pyrojig Posted February 7, 2015 Posted February 7, 2015 My discovery of potassium chloride water softening salt at the local hardware superstore (many years ago) got me started on the path to discovering how to make my own oxidizers. I've made a lot of progress, but I confess, I'm more wrapped up in the engineering of it than pushing forward to complete it. I'm currently working on a small continuous system. I'd like it to have all the bells and whistles, and make a tidy job of it. We'll see in the end whether I've succeeded. WSM A continuous sys is the golden egg . It is something that many wish they had the materials for, and time to build. I believe that only a handful of folks in the pyro community actually have made one. Looking forward to the juicy details of this sys. It seems that if a person had a good way to store or move the finished product , it would be more attractive than a "batch sys " for most amateurs . I think that large quantities( of finished material) may intimidate some from venturing into the "continuous sys". Guess it depends on a persons needs or ability to move materials in a safe manner .
WSM Posted February 8, 2015 Posted February 8, 2015 A continuous sys is the golden egg . It is something that many wish they had the materials for, and time to build. I believe that only a handful of folks in the pyro community actually have made one. Looking forward to the juicy details of this sys. It seems that if a person had a good way to store or move the finished product , it would be more attractive than a "batch sys " for most amateurs . I think that large quantities( of finished material) may intimidate some from venturing into the "continuous sys". Guess it depends on a persons needs or ability to move materials in a safe manner . Most amateurs who run a continuous system, do so only long enough to stock up, then clean, dry and store the system till more material is needed. I suspect if someone sells their home made oxidizer, they do so at the risk of an unwelcome visit from the authorities. WSM
Arthur Posted February 8, 2015 Posted February 8, 2015 If you want to make chlorate or perc for your own use, then estimate your annual usage then estimate the number of amp hours needed to make this much. Then you can have an idea of how much current and how many days you will need to run to produce a year's product. There is NO point n having production plant that is under, or wildly over capacity. BUT you must also consider the temperature of the cell, too low and it makes hypochlorite, too high and it warps.
THEONE Posted February 8, 2015 Posted February 8, 2015 Almost never you have 100% eficiency so you can not easy to calculate it. So how much you think the range of the correct temperature is?
Arthur Posted February 8, 2015 Posted February 8, 2015 I don't believe that 100% efficiency is possible, for a start the cell needs and does get hot from wasted electrical power. However If you have an annual need for 10 kilos there is little point in a system that would make 1% or 1000% of that and current is probably the best indicator of production. If you assume 100% then you will never have a problem with low chloride eating the electrodes.
THEONE Posted February 8, 2015 Posted February 8, 2015 I have now put the electrodes more closely together and the cell now is really hot, i guess more current now flows. Also some of the water evaporated due to the higher temperature.
WSM Posted February 8, 2015 Posted February 8, 2015 (edited) I have now put the electrodes more closely together and the cell now is really hot, i guess more current now flows. Also some of the water evaporated due to the higher temperature. Evaporation is a factor, but don't forget that water is consumed in the process. As more current is used, more water is broken to its component level ions and used to make chlorate or perchlorate. Be sure to avoid letting the electrodes touch each other and shorting out the power supply, possibly damaging it. WSM Edited February 8, 2015 by WSM
WSM Posted February 8, 2015 Posted February 8, 2015 Almost never you have 100% eficiency so you can not easy to calculate it. So how much you think the range of the correct temperature is? Anywhere from 30oC (86oF) to 70oC (158oF) is normal for a chlorate cell but a good average for a high performing cell is about 55oC (131oF). WSM
WSM Posted February 8, 2015 Posted February 8, 2015 BUT you must also consider the temperature of the cell, too low and it makes hypochlorite, too high and it warps. ??? For chlorate, the first step is hypochlorite (OCl-), then hypochlorous acid, then chlorate. Did I miss something here? WSM
WSM Posted February 8, 2015 Posted February 8, 2015 A small part of the SS was out of the electrolite and this part was a little beat eaten by the solution. Maybe this will be the reason. It is a little difficult to me to find some KCL but i will see what can i do... Stainless steel is usually an alloy including iron, chromium and nickel as well as other metals. Both chromium and nickel compounds can be shades of green to blue. WSM
