Biopowered - vegetable oil and biodiesel forum
Biodiesel => Biodiesel equipment => Topic started by: Tony on July 19, 2012, 11:25:26 AM
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There seems to be a lot of noise in the community regarding avoiding non-metal impellers on biodiesel processors. But the original GL design used a CH pump which had plastic impellers, and a lot a commercial processors use vane pumps which often have synthetic vane materials.
Mark is planning on using his multistager with PPO components on his rig. I've got a 100lpm pump with PPO impeller that will fit my rig so I'm also going to give it a whirl.
This one:
http://www.speroni.it/public/en/prodotto_dett.php?id=43
Liquid temperature up to 60°C according to the website but datasheet says 90C - we will see :)
http://en.wikipedia.org/wiki/Noryl
"Noryl is a blend of polyphenylene oxide (PPO) and polystyrene (PS) that was developed by General Electric Plastics in 1966"
"Noryl is stable in boiling water. The precise value of the transition depends on the exact composition of the grade being used. There is a smooth linear relation between weight content of polystyrene and the Tg of the blend."
Debating whether to stay under the 90C or take it up to 105C (they must allow some margin for manufacturing variance surely?) - if it survives this then good - if it fails then at least we'll have conclusive evidence. The pump came to me as a cheapy because it was seized - I don't mind sacrificing it in the name of experimentation.
I'm going to purchase a couple of extra 1" BSP to 28mm pipe adapters so the pumps can be swapped quickly in the case of failure.
Of course I'll take before and after photos of the impeller.
Wish me luck!
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Flippin' £10.79 for 2x 1" BSP male to 28mm compression :o I feel like I've been robbed!
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As Tony has said I'm going to swap my pump over the the PZ5 I had at chugs bash (the one running the eductor we demoed).
This wont be done quite yet as I need to get my holiday fuel done this week, but some time mid august I'll swap it over and do some testing.
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Found the datasheet for Mark's pump Edit: I see Mark also PM'd me the same link - great minds and all that!
http://www.radacontrols.com/onlinecatalog/pdf/p2710_6.pdf
Again, Noryl, but this one is only rated to 70C. Or so they say :)
The datasheet says "group showering" which I'm glad we never got into at the BBB... :o
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The datasheet says "group showering" which I'm glad we never got into at the BBB... :o
We did, all weekend it was raining.
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Hmm, good point...
By the way - how hot do you take your batches Mark? (Thinking of what your pump will be tested against).
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Normally only up the 90° when demething,
but I have taken it up to 105° when dewatering some really bad oil (and my pipe lagging started to melt :o ).
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Pump is now fitted and tested to 3 bar. Heating some oil for it to dewater now.
It does sound like it's suffering bearing failure so I'll give it a few batchs of thrashing and if the impeller survives I'll treat it to some new bearings.
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Tony you have jincksed my pump, it bloue it's shaft seal today >:(
I was dewatering at 95°C, just as it was comming to an end oil started ot pour out.
So I've now been forced to swap the pumps over tonight as I need to get fuel done for my hols.
Here it is bodged into the system
(http://i250.photobucket.com/albums/gg264/mark405td/biopump001.jpg)
Note the blocks of wood holding it up and the stressed pipework, but at least it's not leaking.
It's a lot louder than my old one so I'll not be able to do my late night reacting for a while.
Lets see how long these PPO pumps last.
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Mine is louder too. Been dewatering oil at 105c no problem - so far!
Sorry to hear about the demise of your pump seal...
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Have you done a reaction with yours yet ?
Mine is doing one now.
I'll have a look at changing the seal as at the mo I have no spare pump :-\
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Not done a reaction yet - probably tues/wed at this rate.
Let me know if yours survives the Methoxide :)
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Pump survived the methoxide, but the batch whent T's up.
I've been having problems for a while but the last two batches turned into jelly in the first stage of a two stage non titration.
I've got a lot of thinking to do to work out what's going wrong.
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Presumably that can only ever be caused by water - how are you drying the oil?
Also I remember you saying you're taking the Methanol %age quite low - Methanol itself helps prevent emulsion, so perhaps lowing it where water was present before increases the risk?
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Recently I've gone back to 20%, I was down to 16% just to see how far I could push it.
But as I WBD I didn't see the point in trying to skin a fart any more.
I'm starting a thread on VOD about my reaction problems.
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Did a batch last night and ran my PPO impellered pump at sustained 80C for four hours to give it a good workout.
However during demething the output dropped to about 30lpm (was easily pushing 80lpm before). So I need to have it apart and see what's up. Could just be a blockage, or I've killed it, or it was cavitating with the Methanol just below boiling point (seems to be happening on all the 80lpm single stage pumps I've tried on my rig).
