Dispencing from the top of a keg

[BeerCanuck]

The socket you're using now is probably just heavily chromed tool steel. You will likely not find a stainless eye bolt at your local hardware store, either. McMaster-Carr has some, but they're pretty expensive. I'd probably just use part of a spare stainless tube fitting and maybe machine the threads out of it.

Now that I think about it, it really doesn't need to slip, does it? it just needs to keep the break in the tubing submerged...

I think the slip weight might be necessary based on my trial runs.
The main benefit of the slip weight from observation is that it took up the slack in the hose while keeping the float semi centered in the keg ( off from the walls) while racking.

I'm not sure if a fixed weight would work...The eyebolt would possibly be easier to dismantle/clean.

Cheers
BeerCanuck

 

[mr x]

Canadian Tire and Home Hardware carry ss hardware if you're looking for pieces to try.

 

[DRAGGER]

For the slip weight you could use a large stainless steel nut. Just drill the threads out and bevel the inner edge......

DRAGGER.....

 

[BeerCanuck]

So I visited the local Hardware store and picked up some parts for the new prototype;

Left to right: crazy glue / ping pong balls / golf tees - they call them step tees...fits perfect into beverage hose as you see below

top - float drying after being glued (probably re-glue tomorrow)
bottom - some big stainless steel nuts...good idea Dagger

Cheers
BeerCanuck

 

[BrewBeemer]

Your local marine supply or chandlery will have a wide selection of stainless
for your needs.

 

[BeerCanuck]

Your local marine supply or chandlery will have a wide selection of stainless
for your needs.

I think the stainless steel nut with the thread bored out is a winner idea for the slip weight. (hopefully boring the threads isn't necessary)
The main point of failure I foresee is at the point where the tee is glued to the ball right at the beer line. Probably test the protype by attaching a hose to the tee and slip weight place in jar of beer thats refrigerated..I was going to try and draw a diagram but that would possibly be to pornographic

Cheers
BeerCanuck

 

[LaC - Brew]

This is a funny idea.

But something makes me wonder: What will happen when you get to drink from the keg, and the floater with tubing reaches the sediments in the bottom of the keg? The the hole in the tube will reach the bottom - with sediments - before the float. Then you will have to run a few pints of beer with sediments at this point to get to the clear beer above?

Lars

 

[BeerCanuck]

So I tested the new prototype in a keg;

Seems to rack all right

Cheers
BeerCanuck

 

[BeerCanuck]

So I was thinking again about this project and decided to address the float.
I wikipedia Buoyancy for some inspiration...I wanted to keep it simple and improved.
I had a 1 gallon jug of beer that I was testing in a growler decided to sacrifice it on this experiment;

I noticed the ping pong ball was rather deeply submerged after filling up the wide mouth jar. I didn't like the idea of using a ping pong ball/golf tee and crazy glue either in this application.
I was cleaning an airlock and then the idea hit me for a second float prototype;

Kinda ghetto but its a airlock with the cap from a orange carboy cap on the inside tube and some plastic wrap to seal the top of the airlock...try saying that fast after 3 beers

The two float protoypes are in the fridge in a head to head competition;

Cheers
BeerCanuck

 

[fifelee]

Neat project. These floats are a bit pricey, but they are SS.
http://www.smallparts.com/products/descriptions/mfx.cfm

It seems like the silicone tube is working, but if you run into problems maybe a coiled tube would work.
http://www.freelin-wade.com/products_coiled_tubing_hoses-c-1_27.html

 

[BeerCanuck]

Neat project. These floats are a bit pricey, but they are SS.
http://www.smallparts.com/products/descriptions/mfx.cfm

It seems like the silicone tube is working, but if you run into problems maybe a coiled tube would work.
http://www.freelin-wade.com/products_coiled_tubing_hoses-c-1_27.html

Thanks for the link on the stainless steel floats fifelee.
I like the idea of using the airstop for a float (kiss principal) ....and I thought of a way of securely attaching the airlock to the 3/16 beverage hose..use a short piece of 7/16 hose over this area like the other end of the hose where it connects to the beer out tube;

Cheers
BeerCanuck

 

[BeerCanuck]

The airlock beat the ping pong ball in the head to head competition due to better buoyancy factors/less exterior parts. Decided to test the new float prototype in a keg...it siphoned fully as well;

One thing I like to improve upon is the location of where the beer input under the float is located. In my present configuration (slit for beer input approximately 2.5" down from the buoancey level) the input at bottom would suck trub with 2.5" of beer remaining.

I believe in order for this prototype to work properly I would need to locate the beer input close to the Buonancey level of the float (submerger area of airstop)

Still needs some tweaks
BeerCanuck

 

[FSR402]

This a cool idea I think but what is it going to do when under pressure? Will the 10-15 psi be enough to push the float under?

 

[Chris_Dog]

I don't think the pressure will effect the buoyancy at all (or very little). The beer is under the same pressure as the "air".