WSM Posted February 8, 2015 Posted February 8, 2015 (edited) I've been writing the next edition of the Homegrown Oxidizers series and I've made a drawing defining my method of assembling the cathode pair to surround the anode in either a chlorate or perchlorate cell. This diagram shows the CP titanium parts in grey and the anode in very dark colors. The large cathode plates are cut to about the same size as the anode. Next small titanium tabs are spot welded on the sides and beyond the edges of the cathode plates. Then titanium pillars (of whichever shape) are spot welded between the tabs on the cathodes. The titanium leads are spot welded to the cathode pair and anode, as far from each other as possible so the fittings in the lid don't interfere with each other (see the diagram above). I was concerned that the heavy pillars wouldn't weld properly, but experiments showed that they weld just fine. I fact, the greater mass of the pillars seem to heat more than the plate when spot welding. Be sure when spot welding larger pieces together to allow the welder to run long enough to get a good weld (till they glow brightly near the weld tips and the welder makes a growling sound). To ensure a good weld in these cases, I tend to weld them twice on each spot. WSM Edited February 8, 2015 by WSM
Mumbles Posted February 8, 2015 Posted February 8, 2015 The green color you're seeing is almost certainly some mix of metal ions, especially if it's dark green. Hypochlorite on it's own in a pure state will be colorless. Chlorate cells, some bleaches, etc. will take on a light yellow-green color, This tends to be from a small amount of chlorine gas dissolved in solution. It sounds to me like one of your electrodes isn't all that great of quality, and it's being attacked. Several other manganese salts are red to pink, so the color you're seeing is probably not from permanganate for what it's worth as well.
THEONE Posted February 8, 2015 Posted February 8, 2015 (edited) Be sure to avoid letting the electrodes touch each other and shorting out the power supply, possibly damaging it. WSM If something like this will happened then the power supply itself will shut down... so as long as the power supply is working, everything is ok. Edited February 8, 2015 by THEONE
pex Posted February 8, 2015 Posted February 8, 2015 My sodium chlorate cell, has always a bit yellow green color. I use titanium. I think it's normal. I didnt now about the chlorine gass, i always tougth it was from the titanium Thanks mumbles.
THEONE Posted February 8, 2015 Posted February 8, 2015 (edited) The green color you're seeing is almost certainly some mix of metal ions, especially if it's dark green. Hypochlorite on it's own in a pure state will be colorless. Chlorate cells, some bleaches, etc. will take on a light yellow-green color, This tends to be from a small amount of chlorine gas dissolved in solution. It sounds to me like one of your electrodes isn't all that great of quality, and it's being attacked. Several other manganese salts are red to pink, so the color you're seeing is probably not from permanganate for what it's worth as well. The red color i believe it comes from the mno2. As i told before, with a little H2O2 the red collor turned to yellow - green. With more H2O2 the solution become clear. Also something else. There is also an addition like flesh yellow color around the SS and it does not look eaten, it is like an addition, and every 2 days i use some sand paper to clean it. Is this normal ? Edited February 8, 2015 by THEONE
pex Posted February 8, 2015 Posted February 8, 2015 I made some Mno2 anodes in the past. And te solution always turnt a little pink to almost red
pyrojig Posted February 9, 2015 Posted February 9, 2015 @ TheoneFound that I had much more heat as well, for closely spaced electrodes . I believe that the 5gal bucket cell I ran, was at the max temp one would dare. It peaked 55C* and averaged 50C for the most part. It was fairly efficient, or around 75-80% CE . Not bad for a amateur cell, one not perfectly held at a ph target goal. Hand dosing acid is alot of work+ dangerous and required constant testing of the liqueur . Hot cells will be more efficient ,but stress the cell container and loose water. Well worth the trouble IMO. The 5gal sys was built as a temporary or "disposable " cell container (that one could easily replace buckets for a few dollars ). A permanent cell seems more attractive for someone who plans on years of production . I ran into the prob of too tightly spaced electrodes causing damage to the fittings holding the electrodes . The Kynar was pushed to a point of softening and allowing slight saltcreep. BUT that was getting temps of 80-90C* at the electrode top connections !!!!!!
