Electrolysis test cell for R&D electrical fault troubleshooting

[vonz33]

Hi there,

Trying to finish a job on delivering this electrolytic stack to a local university and having electrical issues.

It's probably pretty simple stuff but I have no electrical engineer around at the moment and trying to troubleshoot the fact that the cell stack is charging the electrolyte positively, affecting the electrical path once the metal housing is closed for operation.

The main problem with that is that once the metal lid is in contact with the electrolyte we are having massive current runaway, therefore, loading up the power supply unnecessarily resulting in a fault.

Picture of the input voltage (from PSU)

https://photos.app.goo.gl/dNJcNGXrRxuVSndy1

Voltage between minus from PSU and electrolyte

https://photos.app.goo.gl/YtB0SbqMw1xtXxvB3

NOTE: This is the main problem, because the electrolyte is in contact with the steel casing so when you close the lid that is negatively charged (as the negative is connected to body) then the fault occurs

Here is a video that is a bit more informative:

Part 1:

https://drive.google.com/open?id=1ZgVVM-iIGV9UXiKTJ8GW3FbsxPYWXx2z

Part 2:

https://drive.google.com/open?id=1-gD4L31mFoKG3D-OhQjeEPh02W1CxKxS

Here is the 3d model on inventor (Disclaimer: I own the copyright, just delete after viewing, if this design it gives you a good idea please let me know and we give you some rights to exploit)

https://drive.google.com/file/d/0By1l7HueUo__Qi1Zc2JpZTNzaEk/view?usp=sharing

Legend: Green = Polypropylene; Grey = 316 Stainless Steel; Blue = Neoprene Rubber

I would like to understand why the electrolyte around the cell is polarized with these particulars since the exact same surface of positive and negative electrode is in contact with it, according to my calculations the electrolyte should have been neutral.

PSU delivers 15VDC
Electrolyte has 11.7v (11.4 on the photo, the balance can vary slightly) potential difference from negative terminal and 3.3v from positive.

Would that be due to an unbalanced polarized surface of electrode in contact with the electrolyte or something else..

NOTE: The effect is the exact same with and without gaskets.

 

[Compositepro]

I have not looked at all your links as they require that I download some apps. I wonder why you would expect any different behavior from your battery than you are observing. A battery consists of two metals in an electrolyte. Your battery case is metal in an electrolyte. So it will form a battery with either of your two electrodes. Battery cases are made from insulators or, if metal is used, the case is one of the electrodes.

I suggest that you read-up on electro-chemical cells.

 

[itsmoked]

Trying to achieve balance with that configuration is not going to happen.
As comp said, getting the enclosure involved is a problem. Why is the case even metal? At the very least both feedthroughs should be insulated. You want to disconnect the cell walls from directly participating in the process.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[vonz33]

I know all that thank you.

If you take a look at the 3D model you will see that the metal end caps are totally isolated.

No download of any kind is necessary to see materials hosted on google.

Let me know if you do not have Autodesk Inventor in this case I can output an exploded view of the cell.

Regards