Julian,
To make sure we're on the same page I'm talking about the 5 or 6 or 7 litres of glyc with the 7% water. Are you saying that only needs to be run for a minute?
I'm sure I read on here somewhere in threads about 7% pre wash that the processor needed to run for an hour, which did seem rather long to me. The wiki page says 15-20 minutes.
The acid should be added to the first wash (after the 7% wash), otherwise you're trying to neutralize the gly as well as the soap.
That makes sense, thx.
I think about 10 mins was the generally the accepted time, but personally even that seem a long time to me. Then my set up seems prone to making emulsions since I fitted Frankenpump, so I err on the cautious side.
Like just about everything biodiesel, it's what suits you, your oil and your processor ... nothing's written in stone. I'd have guessed that with reduced glycerin (missed that bit before), 7% water and an hours pumping, there would have been an increased risk of an emulsion, but more power to you, it worked.
If you're happy with an hour stick with it. What seems to work for me is running just long enough to suck the water in plus a minute or so. It's what ever rocks your boat, but if you're looking to process in a day, it's an area where you perhaps could save some time.
I know Head Womble did some excellent tests with 7% prewashing and concluded that it was extremely effective. I think he tried various volumes and run times, so that might have been where you saw the hour.
Mark ... were your tests and results ever put up on the wiki?
