The Black Box Experiment

[Stevo]

This is my experimentation thread and I would like to introduce:

"The Black Box"
http://img410.imageshack.us/img410/1790/hhobb1dj4.png (http://imageshack.us)

Real creative name, yeh I know... :o

(5 seconds)
http://img410.imageshack.us/img410/4868/hhobb2hj1.png (http://imageshack.us)

(15 seconds)
http://img209.imageshack.us/img209/1289/hhobb3fd8.png (http://imageshack.us)

Sorry for the teaser, more actual info is coming soon as I get it. Here are the basics though:

Plate Config:
+UUUUU- -UUUUU+

Grade SS: 316L (material and cuts by co2cutter)

Case Material: Lexan® Polycarbonate

Case Adhesive: IPS® #16 Weld-On

Case Sealant: Goop® brand Marine Adhesive

Electrolyte: Sodium Carbonate (not Bicarbonate)

Water: Distilled 1 Gallon

Ran this unit for 1 hour. Unit started at 3amps (85*F) and ended at 3amps (95*F).

[precaster1@msn.com]

Well, how many lpm?

[Stevo]

Well, how many lpm?

I'm still working on the top, so it will be completed this weekend hopefully and I will be able to get some lpm readings. My other option is to get a temp container to get this reading, which is what I might do just to see. I have a number in mind, but will wait to share it until I have proof.

[hydrotinkerer]

Did you wrap the cells all the way around with something? Looks like clear plates on the ends

[redneckgearhead34]

How many volts are you running?

Overall I really like this cell. Especially the see through window:D

[bigapple]

how well does that marine goop work? i use ultra black permatex silicone and its good but ive noticed a small leak at the bottom. i too have a polycarb box with silicone sealant across the bottom to assure no leaks. but since i have a small one, i want to get rid of it before it gets worse

[Stevo]

Did you wrap the cells all the way around with something? Looks like clear plates on the ends

Dangit, I knew I would forget something. Yeh the cell is encased in .22" thick acrylic on all sides except for the top and about 30% of the bottom. The green parts you see are pieces of PTFE tubing to block off the extra holes in the plates throughout and prevent voltage leaking. To ensure that the plate sides are well sealed, I use Goop® Marine Adhesive which is holding up exceptionally well since it is a silicone based adhesive and made to withstand Marine corrosion. Overall, I have no heat worries as my cell only reached approx 95*F after running for 1 hour.

Also, I am running (12 Volts / 6 cells) X 2.

[Stevo]

I did a little test today.

Start: 6.5 amps/12v, 2.51 bps. After 1 hour: 7 amps/12V, 2.75 bps.

One thing to note is that when I decided to drop the electrolyte level below the top of the cells, the bubbles per second went up from 1.6 to 2.51 and amps dropped from 7 to 6.5.

Update 9/27/08 20:30
==============================

Did a LPM test tonight and got these results:

250ml | 60 sec | 7 amps | 12 volts = 2.97 mmw

1000ml | 60 sec | 18 amps | 13.4 volts = 4.41 mmw


Back to the drawing board for me. I like Boyntonstu's Amoeba Cell. Going for the dry cell trend.

[Stevo]

It took forever, but I wanted to do it right and I did.

http://img511.imageshack.us/img511/7183/cell5bd7.jpg


375ml - 68 seconds - 4amps @ 13.1V = 5.91 mmw
375ml - 35 seconds - 6.5amps @ 14.1V = 7.01 mmw

So, yeh it's now a completely dry black box. 12 cells as before, but some changes in materials.

Gaskets are made from 1/16" 80A neoprene rubber.
Clear plastic pressure plates are Lexan polycarbonate
Pressure bolts are zinc plated steel
Pressure bolt covers are clear vinyl tubing
Wing nuts, thru bolts and washers are Brass
Terminal wiring is 14 ga solid copper
Solder weld is JB Weld

Electrolyte is KOH. :D
Water is still distilled.

[Painless]

Nice numbers Stevo! Excellent job!

Where did you get the neoprene rubber from?

Did you weld the electrical wires to the plates? I'm not so familiar with welding techniques, what's a JB Weld exactly?

I would be interested to see how your MMW changes (if at all) once you work up to the 1 LPM plus mark.

Russ.

