WSM Posted September 6, 2011 Posted September 6, 2011 Here is a interesting find/LOL moment .. I hooked up my electrodes backwards doing a quick test for spacing.. I have never seen this reaction where the cathode gets a oxidized layer in person, but I have to say it is quite pretty ... Happens really fast btw... 15sec. I got my lid turned around and was scratching my head for a sec, not getting why my cell was only producing 1A , and no bubbles . Anodized titanium can get a rainbow of colors depending on the conditions. I get many colors when I heat titanium tube to fill it with solder. WSM
WSM Posted September 6, 2011 Posted September 6, 2011 DOOM has beffallen my cell This morning i decided to turn off the cooling fan because already i was getting chlorate precipitation, more and earlier than expected, and the fan was apparently keeping the cell at slightly warmer than outside temperature, perhaps 40 Celsius. also the amperage droped by about 4A so i asumed that it was doing what it did last run, so i thought the fan was making little difference, especially since it is focused on the top of the cell mainly cooling the electrode connections, which did help actually.When i arrived home from school , i was shocked The cell was running at 20A again, so apparently the fan cooling the cell lowered the amperage.The cell had become, and stayed so hot, that the plastic over time could slowly be stretched and buckled!What i think happened was that the vent tube had become blocked, and so the gas was escaping through the leaky gaps of the cell (it is capable of leaking out all the gas slightly slower than it is generated), but pressure built up, and the heat allowed the cell to balloon up, until the top popped off, at which time it would have likely had deflated due to the weight of the electrodes.I couldnt really care less that this has happened. My concern is that this may happen to my pvc cell, which could cost me allot of money to fix .I am going to have to get much thicker tubing for the pvc cell, and perhaps two fans blowing on it, to both regulate tempurature below 60C which is when pvc begins to become soft and cool the electrode connections and blow away leaking chlorine gas.I am certainly glad i decided not to use the bubbler You may want to consider using smaller electrodes to help keep the temperature down. I think cutting the anode to match the size of the cathodes might help. Is this a possibility? WSM
oldmanbeefjerky Posted September 6, 2011 Posted September 6, 2011 I got a rainbow comming off the edged of where i sliced a corner of my titanium cathode off with a plasma cutter, when i was seeing if i could cut titanium
oldmanbeefjerky Posted September 6, 2011 Posted September 6, 2011 (edited) You may want to consider using smaller electrodes to help keep the temperature down. I think cutting the anode to match the size of the cathodes might help. Is this a possibility? WSM certainly not.A larger cell though would help right?Also, the current in my cell just dropped by 3A since i turned the fan back on which dramatically cooled it. Its being powered externally with a battery so i know that its not just current draw from the fan Edited September 6, 2011 by oldmanbeefjerky
WSM Posted September 6, 2011 Posted September 6, 2011 certainly not.A larger cell though would help right?Also, the current in my cell just dropped by 3A since i turned the fan back on which dramatically cooled it. Its being powered externally with a battery so i know that its not just current draw from the fan I imagine a larger cell would help. Give it a try and tell us how it works out. WSM
oldmanbeefjerky Posted September 6, 2011 Posted September 6, 2011 (edited) Well it seems im left no choice,The current shape my cell has taken on means it is slowly collapsing each hour if not supported, so once i complete the run (currently 26H into the run , amperage dropped from the peak of the run 21A 5H in , down to 16.2A which is right now, the cell has fluctuated in amperage between 17A - 20A) , ill toss the old cell and see if i can find some of the 150mm screw caps and screw fittings like i have in my backyard, at the old construction site they just removed the entire PVC piping system from because the trees have tapped into it and the house had been demolished anyway. its all in a big pile on the curb waiting to be picked up. I don't like the idea of paying about $30 per piece of 150mm PVC necessary to build the cell totaling $110 . And i am having troubles finding another cell about as big as my last, which is not smaller than the current.If the demolition site does not prove fruitful ill have to look at the dump and hope the idiot now running doesnt know the value of PVC fittings. Also currently in my cell chlorate is building up on the bottom , but the cathodes dont seem to have much problem shoving it all to either side of the electrodes so its basically pilling up around but not on primarily on the electrodes which is good. Edited September 6, 2011 by oldmanbeefjerky
oldmanbeefjerky Posted September 6, 2011 Posted September 6, 2011 Considering the cell behaviour, in which last time it took 2.4KWH to convert make of chlorate, and the fact that i have used 2.1KWH so far, my run is almost at an end! I just hope perchlorate doesnt begin to form overnight, because from what i am getting in readings, The amperage for the last 3 hours has been dropping at a rate of 0.5A/H, meaning that by morning, my cell will be extremely close to 50% the initial average amperage which (currently 15.5A) was between 20-17A. Hopefully the current doesnt drop dramatically overnight and make so much chlorate that perchlorate forms and wrecks the anode!
