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Thread: How to Lower Bright Tank Temperature

  1. #1
    Join Date
    Oct 2003
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    Ottawa, Ontario, Canada
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    13

    How to Lower Bright Tank Temperature

    We are having difficulty bottling as our beer is too warm.

    We are using a 20 hl DME cone bottom unitank as a bright tank. It has two glycol cooling jackets. We have a 5 ton Edwards chiller operating at 30 psi with glycol at 27 degrees, which is within the chiller normal range. There are 2 other 20 hl unitanks, used for fermentation only and the 40 l. surge tank on the filler connected to the chiller. We cannot get the bright beer below 38.5 degrees.

    We are bottling on a PPM filler that is 8 feet from the bright tank. The hose from the bright to the bottler is insulated as is the surge tank on the filler. The beer in the bottle is 51.5 degrees.

    How do I get the beer cooler in the bright and keep it cooler while bottling?

    Ron

  2. #2
    Join Date
    Nov 2003
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    99
    You might need to provide some more info such as:

    - does the unitank have cone cooling, or are the two cooling zone on the straight sides only?
    - what is the glycol supply temperature TO THE BBT and the return temperature FROM THE BBT?
    - bright beer at 38.5F doesn't sound too drastic ... but the 51.5F in the bottle does. How close is the actual filling temperature to 38.5F (i.e. before it hits the bottle)?

  3. #3
    Join Date
    Oct 2003
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    Ottawa, Ontario, Canada
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    Both the cone and side wall of the BBT have cooling jackets.

    The glycol temperature is 27.5 at the BBT supply and 28.5 - 29.0 at the return side. The glycol lines are insulated and this is the first tank.

    We have not measured the temperature at the filler just before the beer is bottled. I will get back to you with that information when we start up again. My guess is that 51 is the temperature in the surge tank.

    I suspect that the pump is responsible for most of the temperature increase. This has also been suggested as the likely cause in another reply.

    The pump is an impeller pump with a stainless steel head and impeller.

    Ron

  4. #4
    Join Date
    Oct 2002
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    Tadcaster, Yorkshire, UK
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    Where is the temperature probe ? Water density is at its maximum at approx 4 deg C, so if your temperature probe is near the top of the vessel, it is likely to be colder up there than lower down, and shutting off the chilling earlier.

    Conventionally, the temperature probes are between, just above the cone of the vessel and one third of the way up the side wall. If the rate of cooling is slow, then you would benefit from one at the top as well in order to prevent a layer of ice forming at the top of the beer.

    The beer really needs to be consistently at no more than 1 deg C to allow for temperature pickup on the filler. One possibility (though I accept possibly very difficult for a small brewery) is to run some pre chilled sterile liquor through the filler and mains to cool everything down from ambient before putting the beer on.

    Cheers
    dick

  5. #5
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    Oct 2003
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    Ottawa, Ontario, Canada
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    Dick
    The temperature probe is on the side wall one third of the way up from the join with the cone, just as you suggest. However as we are by passing the temperature controller, when the beer is below the probe, leaving the glycol running all the time, this should not affect cooling or the final temperature. However glycol is circulating through both jackets, while the beer is only covering the bottom one.

    Your suggestion that we may be forming ice on the top of the beer is an interesting possibility given that the glycol is circulating all the time and that the glycol temperature is -2.8 Celsius. How would you check to see if we had an ice build up and what should we do to prevent it?

    Would the addition of a 10 metre, 1cm in diameter stainless steel cooling coil, connected to the chiller and located inside the cone of the bright tank help?

    We have been running our sanitizing solution, which is about 5 Celsius through the filler, hoses and pump, for about 10 minutes, before we start bottling to lower the temperature following sterilization.

    Fred
    The pump we are using is Fristam #FPX 702 -100, 1" x 1" Tri-Clamp inlet/outlet, with 100mm full impeller, 1" HP TEFC motor, 3500 RPM. Floats in the surge tank (bowl) turn the pump on when the beer level in the surge tank falls below a preset level. It only runs for 3 or 4 seconds at a time. So its hard to understand how this would warm up the beer.

    Our bottles are at room temperature, which lately has been 72 F or 22 C this will result in some of the final increase in temperature. Should we be pre chilling our bottles?

