Hypochlorous Acid Generator

[dik]

Does anyone have a quick discription of a DIY generator for Hypochlorous Acid. Should be easy to make... A matter of electrolysis of salt water. Create a good, cheap really useful disinfectant for Covid 19, I understand... from reading, it's not snake oil.


Dik

 

[waross]

It is the delivery method that is controversial.

[link ]Bill[/url]
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"Why not the best?"
Jimmy Carter

 

[dik]

Do you know how to generate this?


Dik

 

[EdStainless]

This is how many pools are treated. The electrode structures are usually Ti.
And remember that they are trying to generate a couple of ppm.

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P.E. Metallurgy, consulting work welcomed

 

[dik]

Thanks... but any idea of how? a matter of an anode and cathode with a small DC voltage applied and a mild salt solution? Can I do this with a small battery pack? with the anode and cathode being titanium or something similar. Due to chloride ions, stainless steel would likely be inappropriate?

Dik

 

[Latexman]

Maybe you can go to the website of several commercial products and see if collectively they give enough info to reverse engineer it.

Good Luck,
Latexman
Pats' Pub's Proprietor

 

[dik]

Will try...

Dik

 

[waross]

I found these links but something went wrong when I thought that I posted them.
Link
Link

[link ]Bill[/url]
--------------------
"Why not the best?"
Jimmy Carter

 

[dik]

Thanks very much... good links.


Dik

 

[EdStainless]

Yes DC, these are both voltage and current controlled (I believe that V is primary).
In some of them they periodically reverse polarity to refresh the electrode.
Most that I have seen are all Ti.
There are some of these made using high alloy SS grades that work very well also.

If you want a stronger solution you need to look up they make bleach (they start by making pure Cl).


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P.E. Metallurgy, consulting work welcomed

 

[dik]

I understand for the HOCl, that you need a weak saline solution. I'm currently trying to dig up some titanium... and I don't want to remove the plates from my ankle... but, in a pinch...

Dik

 

[3DDave]

https://www.youtube.com/watch?v=R5kcER2Z4-8

 

[EdStainless]

Both salinity and pH matter, you get different species at different pH.As I recall you want slightly acidic (6.5-7) but I will look it up to check.

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P.E. Metallurgy, consulting work welcomed

 

[waross]

If titanium is best, what is second best?

[link ]Bill[/url]
--------------------
"Why not the best?"
Jimmy Carter

 

[dik]

3DDave: Thanks... very informative video.

EDStainless: thanks for the added info. Thinking of cobbling one of these cells together. Was planning to use regular DC charger 12-20 VDC, but it appears the USB voltage of 5 VDC seems to be OK. Also not sure how critical current is.

Dik

 

[dik]

waross: I would think some form of duplex SS would work... many common SS metals do not work well with Chlorides.

Dik

 

[3DDave]

In the comments on that video are discussions from people who do this process for a living and suggestions about what won't work well.

 

[dik]

Thanks 3DD... I didn't look at the comments... will now do that...

Added: I'm about half way through the comments and some of them are better than the video... lots of technical stuff to look up.

Dik

 

[EdStainless]

There is a range of current density that you want.
This is fairly low voltage high current.
And slightly lower pH works a little better (under 6.5).
You can get away with some Ni alloys (C276, Monel 400) or some high alloy SS (AL-6XN).

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[hokie66]

Don't know if it applies to what your are doing, but pool chlorinators use titanium plates with a coating of ruthenium oxide and/or iridium oxide. But they are not producing hypochlorous acid, as pool pH is too high for that.