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Glycol Header Sizing w/ Flow limiters on tanks

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  • Glycol Header Sizing w/ Flow limiters on tanks

    Hey guys, having a bit of an issue with setting up our glycol system.

    We're setting up a brewpub. 10BBL system, 5 jacketed 10BBL fermenters, 10 jacketed 10BBL serving tanks. We're going with Cool-Fit headers, drops, and valves, then the flexible hose supplied by the tank manufacturer (Specific) to connect the tanks. Possibly we will run Cool-Fit all the way to the tanks in the future. Glycol chiller manufactured by Pro.

    Pro sized us with their 5HP MA model. We then began to talk about header size. Specific suggested flow requirements of 2GPM for holding temperature, 6GPM for crashing. Pro came back and told me that that's all well and good, but since the tanks have 1" connections, they will draw 10GPM whether they need it or not. 10GPM * 18 (3 future tanks) * 70% = 126GPM. Pro recommended I go with a 2.5" header, upsize the reservoir to 200gal, and upsize the process pump to 2 or 3 HP. Having worked in a brewery with a suspect glycol system, I decided to go with all the recommendations, and figure out how to deal with the price increases later.

    Of course, being an idiot, I forgot to actually confirm with Pro that I wanted these upgrades, and I learned yesterday that my chiller is built, without the upgrades. I have not ordered the glycol piping from GF yet.

    My options are to either:
    a) Find another buyer for the completed system (possibly not an easy task), and order a new one, delaying me a month or so, as Pro has a bit of a backlog
    b) Explore sizing the system for only the required 2/6GPM per tank specified by the manufacturer. Also we'd be able to maybe reduce the header size, saving a boatload of cash.

    Could we look into adding a 6GPM flow limiter onto each tank? Does a part like this exist that is reliable? If we only had 6GPM max in each tank, that brings the whole system down to 6 * 18 * 70% = 76GPM. If we have some form of adjustable flow limiter that is generally set to 2GPM, and can be switched to 6GPM when crashing the tank, we would reduce flow requirement down to (2*17+6*1)*70% = 28GPM. From my understanding, this would eliminate the need for the upsized process pump and reservoir? Is there a good reason this type of thinking isn't valid? Is there something else I'm over looking?

    I'm discussing this with Pro, GF, and Specific right now, but just wanted to see if anyone here had any tips they felt like sharing.

    Thanks,
    Chris

  • #2
    I have "flow limiters" on my BBTs. I used big globe valves. Keep closing them until you see your tank is not getting down to temp in a reasonable amount of time, then back off a little. I am also thinking of adding valves to three new FVs as they came with 1.5" glycol pipes on the tanks. Three jackets all with 1.5" inlets and outlets is way to big for a 60 bbl uni. I think I could crash the tank from 70 to 32 in an hour. Haha The globe valves are more expensive than balls or gates but they are the perfect design for adjusting flow whereas the others will fail over time as they are not designed to restrict flow.

    I am not saying you should go with the small chiller however. That you really need to crunch the numbers for. The serving tanks are a huge load as they will be crashed most of the time. With FVs there is more time spent at warmer temps so less load. I think I would take the chiller they have now. If you run into problems when you get all your tanks rolling you could buy a small used chiller and run two or three of the tanks off it. In the mean time you will have beer leaving your building and money coming in. Just my opinion.
    Joel Halbleib
    Partner / Zymurgist
    Hive and Barrel Meadery
    6302 Old La Grange Rd
    Crestwood, KY
    www.hiveandbarrel.com

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    • #3
      "they will draw 10GPM whether they need it or not."
      Not really. It would be rare to have every tank on cooling at the same time. And if they don't need it, the solenoid will turn off the flow. I think you would be fine with what you have now. I run 90hl from a 5hp unit on 1 1/2" lines in a very hot tropical climate and have no issues. I wouldn't push it any further, though. Pro Refrigeration are certainly very good at what they do, but maybe this is overkill. A 200 gallon reservoir just gives you a bit of thermal flywheel. It doesn't add any capacity to your mechanical refrigeration; just adds buffer capacity. This is great if you have a 2 stage heat exchanger that takes glycol for the secondary. And adding a 3hp pump seems like a lot. 1 1/2 or 2hp would probably do. I'd try it with 1hp first. The bigger this pump is, the more heat it pushes into your glycol. Smaller is better. And for a header feeding 18 tanks (why no doubles?), you may want at least 2" header feeding the 1" drops. I don't see the value in "flow limiters" as they just reduce flow rate at the expense of duty cycle length. Do you really want the tank temperature to fall slower so that you can have more tanks call for glycol? Or stick with a quick cycle that has higher flow rate? Only reason I can think of for having any kind of limiter is to keep the cycle time longer for the purpose of NOT undershooting your tank temperature when the beer cools to setpoint, the solenoid closes, and there's still lots of icy glycol in the jackets. I've seen tanks drop another 2-3C because the glycol temperature and volume were sufficient to overcool. I'd stick with tank manufacturer's recommendations. Good luck!
      Phillip Kelm--Palau Brewing Company Manager--

      Comment


      • #4
        Glycol supply

        We run a " Lot " more than that on 2 inch supply with a 1 HP pump.
        I would not have serving tanks on a system that is used for cool down heat exchange for the brewhouse.
        Its not a good idea to hard pipe fermentation or other vessels in. Hoses from a header are better for a number of reasons.
        Warren Turner
        Industrial Engineering Technician
        HVACR-Electrical Systems Specialist
        Moab Brewery
        The Thought Police are Attempting to Suppress Free Speech and Sugar coat everything. This is both Cowardice and Treason given to their own kind.