    Ron

  6. #6
    Join Date
    Oct 2002
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    Stavanger Norway
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    320
    I'm glad I'm not the only one with bottling problems.

    I too have trouble with the temp. So I'm learning alot from this post.
    Thanks

  7. #7
    Join Date
    Mar 2003
    Location
    Ann Arbor
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    19
    Heritage,

    I have a similar setup, and I had some of the same problems at start up. Here's what I did, although I can't be sure that it will work for you.

    1. lower the temp of the glycol to hit 25C on the RETURN I would check the calibration of the temp probe before doing this. I trust digital equipment about as far as I can throw it.
    2. Do a little math and figure out where the beer is sitting on the jackets. If the jacket isn't completely hitting the beer....well, you know the rest.
    3. You will not have enough gycol jacket surface area for complete cooling of finished beer. Depending on how good of a job DME did spec'ing the jackets, there will be almost twice as much surface area of cooling jacket for your BBT when compared to your fermenter. There is no chance for you to get the entire beer down to zero without dropping your glycol temp. Remember that there is very little thermal movement in finished beer.

    Just my experience.

  8. #8
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    Oct 2003
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    Pittsburgh, PA
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    Beer-bergs

    The best way to see if you're icing up the beer is to look in the manway after you drain the tank - before you do any cleaning. The gravity of the beer leaving the tank in this case would also be higher since some water has been removed - something easy to check.

    I'd rule out the pump too - not enough thermal mass in a pump of that size to make a difference, and the energy it's putting into the beer to move it seems insignificant.

    Sounds like the bigger issue may be the warm(er) filler you're putting the beer into, or maybe the bottle temp. If it's the filler, you should see the bottling temp come down by the end of the filling run, after the earlier beer has taken much of the heat away from it. Prechilling bottles can be helpful in summer months if you have the cooler space for an overnight chilling.

    Good luck.
    S

  9. #9
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    Mar 2003
    Location
    Ann Arbor
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    Another easy way to tell if the BBT beer is cold enough, or more accurately, if the reading on the fermenter that you are using in place of a BBT is a true indication of the total temperature of the beer, is to drop a sanitary thermometer in-line just after the exit of the tank. If the temperature of the beer rises as you draw off from the tank, you know what the culprit is.

    I suspect that this is the problem.....you will find that as you draw off the fermenter over several hours that the only glycol hitting the bright beer will be the cone jacket, and that's not enough to keep the beer at zero. Couple this with the difficulty in truly getting a fermenter to get a beer to zero quickly (do you crash cool the beer using the fermenter?), and you can get problems at the filter.

    This is what happened to me.

  10. #10
    Join Date
    Oct 2003
    Location
    Ottawa, Ontario, Canada
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    13
    Just checked the gravity, its up, from 1.016 to 1.018, which confirms that the beer has frozen. This explains why we were not able to lower the temperature in the bright tank. So I have raised the glycol temperateure to 30 (from 27) which should stop it from freezing the beer. Thank you for suggesting that we check the gravity.

    For those who have asked the bottom jacket on the DME tank is within 6 inches of the bottom of the cone. So the tank is well designed.

    We have been getting the temperature of the beer in the bright from our CO2 tester. We also have thermo wells in our ss pipe which we are placing at different points in the flow.

    Also noted that it took 45 minutes for a 250 ml graduated cyllinder of the beer to increase in temperature to 65 degrees so that we could measure the gravity. Yet the beer increases from 38 to 51 in less than 10 minutes when we operate the filler. So we are tracking the temperature a various points in the flow to identify the source of the heat.

    You are correct that the pump is not involved as measuring temperature before and after the pump shows no increase in temperature.

    We are now going to measure before and after the surge tank (bowl) and at the fill head and then in the bottle to identify where the temperature increase occurs.


    Ron

  11. #11
    Join Date
    Oct 2003
    Location
    Ottawa, Ontario, Canada
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    13
    Yes we use 2 of our unitanks for fermentors and for crashing the beer. Crashing the beer generally takes 24 -36 hours to reduce two tanks from 66 degrees to 32.

