Magnetic treatment of hard water to prevent scale and corrosion? How does this work?

Question

I ran across this company at their booth at a Tradeshow (2018). They claim to have a chemical free (and as far as I can tell - a power free) treatment method for hard water to minimize scale and corrosion effects downstream. My intuition tells me that this can't be for real, partly because it's "power free", but I also don't understand their explanation for how it works:

"When water is subjected to temperature change (delta T), pressure change (delta P), friction, turbulence and/or evaporation, dissolved minerals, primarily calcium carbonate (CaCO3) and magnesium carbonate (MgCO3), will precipitate out of solution and deposit on the heat transfer surfaces of plumbing systems and equipment in the form of a rock-like build-up, commonly called lime/scale. At the molecular level, the negatively and positively charged ions of these minerals are attracted to, and bond tightly together with, one another, thus forming the lime/scale deposit known as calcite. These mineral deposits are a great insulator and require much more energy to heat or cool water in many different types of residential, commercial, institutional and industrial applications."

They've been around for since 1964, so they are either:

• very good salesmen, with a critical threshold of gullible people, or
• they've discovered some niche effect (unlikely)...

Thoughts?

Answer 1

There's very little data available to evaluate these claims. The manufacturers tend to rely on anecdotal information and testimonials rather than hard data, and no-one else really has any incentive to spend money to test these devices. I did find an article from Penn State University that cites several studies which reported no effect from the devices, and recommends that consumers use caution and have water independently tested both upstream and downstream of the device if they choose that route.

Answer 2

It's snake oil. From a physics standpoint, aqueous chemical reaction dynamics do not couple to magnetic fields.

Answer 3

Your quote is an explanation of how scale works, not of how the 'magnetic' system works.

There is a suggestion that 'magnetic' systems cause the calcite to precipitate out as sand rather than as scale https://patents.google.com/patent/CN201476678U/en

But the U.S. Department of Energy Office of Scientific and Technical Information found no effect in their test https://www.osti.gov/biblio/567404

Answer 4

There were a few papers presenting studies of similar processes published in pretty reputable journals just over 20 years ago. The only one of them that appears to be available open access is https://www.trentatron.com/Studies/Magnetic%20water%20treatment.pdf, which found empirically that, when water had been passed through a magnetic field, dissolved calcium carbonate became more likely to precipitate as the aragonite polymorph, rather than the calcite polymorph; since aragonite has poorer structural integrity than calcite, this might be experienced as reduced scaling. The paper suggests three possible mechanisms for this, two of which operate through the magnetic field removing transition metal hydroxides from the water in ways that disfavour calcite precipitation, and one through a sort of Hall-effect separation of cations and anions. But this test used a static magnetic field, not an alternating one as proposed by the company OP has encountered; and none of the proposed mechanisms quite match up with that claimed in the manufacturer's blurb.

Answer 5

It does not; It has provided entertainment at NACE meetings. Great bunch of sales men over the years. There is no limit to excuses why tests can not be set up wit NACE members providing a test location. Tests have been set up with refinery ,etc, with people with no corrosion background. Disclaimer ; I have not been to Nace meetings in 30 years.