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The Bucket Cell - Start to Finish


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#361 WSM

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Posted 04 November 2018 - 09:20 AM

A few years ago I came across a great find at a yard sale my neighbor was having. I found and bought (for a pittance), a small kitchen counter, water distillation apparatus. This device is enclosed in a stainless steel housing and appeared to be missing a few parts. The space it takes is roughly one cubic foot.

 

With a little work I managed to clean it up and set it up for a trial run. It has a mechanical timer and limited capacity, but when I ran it using some water from my kitchen RO system (~5-50 ppm of dissolved solids, as opposed to ~300-500 ppm tap water), the water dispensed from the device was reading zero ppm dissolved solids!

 

The distiller isn't super efficient, running off an electric heating coil, but when I calculated the actual cost of operation including my electricity rates, I can make distilled water for half of what buying it from the grocery store would cost, and even less if I set it up and run it on my soon-to-be-installed off-grid solar power system.

 

I have the distiller stored on a shelf at the moment, but when I get going on my electrochemical research in earnest, it may play a part in keeping me well stocked with lower cost distilled water. 

 

WSM B)


Edited by WSM, 04 November 2018 - 10:09 AM.


#362 memo

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Posted 21 November 2018 - 10:38 AM

building a new cell my old one was a gallon the new onw is 2 1/2 gallon. what is the biggest cathode and anode can run. mmo and titainium and using a computer power supply at 5 v



#363 Arthur

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Posted 21 November 2018 - 02:07 PM

Probably depends more on your ability to make an interleaved electrode assembly and have it fit into the cell easily. 

 

What current rating is your PSU 5v rail? Aim for 90% of that rating. Maybe use a length of iron (gas) welding wire as a current limiting resistor, or a big array of ceramic or alloy body resistors. At 5v I'd expect to need some current limit I've seen 4.2V at 10A  Most of the voltage raise needed is to overcome the resistance of the entire circuit, nuts, bolts, washers, good copper wire.



#364 WSM

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Posted 09 December 2018 - 07:55 AM

Probably depends more on your ability to make an interleaved electrode assembly and have it fit into the cell easily. 

What current rating is your PSU 5v rail? Aim for 90% of that rating. Maybe use a length of iron (gas) welding wire as a current limiting resistor, or a big array of ceramic or alloy body resistors. At 5v I'd expect to need some current limit I've seen 4.2V at 10A  Most of the voltage raise needed is to overcome the resistance of the entire circuit, nuts, bolts, washers, good copper wire.

 

Current electrical best practices call for running loads at 80% of a supply's capacity (Amperage, not Voltage). This is conservative and probably based on the inrush current of motor loads, and other such demands, but it pays to not overload your supply (plus leave room for unexpected "surprises").

 

Sorry, I do electrical work for a living, and electrical theory is behind a lot of my thinking.

 

WSM B)



#365 WSM

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Posted 09 December 2018 - 08:51 AM

building a new cell my old one was a gallon the new onw is 2 1/2 gallon. what is the biggest cathode and anode can run. mmo and titainium and using a computer power supply at 5 v

 

The size (area in cm2) of your electrodes has more to do with the current (Amperage) you can supply, while not exceeding  0.3 A per cm2 of surface area (less is okay, more is ill advised).

 

The Voltage is "electrical pressure", and the Amperage represents the "volume of electrons" flowing. You only need enough Voltage to drive the reaction. Amperage (current) demand is based on the "real estate" (or area) of your anode with matched cathode(s).

 

The answer is based on the average current output of your power supply, then sizing the electrodes to demand about 80% of that amount, to keep things running without overheating the power supply unit (PSU).

 

WSM B)


Edited by WSM, 09 December 2018 - 08:52 AM.


#366 WSM

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Posted 29 May 2019 - 03:35 PM

The longer I think about Swede's description of a bucket cell, the more practical it appears to be.

To be honest, my first (failed) attempt at a chlorate cell was set up in a 5 gallon HDPE bucket with a lid. I tried to use a graphite anode with a stainless steel mesh cathode. What a mess!

Needless to say, I've moved on and achieved considerable success since then.

Now, as for the bucket cell, I readily admit that the bucket wasn't the problem with my first attempt. Everything else was!!! Swede's major breakthrough was using a thick PVC plate for his BCA, or bucket cell adapter.

