In 1989, the Noble Prize in Physics was awarded to Hans Dehmelt of the University of Washington in Seattle for his work on the fundamental properties of electrons. The Noble Prize was a result of 40 years of research in to the basic properties of electrons. The electron has only four known characteristics: mass, charge, spin and magnetism. And over the preceding years, mass and charge had already been measured to high levels of accuracy but the electron’s spin and magnetism were another story. To speak of the “spin” of something that is defined as a fuzzy bit of electron charge without definite size or shape may seem a bit odd since there is nothing in the ordinary sense of the word to spin. Physicists use the term because of an electron’s ability to store up energy within itself as similar to the way a flywheel stores up energy.
The spinning analogy leads us to the electron’s magnetism. For example, if an un-magnetized iron rod is placed into rotation about its cylindrical axis, it will become magnetized. This is known as the Barnett effect. Also an electron by virtue of its mass, charge and spin is also a magnet. If electrons are provided with the precise amount of magnetic energy, the spinning electron will absorb that energy and flip into alignment.
The exact amount of energy required to produce a “spin-flip” is determined by the g-factor, known as gyro-magnetic ration discovered by Paul Dirac in 1928. Dirac noticed in his experiment whole atoms absorbing and releasing energy as the electrons undergo spin flips.
We should bear in mind that all materials experience magnetic effects. It is merely a question of degree of influence. All the known elements in the periodic chart fall in two categories – paramagnetic and diamagnetic. With paramagnetic materials, the flux draws the materials into the areas of stronger flux. Ferromagnetics are a special sub class of paramagnetics since its iron / magnet attraction is extraordinarily strong. What we see on a daily basis is ferromagnetic interaction. Just because we don’t see strong attractive forces with other materials doesn’t mean that there is no magnetic effect. In many cases the term non-magnetic actually means ferromagnetic. Diamagnetic materials, on the other hand are materials that are driven into the weaker areas of magnetic flux.
Most materials possess paired electrons. However, some (for example iron) have unpaired electrons. It is the action of spin of the unpaired electrons that gives rise to the effect we call magnetism. It is simply the unpaired electron spin that gives rise to its magnetic moment and related field.
Hydrogen for example, in its para or other spin form, can either be paramagnetic or diamagnetic depending on the spin orientation. Ortho-hydrogen with its coincident spins is far more unstable that its para counterpart where the electron / nuclear spins are in opposition. Hydrogen in its para form can be converted to its ortho form by the application of an appropriate magnetic field. This process makes the hydrogen more volatile.
As previously mentioned, the concept of electron spin is similar to our concept of spin in every day non quantum world. In physics there is a fundamental law that states momentum cannot simply appear and disappear, since angular momentum is always conserved in any physical process. When magnetic force is applied, the atomic moments of the molecules tend to align with the directions of the field. As the axis of the electrons becomes aligned with the external magnetic field the angular momentum no longer averages out to zero. Consequently, the reactivity of the atom and the related molecules is enhanced. In octane (C8H18) the carbon content of the molecule in terms of mass is 84.2% while the hydrogen content is 15.8%. When it is combusted, the carbon portion of the molecule will generate 12,244 BTU (per pound of carbon). On the other hand, the hydrogen which comprises only 15.8% of the molecular weight will generate an amazing 9,801 BTU of heat per pound of hydrogen. Thus we can see the importance of hydrogen in generating heat when a hydrocarbon molecule is burned. By altering the spin properties of the electrons, we can enhance the reactivity of the fuel and related combustion process.
MHD application is effective for air also. In this case, as air is a gaseous fluid, “Brownian movement” hampers the effectiveness of its magnetic field. However, selective magnetic field imposed in the propagation of air flow generates a “swirl” motion into the air. This phenomenon is utilized in the air-breathe of a combustion system to achieve complete combustion.
Researchers abroad initially tried to assess the impact of electromagnets on fluids which failed due to a good number of variables for electromagnets to impart a stabilized result in one hand and cumbersome technical intricacies to fit these in different delicate industrial situations on the other hand.
Later, researchers adopted permanent ceramic magnets to suffice the need of selective magnetic fields in the propagation path of fluids. This also resulted in failure as Quantizing Magnetic Effect demands a minimum magnetic flux density of 3000G, which was not available from these types of magnets. Then came the usage of rare-earth magnets that has all the potential to overcome the problems incurred earlier. But the results obtained after using such magnetic preparations did not last long due to their ‘design flaw’ (bi-polarity) that lets the North and South pole cancel each other’s action since the magnetic fields always chose the path of least resistance, being the path of least effect, since with bi-polar devices most of the magnetic forces are merely being transmitted between the two poles.
The latest solution offered by the researchers abroad has been the concept of “Monopole Magnetism”.
One pole suppression technology is an appropriate approach in automobile and industrial fuel savings as well as pollution reduction and in water treatment as far as elimination and prevention of scale deposit problems are concerned. “One pole suppression technology” is based on individual lattice parameter of the magnetic material. The radius of curvature of the unwanted pole is increased selectively to dilute the magnetic flux density of the pole i.e. number of magnetic lines of forces in the suppressed pole is greatly reduced than that of the effective pole. In this case, the vector momentum of the magnetic lines of forces make an acute angle with the fluid motion resulting in quantizing magnetic effect into the fluid molecules.
