Plate Area & amps (or watts) relationship??

[Roland Jacques]

Ive read a post, cant find it now. It suggested that there is a ideal surface area of plates to amps. Anymore amps would accelerate corrosion of SS.

Does anyone know that formula?

2nd part
I wanted to know if that plate "Area" included just one side of each electrode, and both sides of each neutral plates?

If each side of a plate is 12" of area and arranged +nnnnnn- would be 14 x 12 =168" of area.

3rd part
If i slag blast the plates for a 300% more surface area. Does this rule apply to the 12" or the larger 36" per plate area?

[Buster]

It's supposed to be 2-4 square inches per Amp, per side of each plate in a series.
So, in your example of 12 inch square plates in a +nnnnnn- configured cell, you only count one side of 1 plate, which is 12/2 to 12/4 =between 6 and 3 amps for the complete series.

I don't know exactly why this figure was arrived at, but I imagine that it's to do with efficiency/temperature/plate life etc.
It may not be a good recommendation if steam input is useful to the engine as some suggest, if you get my drift. It still needs some more investigation.

Not sure about the slag blasting. In theory it seems like it should increase the number of potential amps but in practice it probably would be adding to heat etc as it would still be the same amount of metal carrying the current???

[Roland Jacques]

That's strange that the number of plates dont factor into the equation somehow.

Also Id think the thicker the plates the more resistance equaling more heat. the thinner the less resistance.

The steam thing is a entirely different subject...

[Buster]

I can understand why the per plate figure is used, as the amps are the same moving through each of the plates no matter how many there are.

The thinner plates is an interesting point I never considered, and you're probably right about that being a factor. I imagine the equation mentioned was based on a particular plate thickness.
It's all just a guide, I suppose, and there's nothing like testing out what actually works best with what we have.

[Philldpapill]

Roland, the number of plates doesn't factor in because you have the same amount of amps passing through those surfaces as well. You need to look at it as "how many electrons per second are jumping on/off of this particular section of plate area".

If the plates were in parallel, then sure - you have more amp draw and more surface area, so the equation still holds.

[biggy boy]

What about plating?
It's claimed that plating the plates with say Nickel or titanium or Platinum,
Reduces the resistance of the plate!
But plating is just adding a layer on the surface of the plate!!
So Yes the new plate surface may have a lower Resistance, due to the plating.
But the current HAS to travel through each plate and on to the next, how is this going to help.
The current still has to travel through the Stainless steel portion of the plate!
I can't see how the plating lowers the resistance of the stainless, beneath the plating??
Current traveling across the plates surface OK I can see that, through it ??

I can see it would make it easier for the current flow to transition (transfer) from the electrolyte to the plate, due to the plating!
Maybe that is the point!!!


Glen

[Roland Jacques]

I think i partially understand this rule, but i really cant get my head around the why's.

I understand the amps going through all the plates at the same amount. But I guess its the role of the plates I'm not to sure about. One part that confuses me is the fact the amps are going through wires, bolts, & terminals with a relatively small surface area, but the area for the plates need to be many times greater.

1. I would think current density rule would have to be primarily concerned with what the electrolyte is. Or more accurately how conductive the electrolyte is. I would think that KOH at 5% would require more plate area than KOH @ 33%. Is this the case?

2. Does the current density rule only apply to the negative and positive electrodes. I cant see how this rule would apply to neutral plates.

In other words, if i used nano coated electrodes, i could push many times more amps through nano plates because they have many times more surface area. A 6x6 nano plate could handle 80 amps 14 volts no problem. (so I hear)
2.a. Couldn't we just use SS neutral plates with the Nano electrode?
2.b. And wouldn't thinner neutrals be better than thicker ones? less resistance...

[Philldpapill]

To be honest, plating plates is really hype. The IDEA is that it increases surface area... BUT that really isn't what's important. You don't really generate most of the heat at the plate boundry anyway. Most of the heat is generated by the resitance of the water itself.

Let's say you have a plate with 10" squared. If the roughness gives the total area 20" squared, you STILL only have 10" squared of water to conduct through... You may have a lower resistance at the water-plate interface, but the bulk resistance of the water/electrolyte is the same.

However, this is only theory(a pretty sound theory), so real world expirements would have to be done to verify it. I'm expecting MAYBE a 1-2% decrease in power loss........