I know PVC is a compatible material in the chlor-alkali cells we build, but realistically, little if any of the electrolyte ever contacts the lid of the cell, so other polymers may do an adequate job as a BCA.

I suggest that the best design of a chlorate cell is one where a gap of about 100mm to 150mm (4" to 6") exists above the cell liquor for ample space to allow the hydrogen bubbles to pop and reduce the tendency to promote salt creep, which causes problems for electrical connections and other incompatible materials outside the cell.

I'm considering whether I should try a BCA made of clear acrylic plastic of about 3/4" (~19mm) thickness?! If it works (and it just may), it would represent a great savings over thick walled PVC plate, PLUS be MUCH easier to source.

Any thoughts?


WSM B)

Edited by WSM, 29 May 2019 - 03:46 PM.


#367 Arthur

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Posted 30 May 2019 - 12:23 AM

One problem I had was that a nylon cable tie I wanted to use lasted just less than ten minutes when in electrolyte spray. 

 

Polypropylene ( PP) was OK as a cell material, and available as nice size lidded jugs from Asda(Walmart) cheaply (£2 -5) intended for keeping juice in the fridge. Always used inside a safety bucket.

 

The down side of PC power supplies is that with changing mobos the need for 5v decreases and the need for 12v increases, so a big psu that would have a 25a 5v rail has evolved into a 10A 5v rail and a 12vrail at 30+ amps. China sends the world single rail PSUs and I've seen 5v 100a on ebay Once you talk of even 50a the wire you use becomes critical, fat wire  of good copper works but CCA wire suddenly shows it's limitations, and most domestic 50a wire is rigid unless you pay lots for welding wire.



#368 WSM

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Posted 30 May 2019 - 12:27 PM

Nylon is totally incompatible with the cell liquor. I'm not certain how well acrylic polymers will hold up, but since we're discussing a thick piece in the lid above the liquor, it may work out.

As for power supplies, I've never used a PC power supply to make oxidizers. My best power supplies have been variable, and some with CV and CC capability. I HAVE used some without the CC mode available; and the powerful, rack-mountable types seem to work well for chlorate cells, IF I tailor the electrode size to the output of the power supply.

I moved up to using welding cable years ago, for leads on my higher powered supplies. I prefer them for hooking power to my electrodes which are mounted through the lid of the cell, using PVDF compression fittings (as described in Swede's blogs).

WSM B)

Edited by WSM, 30 May 2019 - 12:34 PM.


#369 Arthur

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Posted 30 May 2019 - 04:58 PM

I found a 60a 5v psu as a Chinese internal fitting unit with lots of vents in the case and a little adjustment. It works fine, the leads are fat speaker wire.

 

Initially the leads were quite long and they were cut down to increase the current! I can now set the current about 25a with ease and it stays cool over a week of operation.



#370 WSM

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Posted 31 May 2019 - 10:20 AM

I found a 60a 5v psu as a Chinese internal fitting unit with lots of vents in the case and a little adjustment. It works fine, the leads are fat speaker wire.
Initially the leads were quite long and they were cut down to increase the current! I can now set the current about 25a with ease and it stays cool over a week of operation.


Very nice. It sounds like a workable option for a decent sized chlorate cell.

WSM B)

#371 WSM

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Posted 24 October 2019 - 12:38 PM

My work on making pure oxidizers has just taken a big step forward. I just ordered a DI filter which, when added to an RO system will make deionized water.

With pure water and purified starting chemicals, my products should be equal to (or better than) commercial oxidizers.

WSM B)

Edited by WSM, 30 October 2019 - 12:46 PM.


#372 pyrojig

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Posted 05 November 2019 - 10:34 PM

Wow topics getting juicy. Can't wait till my work slows down. I wan to jump in on the band wagon and get my system dialed in to contribute to the thread. Sucks being your own boss. Hard hours and a a- hole of a boss to contind with😋.

#373 WSM

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Posted 08 November 2019 - 01:27 PM

Wow topics getting juicy. Can't wait till my work slows down. I wan to jump in on the band wagon and get my system dialed in to contribute to the thread. Sucks being your own boss. Hard hours and a a- hole of a boss to contind with😋.



Yeah, I want to get going on my system, too!

Years ago I was self employed, also. The worst part was, I had a jerk for a boss!!! );

WSM B)

Edited by WSM, 08 November 2019 - 01:28 PM.







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