WSM Posted September 6, 2011 Posted September 6, 2011 Considering the cell behaviour, in which last time it took 2.4KWH to convert make of chlorate, and the fact that i have used 2.1KWH so far, my run is almost at an end! I just hope perchlorate doesnt begin to form overnight, because from what i am getting in readings, The amperage for the last 3 hours has been dropping at a rate of 0.5A/H, meaning that by morning, my cell will be extremely close to 50% the initial average amperage which (currently 15.5A) was between 20-17A.Hopefully the current doesnt drop dramatically overnight and make so much chlorate that perchlorate forms and wrecks the anode! Don't worry, MMO can't make perchlorate (and I don't remember why). I wish it could; that would make perchlorate production so much simpler. If you take an MMO anode and plate it with lead dioxide (especially the beta form), then yes; you could make perchlorate with it . For perchlorate production our best options are platinum or LD. Between them, LD is the most economical. Fortunately for us, all the action is on the surface of the electrode, so platinum plated titanium (even a very thin coat) will do nicely so long as we don't abuse it. For perchlorate cells, the optimal setup includes 6-7Vdc and higher current density, plus higher temperatures. Fortunately, acid injection is not neccessary. Those who have done it report it goes faster and is much simpler than chlorate production. Instead of chlorine, ozone is the noticable gas emission from a perchlorate cell. I haven't run one yet, but I've paid particular attention to the reports from those who have . WSM
pdfbq Posted September 6, 2011 Posted September 6, 2011 Don't worry, MMO can't make perchlorate (and I don't remember why). It can make perchlorate, but the problem is it only makes perc, like a Pt anode, when the chlorine is low. Also when the chlorine gets too low it will destroy your MMO anode.oldmanbeefjerky almost certain has perc in his cell but the perc will not destroy the anode. Its a too low chlorine level that will do it.
WSM Posted September 6, 2011 Posted September 6, 2011 It can make perchlorate, but the problem is it only makes perc, like a Pt anode, when the chlorine is low. Also when the chlorine gets too low it will destroy your MMO anode.oldmanbeefjerky almost certain has perc in his cell but the perc will not destroy the anode. Its a too low chlorine level that will do it. Is that right? I recall Swede running a a small sample cell "to destruction" and no mention of any perchlorate produced. If I recall correctly, he tried to make perchlorate with MMO and couldn't do it. If OMBJ has some methylene blue he can test for perchlorate with a weak solution of it. WSM
pdfbq Posted September 6, 2011 Posted September 6, 2011 (edited) @WSMYou can not harvest a decent crop of perc because you have destroyed your anode long before.I Have methylene blue and I have destroyed one or two anodes as well, different story, but it was not because of the perc in there .One was 'silicinozed' and the other was because I then miscalculated the density. A lot of water was evaporated and I added something like 20% of water to top my cell. In one hour my anode stopped conducting. I detected perc for days already, but then, by diluting my NaCl leftovers I reached a critical level I guess. Edited September 6, 2011 by pdfbq
oldmanbeefjerky Posted September 6, 2011 Posted September 6, 2011 Ah, goodWell the worry is over, the amperage did not continue to plummet as i has suspected. In my next cell though i think i will look at including some kind of corrosion resistant basket which will hold chloride to replensih the cell as used, like WSM said a few pages back to allow continuous use.
WSM Posted September 7, 2011 Posted September 7, 2011 Ah, goodWell the worry is over, the amperage did not continue to plummet as i has suspected. In my next cell though i think i will look at including some kind of corrosion resistant basket which will hold chloride to replensih the cell as used, like WSM said a few pages back to allow continuous use. The corrosion resistant basket doesn't have to be any more complex than a compatible plastic pipe section with an end cap and holes drilled all around. I picture it sitting vertically (like a soup can on a shelf) but don't limit yourself; use your imagination. A short piece of CPVC duct pipe (it doesn't have to be thick-walled) would easily handle a high temperature cell environment. WSM
oldmanbeefjerky Posted September 7, 2011 Posted September 7, 2011 actually for the basket i was considering some kind of mesh or a pool filter, but that sounds like a much better idea. Out of curiosity, does anyone know for certain how well polyester stands up to the conditions of the chlorate cell. ive heard it works ok, and heard it doesnt work at all.For a future cell idea i want to have the the cell contents constantly flowing into and from (through) a filtered cell , then flow back into the cell for two purposes, which are 1. to catch and remove chlorate as it forms making it easy to extract the chlorate, particularly in a continuous cell, also preventing possible which occur due to chlorate buildup around the electrodes.2. also be able to filter out oxides and other insoluble messy gunk produced when disposable anodes are used, like lead, steel and graphite. Using sodium chloride though for obvious reasons.
