Stirring ideas.

[tweak Junior Member Find all posts View Profile Close tweak]

Hi guys,

I'm making the move from SVO to Bio and getting a processing plant started. I confess I haven't done much searching (however have done much thinking) as to a stirrer setup. Another bio maker I recently got a load of oil from suggested using a pedestal/drill press with a long shaft/paddle, however I am curious as the the RPM of a drill press even on it's slowest speed and feel like it will be too slow?
My two main ideas have been using a cement mixer, they have high torque and relatively low RPM. The one we have here spins around 24 RPM, which I would like to lower to around 8-12 via pulley gearing, I however can't cut this one up as it still gets used.. Currently keeping my eye out for another though.

Another thought was using a washing machine motor I have sitting in the shed together with some form of control unit to slow it down, though from what I know of washing machine motors, what you can do depends greatly on the type of motor it is.

I could like something that I am able to run pulleys off, as I have a nice old gear pump with a pulley drive that I'd like to setup together with the stirrer so as I can switch across to it to pump everything into the appropriate tanks at the end.

Any ideas or tips? What do you guys use? Look forward to hearing some ideas!

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Stirring ideas.

Why do you want it to be slow?
Vigorous agitation will cause better mixing.
If you want a slow motor, try a garage door opener (with chain drive). You could have it away from the processor and chain drive the agitator. They are reversible and work on 12V (AC/DC)

Regards,
Tony

[brenden Senior Member Find all posts View Profile Close brenden]

Re: Stirring ideas.

Hi Tweak, I agree with tony you want to use some speed to mix ans smash the oil and the methoxide. Our system is mixed via a modified boat motor where the prop has been turned down a little ( to stop it spilling out of the reactor tub). The engine has been replaced by an electric motor. Have found this to be succesful.
Cheers Brenden

[tweak Junior Member Find all posts View Profile Close tweak]

Re: Stirring ideas.

True! Thanks guys.. Simply got the impression when I was told first hand that slow mixing was the way to go and thought stirring it too fast would just cause it to go everywhere.

What do you think about a pedestal/drill press then? What do you use Tony?

Cheers.

[wheelbarrow Member Find all posts View Profile Close wheelbarrow]

Re: Stirring ideas.

I had similar ideas of stirring when I started making bio, but found pumping it to be very commonly used and easier to set up. A big thing I was made aware of was to use a brushless motor or nothing that could cause a spark and ignite the methoxide. Might be obvious, but think its very relevant...
Cheers

[Matt Senior Member Find all posts View Profile Close Matt]

Re: Stirring ideas.

Indeed it is, now the way to do it, get and old petrol bowser, the motor is sealed and spark proof, very expensive thing to find. Got one on mine. it on a gate motor as advised and it stirs very well, put a baffle on the side and away you go. Sad thing is the caveman method is as good as this!

[tweak Junior Member Find all posts View Profile Close tweak]

Re: Stirring ideas.

So a year on and after being away for much of it for work or away from where my oil is, I'm back to putting together the processor!
Seems after some more searching that pumping is indeed a lot more common.
I'm currently looking at options for this. I have a 500L tank that I am converting into my processor. Ideally I'm wanting to use a gas flame to heat the tank but may look at heating elements for safety concerns. The tank is an old water pressure tank that I think will be perfect, has a rounded top and bottom with outlets at both ends. Have cut the top off where the curve starts and am waiting on two rings to be CNC'd/laser cut so I can easily access the inside of the tank.
I currently have a medium sized mechanical gear pump and one of the ~ $120 12V pumps off eBay with Viton seals that seem popular on these boards for moving oil, would either of these be suitable for circulating the tank do you think? I would imagine with the size of the tank and the amount I've taken off the top my batches will be around 400L in total volume.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Stirring ideas.

The 12v gear pump will not move enough oil to be effective as a mixer. Depending on the flow rate of the larger one it could be useful. I would aim for a flow rate that turned over the tank contents in 10 - 15 minutes.
You could try a QB60 or QB80 centrifugal pump. They are cheap and some forum members use them for circulation mixing. As long as you have them able to be isolated, so that they could be removed (even with a full tank of oil), so that if it developed a leak, you could isolate it until you have the pump seal replaced.
That said, I have not heard of many of these failing.
Regards,
Tony

[tweak Junior Member Find all posts View Profile Close tweak]

Re: Stirring ideas.

The 12v gear pump will not move enough oil to be effective as a mixer. Depending on the flow rate of the larger one it could be useful. I would aim for a flow rate that turned over the tank contents in 10 - 15 minutes.
You could try a QB60 or QB80 centrifugal pump. They are cheap and some forum members use them for circulation mixing. As long as you have them able to be isolated, so that they could be removed (even with a full tank of oil), so that if it developed a leak, you could isolate it until you have the pump seal replaced.
That said, I have not heard of many of these failing.
Regards,
Tony

Thanks Tony, those pumps definitely are cheap. Do forum members use them for moving oil as well or just circulating once mixed? I just looked through my watch list on eBay and I seem to have put a similar pump on the list some time ago. Will give one of the QB80's a shot if I go with the circulating method. At that price I could always grab two in case one fails, thanks for the the information, will have isolations in place in case of failure.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Stirring ideas.

These are centrifugal pumps. They do not self prime, so you need to have liquid in them for them to pump. I transfer 60 litres, using a gear pump, into my processor, which primes the QB60, then I suck in the other 260 litres using the QB60. Air in the pipes causes pumping issues, but I work it out by turning pump off and on again a couple of times.
Regards,
Tony