Biopowered - vegetable oil and biodiesel forum
Biodiesel => Biodiesel equipment => Topic started by: Oilybloke on January 23, 2013, 06:09:28 PM
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I am building a new processor from a 300ltr s/steel tank (domed top & bottom). I have 120 lpm pump, venturi, eductor & quad core condensor, all to fit 28mm pipework. Can anyone steer me towards some alternative diagrams (I have checked the wiki here) to help with the pipework layout?
I am particularly confused with the eductor placing. If I am two staging, is it placed for optimum performance from the first stage, or second?
Cheers guys!
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I think that's one of the biggest problems with eductors, you're limited to a certain capacity in the processor if they are to work correctly and the main reason why I've not installed one.
I guess the best position would be to suit the first stage as the second stage reaction is usually quite quick.
As an alternative you could try making an adjustable one ... use a couple of "O" rings in place of an olive in a compression fitting and mount it vertically through the top of the processor. You'd need a suitably rated flexible hose to accommodate the movement. I've used this idea to adjust the height of my "never overflowing" wash tank with good effect.
As you go through the build would you mind taking loads of photos? It would be nice to have a wiki page documenting a complete processor build.
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Just a thought
If your starting from scratch is it possible to install a mixing whisk.
I would never go back to pump mixing even if I had to do it on a small scale.
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I am building a new processor from a 300ltr s/steel tank (domed top & bottom). I have 120 lpm pump, venturi, eductor & quad core condensor, all to fit 28mm pipework. Can anyone steer me towards some alternative diagrams (I have checked the wiki here) to help with the pipework layout?
I am particularly confused with the eductor placing. If I am two staging, is it placed for optimum performance from the first stage, or second?
Cheers guys!
check with jamesrl but i am sure he said as long as you have enough mix to meet the minimum 3 inches from the nozzle that is the most important measurement and if it is higher it is ok, but you don't want it any lower than that.
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Just a thought
If your starting from scratch is it possible to install a mixing whisk.
I would never go back to pump mixing even if I had to do it on a small scale.
How would you describe your whisk Paul?
I had a little play with a slow revolving paddle a few years back. I managed to liberate a redundant motor and made a paddle from nylon complete with different sized holes drilled into it. It worked quite well but it did not have the advantages of a pump.
Nige
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I think that's one of the biggest problems with eductors, you're limited to a certain capacity in the processor if they are to work correctly and the main reason why I've not installed one.
I guess the best position would be to suit the first stage as the second stage reaction is usually quite quick.
As an alternative you could try making an adjustable one ... use a couple of "O" rings in place of an olive in a compression fitting and mount it vertically through the top of the processor. You'd need a suitably rated flexible hose to accommodate the movement. I've used this idea to adjust the height of my "never overflowing" wash tank with good effect.
As you go through the build would you mind taking loads of photos? It would be nice to have a wiki page documenting a complete processor build.
Thank you Julian, and yes, I have thought about an adjustable height for the eductor. I am happy to take pictures of the build, but am too much of a luddite to get them posted here! If somebody can help, I am happy to mail them!
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Just a thought
If your starting from scratch is it possible to install a mixing whisk.
I would never go back to pump mixing even if I had to do it on a small scale.
How would you describe your whisk Paul?
I had a little play with a slow revolving paddle a few years back. I managed to liberate a redundant motor and made a paddle from nylon complete with different sized holes drilled into it. It worked quite well but it did not have the advantages of a pump.
Nige
I have used a processor with a paddle, and don't think it matches an eductor for efficiency. I am also thinking along the lines of static mixers perhaps. I know of one system that uses a Saniflow toilet macerator as a mixer!
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Well there's something I've never heard of being used before...a saniflow macerator. Have you seen it in use?
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When I was using standered wvo I could process 3000L of oil using ASM in 45 mins to a complete conversion . I think it's down to matching the paddle to the tank plus I have FPHE inside the tank to help with turbulence.
Not sure of the pump I'd need for similar success.
My paddle is only about 9inch 3blade 1/3 from the bottom
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Three inches from the surface to the top of the eductor and set it up for the first stage.
