Brite Tank Design

[Lonebrewer]

A couple of questions regarding Brite Tank design;
Does it matter if the head space on a Brite tank is 25% or 15%?
Do the dimensions of the tank matter from a short/fat vs tall/skinny perspective? (other than the obvious space considerations).

Any thoughts/help is appreciated
Thanks

[gitchegumee]

It all depends. Just like everything else.

Head space required depends on whether you would ever use it. If you have good control over batch size and are using it as day-in, day-out BBT for production of standard beers, then 15% is more than enough space. I might go 10%. Why would you need more? Regarding short/fat vs. tall/skinny; go for the latter. Tall tanks will exert more hydrostatic pressure at the bottom, where you have your carbonation stone. It also helps carbonation and thermal convection currents to more evenly carbonate and cool. And it's easier to clean the tank as the ring where beer level was is smaller than a wide tank, and the spray ball won't have to cast the cleaning chemicals as far. And it uses smaller footprint. Thinner vessels also benefit from thinner materials of construction for the same pressure (hoop stresses). And they are also lighter (saving money in materials) as the volume to surface area ratio is more ideal (think beer can). And they will be cheaper because the dished heads are smaller--these are almost always purchased elsewhere and are much more expensive than sheet stainless. Most reputable tank manufacturers already know this and can recommend standard designs that take the above into consideration.

[Lonebrewer]

Thanks

Thank you Phillip, that was a great help!

Mark
Lone Barrel Brewing

[BrewinLou]

Will you be carbonating the beer in the bbt? Or do you do it inline? More head space will help carb faster if you are doing it in the tank.

[gitchegumee]

I do it differently..

I don't believe that head space has to have any effect on carbonation rate and quality. How would the carbonating beer "know" whether it has a few cm of head space, or an infinity of head space given the same pressure? Unless you leave head space at low pressure and force CO2 through the beer to raise the pressure in this space. I don't carbonate beer this way, and I recommend against it. Cool the beer, raise the headspace pressure to your desired saturation level, and evenly carbonate to this level. Ideally, there will be minimum gas transfer between the liquid and the head space.

[BrewinLou]

I have never carbed a tank of beer where there was zero pressure rise. I agree that the less co2 that comes out of suspension the better off you are. Back when we where just using a stone in a tank with beer at 32 degrees it took a long time sometimes days to carb up a tank. Not saying the tanks where designed perfectly. But is sounds as though our tanks need more stone to barrel ratio. Both tanks have 24" stones, which is not much in a 60 bbl tank. I would like to see what the BBTs could do with multiple stones or larger stones, but our Pin Point Carbonator pretty much alleviated any issues we had with scrubbing. I would have to take Gitche's advice and call Zahm Nagel about stone to bbl ratios if you are still in the design phase of your bbts.

[gitchegumee]

Forgot to mention the important considerations of carbonation stones. Much depends on whether you have open or closed fermentations, spund your tanks, krausen your beer, and what carbonation levels you desire. In general, you want a very slow CO2-induced convection in your tank as you carbonate. I can tell my BBT is carbonating well when the temperature rises a bit as the tank is slowly rolled, exposing warmer beer on the top to the temperature probe. Locate CO2 stones at about same level as probes--maybe 20% up a dish-bottomed tank. If you have multiple stones, consider putting them at 60-90 degrees from each other, not 180 degrees. Use check valves on your stones. Use a simple rotameter to gauge flow rate. And do consult with Zahm about stone size and placement for your particular needs. Good luck!

[Ted Briggs]

I don't believe that head space has to have any effect on carbonation rate and quality... Ideally, there will be minimum gas transfer between the liquid and the head space.

HMMM- read this: http://en.wikipedia.org/wiki/Henry's_law.
Darcy, Henry and Mr Stokes a a few of a Brewers best friends.

The amount of Co2 in the tank as well as the surface area for transfer matters, Its not just temperture and pressure. However, in practical use your carb stone will have much more power (surface area) to get your beer carbed quickly than lots of headspace. But not too quickly so no need for extra tankspace to hold foam!
A shorter tank will give more consistant Co2 levels, It also decreases particulate settling time. Both reasons horizontals are good secondary's for lagers, unfined, and non-mechanicaly carbonated beer. Large tanks can actualy have stratification of carbonaion levels due to the preassure difference of the tank. But no need to worry until you have large tanks. 50bbls+
That said, +15% is a good average for bbts.

[Lonebrewer]

Tank Design and Carb stones

Thanks everyone for the excellent discussion, looks like I have some homework to do!

Thanks again

Mark
Lone Barrel Brewing