I've finally managed it

[photoman290]

i was going down a similar route to remove abrasives from WMO for my waste oil burner. it blocks the needle valve if i don't filter it a bit. i am now trying a peristaltic pump so don't need to filter it. however i did spend some time working out the best way to filter it. i have one of Nathan's centrifuges you can borrow if you like i am a long way from needing it at the moment. i got a pump and  half coupling for it but haven't fitted the motor to it yet. i was going to use a B and Q pump which i cannibalised. it still needs the oil to be at 65C. you are welcome to play with it if you like. send me a message.

 tried a hydrocyclone, seems to work but you need to heat the oil to 65C to get it thin enough. i then tried an idea from perfo using a self cleaning filter set up . that is still at the experimental stage but from first experiments seems to work well. the advantage  is that you can filter at ambient. being as ambient at the moment is around 5 degrees i have put that idea on hold as i am working outside. the winter is not the time to experiment with oil, what with the wind and the rain.

[Tony]

Mmm lister powered everything, awesome   I'm not envious honest!

[therecklessengineer]

Yes, it was a bit weird - one side was perfect. The other side was f'ked!

No, she's on veggy oil at the moment. If I'm going to run WMO, then I want a centrifuge.

And thanks for the offer photoman, but I'm off back to work next week for 6 whole weeks so unfortunately Lizzie is going to have a little break.

[photoman290]

no problem i am not likely to be doing anything with it before then anyway. give me a shout when you have time to play again and i will get it to you. if you have a lathe you could fit the other half coupling and fit the pump to the motor if you want. i wont get around to it till next spring anyway.

[julianf]

Jolly good.

I see no reason why you couldn't run a Lister on WMO - just be prepared for a little more maintenance, and I think adding a centrifuge for the oil before going into a feed tank for the Lister would probably help somewhat.

I'm getting a fuel consumption value of just about 300g/kWh (excluding heat recovered) which is really very good. The Internet seems to suggest about 500g/kWh. By comparison, a modern medium speed CAT diesel (it's the only figure I can remember off the top of my head) uses about 230g/kWh. Admittedly that's at 200kW.

I have a 5kW UPS that I've acquired. I'd like to hook it up to the Lister so I can run at full load for a few hours a day - generate all my hot water and electricity in that time. When I stop the Lister, the UPS then takes over.

What rpm are you running the lister at?   Ken B. has suggested that running at different rpms gives reasonable differences in efficiency (as you would imagine) however, i forget what the sweet spot was.

WMO -

I think ive mentioned before, but Spencer (the lister chap, who pops up on the various forums) found exhaust valve and bore ware when running off WMO, but not ware to the pre-combustion areas, suggesting that the products of combustion were abrasive.  This would tie in with the reports ive read of the white ash found in (non engine) WMO burners.

If all the above is true, i would wonder as to the additive packages, specifically, the PH buffers (but im sure ive spoken with you about this before??) and am wondering if -

you have a solution?
or thats what causing you hesitation with the wmo?
or something else? : )

Julian

...who's lister, 5kw PMA, and 2.5kw GTI are all just sitting in storage : (

[therecklessengineer]

What rpm are you running the lister at?   Ken B. has suggested that running at different rpms gives reasonable differences in efficiency (as you would imagine) however, i forget what the sweet spot was.

650. Changing the RPM isn't really much of an option. I'm using a 5kW alternator at 3000rpm without an AVR - a few rpm difference on the Lister causes quite a change in output voltage.

It's actually quite handy. Provided a large portion of the driven load is resistive then it self regulates as it approaches full power. RPM drops, voltage drops, supplied power drops. Doesn't work on motors though.

It's not so much the ash I'm worried about, it's the metal particulates. WMO is full of them and I don't really want that going through my injection pump/injector.

I'm not sure where this ash comes from, or what it's composition is. I'm interested to find out...

[julianf]

Hmm.. i wonder how ken was doing it, as im sure he just had one of those ST heads, and i cant think he sorted out a load of gearing.

As i recall, he was going down to not far off 300.  Ive found (on very light testing, without loading) that mine seems to get less stable below 400.

Keep an eye on the whole ash thing - Spencer (just his nick) seems to fall out with people on so many forums, but what he says (as opposed to the way he says it, some of the time) seems to make some sense.

Aren't the ph buffers calcium compounds?  I cant think that theyre that great when removed (by combustion) from the hydrocarbon.

[photoman290]

Hmm.. i wonder how ken was doing it, as im sure he just had one of those ST heads, and i cant think he sorted out a load of gearing.

As i recall, he was going down to not far off 300.  Ive found (on very light testing, without loading) that mine seems to get less stable below 400.

Keep an eye on the whole ash thing - Spencer (just his nick) seems to fall out with people on so many forums, but what he says (as opposed to the way he says it, some of the time) seems to make some sense.