Bonny Posted September 8, 2011 Posted September 8, 2011 The best solution to your problem(s) is to make a larger cell, plain and simple. That little toy cell you have is too small for the current you are running. I don't know why you keep thinking PVC is needed. I made kilos of chlorate using an HDPE bucket. It WILL withstand the cell environment and is cheap.
oldmanbeefjerky Posted September 8, 2011 Posted September 8, 2011 (edited) It is not so much price i am worried about, or cell degradation anymore, its about durability, being leakproof and airtight. There are numerous reasons why i want to use pvc, very few to do with the fact that it is made of pvc though and more to do with the possible uses of pvc fittings and such. By the way, i am still doing my second run, and the average cell amperage has gone form 18 down to 14-12 and seems to be going up and down form there, it does not seem to be dropping any further than that. already the cell has run over 60 hours and the amperage still hasnt dropped the way it did in my last run. already the cell has split 150ml of water and is now by volume less than one third chlorate cake. in my last run the cell went for less than this long and with slightly less chloride to begin with , i think i started with 300 grams and this time im using 350g. Is this normal? the average current for the first 40 hours was 18A wheras in the last run it was 15. i am just very baffled with this all. here is a log of the progress so farhttp://www.text-upload.com/read.php?id=134852&c=4507176 Edited September 8, 2011 by oldmanbeefjerky
pyrojig Posted September 9, 2011 Posted September 9, 2011 (edited) The best solution to your problem(s) is to make a larger cell, plain and simple. That little toy cell you have is too small for the current you are running. I don't know why you keep thinking PVC is needed. I made kilos of chlorate using an HDPE bucket. It WILL withstand the cell environment and is cheap. I do the same... A hdpe bucket is the cheapest and I find the Home Depot ones to be the most durable so far. My cell runs up to 60*C and still no signs of wear on the lid or bucket. Just waiting to see how long that lasts for..... I have done what WSM suggested and cut my electrodes to a 3x5 size and it has allowed me to move the electrodes closer together >>>I should have cut them to a 1.5" x 10" so the electrodes went deep into the bucket and help stir the electrolyte. I now have half the cell at 59c and the other half at 33c. My cell is running at 32A / 4.6V . It is a little over the rated Amp supply of the PS. No overheating on the PS out of the norm. I really need to get a bubble stone or pvc diffuser to stir the cell now.. I am just under a pound of kclo3 a day in production, and hope to improve this with the new adjustments. Edited September 9, 2011 by pyrojig
WSM Posted September 9, 2011 Posted September 9, 2011 I do the same... A hdpe bucket is the cheapest and I find the Home Depot ones to be the most durable so far. My cell runs up to 60*C and still no signs of wear on the lid or bucket. Just waiting to see how long that lasts for.....I have done what WSM suggested and cut my electrodes to a 3x5 size and it has allowed me to move the electrodes closer together >>>I should have cut them to a 1.5" x 10" so the electrodes went deep into the bucket and help stir the electrolyte. I now have half the cell at 59c and the other half at 33c. My cell is running at 32A / 4.6V . It is a little over the rated Amp supply of the PS. No overheating on the PS out of the norm. I really need to get a bubble stone or pvc diffuser to stir the cell now.. I am just under a pound of kclo3 a day in production, and hope to improve this with the new adjustments. Sounds good, pyrojig. I like the idea of a tall, narrow anode with matching cathodes to provide hydrogen lift and keep things stirred up in the cell. Another way to accomplish it with the 3" x 5" electrodes is to attach longer leads to get the electrodes deeper into the cell. Not all the way to the bottom but deep enough to encourage the hydrogen lift I'm referring to while leaving enough space under the electrodes to let the crystals collect without shorting them to each other. WSM
oldmanbeefjerky Posted September 9, 2011 Posted September 9, 2011 ive shut off my cell removed the chlorate, dumped the liquor on the weeds in the driveway, and tossed the cell.I have no idea why it is still going at such a low amperage without dropping further. the amount of water had cut almost in half by the time i finished the cell run, so something was up, there was no anode damage thank heavans. Anyway, form what i can see as much chlorate has formed as was possible at a decent CE
