Hard Water Problem 8

[GJZ]

I have an evaporative gas cooling system which uses fairly hard water. Inlet gas temperatures are typically around 800F, but can be as high as 1000F. Not surprisingly, the calcification that forms on the water spray nozzles affects the quality of the spray and, therefore, the effectiveness of the cooling. Besides installing a water softening system, someone thought there was a special steel available that inhibited the calcification process. If so, the spray nozzles could possibly be made from this steel. Has anyone heard of such a steel?

 

[smile1]

We had a similar process cooling exhaust gas from jet engine test stands. We chemically treated the water stream with an organo phosphate, at about 50 ppm, with a cooling water dispersant. This worked well, inhibiting crystalization. We only used the water once through.

Softening is a good suggestion, or RO, or demineralization. Each depends on how much evaporation you expect in the bulk stream.

A special metal that would inhibit crystal formation? Seems unlikely, or everyone would make their exchangers out of it. It is possible that a material might not allow a crystal to attach, but I am unfamiliar with that application.

 

[xtremetech]

I have had some experience with magnetic water treatment and it works well for some fluids. In high silica and iron enviroments this is not recomended, but we did an experiment at a geothermal plant in my country and we had some results. You can find out about magnetic treatment at

http://www.mhdsystems.com

, I hope this is of some help for you.-

 

[xtremetech]

I have had some experience with magnetic water treatment and it works well for some fluids. In high silica and iron enviroments this is not recomended, but we did an experiment at a geothermal plant in El Salvador and we had some results. You can find out about magnetic treatment at

http://www.mhdsystems.com

, I hope this is of some help for you.-

 

[BobPE]

Yikes, not the magnets again...LOL

 

[xtremetech]

Please, tell us about the magnets, I tried them and got some results with geothermal water, and this is hard to do.
It would be interesting to know your experience.

 

[BobPE]

Here, maybe I can help you with my experience with magnets magnets. I quoted this sales jargon from the web site you mentioned, because this appears to be the only driving force I find on every magnets oriented device site I have seen, so I knew it had to be on this site. For thie interest of everyone here, let me repeate tha sales jargon and I quote:


"Any fluid flowing through the MHD unit is exposed to dense magnetic fields provided by permanent high-strength magnets within the unit. These intense fields are responsible for a physical/mechanical disturbance of the molecular structure of the particles within the fluid. These affected particles now possess an elevated surface charge which is distributed down-line from the unit to existing scale and other suspended scaling particles. As these charged particles come into contact with deposited scale, the crystalline structure of the deposition is physically altered.Rather than being deposited as mineral scale, aragonite crystals clump together to form soft precipitates which are easily flushed through the system."

Lets start by looking at the critical sentences in this statement.



The second sentence reads that there is an electrical/mechanical????????????? disturbance in particles after passing through the magnet. OK, what the heck does this mean? An if there is, so what. And please dont tell me what every magnet sales person does, the magnets are so strong the break chemical bonds. YIKES.... And about these particles in the water, which ones? the water ones? All information was careful to say particles and not molecules or cations and anions, not that next time you read info on magnets. Now to give this site the benefit of the doubt sinces I am not picking on it, I didnt read to see what particles they were focusing on, but I would assume it to be all particles in the water like the others. And for these particles to become charged, they need electrons, period...


Now lets look at the third sentence: The particles possess an elevated surface charge, and of course this occurs after the fluid travels through the magnet. Now magically there is mass creation occuring because somehow electrons are just created from this disturbance. These electrons just appear, which in itself should be marketed since I know a lot of companies building power plants to get electrons. But that has nothing to do with the hard water, so I will go on.

The fourth sentence is what I call the driving force of the magnets theory. The elevated surface charge of the particle stated in sentence three now becomes an officially charged particle, by the magic electrons I am assuming.

The problem with this quoted material is that magnets cannot create electrons to charge these particles. If the water had electrons, we wouldn't need the magnets, and most electrons in water are either tied up chemically or involved in a corrosion process of some type and not available for to charge particles.

So what gives, I have yet to see one legitimate academic article describing this so call softning process induced by magnets. And by legitimate I mean papers prepared by the top Untited States Engineering Schools. I will be honest that I read one paper that could not determine the effect of magnets on changes of studied water quality, but it did not involve softning.

So, now maybe you can understand my problem with magnets, and maybe you can help me with it...I am always open to hearing new ideas.

BobPE

 

[DeltaCascade]

Smile1 seems to have answered the original question quite well But thank you BobPE, for comments on magnets!

