Steam infusion question

**dstar26t** · 08-08-2008, 12:40 AM

I got a steam set-up coming together and used it for the first time with water tonight. I plan on using a propane burner for the pressure canner, the test was done inside on the stove however (obviously). The only question I have is regarding the freaking loud banging! Is this normal or do I need to throttle it to a flow rate low enough to where it doesn't bang? With the braid, it took 8 gallons of water from 150F to 168F in 10 minutes, throttling it slightly to avoid banging. I'll probably go with a copper manifold in the future to get a more even distribution. I guess the holes should be drilled at 90 degrees from pointing down so the steam doesn't go right into the bottom of the cooler.

Here's the set-up:

Here's a vid...you can hear the banging until I throttle it. Then I get back on it again.

http://s86.photobucket.com/albums/k98/dstar26t/?action=view&current=MVI_1094.flv

**Yuri_Rage** · 08-08-2008, 12:56 AM

You need a more even distribution manifold. That stainless braid is probably the cause of the banging. Unless you have a drilled/slotted copper manifold within it, the braid is letting large pockets of steam contact colder wort/water, making the racket you're hearing.

**beerthirty** · 08-08-2008, 01:33 AM

The banging you hear is called "hammering" it is caused by the steam collapsing and revaporizing in the system. In a hardpipe system it can be dangerous because it causes pressure spiking. Basically as the vapor collapses under pressure, the pressure reduces and the water in the line revaporizes violently due to the fact that it is still above 212*. The pressure tries to put it into a liquid state and the heat tries to keep it in a vapor state, as the pressure changes slightly you get repeated condensation and vaporization. In a soft tube system the tubing will absorb the spiking and wont even register on most gauges. But in a soft tube system you also tend to get more pressure difference because of the plasticity of the tubing, which also makes it less dangerous. Note: steam is hotter than water and can burn worse than an open flame. Make sure you tubing is safe to the the temp that water boils at under the max pressure +30% to avoid serious injury.
I think steam heating the mash is a viable alternative, but please be careful. I plan on playing with it one day also. The above info was explained to me by a nuclear steam generating engineer with many years experience. I hope this helps.

**Yuri_Rage** · 08-08-2008, 01:36 AM

See the above post for the lengthy explanation. Then, see my first post for the solution. A distribution manifold tends to buffer the hammering to a dull, even roar rather than a rhythmic banging.

**beerthirty** · 08-08-2008, 02:48 AM

I wasn't trying to steal your thunder Yuri,

you are correct in your way of reducing it. By reducing backpressure you are taking the some of the pressure out of the equation. If the Op understood what was causing it, then he might come up with other ideas that would benefit any who followed.
dstar, you might want to put some holes along the top to reduce the pressure further although this would probably be negligible. As long as the steam is not bubbling to the top of the liquid you a getting full heat transfer as the liquid condenses the vapor to liquid.

**Yuri_Rage** · 08-08-2008, 02:50 AM

No thunder stolen, I just wanted to make sure we integrated all the info.

**kladue** · 08-08-2008, 03:32 AM

IMHO the most likely cause of the popinging and hammering is the large diameter and length of the braid being used to diffuse the steam. With that much surface area it will not be able to expel the water and let the steam diffuse through the braid. You would be able to move all the steam you need with a 2 - 3" piece of braid. Past experience with boilers and steam heat exchange equipment, and the causes of steam condensate hammering in equipment, your problems are from same cause.

**dstar26t** · 08-08-2008, 12:09 PM

Since I'm using the steam manifold also as the drain, how does this look? The holes are drilled parallel with the bottom surface of the cooler so they don't heat it up too much (compared to drilled pointing down like a normal drain). I already have a coil of 3/8" copper so I was hoping that would work. I saw that cookiebaggs used 1/4" copper and his system works well.

Thanks for the help all.
Nate

EDIT: Any opinions on 3/8" tube vs. 1/4" tube for the manifold? Both will have less dead space than the current braid. If the holes were pointing up, I'd have to think that the mash steam heat would get distributed better and I'd only loose less than another cup of dead space.

**beerthirty** · 08-08-2008, 06:03 PM

looks like that manifold would allow as much distribution as the backpressure allowed(hope that made sense) Holes up should provide less backpressure(hammering). I think 3/8 might also but I'm not sure if it would allow more liquid in thus needing more pressure to clear. An engineer would be better suited to that question.

**dstar26t** · 08-08-2008, 06:06 PM

Haha...I AM an engineer (mechanical) but haven't done anything like this since college.

I just searched and found Yuri's set-up and he uses 3/8". Nice vids by the way Yuri.