    The bright is a unitank and the beer in question has been in it since last Thursday and is likely the same throughout at 10 HL. The beer temperature did not increase while we were drawing beer through the CO2 tester.

  12. #12
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    Nov 2003
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    99
    Heritage, thanks for your posting of follow-ups. Please continue to report what you find as you investigate the problem through the filler... Thanks.

  13. #13
    Join Date
    Oct 2003
    Location
    Ottawa, Ontario, Canada
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    We had an interesting afternoon trying to isolate the cause of the 12 degree F temperature increase between the bright tank and the beer in the bottle.

    We installed ss pipe with thermowells, before and after the pump, at the check valve going into the filler and at the surge tank or bowl.

    We put tap water into a tank and measured the temperature it was 70.6 degrees.

    Next we turned on the pump and bottler and noted the temperatures. They were all the same at 70.6 degrees F. So the insulation was working and the water did not pick up any heat while it travelled through 14 feet of hose and ss pipe.

    When we measured the temperature of the water in the bottle it was 71.6. This is a much smaller increase than we had expected under ideal conditions.

    We then turned on the glycol around the surge tank and waited 15 minutes and started up the filler again. The temperature in the bottle fell to 68.6. (the other temperatures remained constant at 70.6) so the insulated glycol jacket works.

    We are left with the question of what causes the beer temperature to rise to 51.8?

    We ran the pump for an hour and then tested the water before and after the pump and the temperature was a constant 70.6

    So is the test invalid because water lacks CO2, alcohol, sugar i.e. we did not use beer?

    We ended the day without understanding what caused to beer temperature to rise to 51.8 degrees. So that all was not lost we cleaned the bottler so that we can bottle beer in the morning.

    The temperature of the beer in the bright is falling now that we have increased the glycol temperature to 30 from 26 and the ice is melting in the bright tank We will measure the temperature in the morning again and adjust the glycol temperature so that we reach 32. Running the glycol on by pass (without the control) has its limitations however once the beer is below the thermowell the temperature control does not work, so we have no choice, the glycol flows and the temperature drops.

    The two tanks we crashed this morning at 10, had dropped from 68 degrees to 50 at 3 this afternoon and at that rate will be at 32 between 2 and 4 tomorrow morning. So the chiller is performing well.


    Thank you for the suggestions and encouragement.

    Ron

  14. #14
    Join Date
    Nov 2003
    Posts
    99
    I think you need to keep going and try to measure the temperature at further locations downstream of the header tank.

    Also, do you notice the same rise in tempewrature at the end of the bottling run? This would indicate whether or not the filling equipment cools down eventually due to the beer flowing through it for a period.

    I did a quick energy balance and, after making a few normal assumptions, calculated that the bottled beer would rise from 32F to 36.7F simply by the heat transfer from the bottle itself. A long way from 51.8F, but it shows the effect of initially warm bottles.

    Keep going - the heat is coming from somewhere, and it sounds like it must be downstream of the header tank. Each reading you take is eliminating possibilities (e.g. the pump), so what you have done is not wasted work!

    I really don't think the difference in properties between beer and water are significant. The heat is almost certainly being supplied to the liquid externally.

  15. #15
    Join Date
    Oct 2002
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    Tadcaster, Yorkshire, UK
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    I suspect the problem is simply the mass of warm metal that you are having to cool with the beer. As previously stated, if the beer temperature drops throughout the run, than this points to this being a major source of heat pickup

    It strikes me that one of the problem you have with your current testing regime is that you are putting ambient temperature fluid through the plant, so you are not measuring temperature pick up due to the warm metal of the filler.

    Suggest you try running chilled liquor through the filler, the liquor temperature being similar to the beer temperature, and repeat the trial. Is it possible to recirculate water through the flooded filler system cooling it as it recirculates ?

    I realise we have the capability, but we flush our fillers out with chilled liquor at 1 to 2 deg C for several minutes immediately prior to introducing beer in order to cool the filler down. We then introduce beer, and then empty the filler. Even after that, the firrst few rounds of bottles off still tend to be a bit fobby due to increased temperature. At other places I have worked on similar large fillers without in line chillers, the problem of fobbing first offs was even more noticeable.
    dick

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