booster

[Bob Boyce]

The simple answer is, your plate spacing is too large. While larger plate spacing will work, it will cause decreased current flow. Optimum spacing is about 1/8" which is about 3 mm.

You should always get lower current flow with 7 cells versus 6 cells, even at the correct spacing, but the amount of hydroxy gas produced for that current flow will be proportionately improved. The key word to remember here is proportionately. In other words, while you may be able to get more hydroxy gas volume with 6 cells, look at how many watts of power you will consume in doing so.

The mindset that more is better needs to be resisted. More hydroxy gas is not always better, not when it costs more energy to produce than it can deliver. Efficient hydroxy gas production is better for this application.

Do the math and you'll see that you were very close to production levels predicted by Faraday. You did very well compared to most that do these experiments. So don't be too disappointed at this stage. Just see if you can get your plate spacing down and try again. If you can't get the spacing closer, then you may want to look for larger plates. Good luck.

Bob

[eco]

Thanks Bob,

I can get my plate spacing down and try again.

eco

[eco]

Hey Bob,

- The electrolyser has been changed, and the spacing between the plates is now 3mm.

- Then I tested it (with air) at over 30 psi over 1/2 hour - OK

- I hooked the device up to and idling car.

- At the beginning it was working at 4.2A, then it constantly grew up to 7A (After thirty minutes). That;s when I measured the gas production and it was around 0.7 L/min.

- I stopped the testing to measure the electrolyte level. Everything was fine. That was no visual change in the water level.

- I continued the testing.

- Now the device started off at 6.2A (as opposed to the first time when it started off at 4.2 A) - it also constantly grew, and ended up at 10.5 A (after thirty minutes). I was measuring the production the entire time.

1. At 7A - 0.8L/min
2. At 8A - 1.0L/min
3. At 9A - 1.0 - 1.1 L/min

.... and finally at 10.5A - 11A the production was about 1.4 L - 1.5 L/ min.

During the testing the current keeps rising and improves the production. I am curious as to why the current is not (more) stable ?

The electrolyser was only slightly warm after the testing (I don't think it is significant at all). The voltage never dropped below 14.2 V (during the enire testing).

I would like see your outlook on this and basically see what you think about the current inconsistencly and everything else.

Thanks,

Davor

[Bob Boyce]

Very well done.

The current rises as the electrolyte temperature increases. This is quite normal and it will stabilize after operating for a certain period of time.

If you tried to run a 6 cell unit for an extended period of time, it would likely get so hot that it would boil the electrolyte. With 7 cells this should not happen due to each cells voltage point being so near to the bottom edge of the exothermic range. We have left 7 cell units operating for days at a time to test voltage/current/temperature stability. We only had to add water occasionally to replace what was consumed.

Welcome to higher efficiency DC electrolysis. With a little tweaking of electrolyte concentration, you may see a bit more improvement in efficiency. Changing over from NaOH to KOH should give about 15% performance improvement, but most experimenters feel that it's not worth the extra expense and risk.

Next step would be to add a controller to boost production even further, but I won't delve into that topic on a public forum.

Bob

[eco]

[Bob Boyce]

[eco]

[Bob Boyce]

[johnh]

[eco]

Hi,
if I use an inflating needle what would me the minimal flow of gas so that it doesn't come to an explosion in the bubbler?
Does the gas pressure have anything to do with it?

Thanx
Eco

[Bob Boyce]

[chemelec]

[johnh]

[eco]

[Chris]