[IM2L844]

Don't get current density (amps per cm squared) mixed up with power density (watts per cm cubed) the main reason for limiting current density is to limit the rate of plate deterioration which not only deteriorates your plates (obviously) but adds that material to the electrolyte causing all kinds of other problems. Of course the two are related in that it requires a certain minimum amount of potential (voltage) to achieve a particular minimum current density, but, as I think Phil was trying to point out, excess power density is a more reliable indicator of whether or not there will be a lot of heat produced, but it can be a little more difficult to calculate...now, I've lost track of the point I was trying to make. Oh well. Did that make any sense to anyone besides me?

[Roland Jacques]

To be honest, plating plates is really hype. The IDEA is that it increases surface area... BUT that really isn't what's important. You don't really generate most of the heat at the plate boundry anyway. Most of the heat is generated by the resitance of the water itself.

Let's say you have a plate with 10" squared. If the roughness gives the total area 20" squared, you STILL only have 10" squared of water to conduct through... You may have a lower resistance at the water-plate interface, but the bulk resistance of the water/electrolyte is the same.



So then doesn't this make the most important factor in determining Current density (or power density) the conductivity's of the electrolyte more than the plate area? So the more conductive your e-lyte the smaller the plate can be. right?


Don't get current density (amps per cm squared) mixed up with power density (watts per cm cubed) the main reason for limiting current density is to limit the rate of plate deterioration which not only deteriorates your plates (obviously) but adds that material to the electrolyte causing all kinds of other problems. ?

So would the rate of deterioration change if i slag blasted the electrodes tripling the surface area? And would thinner neutral plates be better than thicker ones.
Shouldn't they be looked at defferently, electrodes and neutral plates?

[Philldpapill]

That's exactly right, Roland. I have a feeling that this whole "plate area" concept was started by someone trying to sell another form of snake oil - trying to make a buck by suckering someone into buying their "special" plates.

Case and point: Smack's new cells which I saw in another thread. It boasts something like titanium sand blasted plates(or something), and they charge an arm and a leg. It's really just not that important.

In fact, in regards to the "increased surface area increases plate life" - the OPPOSITE is true. If you have more plate area, you have more area for them to corrode, RIGHT?

Like I said - Snake oil. Not much more.

[biggy boy]

Phil
Are you saying then, that plating the plates with Nickel, Titanium, Kryptonite... what have you.
Will NOT effect efficiency?
Or are you saying the cost of having the plates coated (plated) is not worth it, for the small gains you would get??

Glen

[IM2L844]

So the more conductive your e-lyte the smaller the plate can be. right?No. Decreasing the length and width of you plates increases resistance with the same relationship that a wire has ( R = pl/A) Where R= Resistance, p= resistivity of the material, l= the thickness of the plate and A= the length times the width of the plate




So would the rate of deterioration change if i slag blasted the electrodes tripling the surface area? And would thinner neutral plates be better than thicker ones.
Shouldn't they be looked at defferently, electrodes and neutral plates? I don't think so, but I'm not positive. You may increase the surface area, but you are not spreading out the current. Even though you have increased the surface area contained within a specific area, that same specific area will still contain the same amount of current as it did before, but if I were you, I would only be satisfied by researching it for myself through experimentation. If you can increase the surface area 10 fold, increase the amperage 10 fold, keep it there for a while and see what happens

Thinner plates would obey the formula above and have less resistance.

Not sure what you mean by Shouldn't electrodes and neutral plates be looked at differently? As far as what?

[redrat100]

Correct. Roughening up the plate surface does nothing for increasing plate area. Some people sand their plates diagonally in an attempt to decrease the surface tension of the bubbles to the plates. They have found that their bubbles tend to float away sooner giving them some measurable increase in HHO production than with smooth plate surfaces given the same power. I have tried both and found no measurable difference. Solvent cleaning and acid etching also does help production.

And, yes. Thinner plates do decrease cell resistance but you run the risk of the plates warping as they get hotter and shorting each other out. My old cell use .025 SS 316. My new cell will have .005 Titanium plates. If they do short I will add small gasket bumpers between them. (I bought Ti material about 5 months ago, long before Smack thought of it. Just haven't had the time to build it yet). Ti is just about as conductive as SS so no loss in efficiency.

[Roland Jacques]

Red rat 100,
I look forward to see your results with your thin titanium plates. I will tell you that it has been tried a few times before with standard thickness titanium plates with poor results. I think that there not as conductive as SS. (coated plate are a different animal)


As far as textured surface area allowing more production and higher amp draw, I'm not convinced one way or the other yet. But if you look at Alaska Larry's test results you have to think it does make a difference.

