willkho
Posts: 3
Joined: Sat Jul 21, 2007 8:49 am

Electromagnetic field on metal pipe

Postby willkho » Sat Jul 21, 2007 9:02 am

Hi guys,

I have a wire coiled round a metal pipe. I connected it to a pulsating DC current source trying to generate a magnetic field on that coil to see the effect of magnetic filed on various medium passing through that pipe. But I found that the metal pipe is absorbing most of the magnetic field and left little of it that actually penetrates through the pipe. So I cannot continue with the experiment.

The current I had is about 3 ampere and the pipe is 4" diameter steel pipe.

Please advise how can I prevent the metal pipe from absorbing the magnetic field generated by the coil and let most of it to penetrate into the pipe.

Note: I cannot use any plastic pipe as this is the condition of the project.

Look forward to hear from the experts out there.

Thanks

William Kho

Louise
Former Expert
Posts: 921
Joined: Mon Jan 16, 2006 2:17 pm

Re: Electromagnetic field on metal pipe

Postby Louise » Sun Jul 22, 2007 9:53 am

willkho wrote:Hi guys,

I have a wire coiled round a metal pipe. I connected it to a pulsating DC current source trying to generate a magnetic field on that coil to see the effect of magnetic filed on various medium passing through that pipe. But I found that the metal pipe is absorbing most of the magnetic field and left little of it that actually penetrates through the pipe. So I cannot continue with the experiment.

The current I had is about 3 ampere and the pipe is 4" diameter steel pipe.

Please advise how can I prevent the metal pipe from absorbing the magnetic field generated by the coil and let most of it to penetrate into the pipe.

Note: I cannot use any plastic pipe as this is the condition of the project.

Look forward to hear from the experts out there.

Thanks

William Kho


I'm not entirely sure what you are trying to do here, but I think what you've done is make an electromagnet and you want to test various objects inside this magnet? The pipe is just to make a space for the object, and not supposed to be a component of the electromagnet?

Well, my first suggestion would be to go to a plastic pipe, but that isn't allowed with your project. So, have you considered looking up other metals and seeing which ones are most like a plastic pipe (that is, which ones are least conducting or least magnetizable)?

Louise

willkho
Posts: 3
Joined: Sat Jul 21, 2007 8:49 am

Postby willkho » Sun Jul 22, 2007 6:23 pm

Hi Louise,

The experiment has to be done with a metallic pipe, (any standard metal pipe in the market). The challenge is to do an experiment with electro-magnectic field to see the effect on the various medium that is transported by piping. The medium can be water, oil, air, etc..

Do hope to hear from the experts out there.

Thanks

Cheers.

William Kho

Louise
Former Expert
Posts: 921
Joined: Mon Jan 16, 2006 2:17 pm

Postby Louise » Mon Jul 23, 2007 7:49 am

willkho wrote:Hi Louise,

The experiment has to be done with a metallic pipe, (any standard metal pipe in the market). The challenge is to do an experiment with electro-magnectic field to see the effect on the various medium that is transported by piping. The medium can be water, oil, air, etc..


I still don't understand what you are doing, so the help you will get will be limitted, unless you provide an expanded discription of your project.
What properties are you measuring? [And do you really expect to see an effect on the materials you listed? I wouldn't think so...] How do you know the strength of the magnetic field? You say it is absorbed by your pipe, but you you really know that you have a magnetic field? [I understand that current through a wire will create a magnetic field, but can _you_ observe this field for your setup] Lastly, it is really hard to have strong magnetic fields over large distances- a 4 inch pipe is pretty big... can you go to a smaller pipe?

As I said before there is no such thing as a "standard" metal pipe. Pipes can be made of all different types of metal, and even pipes that appear to be made of the same alloy (say "steel") have very different properties. For example, soft steel is magnetizable, and is suitable for making electromagnets, while hard still isn't magnetizable and won't work at all. Since I still don't exactly see what you are doing, I'm not sure which would be best for you, but you should look in to what type of steel your pipe is.


Do hope to hear from the experts out there.


As the expert who responded, I find this somewhat insulting.

Louise

Craig_Bridge
Former Expert
Posts: 1297
Joined: Mon Oct 16, 2006 11:47 am

Postby Craig_Bridge » Tue Jul 24, 2007 1:59 pm

Please advise how can I prevent the metal pipe from absorbing the magnetic field generated by the coil and let most of it to penetrate into the pipe.

Sorry, we can't repeal the laws of physics for you.

If the pipe is highly conductive, you have something close to a "Faraday Cage". If the pipe is ferromagnetic, you have a magnetic permeability shield. If it is both, then you have a an excellent shield for a wide range of Electric and Magnetic fields wavelengths.

If possible, please post a reference to where this project came from. Hopefully it isn't another "sciencebuddies" project that we need to go fix.

If there are good scientific reasons for requiring the experimente to be done inside a metal pipe and you are not restricted to the diameter of pipe, try using a large diameter metal pipe and building a coil on a plastic form inside the metal pipe. The challenge is then to find a way to insulate the means of making an electrical connection to one end of the coil inside the metal pipe. Feed through capacitors are typically used for this purpose in transmitting equipment and various high energy physics detectors.
-Craig

willkho
Posts: 3
Joined: Sat Jul 21, 2007 8:49 am

Postby willkho » Wed Jul 25, 2007 7:22 am

Hi Craig and Louise,

The objective of the experiment is to find out if a magnetic field can be applied to a liquid flowing in a pipeline.

This experiment is based on a proven theory that water reacts to magnetic field because the water molecule is bi-polar. Hence also want to find out what about the effect on other liquid, like oil, diesel, sea water, etc.

As many of such liquid are transported through pipe line, mainly made of steel, the experiment is to find out if a magnetic field of a fix strength (based on constant current supplied to the coil) on a pipe line will have in the medium flowing inside. So in order to see if the flow has an direct effect through a magnetic field, the field needs to be strong enough to penetrate the steel case into the medium.

No point testing it on a plastic pipe because in the real world most liquid are transported through steel pipe.

I do hope you have a better understanding of the experiment now.

Do look forward to an answer from the experts.

Regards

William Kho

Louise
Former Expert
Posts: 921
Joined: Mon Jan 16, 2006 2:17 pm

Postby Louise » Wed Jul 25, 2007 9:02 am

willkho wrote:[cut]
This experiment is based on a proven theory that water reacts to magnetic field because the water molecule is bi-polar. Hence also want to find out what about the effect on other liquid, like oil, diesel, sea water, etc.


Most of the liquids you mention are nonpolar, and will not be effected by a magnetic field at all. At least not unless you have a _very_ big field. Even water is unlikely to be strongly influenced by any magnetic field you can produce. Most of the trick/simple projects using water/magnets are really using the ions in water, and not water itself for the effect. I believe the important quantity is unpaired spins, not whether a material is dipolar or not.

See for example, this webpage:
http://www.lsbu.ac.uk/water/magnetic.html

for a bunch of references, though I would read the actual articles and not the summaries provided, since the author seems to be using them to support the idea that magnetic fields may have healing properties.

This is why I was curious about whether you thought you would see an effect. Again, I have no idea what properties you think you would measure, but I think most of the things you can measure will show either no change, or such a small change that you cannot measure it. For example, viscosity and flow rate are two observables you could measure. Neither will be changed enough (if at all) by a magnetic field so that you can measure it, certainly not for oil and hydrocarbons. Apparently, you can slow down salt water flow with rare earth magnets (but see above).

I am getting the feeling that this is not a science fair project, given your desire to use steel pipes only, but rather some attempt to make a commerical device for the "real world" and thus beyond the scope of this website.

Louise


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