32 replies to this topic

[alany]

To deliver its full 320 A output you'll need to load it with 15.6 miliohms or less because its maximum output voltage is just 5V. 15 mR is a *very* small resistance, you'll need to use #4 wire, bolts and star washers between the connections to have any hope of getting that low a resistance before you even get to the cell. You may do better with extruded Aluminium sections instead of wire, Aluminium would be cheaper than an equivalent amount of Copper. Slip some PVC pipe over them to stop nasty accidents, and don't wear jewelery when working on it, if you short the output with a ring on your finger you'll loose the finger!

I doubt the graphite substrate of your anode will ever be able to deliver that kind of load, you may need to parallel 10 or more. You may also need to Silver plate the contact point with the clamp/wiring at the top of the electrode as well. Have you tried measuring the resistance of the cell? I know it is non-linear with applied voltage, but measure the voltage drop across the cell with an applied current and calculate it.

Large surface areas and close spacings is the only way to lower the resistance of the electrolyte itself seen across the cell. I think your biggest problem will be the graphite substrates of your anodes, they are just like big resistors. You may also find that Titanium isn't a wonderful conductor when you start pulling hundreds of amps through it, even at only single-figure amps I can fry an egg on my Ti alloy cathodes.

[sasman]

alany dont forget i'm not putting 300 amps thru the cell i will have 4 or 5 Anodes(27 amps each) so that works out at 120 to 150 amps total...

I will be happy with a cell running at 100 amps...What i am worried about is i tried to make another Anode with this new PSU my old 400 watt psu gives out 10 to 15 amps.. but when i tried to use this new PSU i only got 2 or 3 amps? at 5 V ...simply put i would not be able to make big anodes with such a crap PSU?..

I have used fairly thick wire it's the type you use to connect car batteries to your car..very thick..

I will get 100+ amps thru the cell even if i have to buy a plating rectifier PSU surely this type of transformer would work.. I dont know how to measure the resistance of an electrolytic cell..

Edited by sasman, 13 April 2005 - 11:57 AM.

[Arthur Brown]

When I worked in a plating plant the conductors were HUGE about 3" by .25" assembled into stacks and knuckle jointed. Expect much power to be lost in the connectors - scale them so that most power is used in the cell. A series arrangement of cells is sometimes used to minimise wasted power, cf the electrolytic preparation of aluminium metal from molten bauxite, ( the heat to keep the bauxite molten comes from internal heating due to the current flow in the cells.)