 

[BeerCanuck]

I was thinking about how the float would react with 12 lbs of pressure applied..probably have a small effect on buoyancy I think...I'll test the setup using C02 shortly I hope.

I decided to drill a hole through the stem in my air lock for beer ingress;

It's the airlock with a hole drilled through the stem. I drilled a small pilot hole using a small drill..I heated drill with propane torch..repeat with larger drill. I also nipped off the restrictor at the bottom of the airlock for good flow.

I put the new prototype in a cornie and performed siphon test..(drum roll please)..it drained;

Cheers
BeerCanuck

 

[mr x]

Time to apply for a patent.

Although I think it might have been better to drill that hole higher and shorten that plastic 'nipple'.

 

[BeerCanuck]

Time to apply for a patent.

Although I think it might have been better to drill that hole higher and shorten that plastic 'nipple'.

If the premise works I will be happy...and if it works for others so much the better

I cut the hole in the stem of the float low because I didn't want the float to ride to high when full (float tips sideways slightly due to small head space in keg and flex in hose. When empty I want the the float to sink draining every last drop of good beer..followed by yeast extraction and hiss...( Ill save that for party poopers or other beer experiments

Cheers
BeerCanuck

 

[jas0420]

Cool project! Very inovative! I haven't quite scrounged up enough parts to switch to kegging yet, so my question that follows is not backed by any experience whatsoever, so be gentle on me.... It is a little off-topic, but stems from reading this thread and the problem at hand.

I know that some folks cut back the dip tube a little to raise it above the sediment layer... It seems to me that the flow into the tube... I'll call it a "vortex" here for lack of a better term... is going to be pointed downward, causing flow to "scrape" against the bottom of the keg. Hence the sediment in the first few pours.

I was wondering if anyone has ever tried attaching a U-shaped extension to the end of a shortened dip tube... Something where the base of the "U" touched the bottom of the keg, and the now upward-facing inlet was as low as possible (above the sediment line which I assume is fractions of an inch) so that the "vortex" is at least aimed upward at clear beer. Seems like ingesting top-down rather than bottom up would leave a much larger percentage of sediment where it belongs...

After writing this, it clicked that my wife is a hydrologist and teaches fluid, so I bounced it off her. She's ill right now and didn't really care to entertain another beer idea, but indicated that it would basically come down to flow velocity... She said that it would cause little turbulent eddies at the inlet regardless of which way it was pointed, so it would probably still pick up a little immediately around the inlet if it was close to the sediment layer height-wise.

Don't know that the results would be any better at all, or if you could get your inlet low enough after bending (or installing elbows) to be able to pull more beer from the keg than normal... Just figured I'd throw it out there though.

Regardless, this is a cool project! Nice work!

 

[FSR402]

Ok here is another thought the snapped into my head. The airlock you are using has "air" in it. What happens when you put it under pressure. Will it push the air out? I'm thinking that it wont if it's sealed. But if the pressure pushes it under the beer and then it leaks you just added an asston of air into the beer. So would you then want to fill it with CO2? If you do, will it float as well?

 

[BeerCanuck]

Ok here is another thought the snapped into my head. The airlock you are using has "air" in it. What happens when you put it under pressure. Will it push the air out? I'm thinking that it wont if it's sealed. But if the pressure pushes it under the beer and then it leaks you just added an asston of air into the beer. So would you then want to fill it with CO2? If you do, will it float as well?

Good point FSR402
I wish they made a see through keg (I'll leave that project for someone else
I want to run one more test of the prototype in my kegerator using water. I want to confirm how the prototype reacts using 12 psi at the beginning and end of the pour using my taps to dispence. I also thought that even if the float failed all that would happen is it sinking to a point just above the trub line.

I want to buy one more cornie and use the C02 dip tube from that in another cornie for the test.
I was also thinking that if I could reclaim the ~1/2" of tube that I usually cut off from the beer out tube toward this protoype...that would be skippy

Cheers
BeerCanuck

 

[Philip1993]

Bouyancy is a function of the difference in mass between the displaced fluid, and the displacing material. As such, any gas fill will be very buoyant.

As for the float: If you "fill" the float at atmospheric pressure, then subject it to 12psi, it better be compressible or strong enough to handle 12psi. You can solve this problem entirely if you can devise a vent that will never below fluid line.

 

[BeerCanuck]

Bouyancy is a function of the difference in mass between the displaced fluid, and the displacing material. As such, any gas fill will be very buoyant.

As for the float: If you "fill" the float at atmospheric pressure, then subject it to 12psi, it better be compressible or strong enough to handle 12psi. You can solve this problem entirely if you can devise a vent that will never below fluid line.

Good to know pldoolittle
I didn't like using the plastic wrap to seal the top cap area of my airlock anyways (I removed it on my last test) and if there is a benefit to not using it so much the better.

