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  • Trouble shooting glycol

    We are getting our two 5BBL unis online this week and I'm having issues with the flow of glycol through the jackets.
    We are using a Foxx 3/4 Hp beer line chiller. It has two 1/3 HP circulation pumps, controlled by Johnson Controllers, and running 3/8" clear poly line from them (the chiller) to the Unis. The tanks are dual zoned but we are running them as one zone. They have a 1" port for the send and return. They are reduced down to 3/8" at each port. The previous owner installed a ball valve and pressure gague at the IN port with the understanding that the valve needed to be manipulated until the PSI hit about 20, then the glycol would better flow.
    I tested the process with one of the tanks six months ago per his instructions. No problems.
    Yesterday, not so much. The chiller is working fine. The glycol is chugging in the lines. In one of the Unis the liquid is making its way all the way through, but it's spotty, lots of air in the line. In the other tank the liquid is not making it through the full loop.
    Thoughts:
    1. Air in the line: very possible but it's a 30 gallon reservoir and it's not pressurized, so why isn't it just being pushed into the bath. Do the reservoirs account for pressure on these units - i have to check with Foxx.
    2. Gravity: the unit send is below the lowest point on the chiller, however my poly lines are a little long and curve up and down in a couple places. Do I need to elevate the chiller/pumps, or take the slack out of the lines?
    3. Temperature: I started my test runs yesterday prior to the glycol hitting its set temp. Can this affect flow?
    4. Frequency: the chiller has sat full of glycol for 6 months with no use. It's all new but can this affect things negatively? Should we avoid turning the unit off once its been running properly? Obviously, once production is underway this wont be an issue.
    As always, any advice is much appreciated.

  • #2
    I would say that one of your problems is the chiller. You should be using a 3HP chiller at minimum and 5HP if your planning for growth. Chillers for draught beer systems are not the correct tool for the job. Also the glycol jackets are most likely on rated to 14.7psi/1bar and if you are exceeding that you will have a good chance of blowing out the jackets. The 3/8 hose is also a big issue and would be restricting the flow, the minimum is 3/4". Are you using solenoids? Did you flush the glycol jackets prior to use? The glycol lines should be either glycol or pvc in some fashion. How are your lines insulated? Here is a bit of info from GF Piping.

    The recommendations from ASHRAE and also what all engineering companies use as a design for the piping system is to have a velocity in the pipes of 5 ft./second or less, and if you have variable speed pumps 7.5 ft./second.
    This to:
    Minimize pressure drops
    Minimize water hammers
    Minimize noise
    Get an energy efficient system

    So check what your fermenters need in flow rate to do the job and then tally up the maximum required flow and we can help you calculate what pipe size needed. If your supplier of the fermenters and bright tank can't tell you what flow rate that is needed there are an "in-between the thumbs" rule that works rather good and that is that you will need about 10 gpm / jacket for a fermenter and 5 gpm /jacket for a bright tank.
    So if your fermenter have 3 jackets you will need a flow of 30 gpm, this is if you parallel feed your fermenter (which is recommended) and if you serial feed your fermenter it will need 10 gpm.

    Here is a note on serial feed vs. parallel feed. Parallel feed = all your jackets are getting the same temperature glycol. Serial feed = you cone jacket will get the coldest glycol and then it will warm up so that your top jackets will have the warmest glycol

    Now you need to estimate how many of your jackets will be calling for cooling at once so that you know maximum required flow rate for the header piping

    Below you can see how many gpm's you can get through COOL-FIT pipes in different sizes at a velocity of 5 ft./s and 7.5 ft./s

    Comment


    • #3
      Originally posted by TiminOz View Post
      I would say that one of your problems is the chiller. You should be using a 3HP chiller at minimum and 5HP if your planning for growth. Chillers for draught beer systems are not the correct tool for the job. Also the glycol jackets are most likely on rated to 14.7psi/1bar and if you are exceeding that you will have a good chance of blowing out the jackets. The 3/8 hose is also a big issue and would be restricting the flow, the minimum is 3/4". Are you using solenoids? Did you flush the glycol jackets prior to use? The glycol lines should be either glycol or pvc in some fashion. How are your lines insulated? Here is a bit of info from GF Piping.

      The recommendations from ASHRAE and also what all engineering companies use as a design for the piping system is to have a velocity in the pipes of 5 ft./second or less, and if you have variable speed pumps 7.5 ft./second.
      This to:
      Minimize pressure drops
      Minimize water hammers
      Minimize noise
      Get an energy efficient system

      So check what your fermenters need in flow rate to do the job and then tally up the maximum required flow and we can help you calculate what pipe size needed. If your supplier of the fermenters and bright tank can't tell you what flow rate that is needed there are an "in-between the thumbs" rule that works rather good and that is that you will need about 10 gpm / jacket for a fermenter and 5 gpm /jacket for a bright tank.
      So if your fermenter have 3 jackets you will need a flow of 30 gpm, this is if you parallel feed your fermenter (which is recommended) and if you serial feed your fermenter it will need 10 gpm.

      Here is a note on serial feed vs. parallel feed. Parallel feed = all your jackets are getting the same temperature glycol. Serial feed = you cone jacket will get the coldest glycol and then it will warm up so that your top jackets will have the warmest glycol

      Now you need to estimate how many of your jackets will be calling for cooling at once so that you know maximum required flow rate for the header piping

      Below you can see how many gpm's you can get through COOL-FIT pipes in different sizes at a velocity of 5 ft./s and 7.5 ft./s
      Thank you for the reply. While not ideal or selected for its expansion/growth ability, running a large beer line chiller is certainly not something I pioneered; it proven to works for various
      nanos on a tight budget. We will graduate to a 3hp system, but for now it's the system we have to work with.
      Again, those are all great insights, however the technician just left and has pointed out the glaring problem: there was barely any liquid in the reservoir. It's routinely 100 degrees here and over the course of the last 5 months our reservoir of water/glycol mix evaporated by about 60-70%! So, we will find and acquire more glycol and try again. Think we can close the thread on this. Cheers.

      Comment


      • #4
        As far as the question from the OP, you are pumping the glycol in the bottom port of the FV and out the Top, correct? I would size bigger coming out of your pump. Step it up from 3/8" to at least 1/2" or 3/4". That will help reduce some pressure. You do not need an air release on your line if it empties into the tank like you said. You may have a loose hose that is allowing air to come in.

        As far as the second post goes, we have been using a 3/4 hp system with a 25 gallon res for 2.5 years on 2 4bbl and 3 7bbl FVs. We can crash the 3's in 24 hours and crash the 7's in 36 hours. The bigger res, like you said you have 30 gallon, makes it work. The 5hp chiller I am sizing out for our 20's coming in only has a 20 gal res. So, bigger res can allow for a smaller chiller.

        Good luck.
        Nick Tanner
        Head Brewer/Founder
        Cherry Street Brewing Cooperative
        Cumming, GA
        www.cherrystreetbrewing.com

        Comment

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