Balancing really long beer lines

[Robko]

I am just last step from getting a job as a headbrewer at local restaurant-brewery (OMG I ve been brewing for 2 years at home only). The brewery only exists for like 3 months and they still have some major bugs. One of them is extreme beer foaming.
They dispense beer directly from a tank that is one floor under the tap. The way from the tank to the tap is like 65 feet of 1/4 PE tubing. What is the reason for getting almost nothing but a beer foam?
The tank is kept at like 38F but the lines are just insulated, not cooled. The beer is, however, recooled by a thing that cools the beer while dispensing (I do not know how to call it in english, basically the one that is under the bar and it has like 35 more feets of stainless beer line in it). They push it by a pure CO2.
What do you recommend? Adding a glycol beer line cooling, managing the beer line lenght, pushing at high pressure using beer gas, adding epoxy mixer?

 

[day_trippr]

The thing that cools the beer just before dispensing is likely a "cold plate" or the functional equivalent made using coiled stainless tubing, either of which has to be submerged in a cold solution to work (see "jockey box").

But that's a pretty hinky solution for a commercial dispensing system, imo. An end-to-end glycol cooled trunk line to chilled faucets would be far superior and almost expected in a commercial setting. The foam problem extant is most likely due to the beer warming in the main line causing CO2 to break out of solution to the point that the "jockey box" can't put it all back together again before the beer hits the spout.

Otherwise, there's a lot of math behind properly balancing the line from beer to faucet. You could play with the only beer line length calculator worth even using, imo, to see what kind of performance various tubing diameters will provide. Often you can go with a large diameter for most of the run, followed by a length of 3/16" ID tubing (called a "choker") fine-tuned for the net restriction for the run.

In the end, you need to balance the line against the gas pressure (and the resulting carbonation level after lengthy exposure). But note that at the extremes, you cannot use straight CO2 to push the beer, but instead need to use a Nitrogen/CO2 mix to avoid overcarbonating the beer while solving the pressure needs to force the beer all the way from vessel to glass.

65' may not be in that ballpark - there's a reasonable chance that using 5/16" ID tubing for most of the run with a choker (5-6 feet) of 3/16" ID tubing would work with CO2 pressures in the range that wouldn't overcarbed the beer.

For general dispensing setup and operation, This guide is worth a look to get started in the right directions...

Cheers!

 

[Ramdough]

Another thing to think about is that your are pushing up one story. There is an exact number of height to pressure, but it is around 1 psi per 2 feet. So if you are going up, you will need pressure from the lift and pressure for the tube restriction.

I am guessing that you need a chilled trunk line as mentioned earlier and you may be overcharging to mush up and through 65 feet of tube.


What pressure are you running?


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