        Comment


        • #5
          Hi Chris,
          Regarding pipe sizing this is our take.
          If your have a specification from your tank producer on how much GPM needed / jacket to achive the job then you should use that value. If the the tank producer can't give you this information then you we normally use the value of 10 GPM / jacket because of all systems we been involved with that is a good "rule of thumb".
          For a bright tank you can normally use less than 10 GPM because as said in the thread you don't have a fermentation process that add heat to your tank. So here 5 GPM to 7.5 GPM is a good rule of thumb.
          So now you add up your needed GPM, first for your individual tank piping and then for the total need for your header.

          So let me give you an example:
          A brewery have 10 Fermenters with 3 jackets each and 2 Bright tanks with 2 jackets each. The tank producer can't give them a specification on how much glyol is needed through the jacket to do the job. So we use the rule of thumb of 10 GPM/ jacket for fermenters and 5 GPM / jacket for the bright tank.
          We now have 10 Frementers x 3 jackets = 30 jackets x 10GPM = 300 GPM
          We have 2 bright tanks x 2 jackets = 4 jackets x 5 GPM = 20 GPM
          So our total need is 320 GPM
          Now we ask our self how much will be calling for cooling at the same time and in this case we estimate 70%. So our design flow will be 320 GPM x 0.7 =224 GPM
          Next we ask our self if we expand do we want the same piping system to hande the expansion and the answer is yes. Now we need to add that flow demand to our calculation.
          In this case we wanted to be able to add 5 more fermenters with 3 jackets each and 1 bright tank with 2 jackets.
          5 fermenters x 3 jackets = 15 jackets x 10 GPM = 150 GPM
          1 bright tank x 2 jackets = 2 jackets x 5 GPM = 10 GPM

          So now our new design flow will be 300GPM + 150 GPM +20 GPM+10GPM =480 GPM x 0.7 = 336 GPM

          Now we need to size the pipes so that they can get you the needed flow without to much head pressure and pressure drop. Here we use a common engineering value of the velocity (the speed of the flow) in the pipe of 5 ft/second and never over 7 ft/second. With this velocity you avoid water hammers and your pumps are not running crazy.
          So if I do the calculation for 336 GPM for COOL-FIT Plus pipe as a header pipe you will need a 6" pipe to be under 5 ft/s in fact your velocity would be 4.58 ft/s. If I check if it would be possible to go down one pipe size and take a 5" pipe instead it would probably also work because the velocity would be 5.98 ft/s. So lets try to get down two pipe sizes to a 4" pipe, now our velocity going to be 9.44 ft/s so that is definately not recommended.
          If we would do the same calulation for the piping and only caclulated with the initial load before future expansion(224 GPM) that recomendation would be a 5" pipe (3.99 ft/s) and 4' pipe could possible work (6.3 ft/s)

          Let me give you an example of pressure drops for the first calculation with a design flow of 336 GPM.
          Say that you have 300 ft of piping and 10 bends in your glylol loop, following is what the total pressure drop would be for the different pipe sizes due to the difference in velocity.

          6" piping system = total pressure drop of 2.6 PSI
          5" piping system = total pressure drop of 4.7 PSI
          4" piping system = total pressure drop of 14.9 PSI

          I hope this give you an idea of how the system works and please don't hesitate to contact me if you have any questions.

          Dan Strömberg
          Cooling Market Segment Manager
          Phone: +1 714 368 4196
          Fax: +1 714 368 4197
          Mobile: +1 951 642 2339
          Dan.Stromberg@georgfischer.com

          Georg Fischer LLC
          2882 Dow Avenue, Tustin, CA. 92780
          United States
          GF Piping Systems is the leading flow solutions provider across the world. We enable the safe and sustainable transport of fluids. Our business is driven by maintaining industry-leading sustainability levels, innovating through digitally enabled solutions, and investing in a culture built on performance, learning, and caring.

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          • #6
            Yes very true Steve. It will only be heavy btu when actually crashing.
            Joel Halbleib
            Partner / Zymurgist
            Hive and Barrel Meadery
            6302 Old La Grange Rd
            Crestwood, KY
            www.hiveandbarrel.com

            Comment


            • #7
              Another way to limit flow to each fermenter is to have a programmable temperature controller. When you are crashing a fermenter from say 68 F to 40 F, have the controller lower the setpoint by 2 F per hour. The tank will get all the flow it needs to lower the temperature at whatever ramp rate you want.
              Linus Hall
              Yazoo Brewing
              Nashville, TN
              www.yazoobrew.com

              Comment


              • #8
                That's brilliant Linus! Use the controller as the limiter. There's another technique I've used to have the glycol temperature as a permissive to the fermenter temperature controller. You only cool your fermenter when the glycol is cooler than the fermenter setpoint.
                Phillip Kelm--Palau Brewing Company Manager--

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