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  • Cannot get BBT temperature down

    Hello,

    This is my first post so if I don't have all of the information you need, please ask. I have a single jacket 30 bbl BBT which I have filled about 8 bbl worth for a test batch. I cannot get the temperature down below 46F even though I have the controller set to 36F. I transferred the beer under pressure from my FV and that seemed to go well. The CO2 pressure is currently at 15PSI and holding steady from the transfer. The temperature at the glycol chiller which is outside is set to 27F and I have a thermostat on my supply header inside and it reads 32F. The pressure on the glycol lines are set at 15PSI and the reading is on the return side. I get frost on the piping around the inlet solenoid valve and also some ice buildup on the outlet port of the tank. I also feel the glycol solution in the pipe coming out the outlet of the tank.

    I removed the thermocoupler from the thermowell and inserted a hand held digital thermometer in the thermowell and it read around 46F as well. The thermowell is at the same height on the tank as the inlet to the jacket. I also have an autovent at the highest point in my glycol loop and if I turn the chiller pump off I do hear air releasing from it for a few minutes and then it stops.

    I have tried to lessen the pressure on the glycol loop thinking that more contact time would be better. I do have some heat transfer compound on order for the thermowell but I cannot think that would help more than a few degrees. Also, this BBT is not in a cold room.

    Thanks,
    George Adams
    GAEL Brewing Company
    Geneva, NY
    George Adams
    GAEL Brewing Company
    Geneva, NY

  • #2
    Is the thermowell below the liquid level of 8BBL of beer? If not it's reading the air temperature in the tank not liquid.

    Comment


    • #3
      Originally posted by krichard View Post
      Is the thermowell below the liquid level of 8BBL of beer? If not it's reading the air temperature in the tank not liquid.
      According to my sight gauge it is.
      George Adams
      GAEL Brewing Company
      Geneva, NY

      Comment


      • #4
        Originally posted by gaelbrewing View Post
        According to my sight gauge it is.


        Try pulling a sample of the beer and take the temp using a handheld thermometer.

        Comment


        • #5
          Originally posted by briangaylor View Post
          Try pulling a sample of the beer and take the temp using a handheld thermometer.
          It read 47F.

          Thanks,
          George Adams
          George Adams
          GAEL Brewing Company
          Geneva, NY

          Comment


          • #6
            Originally posted by gaelbrewing View Post
            It read 47F.

            Thanks,
            George Adams


            Is this your first time using this tank? Or the first time using it with this low of volume? BreweryTech may be on to something if its the latter.

            Comment


            • #7
              You may well not have enough beer in the tank for the cooling jackets to work effectively. Without enough area for heat transfer you're not going to get effective cooling.
              Also you should dial back the pressure on the glycol system. Most glycol jackets are rated for 15 psi MAX - you want considerably less than that on the outlet. Ideally you want close to 0 psi on the outlet pressure.

              Hope that helps
              Manuel

              Comment


              • #8
                How long is the run from your chiller to the tank? The glycol will warm up across a given distance regardless of insulation.

                Comment


                • #9
                  Originally posted by mmussen View Post
                  You may well not have enough beer in the tank for the cooling jackets to work effectively. Without enough area for heat transfer you're not going to get effective cooling.
                  Also you should dial back the pressure on the glycol system. Most glycol jackets are rated for 15 psi MAX - you want considerably less than that on the outlet. Ideally you want close to 0 psi on the outlet pressure.

                  Hope that helps

                  Just thinking off the top of my head, wouldn't the jacket surface area to beer volume ratio be roughly the same regardless of where the top of the beer is on the jacket? The only variance may be on the dish bottom but I had my manufacturer put the jacket down as low as possible on the tank in order to minimize that as much as possible. I would also think that the beer would be colder at the sides near the jacket than the middle.

                  I also relieved some head space of CO2 from the CIP port for a second or two with the thought of gently causing some movement.

                  I did take your advice and dialed back the flow at the inlet of the jacket before I left for the evening. We'll see in the morning.

                  Thanks,
                  George Adams
                  George Adams
                  GAEL Brewing Company
                  Geneva, NY

                  Comment


                  • #10
                    Originally posted by BreweryTech
                    Is the beer level above the top of the cooling jacket? You may not have enough volume in the tank to create a convection strong enough to recirculate the beer. Have you bubbles in CO2 from the carbonation stone and/or the bottom drain port to see if moving the beer has an effect on cooling?
                    The top of the beer is above the bottom of the cooling jacket. All CO2 in the tank has come from the stone and pressure has increased slightly from transfer time. My CO2 volumes are reasonable for the pressure/temperature.

                    The convection idea gave me a thought as I relieved CO2 head pressure from the CIP port for a second or two and I did that several times. The thought is that I could gently circulate the beer that way. But thinking about it wouldn't the colder beer be at the sides near the jackets and warmer in the middle. Since my thermowell is only 12" inside the tank I would think that it would be near the coldest section of the tank.

                    Thanks,
                    George Adams
                    GAEL Brewing Company
                    Geneva, NY

                    Comment


                    • #11
                      Originally posted by mikeyrb1 View Post
                      How long is the run from your chiller to the tank? The glycol will warm up across a given distance regardless of insulation.
                      The run from the chiller to the tank is about 40 feet, all insulated. I have a thermostat on the supply header which is about 15 feet from the inlet of the tank and it reads 32F. Frost builds up on both the inlet and outlet ports of the tank but more so on the inlet.

                      Thanks,
                      George Adams
                      GAEL Brewing Company
                      Geneva, NY

                      Comment


                      • #12
                        How long has the beer been in the tank? I had the same issue with a half filled tank and it was stratification. Have you tried blasting a burp or two of CO2 in via the bottom valve and checking temp again in 20 mins? Your Thermawell is a lot closer to the top of the beer than it was designed to be. There is not enough convection in a tank that every ounce of beer will be the same temp. The longer it sits the more likely you will have issues. Just a thought. Peace.
                        Joel Halbleib
                        Partner / Zymurgist
                        Hive and Barrel Meadery
                        6302 Old La Grange Rd
                        Crestwood, KY
                        www.hiveandbarrel.com

                        Comment


                        • #13
                          Originally posted by BrewinLou View Post
                          How long has the beer been in the tank? I had the same issue with a half filled tank and it was stratification. Have you tried blasting a burp or two of CO2 in via the bottom valve and checking temp again in 20 mins? Your Thermawell is a lot closer to the top of the beer than it was designed to be. There is not enough convection in a tank that every ounce of beer will be the same temp. The longer it sits the more likely you will have issues. Just a thought. Peace.
                          Thanks for the info. It is stratification. The beer has by now been sitting for a while. I did get it to go down a few degrees but not down to the mid 30's as I would hoped. I have no problems getting my FVs on the same glycol loop crashed down to the 30's.

                          Thanks,
                          George Adams
                          GAEL Brewing Company
                          Geneva, NY

                          Comment

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