Does anyone know how long it actually takes water
to settle through the BD wash process.

The answer depends on a bunch of things. So here, in no particular order, are things which can influence how fast your wash water settles out:

1. Which wash is it? If it's the first wash, that's when you have maximal contamination from soap, glycerin, etc. This one takes longer to settle.

2. What wash method do you use? If you use a static wash first, which is the least aggressive way to wash, the wash water starts on the bottom and stays there. Or maybe you use the foolish and risky violent prop washing advocated by JTF (Journey to Forever). You could easily end up with an emulsion that will never separate out. Or maybe you mist wash, or maybe you bubble wash, or maybe you wash with a lawn sprinkler like Legal did. All of these methods will produce somewhat or wildly different settling times.

3. What temp is your wash water? I like it hot and find that it settles faster if it's 120-125F vs 50F.

4. Is your water hard or soft? Soft water is reported to be capable of removing more contaminants per wash cycle, but more prone to emulsions and theoretically slower to settle. Hard water should theoretically be faster to settle. I only have hard water available and have had good luck with that.

5. Was your raw oil contaminated with water to start with? If so, you undoubtedly made a bunch of extra soap in your primary reaction and you are at much greater risk of creating an emulsion that might not settle out on its own for a year.

And I'm sure there are a myriad of other factors that can affect this.

For my setup, I find that the first good bubble wash take a few hours to settle well. I like to leave it overnight. For my last wash, it settles like crazy and is probably done in 20 minutes once I turn the bubbles off. I still let it sit for a few hours before draining the water. The sooner you drain the wash water, the more biodiesel you lose and your yield goes down a bit.

How's that for complicated?

Finest regards,

troy

Troy, you just confirmed a few doubts I had. I misted on all my washes, with a batch contaminated with water, and my wash water temperature was ambient. Best I can tell, is that my water is on the soft side. ...And I lost 1/6 of my fuel in emulsion.

yep that was complicated alright. guess I don.t have most of the answers to the questions you
asked. I will experiment with it. thanks