Thanks Rick. I'll look at that.

Inspired from the work JohnO did detailed HERE I decided to make one out of some copper bits.

With a 1/4 hose it sucks up room temp veggie oil at about 1 liter in 55sec. I hope that will be enough.

I know in the first picture that the nozzle does not look like it is in the center but it is in the final assembly.

venturismall.jpg (17 KB, 90 downloads)

Here is another picture.

venturismall2.jpg (19 KB, 92 downloads)

Paulb3: you're an inspiration. Tell us about the nozzle. I'll be very interested to hear how it works for things other than sucking oil.

Cheers,
JohnO

You know I don't really remember what the copper bit is called that I made the nozzle out of but from information that you provided in your build and from a few messages back and forth from Rick Da Tech I was able to do it.

The nozzle is a 1/2" tube that is rounded at one end with a 1/4" hole drilled into it. 3/4" male NPT fitting with a 1/2" to 3/4" reducer that had the 1/2" stop numbs filed out. And then a 1/2" female NPT fitting on the end. The draw/vacuum side I did a similar thing with the left over 1/2" copper tube from the nozzle as the part is about 8" long that is cut down. The 1/2" tube is about 3/8" above the nozzle in the TEE.

Right now the only way I could test it was to install it in my appleseed setup and the back pressure on the pump is between only 8 and 9 psi.

EDIT: The hose is more like 3/8" the ID of the barb is a little larger than 1/4" but the OD of the barb is a little over 3/8"

If you need more suction, make the hole smaller. It's a balancing act, between flow rate of the pumped oil, and suction created in the venturi. Are you going to use it for methanol recovery, or to introduce methoxide into a biodiesel processor?
Cheers,
JohnO

Just going to use it as methanol recovery. I introduce the methoxide the traditional appleseed fashion.

Just a small update I got about 2" Hg with my cobbled together venturi. Finally borrowed a gauge from a friend.

Can anybody draw me up a venturi design which I can show to a machine shop? This will be basically for methoxide injection and my pipe diameter from the pump is about 1/2"

Hi all ,I'm a long time lurker and reader .I've just finisher a GL1 day rig and now thanks to nzunimogger I have a successful venturi! 6 attempts at copper beating in 20mm pipe , some success but not sufficient suck .The poured lead around a turned wooden plug inside a threaded 20mm brass pipe proved excellent .I use a 40l per min pump and found a 6mm venturi apperure with a 5mm inlet gives me 1 litre per min up take at 1 metre lift ..

I'm happy ....and thanks for the idea nzunimogger !

A comment about lead: it is one of the metals used to polymerize vegetable oil. The others were copper and iron. Using a poured-lead venturi might lead to shortened storage life, in theory. "Shortened storage life" might mean "only 2 years", or might mean "only 1 year", but probably not "only 1 month". The effect (when making paint) is greater with lead with than copper or iron. My system uses some copper, and my SVO and Biodiesel seem to store ok for over a year in a steel tank, and at least 2 years in a plastic tote out of the sun.
PeterSibley: congratulations on a successful venturi! Let us know what your fuel storage life is, and if you see any signs of incipient polymerization. I doubt that you'll notice any difference compared to any process that avoids lead and copper entirely, but it would be nice to have someone's actual experience as part of the record. I expect someone (with no first-hand experience) to warn us that your fuel will rapidly degrade.
Cheers,
JohnO