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I was at Julians the other week and he's given me a new seal that might fit my 110lpm pump,
so hopefully I'll have that ready just in case the PPO pump gives up.
Hopeing to do a full reaction on Monday, will post the results.
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Well the reaction is done, two stage non titraion, crystle clear 90/10 pass (with no jelly :) ).
The pump however didn't do quite so well, the immpeller has melted and eaten it's self.
Here are some picks
This is the spare set of immplers I had just in case.
(http://i250.photobucket.com/albums/gg264/mark405td/001.jpg)
and this is the set I've just tacken out
(http://i250.photobucket.com/albums/gg264/mark405td/003.jpg)
(http://i250.photobucket.com/albums/gg264/mark405td/004.jpg)
(http://i250.photobucket.com/albums/gg264/mark405td/005.jpg)
(http://i250.photobucket.com/albums/gg264/mark405td/007.jpg)
As you can see these PPO pumps just don't stand up to bio being demethed at 90°C
What's your looking like Tony ?
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Wow. Well that answers that then!
Mine is performing very poorly. I suspect it looks the same but I've not had it apart yet to find out. Will post photos when I do.
Incredibly photos - now if anyone asks about them you can present that as evidence. In fact I think we need a wiki page on pump materials.
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I have a few more photos and will keep the inturnals if you'd like to see them.
The new (second hand) set is still hard and not flexable, but the old set can be manipulated and you can scrap the surface with your finger nail.
Bio has well and truely eaten away at it.
I'm glad it didn't sell at the BBB, it would have been a bit embarising.
Mith busters has nothing on us bio boys.
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Well mine appears to be holding up mostly.
It's a slightly different material, which is cream in colour. The slow flow was due to blockage (black crispy bits jamming the pump impeller) rather than impeller failure.
The main body of the impeller is still hard, however the "eye" can be scratched with a thumbnail - and looks like it has prematurely worn. So I'll keep using it however I suspect it'll go the same way as yours.
Pictures of both types and how they fail will be completely invaluable for the wiki.
How many batches has yours done? (Mine has only done one, though it was deliberately extended to stress the pump).
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Mine did the first stage of a jelly batch, some of wich no doudt sat in the pump for 12 days or so.
Plus dewatering, two stages and almost a full demeth at 90°c.
So not that much work but will have sat in veg/meth/coustic for quite a stort time concidering we were hopeing for a long term pump test.
Mind you I think my pump was rated at 70°C max continuse use with water.
As yours is starting to go soft on the surface I expect it will go the same way in time.
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Well the bits blocking it appeared to be bits of dark plastic like material, perhaps broken or worn away from the eye of the impeller or where the eye of the impeller mated to the housing.
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I pulled loads of little bits out of my pump, so yes yours may be the same.
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Like you say, I expect it'll go the same way as yours.
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Mark I've put your pics up here mate:
http://www.biopowered.co.uk/wiki/Pump_-_buyers_guide
Any comments and additions to the pump buyers guide would be welcome (edit away folks!)
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Looks spot on to me mate.
Couldn't have done a better job myself.
Do you think we should put this on VOD for all to see ?
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Post away chap. I'll add my pics as and when my pump fails as it surely will.
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Do you think we should put this on VOD for all to see ?
Rather than a dedicated VOD post, how about posting a reference to this thread to maybe increase the traffic here a bit?
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Do you think we should put this on VOD for all to see ?
Rather than a dedicated VOD post, how about posting a reference to this thread to maybe increase the traffic here a bit?
T'is done.
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Well my pump made a massive squeal today and the pressure dropped - took it apart and the impeller was all distorted and fell apart easily. Added the pics to the wiki page.
http://www.biopowered.co.uk/wiki/Pump_-_buyers_guide
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Just cought up with this thread :-[
How many batches did yours last Tony ?
Looks as if it faired better than mine did.
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Just a couple - pretty poor really!
The biggest initial problem was that as the impeller softened the two faces curved into the gaps between them - the performance dropped significantly then. The material was obviously losing its rigidity and turning to cheese.
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Sounds familiar.
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I think we need to add to this thread that not all plastic impellors are the same,
I have a Stuart Turner 903 pump that was running my reactor for around 18 months and is now my dispencing pump,
this has been faltless thoughout this time.
So not all are unsuitable for bio use.
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I guess Graham Laming wouldn't have had any success with his central heating pump if the impeller had crumbled on that so they must come in different flavours.
Mark, do you know the material used in the Stuart Turner?
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No I don't, it's an old one that was given to me and all the info has rubbed off of the plate.
Here's a pic of it if it helps
(http://i250.photobucket.com/albums/gg264/mark405td/BIOPRO014.jpg)