Bench Tested a new cell (fun)

[cabrera]

So today I tested a new 21 Plate Dry Cell and had so much fun!!! :icon_lol:
I made a nice 28% KOH mix in a glass tea jar (mixing it it got nice & warm) poured it into the reservoir connected the 12 volt battery to the PWM an the first problem I encountered was the pump. The junky hose clamps that I bought at harbor freight leak. I got sprayed right in the face. (I was of course wearing a full face shield & caustic gloves) So then I had to swap out the clamps...what a mess. I like the way KOH leaves a slippery residue when you wipe it up.

Ok so I replace the clamps & fire it up again. I noticed 2 things:

1. The reservoir swells a bit after a few minutes
2. When I shut off the setup, the reservoir collapses a bit.
3. According to my gas meter I am only producing 1/2 liter per minute.

Is the swell normal?

Would tapping in a one way valve to allow the reservoir to suck after I shut it down be a good idea?
I am using an oxygen in-line meter

has anyone use this to measure output? I'm not sure if it is accurate.
I have a lot of bubbles at the end hose ( I will get a video soon).
Here's the setup:
My reservoir feeds the pump which feeds the cell which goes back to the reservoir then the gas goes to the scrubber with 10% vinegar solution & a brass stone filter, then to a flame arrestor filled with bronze wool.
I get absolutely no vapor and good amount of bubbles. Is there a better way of measuring output?
I suppose I will get better output once it is hooked up to the car. Right now the one battery is powering the cell & the pump.
I read 9 volts and 18 amps at my gauges.

[Humanoid_1]

Hiya,

I'd be inclined to use a weaker solution - 28% is very strong and simply means there is less water to be converted to HHO - is like reducing the surface area of your cell, potentially reducing its efficiency.

I'd add only enough KOH to allow the desired current draw of your cell – maybe a little over it, but not too much.

That whole expanding and shrinking reservoir thing sounds a little odd... maybe some more info about the res itself would help...?

The inline oxygen flow meter will read a little low on your production as the Hydrogen component of the gas is lighter/finer than O2 and so as it passes through the flow meter has a lesser effect on it - so you should be getting a bit more than 1/2 a litre a min

The classic fill a bottle test works pretty well for accuracy (as long as not producing steam) then compare this result to your flow meter so you can know what its reading really equates to.

Good luck!

[astrocady]

I have a flow meter that looks just like the picture you posted and so far I think it is junk. The ball bounces up and down so much it is hard to tell what the reading is. I use the bottle test method, but do stick the meter in everyonce in a while just to see how it reads.

I will say this, as I have increased the production of my cells, I have noticed that the guage works better. I suspect it may work fairly well upwards of 3 liters or so. I am going to observe a dyno test on a large HHO system next week, and I'll try to remember to take that thing with me and see how it works with higher producing cells.

[Roland Jacques]

I have a flow meter that looks just like the picture you posted and so far I think it is junk. The ball bounces up and down so much it is hard to tell what the reading is. I use the bottle test method, but do stick the meter in everyonce in a while just to see how it reads.

I will say this, as I have increased the production of my cells, I have noticed that the guage works better. I suspect it may work fairly well upwards of 3 liters or so. I am going to observe a dyno test on a large HHO system next week, and I'll try to remember to take that thing with me and see how it works with higher producing cells.

If you create backpressure down steam of those type flow meters it will minimize the bounce. Just put a needle Valve before it and close it until the bounce stops.
The air ones are off by about 30-35% on the low side with HHO. They are OK for reference but IMO not good for accuracy.

[cabrera]

The inline oxygen flow meter will read a little low on your production as the Hydrogen component of the gas is lighter/finer than O2 and so as it passes through the flow meter has a lesser effect on it - so you should be getting a bit more than 1/2 a litre a min

I have a flow meter that looks just like the picture you posted and so far I think it is junk. The ball bounces up and down so much it is hard to tell what the reading is. I use the bottle test method, but do stick the meter in everyonce in a while just to see how it reads.

My H.S. aged son explained exactly what you both are saying. Why is the meter is reading so low?
Hydrogen has an atomic weight of 2,01594 g.mol
Oxygen has an atomic weight 15.999 g.mol.
Basically Oxygen is 8 times heavier than Hydrogen so the meter is going to be WAY off.
Who thought I would need to remember HS chemestry & that damn periodic table more than 30 years after I graduated!!!

Time to make a bottle!

[cabrera]

If you create backpressure down steam of those type flow meters it will minimize the bounce. Just put a needle Valve before it and close it until the bounce stops.
The air ones are off by about 30-35% on the low side with HHO. They are OK for reference but IMO not good for accuracy.

No mine didn't bounce, actually it was quite steady.
I did make one mistake. I hooked up the hoses to the cell reversed so my pump was forcing the KOH in reverse. I realized that when I stoped the pump & the liquid flow reversed!