Freezing Water and Pressure

Already used to crack stones.

First find something of infinite strength.

You can't even do one of Mr. Einstein's thought experiments when starting from a bogus begining.

O.K., I'll put it another way. If you put water in a VERY STRONG container, and attached a pressure gauge, how high would the gauge go?

I had a case where water got into what I can call a box about 4'x4'x2', made with one and one half inch plates, reinforced with 8"x3" stiffeners about halfway up, filled with water through the ratholes. In the New England winter, the water froze and buckled the plate/reinforcing plate combination, outward by one and one half inches. It caused quite a stir next morning.

I didn't bother to calculate the forces involved, all I had to do was to show that it was still fit for it's intended use.

Perhaps you didn't find it interesting, but I certainly did. I see the ability to bend that size of reinforced 1.5" steel plate that much in a single night as an excellent example of the forces exerted by freezing water!

It wouldn't. It would either freeze up or it would self-disassemble, were it the weaker of the "VERY STRONG container"/pressure gauge system.

The strength of the heat exchange surface within the "VERY STRONG container" also requires consideration.

The compressibility of water and ice can be found from graphs and tables. Try Kempe's Engineer's Yearbook, any edition.

Besides I am too lazy to do the calculations, it is possible to estimate the resulting force. Just use the difference in the specific volume of the water before and after freezing ( do not forget that the expansion occurs in liquid state while cooling between 4 and 0 degC ) and translate this volume difference to the resulting elastic deformation of your very strong container. By restraining the water expansion, it is possible to calculate the pressure using the elastic modulus of the water.

Economic use? Yep. Quite easy to crack things - as already mentioned, cutting rocks is the most evident use.

If volume were constrained constant, and temperature reduced, 'normal' hexagonal ice would not form. Normal ice is the only arrangement that is less dse that than the liquid immediately preceding the drop in temperature.

If you have containment for constraining the volune to a constant, then you have the means for manipulating material at the tremendous pressures involved, and any economic benefits which might accompany.

benbenben

Curiouser and curiouser, thanks. Ice Nine anyone?

Kurt Vonnegut

Very interesting question. GA lynlynch for the linked answers especially Vince Calder - different forms of ice under pressure. And of course, some differences in melting temperature.

My own (ahem) experience of "the force" starts with the occasional bottle of champagne or beer nipped into the freezer to chill and forgotten! Champagne bottles are great, their corks are impressive but no match for the fully frozen bubbly. Frothy ice bursts forth; inside the bottle slushy ice.

At one time, I was wanting to use bottles of water as a building material for solar mass, but concerned about the risk of freezing. Did a couple of freezer tests with a water volume reduction to allow freezing space. Ergh: wine bottles smashed in two, right around the middle. Ice did not expand politely into the available space at the top (at least, it didn't seem to, from the results).

Nucleation sites are another interesting concept, in the freezing/antifreezing.

Economic: other than breaking, I suppose if the behavior of the ice and its containment was very clearly defined it could also be used for shaping.. not sure what material (or immovable object) would benefit and be economical to work with "the slow irresistible force"....

...except that Vince did not say whether a sealed pipe of that type would burst when water froze in it, nor at what temperature. Most of the frozen pipes that I've seen (not that many) split at the weld seam. I presume Vince was talking about seamless pipe.

:) I've seen also cola drinks forgotten in the freezer, but did not break the bottle. however, the instant they were opened, the liquid just froze.

The increase in pressure should lower the freezing temperature of the water, reducing it's expansion due to freezing. The increase in pressure would also act to increase the temperature of the water. However if you kept drawing heat from the system you would end up with water in a state where it wanted to freeze, but due to environmental limitations could not. Therefore the reaction would result in supercooled water

The gauge might get to the pressure required to produce irreversible deformation of the container, if it has been selected correctly. If the container has been designed to give a burst pressure of, oh, say 150barg, then that is the maximum sort-of-pressure that the gauge will read. Then there will be a bang, and the reading on the gauge will drop.

The container will, of course, be scrap material after this experiment, having been pressed beyond its elastic limit, which renders the purpose of the experiment questionable.

In summary, it is the strength of the container that will determine the pressure, and not the ice within it.

Pressure can be estimated on basis that the container volume stays unchanged. If the water were unconstrained the resuting ice has SG ~ 0.915, so volume change on freezing = 1/0.915 - 1 = 0.092

According to my data, the bulk modulus of water = 2*10⁴ bar. Making the assumption that the bulk modulus of ice is about the same, pressure rise =

0.092*2*10⁴ = 1840 bar.

However, as increased pressure lowers the freezing point of water (due to the fact that it expands on freezing) the temperature would need to go well below 0°C for it to freeze. Just how low could be estimated if somebody needed to.

Cheers.....Codey

The container volume will change, though, on the basis of its construction geometry, its thickness, and the modulus of elasticity of its materials-of-construction. It is this that will determine the pressure inside it, and not the ice.

Thanks Steve, I've never seen anything that freezing can't burst and now I see why, I was just looking for a round number out of curiosity, and you have provided it. I have seen 15,000 psi valves burst, so I guess it stands to reason.

I guess some kind of titanium sphere 2' in diameter, with a 1" cavity might hold for a while, but what would I do with it? lol

Thanks to all that replied.