Thread: Freezing rain

Hello everybody, I am designer and my task is to create a shelter from the rain.

I was wondering-is it possible that very fine net of metal with very small cells (about 1or 2 mm) would catch drops of water and freeze it?
Therefor creating ice shelter which will be able to protect people from the rain and do not melt during the rain but afterwards?

Does it sound comepletly impossible for you? Or there is a chance that it can work?
I have no idea about qualities of different metals but I know that survace tention of water is very high, thus rain drop can stuck in the cell and
if metall will be able to cool it very fast down then it would freeze. But would it be able to resist hit of coming rain drops?

Probably it is just a crazy idea but I hope you will be kind to help me to figure out can it work or not

How do you intend that the metal 'net' would freeze the water? Obviously a simple net of metal will not work. You would need, for example, to have hollowwire through which you could pump refrigerated liquid. Of cours in that case the surface tension will act against you and you would have to pump at quite a high pressure, which on fine wire is going to lead to problems.

Also how do you limit corrosion of the wire internally and externally. I suppose you could plastic instead of wire, but you would still be left with the problem that it will take a significant time to freeze the water. If the rain is heavy that time will increase. In many instances the rain shower will have stopped before you can get any protection from the device.

Sorry to be negative, but I think you may be correct: it is a crazy idea.

I can see the possibilities for the process in technical clean environments.

Even if you could come up with a design that would work when first built, how it could cope with the rough and tumble of life with schoolkids, dust, pollen, bird droppings, diesel exhaust, kicks, chips, scratches and dents is way beyond me. The prime requirement for street furniture of any kind is robust, sturdy construction materials and impregnable design.

The kind of finely tuned process you're discussing is not suited to this kind of project.

Thank you, John Galt, I see that it won't work now. But if to consider the idea as a concept, would it be possible to create something like this, using nano technologies for instance?

adelady, thank you for your answer. I think that if it is possible technilogically then everything else can be solved. For example, surface can be placed very hight, not allowing to damage it.
Rain water can wash it from dust, pollen and even maybe from bird droppings

Unless you're talking about a very, very big structure beyond the usual street furniture type of bus shelter, a much higher roof won't work.

A high roof on a structure say 3m by 5m (pretty large by bus shelter standards) would allow rain to be blown in by almost any shower. The kind of rain that wouldn't be blown in, a light, steady drizzle say, wouldn't bother too many people anyway.

As for washing away dirt and bird droppings. Much of those materials would get into your mesh structure, so the only way for them to be washed away would be through the mesh. Defeats the purpose a bit.

For adelady. What are the principles involved in our house refridgerators? Heat is drawn from the interior of the Cabinet and passed to cooling tubes, normally observable near the back panel. Is the use of Refrigerant Gas, where the principle appearrs to be a vapourisation of super cooled liquid Gas in a cycle of Vapour/ Liquid to operate through a Thermostat cut in cut out temperature range?

The super cooling of any structure material would be a pre-requisit to the Thread Logic. Could not be viable in the normal understanding, but I like the Concept, and there is more here than meets the eye. westwind.

westwind, thank you! That was relief

Have you considered trying your idea out. Something like freezing a small piece of screen door materials and holding it outside for a few seconds to see what happens to the drops? Do they just pass through? Do they start to freeze and form the seal you want. Keeping it all cold enough would be a problem--most freezing rain is supercooled which helps prevent the heat of fusion from melting the icesurface--your system would have to chill to compensate. Not sure how you'd do that. Peltier cooling chips dispersed throughout the mesh?

No, I didn't I understand that there are a lot of challenges in this idea but I can't stop to think about it.
I have no idea what is Peltier cooling chip, Lynx_Fox

I suppose that after the rain the ice cover will melt, leaving the mesh without ice and, hopefully, without birds droppings.

I guess they are also called thermal-electric coolers. Perhaps they are spaced and embedded in the mesh so the cool side attached to the mesh, while the excess heat is allowed to rise or even be shunted away with liquid. A super-cooled fluid tubing embedded in the mesh might work better.... No matter what you've got to figure out a way to cool the mesh and dispose of the heat of fusion.

Wouldn't a tarp do the same thing...but without all the moving parts?