Hello all,
Sorry Ive been out of town taking care of a family emergency. Back now and ramping back up.
My final design came after about 10 prototypes mainly working out the leak, corrosion, and safety issues. I also experimented with different electrode material as well. I also build Hydrogen fuel cells and HHO cutting rigs, using stainless electrodes. Ill post photos of my latest unit if your interested. Im in the process of patenting the electrode design. You would be surprised how much I leveraged from my HHO cell designs.
Anyway back to the topic:
The unit you built reminds me of a past unit I built. Your design will work, but there are problems you will eventually run into.
1. If you look at the photo of my top anode, you will see it is totally sealed on the sides with RTV. The connection to the carbon is made with a stainless rod that runs down into the carbon disk through the top PCV cap.
The point of contact is where you will run into problems. Any metal/wire at the point of contact on the carbon will corrode quickly and eventually create an open if it is not sealed from the fumes.
The carbon is sealed at the sides and the column is filled up to and past the side carbon seal. At no point on the outside of the PVC cap can the carbon break the surface of the acid. This is very important. You want to keep the chlorine under the top surface of the acid. Keeping the carbon submerged will produce chlorine up to where you have it sealed off with RTV, therefor only producing chlorine up to that point, keeping it contained under the top surface.
If you just stick the anode into the solution you will allow the reaction to take place at the surface of the acid allowing corrosive fumes to escape. You will corrode everything around you thats metal, including your air conditioning vents. If your in a barn or shed, things will start falling off the walls due to the nail corroding through. Trust me on this one, Im still dealing with damage to my air vents.
2. Your design using the carbon as the entire bottom plate was the first design I tried. As you found out the carbon is porous and the acid will eventually find its way through. If you want to continue that design you may want to grab some paraffin wax at your local hobby shop. I used it for a while to quickly patch leaks. It works as long as your temp doesn't melt it.
Wax was safe to use due to it wont get dissolved into your solution.
Always put your unit in a larger container. This will allow you to contain leaks that may occur when your not around.
3. The carbon disks Im using are about 1" thick and will last about 4 months running 24/7.
The anode in my photo is actually 2 stacked on top of each other.
4. Using PVC as the reactor container, will eventually get brittle. Im finding the best is still glass, as if flexes with the heat. RTV makes an excellent seal when you use glass and you'll run into less problems.
5. You must use RTV or curable silicone. Epoxy, glue, liquid weld, etc. will be devolved, or will eventually leak.
6. I even tried running a coted wire designed to be submerged in solvents (its used primarily in the oil and gas industry) but the solution got into it at the point of contact to the cathode. IF this happens the current WILL NOT continue through the cathode. It will usually cause an open, and is a real pain to replace mid reaction. Do yourself a favor and buy a $10 glass drill bit and a glass vase/large pickle jar/glass 5gal water bottle, and slowly drill the small hole in the side/bottom for a wire to the carbon.
The best way is to put a 1/2" of rtv in the bottom of your container.
Let it cure.
Then place your carbon flat on top of the cured rtv.
Fill the remaining space around the carbon disk.
Let it cure.
After everything is cured, THEN drill the small hole in the side of the glass passing through the RTV, and straight into the disk (I go about 1" in)
Slide a wire/piece of wire hanger into the drilled hole (making sure to make a good connection to the disk)
Turn the container on the side and seal up the connection with some more RTV.
Your then good to go.
I will be selling the carbon disks on my website. I will have them posted this week. If I have the permission from this sites moderator I will post the URL.
I will be selling the 4"x1" disks shown, as well as larger 12"x1" ones.
Ill also post more detailed photos of my rigs if your interested. If you want particular photos just let me know.
