Recirc e-BIAB pickup

[thuperman]

I've been designing an e-BIAB recirc upgrade of my 40L Crown urn for several months and thanks to dozens of AHB articles, I'm getting pretty close.

One question that I haven't been able to solve (there are many more, I'm sure), is why so many people put barb connections on their input and output connections. Here's an example:

Wouldn't this defeat the purpose of trying to keep the connections full-bore and, hence, reduce the flow that is possible with the pump?

What benefits are there to adding the barb connection as opposed to just stopping with the 90 elbow?

Cheers!
:beer:

 

[thuperman]

Sorry, I realise that I am an idiot for two reasons.

1) You can buy full-bore barb fittings.
2) I need barbed connections elsewhere in the system.

Apologies, I've got a 2 year old and a 2 week old, so I'm living on minimal sleep.

Final question in the original post still applies.

What benefits are there to adding the barb connection as opposed to just stopping with the 90 elbow?

Appreciate any advice.

 

[dblunn]

You can add a piece of silicon hose to get the output near the surface level.

 

[MitchD]

It about velocity. Without the barb the water will easily rush out of the elbow, add a Barb with reduced diameter and you get some back pressure and you will now create a whirlpool

 

[thuperman]

Thanks for the help, guys! I think dblunn has explained why you'd want a barb on the top return and Mitch has explained why you'd want it on the bottom (whirlpool) return.

Would a barb on the outlet just be to help pickup from closer to the bottom of the urn?

 

[ratchie]

Would a barb on the outlet just be to help pickup from closer to the bottom of the urn? Yes it also keeps the pick up close to the pot wall, closer than using a compression fitting and pick up tube. also looks neater.

 

[thuperman]

Thank you.

 

[thuperman]

MitchD and others, maybe just as a quick follow-up. Have you actually installed a reduced bore barb in your whirlpool return? How small did you go? Let's say 13mm is full bore, would 10mm or 8mm be appropriate?

Cheers!

 

[fdsaasdf]

I've installed a 10mm ID barb on the whirlpool outlet to increase the velocity of liquid returned to the kettle from the 13mm ID, however by eye I can't notice a difference between them.

 

[MitchD]

I've tried no barb and there was no whirlpool,then I used a 1/2" Od barb and it was enough for a whirlpool. That was all the R&D I performed though I would like to try a 30 degree elbow to change the angle the whirlpool is "squirted" out at.

 

[fdsaasdf]

I use a 45 degree elbow and it seems to angle the returned wort enough to keep it rotating

 

[thuperman]

Thanks guys. I might do some experimenting when the bits and pieces come in.