WSM Posted February 9, 2015 Posted February 9, 2015 (edited) There is also an addition like flesh yellow color around the SS and it does not look eaten, it is like an addition, and every 2 days i use some sand paper to clean it. Is this normal ? When pyrojig ran his bucket cell, as described above, he showed me photos of a tremendous buildup of salt crystals above the liquor in the cell. The effect was caused by salt spray (from the breaking hydrogen bubbles) above the liquid level, flash-drying as it hit the hot leads. It sounds like something similar may be happening in your cell. What do you suppose it would do if you left it there for several more days? WSM Edited February 10, 2015 by WSM
WSM Posted February 9, 2015 Posted February 9, 2015 If something like this will happened then the power supply itself will shut down... so as long as the power supply is working, everything is ok. If the power shuts off, it's best to take the electrodes out of the cell. If the electrodes sit in the cell without power, the liquor attacks them and causes irrepairable damage. It's not fast, but it is measurable. WSM
THEONE Posted February 9, 2015 Posted February 9, 2015 It sounds like something similar may be happening in your cell. What do you suppose it would do if you left it there for several more days? WSM I have not try it. Surely it will work but i am afraid that this will may reduce the electric surface of the cathode.
WSM Posted February 9, 2015 Posted February 9, 2015 (edited) I have not try it. Surely it will work but i am afraid that this will may reduce the electric surface of the cathode.I must have misunderstood your description. The coating is over the electrode and not just the lead? I presumed you meant just the leads when you described the portion above the liquid. WSM Edited February 10, 2015 by WSM
THEONE Posted February 9, 2015 Posted February 9, 2015 (edited) I must have misunderstood your description. The coating is over the electrode and not just the lead? I presumed you meant just the leads when you described the portion above the liquid. WSMThe anode is a mno2 titanium substrate (6.7cmx25cm) and the 2 cathodes (5cmx25cm) are 316 SS. This think like a yellow flesh it appears to the cathode, and it is more at the points that it is close to the anode. The anode is very clean at all. What do you mean by the word "lead" ? Sorry but my english are not very good. Edited February 9, 2015 by THEONE
WSM Posted February 9, 2015 Posted February 9, 2015 (edited) The anode is a mno2 titanium substrate (6.7cmx25cm) and the 2 cathodes (5cmx25cm) are 316 SS. This think like a yellow flesh it appears to the cathode, and it is more at the points that it is close to the anode. The anode is very clean at all.What do you mean by the word "lead" ? Sorry but my english are not very good.English can be confusing. The same spelling is used for two meanings: 1) lead, pronounced led, a soft metallic element with the chemical symbol Pb, and 2) lead, pronounced leed, meaning an electrical lead. The second description is the one I was referring to (an electrical connection or terminal). WSM Edited February 10, 2015 by WSM
WSM Posted February 10, 2015 Posted February 10, 2015 I have not try it. Surely it will work but i am afraid that this will may reduce the electric surface of the cathode. Maybe, and maybe not. One thing many people forget is the "metallic" nature hydrogen can take on in the right circumstances. The hydrogen bubbles themselves can be electrically conductive on the surface of the cathode when the cell is running. I can't quote the reference but something may be revealed by a Google search. WSM
Differential Posted February 10, 2015 Posted February 10, 2015 That makes sense. I'm running a chlorate cell and I keep seeing bubbling not just at the cathode, but along the foam.
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