Aren't the ph buffers calcium compounds?  I cant think that theyre that great when removed (by combustion) from the hydrocarbon.

is spencer the nick of jeremy, janananda? used to be on VOD till someone upset him? if so what he says does make a lot of sense.

i did find a link to using sodium sulphate to clear particulates from wmo. havent tried it yet so dont know if it works.

[therecklessengineer]

Hmm.. i wonder how ken was doing it, as im sure he just had one of those ST heads, and i cant think he sorted out a load of gearing.

As i recall, he was going down to not far off 300.  Ive found (on very light testing, without loading) that mine seems to get less stable below 400.

You can rectify to DC (or generate DC directly) then invert to AC. I can just about pull 4kW at 650rpm - at 300 you're going to be generating less than half that - maybe 1.5kW. Not an option for me if I want a cuppa!

You also need to be mindful of the hydrodynamic wedge lubricating the bearings. Too slow and it'll wreck the bearings. A back of envelope calculation suggests 400 rpm as a minimum running speed for a 2" crankshaft. That's by no means gospel - I'm using 'about right' figures from what I know about much larger rotating shafts to work it out.

[julianf]

Spencer(4 numbers) is not our american friend.  The chap im talking of is uk based - which may account for the break down in communications that i see on some of the US forums? : )

My issue with generating at higher output is that i am planning on using the grid tie inverter, and then, any overproduction is just 'wasted' (flows back into grid). (edit: from the comments below, it seems that there will never be any point in running the engine unless the cnc machine or reactor are fired up)

Our load at the moment, as im typing this, is 129watts (or there abouts - accuracy of the OWL monitor is questionable)

All our cooking is done on the solid fuel rayburn, as is our heating (except for the morning toast / brew, as its not hot enough quick enough).  The high energy things are my CNC machine, when its milling, and the reactor on demeth (pre-heat has been / will be from the rayburn).



Your post has got me wondering if we shouldnt just get a big ups and save the standing charge!

[Dickjotec]

It is just possible that if the lister is running CHP then the legacy RHi that comes in in June next year may be available.
Reckless if yours is an 8.1 the design rpm of that is 800 I think rather than 650. My lister with over 10000 hours in my ownership runs at around 500 rpm and outputs 2kw to the GTI. When it has just been services the voltage is reasonably stable at around 300v DC.
The main problem that I experience, other than coking up is the nozel in the injector sticking. This causes poor starting but is easily fixed. Mine starts and runs on veg.
When the 'new' som is operational I will have to run that at 800 but I will rectify and smooth the AC to get my nominal 300v DC for the GTI  Not sure how to smooth it yet though, can't find how to calculate the capacitor value to get less than 5% ripple.

[therecklessengineer]

Not sure how to smooth it yet though, can't find how to calculate the capacitor value to get less than 5% ripple.

At what loading? I think I can work that out for you.

Mine's definitely a 6-1!

[Dickjotec]

Not sure how to smooth it yet though, can't find how to calculate the capacitor value to get less than 5% ripple.

At what loading? I think I can work that out for you.

Mine's definitely a 6-1!

I assumed 8.1 as you have a 5kW alt. the 6.1 is usually 2.5kW. What output do you get?

Thanks for the calc offer. The loading will be 2kW. It is very easy to set the load with the GTI, providing the system can deliver it, you can just dial in the output you want and it will deliver it regardless of the voltage, within reason. My GTI has stable output between 600 and 220V DC.
I will be using a bridge rectifier on the standard 240V alternator. The frequency is not particularly stable on the SOMs neither, for that matter, is the voltage! The smoother the output the better from the GTI point of view.

[therecklessengineer]

Yes, my alternator is oversized. It was free, so I can't complain.

6hp roughly equates to 4.5kw. I can just about pull 4kw measured electrical - but the fuel rack is fully over and there's a lot of smoke! 3kw is what I consider full realistic load at constant duty.

Done the maths. I assumed a frequency of 50hz, and gone with worst case assumptions so the resulting value will be oversized. I got 10,000µF.

I've got an old broken UPS at home with some big caps. I'll see if they're anything like the right rating - if they're OK I'll stick them in the post to you.

[Dickjotec]

Yes, my alternator is oversized. It was free, so I can't complain.

6hp roughly equates to 4.5kw. I can just about pull 4kw measured electrical - but the fuel rack is fully over and there's a lot of smoke! 3kw is what I consider full realistic load at constant duty.

Done the maths. I assumed a frequency of 50hz, and gone with worst case assumptions so the resulting value will be oversized. I got 10,000µF.

I've got an old broken UPS at home with some big caps. I'll see if they're anything like the right rating - if they're OK I'll stick them in the post to you.

That makes sense for the power, I have not tried mine over 2.5 as that is the maximum GTI rating over a short period.
Thanks for the cap offer. I have a spare main bearing housing if you want one, as a swap for the cap, to replace your split one. I assume it is the same fitting as a normal one?