My indirect experience with magnetic water treatment is from, alas, testimonials about how great they are. Typically, a boiler water system is chemically treated to prevent scale and corrosion, with good results (boiler feedwater deaeration to remove corrosive dissolved oxygen is a separate topic). Then, the operator switches to magnetic treatment and still gets apparent good results, saving operating cost and work of applying treatment chemical ... hence the testimonials. This appears to be from a misunderstanding of the originanlly specified chemical treatment program. The operator's boiler tube corrosion rates may have accelerated, but the operator, particularly the unsophisticated one, like one operating lower pressure boilers, is not likely to notice (5 or so years boiler tube life instead of 30+?). When the operator gets future unexpected boiler feed water contamination of water hardness, scale WILL form. The insurance benefit of the original treatment is no longer there. When the boiler efficiency drops due to scale, or if it gets so bad that chemical cleaning is needed, where are the testomonial makers then? Embarassed! Hiding and not motivated to advise their competitors of its folly.

It seems that there is no funding to disprove magnetic water treatment device efficacy and perhaps that is the problem. ... except at eng-tips.com?

Buyer beware ... perpetual motion machines for sale!

Just an(other) opinion.
Cheers//

 

[FM9779]

your problem is solved.. In Germany, Holand, spain and other countries are using a special kind of magnet, not any normal magnet that you can find in the market. I saw some studies about spraying steamd and hight tempreture wated. They used this type of magnet and there where no existance for any Caco3 at all except a small layer less than .1mm

The only company whom manufacturing this kind of magnet because they invented it is SKW system Gbbh

we are using this king of magnet in our melitary war ships and destroyers, they prevent any scaling, corrosion and any marine growth

 

[bimr]

I do not believe that there is any special steel that will inhibit calcification. You might find a steel that will holdup better to the corrosion.

You might want to consider using a demineralizer rather than a water softener.

As to magnets, magnets are junk science and anyone who promotes such is a quack. If you promote magnets in the US, you are a US quack. If you happen to be from Germany, well then you are a German quack. Quack, quack, quack. Check the link before quacking any further.

http://www.csicop.org/si/9801/powell.html

End of discussion.

 

[orenda1168]

For what it's worth, I'd like to put in my two cents about the magnetic treatment question. In the early and mid-1960's, several US petroleum refineries extensively and rigorously evaluated magnetic control of process water calcium/magnesium fouling as a potentially very economically attractive means of reducing/eliminating process water chemical treatment costs.

None of the evaluations were able to substantiate the claimed ability of the magnetic treatment technology to control hardness deposition. The technology was subsequently debunked as trash science and discarded.

Dick Kersey

 

[FrancisM]

The use of conventional antiscalants will work very well. They can be added to the solution to prevent crystallization of solids in the solution.

Call GE Betz for details, or email me for details.

 

[25362]

A side note on deposits of CaCO₃ in nature. Of the speleothems, aka cave formations, stalagtites and stalagmites are formed not because of water evaporation but because of lack of sufficient CO₂. In the reaction:

CaCO₃(s) + CO₂(g) + H₂O(l) <=> Ca⁺⁺(aq) + 2 HCO₃^-(aq)​

It's not the lack of water but the lack of sufficient CO₂ that shifts the reaction to the left and precipitates CaCO₃.

 

[jmj5152]

I am new to this site. Interesting discussion on magnets. is it at all possible that (and I may be suggesting this with a subconscious level of jest)some excited state of electrons create a form of non scaling CaCO3 particles?

 

[25362]

I found one site that speaks of electric fields:

http://scale-watcher.com/swscience.html

 

[BobPE]

I also have a good refernece for magnetic water treatment.

http://www.csicop.org/si/9801/powell.html

BobPE

 

[cub3bead]

I have seen the effects on the tower fill where magnetic treatment was deployed to replace their chemical treatment program. It is truly amazing how much CaCO3 can be deposited on high efficiancy film fill. The company they are now back on a chemical treatment regime because the thermal performance of the tower declined due to the restricted gas path in the fill.

 

[BobPE]

cub3bead:

The scary thing is that magnetic treatment seems to have a life all its own outside of the engineering world. I even find it in our engineering world at times and it makes me very concerned. In the situation you describe, how did the magnetic treatment system get deployed? Was it engineered or just a salesperson approach?

BobPE

 

[jmj5152]

BobPE: Thanks for the website. Implications from research papers are that very short term effects like rounded, smoother scale formation may take place, but crystal structures formed beyond the magnetic field may revert to jagged edge form, promoting scale formation.

 

[cub3bead]

BobPE,

A good, quick salesman and a MBA spreadsheeter with no real world experience. The business case rather than chemistry won out. Oops.

cub3bead