Cell Production, Important Data
I made an accidental discovery today, and it was so fundamental to the proper production of an HHO cell that I had to get into an article and get it posted. It may shed light on why some HHO systems may have failed for mysterious reasons, and may well debug systems that aren't working up to their full potential. It came about while I was working at my test bench, trying to test a new PWM (HHO cell power supply) that I am developing. Let me tell you the story as it unfolded as it will help you understand this fundamental discovery about HHO cell production.
A Funny Thing Happened on the Test Bench Today...
The bench power supply that is feeding into my PWM was set for 27.7 volts, and at that voltage is capable of providing over 100 amps. The PWM was one of our 100A Commercial PWMs, and the cell was one of our Quad Stack 12" x 12" Commercial cells. This is a 25 plate cell, which in the past I've run up to about 110 amps and 15 LPM as measured on my Alicat Scientific HHO flow meter. Because I was running a nominal 24 volt system, the cell was configured as 2 stacks with 11 neutral plates in each stack, and 3 cables between the cell and the PWM. This is a very standard setup and is equivalent to a 12 volt system using 5 neutral plates.
Initially I had set the amperage at 20 amps, which started out just fine. The PWM was running at about 50%, and the cell was producing about 2.5 LPM (Liter Per Minute). The reservoir was nearly empty, but because the cell and connecting hoses were full of electrolyte, it didn't matter. Everything worked normally. However, after only a minute or two, I could hear the power supply change it's pitch slightly which alerted me to the fact that it was starting to produce less amperage. Even though the PWM was now running at 100%, the cell was unable to sustain 20 amps anymore. For my purposes, I didn't need any set amount of amps, so I reduced the PWM to 10 Amps. The PWM was then able to control the amperage again.
However, after another couple of minutes, I heard the power supply change pitch again, and sure enough, the PWM was dropping below 10 amps. This continued to get worse and worse until the amperage was under 3 amps. The 3 quart reservoir, which started out nearly empty, was now nearly full. The cell was practically empty! I checked for things like blockages in the hoses and such, and found no possible reason for this to have occurred. I couldn't figure out why this system was behaving this way.
I always keep defoamer in my test bench electrolyte, but I noticed a very small amount of foam in the reservoir. I didn't think it was possible that lack of defoamer could cause this issue, but just in case, I added an additional ounce of defoamer. The system was still running at 3 amps or so. At first it was such a tiny change that I almost didn't notice it. But the level of electrolyte dropped slightly. After a minute of two, the electrolyte level in the reservoir was dropping faster and faster. Pretty soon it was almost back to its original level, nearly at the bottom of the reservoir, and I was running 10 amps again.
I had originally intended to run the system at 20 amps, so I re-set the PWM for 20 amps. When the system started up again, the reservoir again started refilling with water. In just a few minutes, the reservoir was almost full again! There was no foam at all showing, but because it had worked before, I put in another two ounces of defoamer into the electrolyte. I wanted to be sure that any foam inside the cell was fully handled. Again, very slowly at first, and then faster and faster, the electrolyte lever dropped in the reservoir, until the system was again able to run at 20 amps. Further, the level continued to drop until it reached it's starting level, which was very near the bottom of the reservoir. When it was at the bottom, the system was running 20 amps, and was under complete control by the PWM. The PWM was running at 40% power, and the system was producing about 2.5 LPM of HHO as measured on our Alicat Scientific flow meter.
I let that system run for about 8 straight hours, and nothing changed after that. The duty percent stayed stable, and the amps and HHO flow stayed the same all day, every time I checked it.
What Does This Mean?
This experience was a real eye opener for me. I had never seen this phenomena before. I've heard reports from customers in the field, that in hindsight was clearly caused by this same problem. But never on our systems, either on the test bench or in our vehicles. We've been using defoamer as a standard electrolyte additive for years. We include it as a standard part of our kits and so our kit customers don't usually have this problem either. However, it is clear that we didn't understand just how important the defoamer was. And it may well be that people are having trouble getting their systems to work because of this same phenomena.
It appears that even when enough defoamer is in the system so that there is no visible foam in the reservoir, it may not be enough. Inside the cell, there may be enough foam forming so that the electrolyte cannot refill the cell unless a pump is used to force the electrolyte back in. The result will be that the reservoir level will go up and may even overflow into the dryer, or worse, if you have no dryer, into the engine. And the amps will go down and be difficult or impossible to sustain the desired amount of HHO production. Adding more electrolyte will not help in this case as the added electrolyte will not solve the actual problem (foaming) and in fact will make it worse. Any time you are unable to raise the amps by adding more electrolyte, this problem should be suspected.
The solution for this issue is more defoamer. Apparently, the additional defoamer will break up the bubbles that from inside the cell, between the plates, and make it hard for the electrolyte to return to the cell. It takes a little time for the new electrolyte to get in the cell and start to break up the existing bubbles, but after it starts to work, the electrolyte level in the reservoir will drop rapidly until the cell is full again and working normally. It should be noted that we have never seen any drop in HHO production due to the use of defoamer. It seems to have zero effect, although I haven't tried really high concentrations. But we have used up to about 1 ounce of defoamer to 1 quart of electrolyte with no effect whatsoever.
Where Can I Get Some?
We use this brand, which is available from our local hardware store: Spa Time Antifoam. The active ingredient is called polydimethylsiloxane, which also goes by the named PDMS, and dimethicone. It may be described as "an oil-free silicone compound" or "silicone emulsion". Many companies don't want you to know exactly what they use so you'll use their brand instead of someone else's cheaper brand of the same thing. Other brands may need more or less volume to achieve the same effect. Look on the label for the key words listed above and it will work. It will always be an emulsion so it is a milky white liquid - never dry. You can get if from your local hardware or pool/spa supplies store. You can get the same product we use online from www.poolgeek.com.
If you have a mysterious problem where no matter how much electrolyte you add, you can't get the amps to come up, then this is the solution to the problem. To test for this issue, start with a cold system. You can temporarily raise the amps on your constant current PWM, if you have one (which you should for optimum system performance). Notice the electrolyte level in your reservoir, and turn on the system. If your electrolyte level rises significantly, then you likely are having this issue. Add an ounce of defoamer, and let it keep running for about 5 minutes. The electrolyte level should drop back down to the same level as when you first started the system. This indicates that the cell is full of electrolyte, and not air bubbles, and the cell will run at optimum.
You may now find that you have added too much electrolyte in order to solve the amps problem earlier. The cell may run "hot", by which I mean, it may run at too many amps if you have no PWM, or that the PWM is now running at too low of a percentage (below 25%). In this case, you should drain the system and start over. But now that you are able to add the defoamer, you will need much less electrolyte to maintain the desired amperage.
I hope this information helps you find success with your HHO system.