What wrong with my reactor :-(

[nst6563]

I've seen numerous times that the input holes should be alternating. 1st on the left, next on the right, then left again, and so forth.

I'm unable to do that with the set of plates I have so they're all in line. If you have a flow issue that may be part of it.

For your brown water - it sounds like either impurities in the distilled water or possibly the plates weren't passivated correctly/enough/contaminants in the passivation. With 316L I wouldn't think there would be much discoloration at all - especially low amps.

First thing I think you should do is check if the flow problem really is the problem. Then Re-mix a fresh batch of electrolyte and re-run Try to keep at the same amperage as before. See if the brown water goes away. Get some Neodymium magnets (they're like $2 at Harbor Freight) and put them on the input line to the reactor - this will tell you if you have magnetic (iron) contaminants leaching from your ss which could be causing your discoloration.

[Quebecker]

Hi,

I disassembled my reactor ....
I think my problem is the glue that I used as insulation ???

Here a picture of one plate


other side



close up view


Here is a picture of my endplate vs a regular plate.You can see that the input hole of the endplate does not correspond with those plates

[Quebecker]

For now, I just finished cleaning the plates , tomorrow I will do the passivation and assembly of the reactor



Do you think I could install the plates alternately so that the input hole is once again on the right, once left. And so in order to have staggered input hole ?

Like this ?

[myoldyourgold]

Do you think I could install the plates alternately so that the input hole is once again on the right, once left. And so in order to have staggered input hole ?

Yes that will help. I would also suggest you insulate the spot opposite the hole.

How are you measuring your electrolyte concentration?

[nst6563]

I think the glue you used is part of the issue. Weldon 16 is what I've seen used the most - and for good reason. Here is a photo of one of my plates after I gave it a good hard run in one of the reactors I had assembled after the weldon16.

The area sealed by the weldon looks virtually un-touched and as if it were never used.

What did you clean the plates with? You may not need to re-passivate then. Simply expose them to O2 for a while and then re-assemble.
Passivating is the process of making the SS as corrosion resistant as it can be. The citric acid bath (or nitric if that's what you chose to use) removes surface contaminants and removes surface and near surface iron leaving the more corrosion resistant metals at and near the surface. Once it's removed from the passivation bath and rinsed completely with distilled water the oxidation begins. The oxidation is the protective layer on the ss that gives it it's stainless qualities. The more uniform this layer is the better protection and the same with thickness. Do not stack them after passivation, hang them. Don't hang them near other metals as this could be a cause of contamination.
Once the ss has been passivated there shouldn't be a need to re-passivate unless the surface has been etched in some way.

I've taken Carter's advice of wiping down everything with acetone during assembly. Endplates, gaskets, plates, the whole 9 yards. I have had better success overall and less leaks as a result.

[Quebecker]

Yes that will help. I would also suggest you insulate the spot opposite the hole.

How are you measuring your electrolyte concentration?

Tomorow, I will make a new electrolyte

500 mg NaOH + 2 liters (2000ml) distilled water
500 / 2500 * 100 = 20%



What is the purpose of the insulation ?

[myoldyourgold]

500 mg NaOH + 2 liters (2000ml) distilled water
500 / 2500 * 100 = 20%

I think you meant:

400/2000 * 100 = 20% 1 liter of water 1000 Grams will require 200 Grams NaOH for a 20% solution. Specific gravity of 1.2191 at 20º C.

I use a hydrometer and only use 10% to 12% which is not more than a specific gravity of 1.1309 at 20º C

I hope I got that right some times I forget my metric numbers along with a lot of other things. LOL

[nst6563]

What is the purpose of the insulation ?

The insulation will prevent current leakage around the edges of the holes and thus cause the current to pass through the rest of the plate area (which is what we want).

[D.O.G]

I think you meant:

400/2000 * 100 = 20% 1 liter of water 1000 Grams will require 200 Grams NaOH for a 20% solution. Specific gravity of 1.2191 at 20º C.

I use a hydrometer and only use 10% to 12% which is not more than a specific gravity of 1.1309 at 20º C

I hope I got that right some times I forget my metric numbers along with a lot of other things. LOL

Um, actually, Quebecker had it (nearly) right the first time.

2500 grams of 20% electrolyte = 500 grams of NaOH + 2000 grams (2 litres) of distilled water.
Depending how much you need, just use one part NaOH to four parts water by weight.

[Quebecker]

I think you meant:

400/2000 * 100 = 20% 1 liter of water 1000 Grams will require 200 Grams NaOH for a 20% solution. Specific gravity of 1.2191 at 20º C.

I use a hydrometer and only use 10% to 12% which is not more than a specific gravity of 1.1309 at 20º C

I hope I got that right some times I forget my metric numbers along with a lot of other things. LOL

Chemical formula for calculating concentration

mass of solute / mass of solution* x 100

* Mass solute + solvent