Cheers
BeerCanuck

 

[Philip1993]

I was thinking about how the float would react with 12 lbs of pressure applied..probably have a small effect on buoyancy I think.

Yes, but you can probably ignore it. The airlock will only be about 0.169% less buoyant at 12psi. But, if you're concerned, factor in that it will be about 43.4mg less buoyant at 12psi.

Seriously though, for those curious. Fluids are incompressible. Hence, the positive buoyancy of the submerged airlock does not change with pressure. The only variable is the weight of the airlock and it's contents (air/co2). Since the volume or temperature of the airlock does not change, there are 1.857 more volumes of CO2 in the airlock at 12psi than at atmospheric pressure (14psi). But, since CO2 only weighs 1.97mg/cc having 2x as much is no big deal...

I didn't like using the plastic wrap to seal the top cap area of my airlock anyways (I removed it on my last test) and if there is a benefit to not using it so much the better.

Don't think of your float like a toilet tank float, instead think of it like a boat with a very small cargo hole. Since the top is open, the cargo hold will always be full of CO2. The upside of this design is no air, pressure, or strength issues. The downside of this design is that sloshing can swamp the boat. If you go with a sealed float, you don't have to deal with swamping, but you do need to make sure that it won't crush under 12psi. That won't be as hard as it sounds. Beer bottles, and caps all withstand this pressure regularly.

 

[BeerCanuck]

Yes, but you can probably ignore it. The airlock will only be about 0.169% less buoyant at 12psi. But, if you're concerned, factor in that it will be about 43.4mg less buoyant at 12psi.

Seriously though, for those curious. Fluids are incompressible. Hence, the positive buoyancy of the submerged airlock does not change with pressure. The only variable is the weight of the airlock and it's contents (air/co2). Since the volume or temperature of the airlock does not change, there are 1.857 more volumes of CO2 in the airlock at 12psi than at atmospheric pressure (14psi). But, since CO2 only weighs 1.97mg/cc having 2x as much is no big deal...



Don't think of your float like a toilet tank float, instead think of it like a boat with a very small cargo hole. Since the top is open, the cargo hold will always be full of CO2. The upside of this design is no air, pressure, or strength issues. The downside of this design is that sloshing can swamp the boat. If you go with a sealed float, you don't have to deal with swamping, but you do need to make sure that it won't crush under 12psi. That won't be as hard as it sounds. Beer bottles, and caps all withstand this pressure regularly.

I appreciate the input pldoolittle.
Based on the above would you concur that a float with a small pressure hole would be the optimum design? I am thinking a replacement solid cap for the airlock with a small pin hole in the top to equalize pressure would be best in this application.

Cheers
BeerCanuck

 

[DirtyMick]

Interesting design. I had a quick thought.
Once the Keg is pressurized and you start pouring beer, will this 12psi pressure differential on the hose inlet make the hose and float gyrate around inside the keg, thus stirring up sediment at the bottom of the keg? Just a thought...
I just keep thinking of a water hose whipping around when left full on and unattended. Maybe having the slip weight will help subdue some of this action???

 

[BeerCanuck]

Interesting design. I had a quick thought.
Once the Keg is pressurized and you start pouring beer, will this 12psi pressure differential on the hose inlet make the hose and float gyrate around inside the keg, thus stirring up sediment at the bottom of the keg? Just a thought...
I just keep thinking of a water hose whipping around when left full on and unattended. Maybe having the slip weight will help subdue some of this action???

The pressure will be applied using the C02 input on the keg. The beer out wont be affected to much I believe. Your idea might have application for people looking to force carbonate quickly though

Cheers
BeerCanuck

 

[shafferpilot]

On your next test, grind up a cork and something non-bouyant (maybe metal filings?). If cork comes through the outlet, that's a simulation of picking up foam from the top of the beer. And when the filings come through, that's the sediment. I'm sure there's some material that'll work a lot better than filings, but I'm workin on my 3rd pint right now

 

[BeerCanuck]

On your next test, grind up a cork and something non-bouyant (maybe metal filings?). If cork comes through the outlet, that's a simulation of picking up foam from the top of the beer. And when the filings come through, that's the sediment. I'm sure there's some material that'll work a lot better than filings, but I'm working on my 3rd pint right now

I am pretty satisfied with my current design enough to test with real beer shortly.
I called to place an order for 1 5Gallon and 1 2.5 G cornies.
Once I have the extra kegs I plan on testing with real beer. I believe that the beer at the top of a keg should be more clarified. It would be interesting to confirm if the beer carbonates quicker as well...I believe this would be a reasonable assumption.

Thanks for the support and helpful critiquing.
BeerCanuck

 

[EricS]

Wow, pretty awesome idea. The only issue I see is if your keg starts to freeze it will do so from top to bottom. Since the outlet is at the top suspended by the float you will not be able to grab a pint while you are waitng for the thing to defrost

 

[shafferpilot]

If you have a keg freezing problem, you're keeping them way too cold.