Hi

I've added a bit more info here.

Hope it helps, and feel free to ask if you need any more info.

Cheers,

Graham

Thanks for keeping us updated with progress on your rig - do you have a pat pending?

I have a question about the sight tube. Basically, I wonder if a separate tube is even necessary. Why do we need a sight tube - to check the initial fill level, to check for separation and assist in running off the by-product. Well, if we use a pre-processing tank (as you currently do I believe), to pre-heat the oil and strain off the worst of the crud, it's a simple matter to mark the inside of that tank with the charge of oil required. Once the reaction in the main tank has finished, if just the section of piping below the circulating pump is reinforced plastic hose (and assuming that the pump is above the glyc settling level), we can easily see when settling is done and can monitor the level as the glyc is run off.

Second query... Your layout is pretty tidy as it is but it could be made even more so if a four way connector were available (like the black iron one used in the original appleseed processor). I've not seen one in compression or solder fittings. Does anyone know if such a fitting exists in copper or brass?

Finally, I've been thinking about the pre-processing and post-processing (wash) tanks. The HWC we're using for the reaction vessel is 117 litres. I'm guessing that it should cope with 80l of oil plus the meth leaving 15 litres or so headroom. Is this what you use? If we use a 45 gallon drum for pre and post processing, they're always going to be less than half full so, for compactness, we could use smaller tanks. Since we need to heat both tanks (I want to try drying using the heat-and-compressed-air technique) an obvious candidate would be a tank similar to the reaction vessel itself. A plumber aquantaince tells me that he's ripping these out all the time when he does domestic replumbing jobs so they should be fairly easy to come by.

Sorry, I seem to have waffled on a bit.... I'd be interested in your comments and thanks again for sharing your knowledge!

Cheers

Nick

Hi Nick

I'm learning as I go - there are always ways to improve, and most of what I've done has been picked up from ideas others have suggested.

A sight-tube is not necessary for measuring charge, as you say, the feeder tank is easy to mark with grads.

Your idea of clear tubing below the pump is good.

But you must make sure you get good rigid hose that won't collapse under the pump's suction when its at 60 degrees C. The hose I have is really sloppy cheap stuff and would constrict the flow too much when running under partial vacuum.

I've not seen a 4 way junction for copper pipe, but I'll keep my eyes open for one.

My filter tank needs to be upgraded fast! It is only about 60 litres or so and is plastic, so I don't heat it directly. Instead I pour in heated oil at around 45C, using a bucket to transfer from 205 litre heating tank to filter tank!

I have a horrible method of preheating the oil, using a hand-held(!) immersion heater which I swish around in the preheat tank. With a fixed element I get too much scorching of crud onto it.

My idea for the heating tank and later for the bubble wash and also the drying tank is to use 205 litre drums with a pair of 3kW 'bendable' heating elements, wired in series, to give 1500 W. Should prevent scorching, because you can get these elemens in 2.44m length, so I'd have 1.5kW distributed over 4.88m length, coiled near the bottom of the tank. Nice thing is that they can be brazed into the tank, or secured with 6mm compression fittings. Take a look at http://rswww.com and enter 200-1285 in the search box at the top of the page.

I like having the wash and drying tanks twice the volume of oil, because I can get a decent charge of water in there, and I can draw off well above the water/oil level. The oil gets cleaner the higher up you go, after its been settling a while. What gets left behind just adds to the next batch's level.

I saw a nifty idea for mist washing or even bubble washing with a constant trickle flow of water - automatically drains water from the bottom at the same rate as you put it in. I couldn't find the original post, but here's a diagram to explain...




I've added this and other new info about process thermometers and weighing scales to 0.1 gram at my summary page.

Graham,

nice job on the setup and great work with the summary webpage, and I'm well surprised that no one has jumped in yet and told you that you cannot use copper with biodiesel.

Chug

Hi Chug,

Copper is fine, as you know from your own experience. Have you seen any greening on your copper or brass fittings? I haven't on mine.

Cheers mate, have a healthy and happy new year!

Nice job indeed....

Someone (there's always one - this time it's me) has already asked the question of the suitablity of copper given what we're putting through it - thankfully for us Brits, it seems not to be a serious problem.

Regarding the scorching of the oil, would circulating the oil with a pump achieve the same result thereby allowing a 3kW element to be used? How long will it take to raise up to operating temp with just 1500W - in low ambient temperatures like we have now?

Cheers

Nick

quote:

Posted 28 December 2005 05:30 PM
quote:
Originally posted by Twenty4Seven:
I have a source of WVO - just need to source the meth.

Nick


Have you tried http://www.yell.com

9bar

Fisher are fairly close to me and would be the obvious source. The problem is I don't have business premises and they won't deliver to a private address.

Cheers

Nick

quote:

My idea for the heating tank and later for the bubble wash and also the drying tank is to use 205 litre drums with a pair of 3kW 'bendable' heating elements, wired in series, to give 1500 W. Should prevent scorching, because you can get these elemens in 2.44m length, so I'd have 1.5kW distributed over 4.88m length, coiled near the bottom of the tank. Nice thing is that they can be brazed into the tank, or secured with 6mm compression fittings. Take a look at http://rswww.com and enter 200-1285 in the search box at the top of the page.

Just a thought... if I understand your rationale correctly, the problem is the concentration of heat in a small area ... which you hope to ameliorate by spreading the heat over a wider area? Wiring in series doubles the resistance and drops the power to 1500W. Wiring in parallel would give you back 3kW but still spread over 4.88m length of element - which is still an improvement over the original element. Worth a try?

