Inline aeration (not oxygenation)

[Kepler]

Hi all, I'm looking for some advice on how to make inline aeration using an aquarium air pump work.

I have a 2 micron airstone inline after my plate chiller. It's connected to my aquarium pump which has max pressure of 2psi.

My problem is, unless I'm running my chugger at really low flow, the wort runs through my airstone backwards into the hosing. If I run the pump at low flow I'm not sure the wort is actually getting aerated. Also means I can't adjust flow to regulate the temperature out of my plate chiller.

Seems like I need a higher pressure aquarium air pump. Any ideas what psi would be necessary? Has anyone made something like this work?

I want to stick with air not oxygen for various reasons.

 

[IslandLizard]

Just hang the hose with your air stone inside your fermenter while you're filling it. You probably need to tie a weight (a spare stainless fitting, or so) on the end of the hose to keep it submerged.
You can let it pump air for a couple hours if you want. Just cover the fermenter so nothing can drop in.

When wort is backing up, obviously the pressure from the Chugger is higher than the airpump's. Or the stone is too restrictive for the airpump's pressure to push air through. 2 psi is not much.

 

[bracconiere]

maybe a check valve for the air hose?

 

[Kepler]

Just hang the hose with your air stone inside your fermenter while you're filling it. You probably need to tie a weight (a spare stainless fitting, or so) on the end of the hose to keep it submerged.
You can let it pump air for a couple hours if you want. Just cover the fermenter so nothing can drop in.

When wort is backing up, obviously the pressure from the Chugger is higher than the airpump's. Or the stone is too restrictive for the airpump's pressure to push air through. 2 psi is not much.

Thanks, actually until now I've been doing exactly that - hanging it into the fermenter for 20 mins or so. But I wanted to try a new hard plumbed setup to do it inline.

So the pump is plenty strong to push through the airstone. But I guess not strong enough to fight the chugger pressure. I think the chugger classic max head is 18ft which is about 5.8 psi. Given the air stone is after the plate chiller I figure the chugger pressure must have dropped to at least 4psi. So maybe that's the strength air pump I need to make this work.

 

[Cool_Hand_Luke]

You could try putting a venturi right at where you have the tee for the air stone and air pump hose. That would drop the pressure at that point and help draw the air in. Essentially give the air pump a boost.

 

[IslandLizard]

But I wanted to try a new hard plumbed setup to do it inline.

I doubt by using just air you can get enough oxygenation in an inline assembly like that. To get an idea, you could measure the volume of gas (air) output from the stone using water in an inverted container or graduate.

I'd stick to 20' (or an hour) in the fermenter. The good thing is, you can't overdo it with air, 8 ppm of DO is about the max you can achieve at 65F.

 

[Kepler]

You could try putting a venturi right at where you have the tee for the air stone and air pump hose. That would drop the pressure at that point and help draw the air in. Essentially give the air pump a boost.

Thanks, could you explain how this would work? What would I need to do exactly?

 

[Cool_Hand_Luke]

Thanks, could you explain how this would work? What would I need to do exactly?

I can sketch something for you. What's your tubing set up look like now? Can you upload a photo or a simple sketch?