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Did you try local pet/aquarium stores or a garden supply that has drip irrigation tubing? If no luck there, try U.S. Plastics. Go to "Tubing & Fittings" from the drop down list, then pick "Kynar, Nylon and Polypropylene Tube Fittings", for a variety of fittings. The one I used to connect to the bottom is the 'tube-to-tube bulkhead fitting'.

[This message has been edited by Bob (edited 12-30-2002).]

OK, so in the whole design there will only be two containers, including the gas collecter, right? In the second sketch of the digester the container you replaced jugs 2&3 with is the gas collector you just explained, right? Also, how should the Ph level be checked, and how should stuff be added (like chicken poop and bicarbonate, or whatever needs to be put in) without letting air in with that design?

I looked on the U.S Plastic Corp and only found a Nylon Elbow Tube and Hose fitting and a Nylon Union Tube and Hose fitting. Is that what you used? And is there more than that? Thankyou for your help.

Oh, one other thing(sorry) I went to U.S. Plastic Corp, Sheet, Rod, Shapes on the pull down menu, and then to PVC Sheet and shapes. What(exactly) did you use?

"In the second sketch of the digester the container you replaced jugs 2&3 with is the gas collector you just explained, right?"

Right.

Also, how should the Ph level be checked, and how should stuff be added ... without letting air in?"

I was assuming that this would be a batch feed digester, meaning that you only fill it once, at the start of the experiment. For a simple little benchtop digester like this, I was also assuming you could remove the cap to check pH for a few seconds without disturbing the digestion process enough to affect it. Without disturbing any more than necessary, lift the cap, dip a piece of litmus paper (or pH meter probe) into the soup & replace.

But here's a sketch of a little more sophisticated design, that will allow you to remove a small amount of liquid for testing without opening it up, plus make it easier to agitate. Just turn it upside down. It will work either side up. To remove liquid, add a tee to the line, and open the pinch valve shown as "closed".



(Sketch is from Biogas Handbook)

re PVC sheet, I used 1/4", but only because that's what I had laying around. If I'd had 1/8" I would have used that instead. It doesn't really matter. (I only used PVC because it is easy to glue.)

Shadow?

How goes the experiment?

Well, I emailed Shadow to see how it went, but it bounced.

Now I'm disappointed.

I also thought it had been too long since anytyhing was posted here, so I'd better drop everyone a line and see if some conversation started up again...

Hi Guys, not sure what happened to Shadow, but this post has been helpful to me in getting together a little home brew project. Thanks for your efforts working with newbies!
Farmer

Hey farmer,

Glad you found it. When you get it built, post some pictures!

Can you resent pictures of the latest version of the digester. I came across this site and would like to try and build one for a science workshop I am leading later this summer.

I'm not sure which pictures you mean, lyga. Are you referring to images posted here in this topic?

I could not open the pictures posted on:

Postby Bob on Tue Nov 26, 2002 5:53 pm
ok, here are some pictures of a simple gas collector. The pieces are:

Can you repost?

I fixed it, lyga. (The links got broken when I upgraded to a new version of the forum software.) Thanks for the heads up.

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