[Stevo]

Thanks! I purchased the neoprene sheet from http://www.mcmaster.com. I am also very curious to see if the overall cell efficiency changes as I approach the 1 lpm mark. I will be doing a test today trying for 1 lpm to see what the results are. Oh yeh and JB Weld is not actual "welding" per say but more of a higher heat epoxy (400-500*F) that even has insulating properties besides holding very steady. It's a two-part, even mix epoxy that dries gray and can be found almost anywhere. http://jbweld.net/

Stephen

[Stevo]

More test results:

375ml - 1:17 5.7a @ 12.48v = 4.11mmw (2.08v/cell) Hooked to battery charger
375ml - 0:37 6.34a @ 13.9v = 6.90mmw (2.31v/cell) Hooked to car battery with car running.

Seems like the "sweet spot" for this cell is 2.3v/cell and higher. I also think my battery charger is about to kick the bucket. :(

[Stevo]

Adding a pic of the PWM inside the box I will use. Box will be sprayed black except for LED area and will remain open in the back to ensure airflow and ease of usability. Front will be sealed with another piece of poly. Image attached.

I am also incorporating this ammeter guage:

30 amp ammeter (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMEWNX%3AIT&viewitem=&item=280273589238)

Overall, the PWM works great from my initial tests and now I am that much further to installation. My cell efficiency is stuck right at around 7 mmw as of now.

[Stevo]

I changed a few things out. First, I made the connections more solid by removing the JB Weld and solid copper wire. Then I made new gaskets and removed 2 neutral plates. Its a 4n2 config now.

10.38 V (Yes, less than 12)
7.2 amps
300 ml
30 seconds

= 8.70 mmw

That's the best I could do with my little battery charger, which is not bad at all. Then I did a test with the unit hooked up to my car:

12.7 V
15 amps
375 ml
20 seconds

= 5.91 mmw

[H2OPWR]

how well does that marine goop work? i use ultra black permatex silicone and its good but ive noticed a small leak at the bottom. i too have a polycarb box with silicone sealant across the bottom to assure no leaks. but since i have a small one, i want to get rid of it before it gets worse

Marine Goop is the bomb. Everything else is in a contest for second place. The only draw back is curing time. At least 24 hours.

[Painless]

Stevo,

How is your dry cell doing? Did you ever push it over 1 LPM?

[Stevo]

Painless,

Yeh I got it to 1.12 lpm yesterday (5.9 mmw), but ended up finding a gas leak in the new reservoir that I purchased. The reservoir is great as a whole but will be getting a new 1/8 neoprene shore 50 OO gasket to replace the much firmer and cheaper neoprene gasket which wasn't sealing so well. I bet that after that I will be seeing around 1.3-1.5 lpm, which is just what I have been shooting for with my little 1.8L engine. I am also going to be replacing the polycarbonate end plates with 1/2" thick UHMW in black. Right now the setup is (11) 2.75" x 4.5" plate.

I sent my blueprints off to scm (http://www.hhoforums.com/member.php?u=2129) today to get a quote for (26) 4x4 custom plates for my next generator, which should easily push 3+ LPM. I'm trying to keep it as small and cube like as possible.

[Painless]

Looking good Stevo,

I'd love to be able to build a dry cell out of some proper stainless steel sheets. Your MMW's are awesome. You should check out the dry cell work by jdcmusicman and david7900 on youtube. These guys are both doing great work. Jdc has created a holeless dry cell!

My 25 plate cell is at 2.33 LPM at the moment, around 5.4 MMW. I'm working on a small 7 plate version right now.

I picked up one of the reservoir tanks you recomended yesterday. I had one of these before but the seal went on the bottom. I just need to find a way of sealing the cap too. I was thinking of trimming off the lip and using a PVC pipe pressure test seal cap from Lowes. Have you seen those? They are a piece of expanding rubber between two pieces of plastic. You tighten the wing nut on top and the rubber is forced out, completing the seal. Might work pretty good.

Russ.

[Farmercal]

Stevo, how did you mount the barbed hose end to that first plate? It seems like there isn't much clearance between the plates to put anything to hold it on. Did you just goop it?