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Interesting that alternative mixing methods should come up. I've done several Dr Peppers today and was surprised at how just a little vigorous shaking could get a decent looking reaction.
And Macerators ... years ago I worked for a company who experimented with fuel emulsification. To mix heated, heavy marine diesel and water, they developed a thing that looked like a pump with a peripheral turbine pump impeller, but it had no pumping action. It relied on fuel flow for throughput. The serrated edge of the "impeller" with a very tight tolerance to the body, was supposed to create cavitation and emulsify the fuel. I've always wondered how the idea would perform if making bio.
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Well there's something I've never heard of being used before...a saniflow macerator. Have you seen it in use?
Wouldn't that make sh!t bio, though? :-X
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So, I'll be using this design......http://www.biopowered.co.uk/wiki/Processor_-_with_Methanol_condenser_(GL_design), but I have a couple of questions.
Regarding the venturi: my existing one is at right angles to the main flow (so only air or meth-oxide ever flows through it) and this seems to make more sense to me, inasmuch as it does not restrict any flow of oil into the tank. Am I right?
There is a vent from the glyc collection vessel, how necessary is this?
All comments appreciated,
Nick.
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Well there's something I've never heard of being used before...a saniflow macerator. Have you seen it in use?
What about building an 'all in one bog/processor'?
No need to leave the garage for a dump then!! ;D
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Regarding the venturi: my existing one is at right angles to the main flow (so only air or meth-oxide ever flows through it) and this seems to make more sense to me, inasmuch as it does not restrict any flow of oil into the tank. Am I right?
There is a vent from the glyc collection vessel, how necessary is this?
All comments appreciated,
Nick.
A well matched venturi has very little effect on pump flow, no more than 2 - 5%. As the venturi is only used to inject the methanol and demeth when an eductor is employed why worry about the flow.
Venting the Glyc vessel is down to the users discretion, do you WBD, how well vented is the work area? to be safe a vent is advisable, seal the whole thing.
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Regarding the venturi: my existing one is at right angles to the main flow (so only air or meth-oxide ever flows through it) and this seems to make more sense to me, inasmuch as it does not restrict any flow of oil into the tank. Am I right?
There is a vent from the glyc collection vessel, how necessary is this?
All comments appreciated,
Nick.
A well matched venturi has very little effect on pump flow, no more than 2 - 5%. As the venturi is only used to inject the methanol and demeth when an eductor is employed why worry about the flow.
Venting the Glyc vessel is down to the users discretion, do you WBD, how well vented is the work area? to be safe a vent is advisable, seal the whole thing.
Thank you Jim, I understand. So, should I branch the feed pipe to the top of the tank so that one fills (via the venturi), and one pumps to the eductor? I have a ginormous work area, plenty of ventilation, so reasonably happy with glyc venting, but might try to incorporate it.
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Just bumping this thread really.......is it better to have two pipes running from the pump to the tank i.e. one feed via the venturi to the eductor, and one straight through to just fill the tank?
Cheers guys!
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Im not sure if this is what you are asking, but -
For filling the reactor with veg, i doubt that flow is that important? If it takes 1,3,5 mins longer or shorter, is that worth thinking too much about?
If you are talking about filling through the venturi, as in through the sucking port - i know people do, but id much rather use a pump to pump or suck the feedstock in. Besides, i find the venturi gets blocked if im not carefull.
As i say, im not sure if that is relevant to what you are asking or not!
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I guess the concern is blocking a small orifice with BCBs in the oil. Depends on your setup really and how you fill the tank. Personally I wouldn't want to have to load the tank up with cold oil via the venturi.
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There's no need to have a dedicated pipe just for filling, yes the venturi will slow down the flow of cold oil,
but all you have to do is run the oil through both the venturi and the eductor and it's fine.
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A lot of fuss over nothing, just run the oil through the venturi, you'll need a fair sized bit of crap to block it.
Anything large enough to block even the smallest venturi throat will have to get past the pump impeller first, think about it.
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A lot of fuss over nothing, just run the oil through the venturi, you'll need a fair sized bit of crap to block it.
Anything large enough to block even the smallest venturi throat will have to get past the pump impeller first, think about it.
Not if its the side ports that are blocking.
...and theyre much more of a pain to get clear : (