Application of MHD principles and their advantage on water conditioning
The hypothetic works on the application of “MAGNETO HYDRO DYANMICS” (MHD) in the mid nineteen forties by Alfven opened a new arena of study on the remarkable simplicity and effectiveness of magnetism. The study of an electrically conducting fluid moving relative to a magnetic field is called “Magneto Hydro Dynamics”. It is found by experiments that molecules of any fluid in motion change their structure (molecular structure but not the structure of the molecule itself) under the influence of selective magnetic fields imposed in the propagation of the fluid.
Russian engineers applied this phenomenon commercially in the process water system to get rid of scaling problems within the water carrying pipes / tubes.
Scale is one of the banes of industry. It narrows pipes, blocks jets and is expensive to clean up. Mineral compounds in the water, such as calcium or magnesium carbonate, sulphate or chloride form these deposits when they precipitate out of the water, lining pipes with furry deposit.
Calcite is one of the major culprits of scale. It is the commonest form of calcium carbonate occurring naturally as an essential ingredient of limestone, marble and chalk. Water passing over such rocks dissolves calcite which may then form a stony scale inside pipes and tanks. Rock like deposits appear on boiler walls and tubes when water heats up or evaporates. The problem increases as water gets hotter. Water with 145 PPM of calcite flowing ate 5000 litres a day can produce 4.8 kilograms of scale each year at 60o C. At 80o C, it produces 29.9 kilograms.
Magnetic fields can affect this precipitation. It could change the size of particles of precipitated compounds, the ability of crystals to form, their shape and alter the solubility of compounds. An increase in the size of particles can have two beneficial effects. First, the larger crystals will not coagulate to form scale in the same way that the smaller crystals would. This is the purpose of the magnetic field. Secondly, the presence of the larger crystals disrupts the equilibrium between the fluid and any existing scale. Smaller particles, in general, dissolve more easily so larger particles will reduce the local concentration of calcite in the solution and remove the existing scale. Electron micrographs of calcium carbonate scale produced by evaporation show the crystal size increases when the fluid is treated magnetically. Associated with these differences in size are changes in crystallinity or the ability of precipitates to form crystals, which we can observe after magnetic treatment. The magnetic field affects the growing crystals. Under an electron or optical microscope, we can see, for example, that in a solution of calcium sulphate dehydrate, large single crystals form in the absence of a magnetic field. Within a magnetic field, smaller groups of crystals precipitate.
Studying the solubility of calcium phosphate, we found that magnetic fields alter the solubility or levels of super saturation of solutions used in phosphating industry. On a crystal, the external faces are the slowest to grow as the crystal develops. Adding chemicals to a saturated solution can change the growth on one set of crystal planes relative to other planes, altering the shape of the crystals. There is considerable evidence that applying a magnetic field to growing crystals also changes the relative growth of their external faces. These changes in crystallinity and in–crystal structure must arise because of interaction species, the induced magnetic field on the charges species and rate of flow of fluid, could together produce energy that, by normal collision process between molecules, could act downstream in the system, removing or preventing scale. The amount of energy produced in this process in typical scale forming systems is likely to be small. Although it may contribute to the overall process, it seems unlikely that it explains the observed phenomena fully. The energy available to single ions from this process might perhaps alter the way in which these ions interact with the growing crystals in the fluid. This energy might be important in modifying the way in which crystals form around a nucleus.
Another possible explanation is the change in nuclei. Magnetic field modifies crystal nuclei. The nuclei on which the crystals start growing and growing crystallites are very small and have charges surfaces. As they pass through the magnetic field, these charged particles encounter considerable forces as the magnetic field interacts them. This distinguishes fluids treated magnetically from untreated fluids. The magnetic field acts at the surfaces of the crystallites, modifying the nature of the charges at the surface. This alters the growth of the crystals in general and on specific planes. The size of the crystal will change as the pattern of growth in the field alters. The ability to form crystals alters as the relative rate of growth of specific planes of the crystals respond to the magnetic field. This also changes the crystal’s shape. As the relative energy available to the growing crystals vary with and without the magnetic field, so will the crystal phase. In turn, as crystals grow differently, their solubility or levels of super saturation in fluid alters. This explains why scale starts to dissolve; the equilibrium between the fluid and the precipitate changes because crystals are growing in the different way. At the interface between solids and fluids, diffusion layer arise between the solution and the faces of the growing crystal. The growing faces each carry a distinctive charge and this is where magnetic field works.
THIS IS AN EXTRACT FROM THE THESIS ON THE STUDY OF MHD PRINCIPLES ON LIQUID FUEL COMBUSTION AND WATER TREATMENT BY AMIT MITRA RESEARCH SCHOLAR, MECHANICAL ENGINEERING DEPARTMENT JADAVPUR UNIVERSITY KOLKATA