Nano plates, one side coated, 1 stack 6x6 +nnnnnn- 6 LPM, 60 amps, (approximate numbers)
Slag blasted 1 stack 6x6 +nnnnnn- 2.5LPM 28 amps
http://www.youtube.com/watch?v=h5-u3-SnYJk&feature=channel_page
You might want to look at some of his other videos very interesting stuff. (Cant wait to see his Urea results)

"Nickle Slag" blasting is gives VERY course texture, more than "non-skid" you cant compare the to sanding or even sand blasting. down side you have to use thick plates.

[Roland Jacques]

FWIW 1 hour interview with Larry on the Nano plates... linky
http://www.ustream.tv/recorded/1642004

[redrat100]

Red rat 100,
I look forward to see your results with your thin titanium plates...I think that there not as conductive as SS. (coated plate are a different animal)

As far as textured surface area allowing more production and higher amp draw, I'm not convinced one way or the other yet. But if you look at Alaska Larry's test results you have to think it does make a difference.

Thanks Roland- yup, I'm looking forward to results as well. Ti is not new, I know. I'm also building a cell using copper plates. Yes, I know they will corrode like crazy and will never last long enough to go in my car. But I just want to experiment with plates with different conductivity. Here is a link comparing the conductivity of different metals.
http://wisetool.com/designation/cond.htm
I know about Larry's nano plates but have not been following his results since he stopped posting here. But I do know that others have roughed up their plate surfaces, not for less current draw, but for less surface area for bubbles to stick to. But, I sure hope that he hits on a break through. We'll see.

[Philldpapill]

Guys, if you look at the resistance of the plate vs. the resistance of the elctrolyte, we are talking ORDERS OF MAGNITUDE difference. VERY little power is lost in the plates. Just a ballpark figure, I'd say maybe 1 or 2% is lost in the plates, while the other 98 or 99% is dissipated in the electrolyte solution. You just don't have THAT much voltage drop from the plates.........

[biggy boy]

Guys, if you look at the resistance of the plate vs. the resistance of the elctrolyte, we are talking ORDERS OF MAGNITUDE difference. VERY little power is lost in the plates. Just a ballpark figure, I'd say maybe 1 or 2% is lost in the plates, while the other 98 or 99% is dissipated in the electrolyte solution. You just don't have THAT much voltage drop from the plates.........

Then that would lead me to believe the size (surface area of the plate) is important. Bigger is better, up to a certain point!! to help over come the electrolyte's poor resistivity and aid it in transferring the current flow (electrons transfer).

[redrat100]

...VERY little power is lost in the plates... ...maybe 1 or 2% is lost in the plates... ...You just don't have THAT much voltage drop from the plates.........

Agreed. But, would you not agree that this technology is all about efficiency where ever we can get it? Advances in this technology will come in very small increments considering how long it has been around. If I can gain a percent or two in efficiency using a better material, I will take it.

[Philldpapill]

Yeah... But you gotta put things in perspective, too, RedRat. If a typical PWM us supplying 50A, at 12V, that is 600W of power being delivered. If we are wasting 1% to 2% of that 600W in the resistance of the plates, then that's like 6W to 12W of power.

One horsepower is 746W. If your car uses 20hp at crusing speed, that's about 15kW. A 12W waste of power isn't even going to make a 0.1% difference in your gas mileage...

However, 0.1% here, 0.2% there starts to add up when you have inefficiencies all over the place, so you are right, anyway! Just don't spend $2,000 on nano-coated plates to gain 0.1% MPG.

[redrat100]

Just don't spend $2,000 on nano-coated plates to gain 0.1% MPG.

No worries there! Good experiment but my piggy bank is not that big. Besides, at $3 per gallon it would take me about 20 years to break even.

[Roland Jacques]

Not sure what you mean by Shouldn't electrodes and neutral plates be looked at differently? As far as what?

I think i can explain my thinking on this. Mind you electricity is one of my week suites.

Neutral plates, just pass current form one cell to the next. So the thickness does not matter Right? Only the area (cross section) matters. Neutral plates take current from a relitivly large area and pass it on to another large area. So I look at a 6x6 SS neutral plate like i would a 6x6 solid SS wire transferring current from one cell to the next. So neutral plates wont have any problem with this.

The electrodes, on the other hand take current from a small area (a contact point) and has to disperse it out to the large area. So I would think that the thickness From that small point would matter for the electrodes.

This is why i think they need to be considered differently.

I hope this makes sense. Thanks for bearing with me.