Electrostatic emulsion separation [Bill Sloman]

If smaller oil droplets are slower to coalesce, you’d expect their concentration to increase with the number of cycles, unless you allowed enough time for the smallest ones.

Since the dielectric force goes like the volume, and the drag goes like the area, that’s not too surprising.

Cheers

Phil Hobbs

Hmm, Maybe, I'll save a portion of the next drain and let the water evaporate to see if there is an oil left. I may also run a much longer test to see if it clears, the level of water in the vessel is real close to the proper percentage at 10 minutes, I have let it run 20 minutes though. More fun! Thanks for the input, Mikek

What more needs to be said? I certainly can't think of anything to add.

I don't know, I have confusing results. I ran a two hour test and drained the water onto a paper towel and a piece of printer paper. I see no hint of any oil on either paper. I did see an ever so slight increase in the clarity of the water. So maybe 2 hrs is not enough time to remove tiny droplets, if they are there, or it is something else. Running the numbers going from 20 minutes to 2 hrs removed an extra 1.5% of water from the oil. At the facility their chemist can more accurately measure how much water is left in the oil. I went from 22.5% water at 20 minutes to 23.4% water at 2 hrs. Crude measurement using a ruler, but usable for estimates. Another item, there is a thin black line between the water and oil level they call a rag layer, I would use flock layer. What could this layer consist of? It does get thinner in the two hour run. Here's a picture of the layers at 20 Minutes and two hours, with an inset of the slight difference of clarity.

More fun today. Thanks, Mikek

A little explanation, I have an LED light on the back side of the vessel to help the camera see what is happening. I let the vessel drain over night, The first test with emulsion that has been treat several times, had a clear transparent water. The very next test the water was cloudy you could not see through it. It turns out to be a simple explanation. There is oil left on the glass after draining, making the water seem cloudy and opaque, it is the oil on the glass that make it opaque. When I left it over night most of the oil drained of the glass to the bottom. Mikek

Is it safe to assume that the electrodes are on the outside, not in contact with your emulsion?

Can you rinse the glass container with rubbing alcohol? It would have an affinity for the oil plus water.

- John

At this point the clarity is not a problem, now that we know it is oil on the glass, until we figured that out we weren't sure why the water was milky. It wasn't milky, we were just looking through a layer oil. If you would like to see a short video, I put a dropbox link. At 10 seconds look at the top 2/3 of the tube to see all the globules of water falling. It gets very slow after 45 seconds. Start the video over and watch all the waves at the bottom of the tube. Without power it takes about an hour to get close to that amount of separation.

Mikek P.S. Starting to craft ideas for a stainless steel version.