Low Conductivity Water

[unclesyd]

I'm trying to make high purity water by zone refining, I can do it using a large containers but are not so successful using !/2 L bottle as the core doesn't end up in the middle/top.
Any ideas on freezing from the bottom up or from the sides.

 

[ivymike]

you mean you're after ways to make a bottle of water freeze from the sides inward? Is a very large thermal gradient enough to do it?

 

[Compositepro]

Water can only freeze where heat is being extracted. Insulate the top part of the bottle really well and put it in the freezer. Keep in mind that convection currents in water reverse at about 2C where water is at maximum density.

 

[TheTick]

Distilled or RO water not good enough?

 

[VEBill]

My workplace uses "deionized water" for cleaning circuit card assemblies. I think it's made using filters.

The reverse osmosis filter system in my kitchen was under $200. I believe it makes water that's even cleaner than the deionized water at work; but I'm not certain of that.

 

[TheTick]

What application? EDM?

 

[IRstuff]

Generally, RO/DI water is processed via:

> Sediment filters
> Reverse osmosis
> Resin de-ionizers
> UV

Does zone refining work with water? There's about 1300°C difference between zone refining for silicon vs. water. The diffusivities would be radically different, and it would seem to be further hindered by the lack of single crystal behavior in water, wouldn't it?

TTFN

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[unclesyd]

ivymike and Compositepro,

Both suggestion rung some bells from my days around an ice plant. The ice cans are frozen by immersing the cans in circulating brine tank, so it will freeze from the outside to form a pipe. Also there is an air bubblier that takes care of the circulation in the can. The clear ice you see carved is 72 hour ice and the core is washed out three times.

Yes I know there is cheaper water but this approach is dictated

Ye,s zone refining works with water/ice. Check the ice formed on a lake. We have ice machines on fishing boats that make ice from sea water. It can be a little salty but can be adjusted to give ice with very low sodium.

Before the advent of ice plants ice was harvested in New England and shipped to the Gulf Coast. Aside from the cork insulation on the cargo hole it was packed with sawdust.

 

[TheTick]

DI comes before RO, both in the dictionary and in the process. Typically, you want the water going into RO as clean as possible, to burden the membranes as little as possible.