[BoyntonStu]

Looking good Stevo,

I'd love to be able to build a dry cell out of some proper stainless steel sheets. Your MMW's are awesome. You should check out the dry cell work by jdcmusicman and david7900 on youtube. These guys are both doing great work. Jdc has created a holeless dry cell!

My 25 plate cell is at 2.33 LPM at the moment, around 5.4 MMW. I'm working on a small 7 plate version right now.

I picked up one of the reservoir tanks you recomended yesterday. I had one of these before but the seal went on the bottom. I just need to find a way of sealing the cap too. I was thinking of trimming off the lip and using a PVC pipe pressure test seal cap from Lowes. Have you seen those? They are a piece of expanding rubber between two pieces of plastic. You tighten the wing nut on top and the rubber is forced out, completing the seal. Might work pretty good.

Russ.


Russ et al,

I have been thinking about reservoirs and their bottom connections.

Why not make all tubing connections out the top and siphon?

BoyntonStu

[Painless]

You would need to prime the cell for this to work I think.
I know, from experience, that having the return hose even slightly under the electrolyte will result in the fluid ceasing to flow.

What are your thoughts of benefits to this method, Stu?

[BoyntonStu]

You would need to prime the cell for this to work I think.
I know, from experience, that having the return hose even slightly under the electrolyte will result in the fluid ceasing to flow.

What are your thoughts of benefits to this method, Stu?

There are 3 tubes going into the reservoir cover:

1> Gas output to bubbler, etc.

2> Input gas from dry cell - inside tube can terminate above or below the electrolyte level.

3> Electrolyte output tube terminates at bottom of reservoir/

Prime by blowing into the output tube while blocking off the gas input tube barb but allowing gas output tube from cell to pass fluid into a container later to be poured back into reservoir.

Are you saying that having the gas under the electrolyte just passes hydroxy or that it stops production?

I have tested various height differentials and it appear that it must be fine tuned for best MMW. If back pressure is too small, there will be pumping and air pockets will reduce current.

BoyntonStu

[Painless]

I definitely think its worth experimenting with, the only caveat is that too much back pressure on the return will cause the cell to empty as gas will push electrolyte up the fill tube.

[BoyntonStu]

I definitely think its worth experimenting with, the only caveat is that too much back pressure on the return will cause the cell to empty as gas will push electrolyte up the fill tube.

Back pressure will be exactly the same for a tube coming out the top with its entry dipped into the bottom of the reservoir as a tube coming straight out the bottom.

The gas coming from the cell to the the top of the reservoir will also be at the same pressure as in any bottom feed reservoir.

BoyntonStu

[Stevo]

I ended up having the remove the polycarbonate all together as I wanted to see what would happen when elyte and poly are in the same areas. Essentially, when you throw in electrolysis, things are sped up very rapidly. Anyway, I can use the poly for other things/projects.

http://farm4.static.flickr.com/3185/2986838602_bb5a6f1f37_o.jpg

Now, it's UHMW. 1/2" thick. Awesome material. I highly recommend.

http://farm4.static.flickr.com/3192/2985982685_7d48b33483.jpg
http://farm4.static.flickr.com/3033/2985982637_20306813cc.jpg
http://farm4.static.flickr.com/3189/2986838462_cd8ff211ae.jpg

[Stevo]

http://farm4.static.flickr.com/3179/2985982545_6928041beb.jpg
http://farm4.static.flickr.com/3008/2985982505_bd6d10af76.jpg

[Stevo]

I picked up one of the reservoir tanks you recommended yesterday. I had one of these before but the seal went on the bottom. I just need to find a way of sealing the cap too. I was thinking of trimming off the lip and using a PVC pipe pressure test seal cap from Lowes. Have you seen those? They are a piece of expanding rubber between two pieces of plastic. You tighten the wing nut on top and the rubber is forced out, completing the seal. Might work pretty good.

Russ.

I really like my reservoir from AutoZone. I replaced the cheap seal with 1/8" thick shore 50 OO neoprene foam material from mcmaster.com. Sounds like the PVC pipe pressure test seal cap might work too. I really like the reservoir because you don't have to go drilling any new pipe fittings. They are all right there ready to go. Works great. I am also using heavy duty all neoprene 5/16" black hose now as this type of hose creates a much tighter seal around the inlets and outlets that doesn't allow gases to escape. Basically, if the pressure were to get too high, the cap would just pop off.