes. It is usually held by a chain that you drape over a hook. You turn the rakes, removing some of the spent grain, then you drop the "BAR" to push the rest out. It is a pretty effective way, but requires using your hands to drop the plow. You then have to lift the plow back up and lock it with the chain when done. Not very labor intensive, but you do have to reach in the tun. Premier likes this system.

        Design "B" has "automatic" rakes that flip outwards when you run your motor in reverse. It is very important to remove a good portion of grain in the FORWARD position before turning the motor in reverse to prevent breaking off the bottom rakes. It is just about as effective at removing grains, but only requires you to change the motor speed/direction. Virtually no labor, which is my preference. DME likes this system.

        Design "A" should be avoided unless there is a SIGNIFICANT cost reduction, as you will spend much more time graining out manually. If you have cheap labor (like here in India) it may not be a problem. Then the only labor is your voice, which is technically less that your finger on the motor button (depending on your labor I suppose). But time is money. Generally used only in 10BBL or less. The 30BBL I used this on was a PITA!

        I tend to prefer lifting fins as well, although a combination has shown to be very effective for me. Lifting fins are very nice if you make beers prone to sticky mashes.

        The bigger question is, do any of your options offer under-screen spray nozzles? That would be my preference over removing the screen plates each time.

        Comment


        • #5
          Looking at those I would say that all 3 pictures have too few rakes to properly work for cutting the lauter. For that to work the you need to have quite a few rakes spaced close together and the rakes need to have adjustable height. There are a lot of manufacturers currently building rakes that are only useful for mash in and not for the lauter.
          Manuel

          Comment


          • #6
            Can we get something straight.

            This sort of design is not for mixing the mash. It is for raking the grain bed in the lauter tun to help maintain porosity during run off. If you spin the rakes fast enough, they will help to mix to a limited extent, but not enough to mix thoroughly enough to be able to carry out accurate and consistent rising temperature mashes. The rakes are meant to be rotated very slowly so the bed does not move round - I can't find the rotation speed used by some of the big (7 to 12 metre tuns) I have worked with. Just because a 20 hl tun is smaller diameter, doesn't mean they can or should be rotated faster.

            So ideally, the rakes should be capable of being raised, to minimise the channelling effect by running them at a constant height.

            As has already be said, there are too few rakes in any of these examples, though picture C is closest.

            The discharge arm as shown in C is my preferred sort of design providing it is raised completely clear of the grain bed during lautering as if raised, it will not mix the bed at all, unlike the swivel rakes in picture B. But it looks as though it is fixed in position at the bottom of the rakes. The results of mixing the bed during runoff are disastrous - I have seen this at a couple of large breweries where the rakes were not clear of the bed and the quality of the wort and the runoff gravity profile was awful. And the flights in picture B are too steep and will mix the bed, and may cause sufficient resistance to rotate the bed.
            dick

            Comment


            • #7
              Originally posted by Lino4.kim View Post
              Thank you for your advise.

              No one offered me under-screen spray nozzles.
              Do you have experience with this function?

              I think the hole of falesbottom is very small so that the spaying cannot pass through the screen up.

              If it helps, I would add this function.

              Lino Kim in Bogota, Colombia.
              The idea is not to spray up THROUGH the screens, but simply to wash the bottom of the screens and flush sediment that accumulates at the bottom. You can spray the top with a hose. This way, you don't need to remove the screens between multiple mashes for fear of sticking the second or third batch. Still need to clean your screen periodically though and I caustic soak periodically as well. That stuff is magic! CIP daily (or once production stops) of course.

              It has not been my experience that turning rakes in any of these configurations is a problem during runoff as I have not seen significant channeling, sticking, or clarity issues. I have, however, been equipped with VFDs on my pumps and as such, my typical method is to "cut" the bed by spinning 1/2 or 1 full turn, very slowly, about halfway through. I stop my sparge water(or trickle it), and slow my VFD pump considerably, until almost stopped. I then slowly increase VFD back to normal, and start sparge again. With this method I have typically seen 82-90% efficiency depending on the beer. It helps if you have a sight glass between lauter and kettle so you can monitor turbidity and flow rate. Usually if I have some turbidity I keep the VFD slow longer and it tends to clear up quite quickly. I have never had any issues with hazes or tannins in the final product, but your mileage may vary.

              This range of efficiency has been good for me, more takes longer and cost me more in labor than the extra grain. I'd go mash filter if this wasn't enough.

              Comment

              Working...
              X