WSM Posted September 9, 2011 Posted September 9, 2011 actually for the basket i was considering some kind of mesh or a pool filter, but that sounds like a much better idea. Out of curiosity, does anyone know for certain how well polyester stands up to the conditions of the chlorate cell. ive heard it works ok, and heard it doesnt work at all.For a future cell idea i want to have the the cell contents constantly flowing into and from (through) a filtered cell , then flow back into the cell for two purposes, which are 1. to catch and remove chlorate as it forms making it easy to extract the chlorate, particularly in a continuous cell, also preventing possible which occur due to chlorate buildup around the electrodes.2. also be able to filter out oxides and other insoluble messy gunk produced when disposable anodes are used, like lead, steel and graphite. Using sodium chloride though for obvious reasons. Polyester (like surf board resin or Bondo automotive repair resin) doesn't hold up well in contact with the liquor in a cell. It appears polyethylene (5 gallon HDPE bucket) does work in a cell with pH control (I'm not sure how long in a cell without pH control). I've tried epoxy in a cell and it doesn't last as long as I had hoped. PVC will bleach the color but seems to hold up well (so far) and is happy below 60oC. If you need other suggestions of materials or for a specific purpose, just ask. WSM
WSM Posted September 9, 2011 Posted September 9, 2011 (edited) It is not so much price i am worried about, or cell degradation anymore, its about durability, being leakproof and airtight. There are numerous reasons why i want to use pvc, very few to do with the fact that it is made of pvc though and more to do with the possible uses of pvc fittings and such.By the way, i am still doing my second run, and the average cell amperage has gone form 18 down to 14-12 and seems to be going up and down form there, it does not seem to be dropping any further than that. already the cell has run over 60 hours and the amperage still hasnt dropped the way it did in my last run. already the cell has split 150ml of water and is now by volume less than one third chlorate cake. in my last run the cell went for less than this long and with slightly less chloride to begin with , i think i started with 300 grams and this time im using 350g. Is this normal? the average current for the first 40 hours was 18A wheras in the last run it was 15. i am just very baffled with this all.here is a log of the progress so farhttp://www.text-uplo...34852&c=4507176 I like PVC with it's thicker walls which can take fittings and be plumbed easily, as OMBJ says. The main limitation is temperature (60oC, tops) and I wish I had access to large diameter CPVC which can handle up to about 93oC!!! I wonder if your cell was depleated of chloride and was just splitting water molecules; or was something else going on? It's hard to say without more information. WSM Edited September 9, 2011 by WSM
Bonny Posted September 9, 2011 Posted September 9, 2011 Polyester (like surf board resin or Bondo automotive repair resin) doesn't hold up well in contact with the liquor in a cell. It appears polyethylene (5 gallon HDPE bucket) does work in a cell with pH control (I'm not sure how long in a cell without pH control). I've tried epoxy in a cell and it doesn't last as long as I had hoped. PVC will bleach the color but seems to hold up well (so far) and is happy below 60oC. If you need other suggestions of materials or for a specific purpose, just ask. WSM I've never run a ph controlled cell. I did 4 or 5 runs with the same HDPE (Home Depot) bucket and it's still fine.
WSM Posted September 10, 2011 Posted September 10, 2011 I've never run a ph controlled cell. I did 4 or 5 runs with the same HDPE (Home Depot) bucket and it's still fine. That sounds excellent. I may have to try a bucket cell and see how it goes. Thanks for the information, Bonny. WSM
Bonny Posted September 10, 2011 Posted September 10, 2011 That sounds excellent. I may have to try a bucket cell and see how it goes. Thanks for the information, Bonny. WSM No problem. (HD)PE is quite resistant to chemicals (I work in plastics). I think overall a PVC cell would be better, but given the cost, a great (entry level) bucket cell is the way to go. For venting and electrode attachment,(after several runs) I bolted a flat PVC plate to the lid (cut out the lid as needed). This simplified attaching electrodes and vent fittings using PVC cement. However, the bucket cell with standard lid works just fine. Salt creep always happens, but in my case efficiency was never an issue, making unobtainable oxidizers was.
Arthur Posted September 10, 2011 Posted September 10, 2011 Swede's main project (well blogged!) was a CPVC cell fabricated from thick sheet and welded. His second project (also well blogged) was his Bucket Cell, made from a snap top bucket (HDPE) with a CPVC bucket cell adaptor (BCA) fitted (all well blogged). Take a big (5 gal) bucket with snap top lid which can be disposed after several runs, and fit a well engineered rigid CPVC plate with all the electrodes, stirrers, vents etc. Swede used Titanium screws for corrosion resistance and viton gaskets. The BCA should work well for a lifetime, the bucket may need replacement after a few runs.
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