cogreslab said:
To Pragmatist:
Both your points (magnetised fluids; the AB expt.) are well taken , and I would have made them myself. Yet, how is it that static magnets applied to domestic water systems are shown to eliminate limescale (calcine salts); and I believe these were confirmed by the reputable Cranfield Institute? They have a good paper on their website about magnetising fluids.
Thanks to Timble and EHocking, you both pipped me, unfortunately I was still searching for the link, should have checked the forum instead!
Roger: Please would you provide links when you refer to external documents, I keep wasting time trying to find things you're referring to. Thanks.
Anyway, to the matter at hand:
1. My previous comments relate to pure water in static magnetic fields. I was not taking limescale into account because it wasn't mentioned before.
2. The research at Cranfield refers to flowing water in a static field, which would be equivalent to stationery water in a changing field.
This latter is quite different to stationery water in a stationery field, which is what you would get if you put a glass of water on a static permanent magnet coaster. I presume (correct me if I'm wrong) that the instructions for use of said coasters do not say to vigorously stir or agitate the water in order to get them to "work", do they?
Firstly let me draw your attention to the comment on Fig 2 on the Cranfield link: "These effects were only apparent with a sufficient flow velocity through the field." In other words, the effect described by Cranfield is not relevant to stationery water in a stationery field, indeed it says elsewhere that in such an event no effect is observed.
I'm surprised that the people at Cranfield are having trouble working out what is happening, one thing seems obvious to me. Water exists in an ionic state, so do solids solvated in it, such as limescale. Limescale would consist of Ca++ and CO3-- ions dissolved in water. Now, if you move a charged particle through a magnetic field, the path of the particle will be deflected. In fact it will describe a circular path. The same principle is used in a cathode ray tube to form a TV picture. And even more relevant, it is the principle used in the mass spectrometer to separate ions.
I believe it would be relevant in this case, as the flowing water passes through the field, the calcium ions would be deflected sharply to one side of the pipe, whilst the carbonate ions would be sharply deflected to the other. The result would be that these ions would impact the pipe. If the pipe was made of copper, then I would expect that the increased concentration of ions in close contact with the surface of the copper, under the influence of electric microcurrents in the water which would also be generated by the passage of the ion through the field, would result in some electrochemical exchanges with the copper of the tube. It would be feasible to propose that some copper ions go into solution and form complexes with the calcium carbonate and other impurities, resulting in different types of crystal formation. This hypothesis could easily be checked by examining the output for various forms of transition metal complexes, and in particular copper complexes, all of which I would expect to be more soluble than a pure calcium complex. I note that there appears to be a conspicuous lack of chemical analyses on the Cranfield site, so I wonder to what extent they've tested for this, although to be fair, they do mention a theory of "impurities" but with no further mention as to any results in this area. Seems rather obvious to me. As far as I can see, they've concentrated on crystal form analysis, which would be quite misleading if complexes were present. There is also no mention of the pipe material in these studies and what effect different types of material may have on the results, which is rather disappointing.
The rate of deflection would be proportional to the velocity of the ions passing through the field. In other words, the faster the water flows through the magnets the more pronounced the effect. In the case of stationery water in a stationery field (which is the situation with your magnetic coasters) there is not going to be any such effect.
I daresay there would be a number of other possible effects as well. Either way, it's obvious that the magnetic field will cause an artificial separation of anions and cations in the flow water and also that it will temporarily cause increased concentrations of certain ions in some parts of the flow. It may even be as simple as, that concentrating more calcium ions together in one area promotes the formation of larger crystals. A perfectly logical conclusion that would tend to be supported by the comparitive pictures on the site.
In any event, I don't see anything surprising here, it's just electrochemistry in one form or another. And there is no evidence that there would be any effect on pure water. Indeed, it actually says that the effect is most pronounced in supersaturated solutions with a high ionic load.
Do you claim this is the principle behind your magnetic coasters? In fact, what DO you think is the physical effect of your coasters?
You should quit the cleaning service Pragmatist to become a teacher for kids which is one of the most difficult and honorable jobs in the world.
[JOKING!!]