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maztra
12-15-2009, 02:25 PM
My name is Bart and i'm from the Netherlands. Since a few months i'm into the hydrogen. Here are my findings so far.

Here is my third attempt. It's a wet series cel with 6 plates. (i intended to do 7 plates, but i forgot to put a 7th plate in...)

http://i3.photobucket.com/albums/y96/matramurena/IMG_4744-640.jpg

This is submerged completely in water and soda. To block current leakage, i closed the sides and bottom with some kind of resin cement. Testing this cel showed very little bubbles from within the cells. So i increased the amount of soda. Still very little bubbles within the cells, but i was getting more bubbles from the outside of both outher plates. It seemed like most the current was traveling around the cel???.
Then i coated the outher survices with polyester resin. But when i was testing this, the resin was coming loose. It seemed like hydrogen was still produced under the coating, and working the coating loose.
I needed better coating.


Here is my third attempt. It's a wet series cel with 7 plates. completely submerged in water and NaoH.

http://i3.photobucket.com/albums/y96/matramurena/IMG_4747-640.jpg

http://i3.photobucket.com/albums/y96/matramurena/IMG_4746-640.jpg

To prevent current leakage, i did some clever things. (disclaimer: personal opinion). I got some poly-urethane resin. I made two trays to close the sides. I poured some resin in a tray, put 7 plates upright in it, and let it set. Same for the other side.

To prevent current leakage around the tops and bottoms of the plates, i made a bath with about 1/2 inch of resin. Then i dipped the top and bottom in the resin. That way top and bottom 1/2 inch is coated in resin. So if the current wants to leave a cell, it has to travel through 1/2 inch water before it is beyond the plates.
The outsides of the outher plates are coated in resin. And i made two stainless strips for power supply to the cell. These strips are also coated.

Testing showed more bubbles at the exposed nuts of the strips, than in the cells. I solved that by covering the nuts in silicon sealant. Then i noticed that the resin was coming loose from the outher plates......:(

My conclusion: current leakage is very bad for the efficiency of a series cell, and it is very very hard to prevent current leakage.


Then i learned about dry cells. It seems to be an ideal design in terms of current leakage, but there are holes in the plates. So there's the leakage again.

maztra
12-15-2009, 02:27 PM
Here's my fifth attempt. It's a (very) dry cell 6 plates. I choosed to do 6 plates instead of 7, because commercial dry-cells have 11 plates, which is 2x 5 cells.

The difference with a normal dry cell is, that there are no holes in my plates. Instead there are hoses. Per cel there is a hose at the bottom to supply water + NaoH, and at the top a hose to take water + hydrogen.

http://i3.photobucket.com/albums/y96/matramurena/IMG_4799-640.jpg

http://i3.photobucket.com/albums/y96/matramurena/IMG_4800-640.jpg

I made a case which is in all directions 3mm bigger than the plates. A plate got silicon sealant all around, put it in the case, and stick two hoses through the case. Then the next plate on top.

Then i poured poly-urethane resin in the case. The cell is completely submerged in resin.
Now there is absolutely no way for current leakage!

A little water pump is pumping water from a container to the 5 bottom hoses. The 5 top hoses are fitted to the container.

http://i3.photobucket.com/albums/y96/matramurena/IMG_4821-640.jpg

http://i3.photobucket.com/albums/y96/matramurena/IMG_4819-640.jpg

Tests are looking very promising. Loads of bubbles.

Some numbers:
5 cells in serie
4mm gap (because the hose is 4mm)
exposed area of each plate is about 2,5 inch x 5,5 inch
stainless 304, sanded in cross pattern
10% NaoH
7A
0,35 LPM.

Well, that's it so far.
Next cell will be about the same, but much bigger. It will have 13 plates (2x6 cells), 6x6 inch plates, gap 3mm, and 3mm hose. Think i will do 4 hoses at the bottom, and 7 hoses at the top. The hoses will be about 1 inch long. At the top and bottom will be a collecting area where the hoses will end. A pump will be included in the design.
And it's time to get me a pwm.....

H2OPWR
12-15-2009, 05:11 PM
Here's my fifth attempt. It's a (very) dry cell 6 plates. I choosed to do 6 plates instead of 7, because commercial dry-cells have 11 plates, which is 2x 5 cells.

The difference with a normal dry cell is, that there are no holes in my plates. Instead there are hoses. Per cel there is a hose at the bottom to supply water + NaoH, and at the top a hose to take water + hydrogen.

I made a case which is in all directions 3mm bigger than the plates. A plate got silicon sealant all around, put it in the case, and stick two hoses through the case. Then the next plate on top.

Then i poured poly-urethane resin in the case. The cell is completely submerged in resin.
Now there is absolutely no way for current leakage!

A little water pump is pumping water from a container to the 5 bottom hoses. The 5 top hoses are fitted to the container.

Tests are looking very promising. Loads of bubbles.

Some numbers:
5 cells in serie
4mm gap (because the hose is 4mm)
exposed area of each plate is about 2,5 inch x 5,5 inch
stainless 304, sanded in cross pattern
10% NaoH
7A
0,35 LPM.

Well, that's it so far.
Next cell will be about the same, but much bigger. It will have 13 plates (2x6 cells), 6x6 inch plates, gap 3mm, and 3mm hose. Think i will do 4 hoses at the bottom, and 7 hoses at the top. The hoses will be about 1 inch long. At the top and bottom will be a collecting area where the hoses will end. A pump will be included in the design.
And it's time to get me a pwm.....

Nice Start, I love the creativity and quest for more effeciency that you have shown. Just some friendly experienced advice. You need to find another way to seal the plates other than resin or glue of any type. I have tried over and over. Nearly every type of glue or epoxy imaginable. Inside your cell under power the environment is very harsh. From what I have seen all types of glue will fail. The best I have found is Marine Goop. It still fails but much slower. Good Luck.

Larry

maztra
12-15-2009, 11:42 PM
The cell is completely surrounded by resis. It doesn't matter if the resin comes loose from the plates, because the cell remains sealed in the resin.

H2OPWR
12-15-2009, 11:59 PM
The cell is completely surrounded by resis. It doesn't matter if the resin comes loose from the plates, because the cell remains sealed in the resin.

I hope you can make it work but I have found that the glue will turn to mush with some time and heat. The current will start leaking around the plates and the cell will fill with goo. I hope you have better luck than I have had. It would certainly make a build much simpler.

Larry

maztra
12-19-2009, 03:47 AM
What do you guys think of the the production of 0,35 LPM? Is it good or poor considering the size?



6 plates +nnn-
4mm gap
exposed area of each plate is about 2,5 inch x 5,5 inch
stainless 304, sanded in cross pattern
10% NaoH
7A no PWM


http://i3.photobucket.com/albums/y96/matramurena/th_MVI_4818.jpg (http://s3.photobucket.com/albums/y96/matramurena/?action=view&current=MVI_4818.flv)

maztra
12-25-2009, 06:45 AM
Started to make a new cell. This will be the ultimate design. It's a 13 plate 6x6 inch, -nnnnn+nnnnn- dry cell, with no current leakage.
I came across a very interesting matarial. It is a plate, 3mm thick, and hollow with channels. This is perfect to isolate the cells.

http://i3.photobucket.com/albums/y96/matramurena/IMG_4875-640.jpg

Have to make a case, weld some struts for power supply, and embed it in resin.