Hi Nick

Yes, I'm not sure yet how long 1.5kW would take to get up to cooking temp. 2 elements in parallel would give 6kW, maybe just 1 element will be enuf - only one way to find out for sure! I've got some lagging set aside for the 45 gal drum idea, so I'll try to make it as efficient as poss.

As to meth, need to find someone local with business premises willing to buy for you, or another local brewer with spare available. Perhaps a small family owned garage?

Fisher is quite pricey unless you buy 205 litre container, which, to be honest is a real pain to handle. I think that's around £135.00 from them.

Try albion chemicals in liverpool, they do 25 litre containers and should have a local depot for you. Make sure you let them know you are shopping around, and mention the Fisher price of £135 for 205 litres AND that Fisher don't charge carriage, so you're looking at £0.66 a litre all in.

Haggle like heck - you should be able to get them to drop their pricing, but it will depend on how much you are willing to buy, of course.

I don't think you'd get much better than double that price for a single 25 l container, plus a £30 carriage charge, from Albion.

Add VAT to all those prices, by the way.

Good luck!

I have had no signs of greening on any of the copper or brass parts in over 1 year of use, and I have used a 2.2 kw kettle element to heat wvo with pump circulating with no noticable scorching.

Chug

quote:

Yes, I'm not sure yet how long 1.5kW would take to get up to cooking temp. 2 elements in parallel would give 6kW

Doh!! I should have engaged brain before hitting keys.... two 1.5kW elements in parallel would give 3kW of course. Good luck with the experiments......

.... and Happy New Year to all!

Cheers

Nick

[QUOTE]Originally posted by GrahamLaming:
I saw a nifty idea for mist washing or even bubble washing with a constant trickle flow of water - automatically drains water from the bottom at the same rate as you put it in. I couldn't find the original post, but here's a diagram to explain...



--------------

Did you build it in the end Graham and if so, how well does it work?

Cheers

24/7

Hi 24/7

I use this system apart from the 2 bottom tubes.
I just sipon out the BD and water and keep the tank on the floor.

BUUUUTTTT !! Make sure your siphon tube has enough diameter to cope with twice (safety margin) the maximum flow rate of your mister input.

My mister was running off a mains water feed via an old tap, which I guess was around 10% open for my 'ideal' wash water feed rate when I started. Looked great.

I came back to check on things later in the day to find my tank was overflowing. The mister flow rate had risen to more than my siphon could cope with.

A lot of swearing and a lot of mopping up. But wiser ....

Hi Graham - thanks for the ideas re the copper water tank. I have one of these i'm about to set up and I'll copy your idea. As for the pump, I have an ordinary 3-speed central heating pump - do you think that would work ok?

Hi Jehu

Yes, works fine, that's what I have. A Grundfoss UPS15-50. I run it on full power - is a nice little pump, plenty of output for this application.

I have since moved the pump down to as low as it will go in the vertical pipe, to help with priming when filling.

No problems with glycerol fouling, I use a 5% water pre-wash, which helps settle out the glycerol quickly for a good separation and drain-off. Then I circulate the remaining BD to dilute any of the little remaining glycerol within it before I empty the tank and wash.

The BD has completely removed the paint from the outside of the pump, but the seals and impeller all look to be fine.

Thanks Graham. I hope to be set up by next week - I've bought a cheap metal 8x4 shed to house it in.
I think my tank is smaller than yours - something like 120 litres, but taht'll do for now. Cheers!

quote:

Originally posted by GrahamLaming:

I have since moved the pump down to as low as it will go in the vertical pipe, to help with priming when filling.

Now he tells us! After I'd faithfully copied the original design.... LOL!
My 'big rig' finally gets to see the light of day this weekend - pics to follow

Nick

I think GL's design is pretty good, I'll probably borrow heavily from it to build my processor.

However, I have a couple of questions, which probably seem devastatingly obvious to the pro's but not to me...so at the risk of public ridicule...

In GL's design, does the oil get circulated from the bottom and into the top i.e. anticlockwise in the picture...or vice versa?

When the reaction is finished, and the pump is switched off to settle. How do you flush the oil/meth/glyc that's left in the pipes back into the tank?

Thanks

Hi Chester,

And sorry, Nick - I've edited my original post now to explain my change.

Yes Chester, the flow is anti-clockwise. I have now moved the pump down to the lowest part of the vertical tube.

At the end of the reaction, after 2 hours at 55 degrees C, I add 5% water (pre-wash) and circulate for 20 minutes.

Stop the pump and leave for 45 minutes for the glycerol layer to settle.

Drain off the watery glycerol via the lowest valve.

Recirculate the remaining biodiesel for a couple of minutes to pick up and dilute any remaining glycerol in the tubing/pump.

Pump out the bulk through the top right tube, into the wash tank.

Drain the remainder (about a litre) from the lowest valve into a bucket and transfer to a wash tank.

I've just run 2 x 80 litre batches this evening and another 2 due for tomorrow - it is so much easier now the weather is warming up. This winter has been a pain for BD! My shed is open and unheated.

I managed to get am old hot water tank from a scrappy today, hopefuly it'll be fine for a processor. The only thing that concerned me slightly is it's one of those indirect heated types with a coil of pipe in the tank, would this cause any problems that you can think of?

All the plumbing threads look in good nick so I'm confident it can be adapted.