Last batch which I thought emulsified during 7% wash looks like it didn't, infact it was behaving quite normally.
Background ...
Fitted a bigger pump which, coupled with convoluted pipe work, contrived to create emulsions whilst pump washing. The answer I thought was to employ the little Mono with a much lower flow rate and gentle pumping action to do the washing.
Issue this time ...
Added 7% water after quite a heavy demeth, and took a sample after a short while. The sample was a thick dark brown gooey liquid. Based on previous experience I assumed it was an emulsion and tried splitting it with acid which appeared not to work. Leaving things in the processor with the sight glass valve open, very slowly bio started appearing on top of the emulsion.
Thinking this was a good thing I left it a little longer and ended up with what looked to be around 50% bio.
Today I decided to drain the emulsion and check out the bio that had split. Whilst draining, the % of bio increased in the sight glass. I ended up draining just the right volume of glycerin/water mix (circa 25%) before discovering about 75 -80 ltrs of bio.
What I recon happened ...
The batch went quite normally (but there's me expecting an emulsion based on last batches) but in using the Mono at 17 ltrs/min to water wash, I recon the glycerin was separating in the processor quicker than the pump could remove it, hence all it was doing was circulating glycerin rather than doing any meaningful washing.
All I ever saw at the sample point was a flow of water and glycerin and made the assumption that this was again an emulsion.
Batch has now had an acid wash with Frankenpump followed by a water wash. I'm only running Frankenpump, long enough to get the water in via the venturi and all seems to be well so far.
Just though I'd post up in case anyone else comes across the same problem with low capacity pumps.
