Author Topic: Experimenting with PPO impellers on biodiesel equipment (Read 13332 times)

Tony · « **Reply #15 on:** July 26, 2012, 09:17:15 AM »

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).

Head Womble · « **Reply #16 on:** August 04, 2012, 03:48:48 PM »

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.

Head Womble · « **Reply #17 on:** August 07, 2012, 07:43:09 PM »

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.

and this is the set I've just tacken out

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 ?

Tony · « **Reply #18 on:** August 07, 2012, 09:42:52 PM »

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.

Head Womble · « **Reply #19 on:** August 07, 2012, 10:05:00 PM »

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.

Tony · « **Reply #20 on:** August 08, 2012, 08:48:14 AM »

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).

Head Womble · « **Reply #21 on:** August 08, 2012, 09:48:12 PM »

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.

Tony · « **Reply #22 on:** August 08, 2012, 10:27:48 PM »

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.

Head Womble · « **Reply #23 on:** August 08, 2012, 10:39:07 PM »

I pulled loads of little bits out of my pump, so yes yours may be the same.

Tony · « **Reply #24 on:** August 08, 2012, 11:22:19 PM »

Like you say, I expect it'll go the same way as yours.

Tony · « **Reply #25 on:** August 13, 2012, 01:50:40 PM »

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!)

Head Womble · « **Reply #26 on:** August 13, 2012, 10:10:33 PM »

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 ?

Tony · « **Reply #27 on:** August 14, 2012, 12:48:26 AM »

Post away chap. I'll add my pics as and when my pump fails as it surely will.

Keef · « **Reply #28 on:** August 14, 2012, 08:57:16 AM »

Quote from: mark on August 13, 2012, 10:10:33 PM

.
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?

Head Womble · « **Reply #29 on:** August 14, 2012, 10:55:05 PM »

Quote from: max.print on August 14, 2012, 08:57:16 AM

Quote from: mark on August 13, 2012, 10:10:33 PM
.
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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Experimenting with PPO impellers on biodiesel equipment