Eddy current heating

Fig. 10. The Groth ZG 5 centrifuge. R, rotor R, stationary shaft T, Teflon seal K, K, chambers for gas scoops S, S2, scoops V, gas supply M, manometer Z, Z2, tapping points for enriched and depleted gas P, P2, vacuum chambers E, electromagnet for eddy current heating Tb, Tb2, temperature measuring devices K, cooling coil and D, D2, labyrinth seals.

There are several tricks described in the literature [28-39], which must be kept in mind in projecting a good superconducting thermal switch. High-purity metals are used in the form of thin foils or wires in order to increase kn and to reduce eddy current heating. An useful discussion of the constructive details of thermal switches is given in ref. [40]. 

Hyperthermia and thermoablation have been accomplished using capacitive or inductive coupling of rf fields (10-100 MHz), microwaves (> 300 MHz), ultrasound, lasers or external heat [171-177]. Macroscopic metal implants of Cu and other high-conductivity metals have been used to induce eddy-current heating. The absorbed power per mass is called the specific absorption rate (SAR), which can be expressed as... 

They have a tank, which tends to retain all magnetic fluxes inside the unit. This is important when the location of the reactor is being considered. The radiation of the flux can cause eddy current heating in adjacent steelwork and magnetic interference with other nearby electrical and electronic circuits. 

The magnetic profiler uses independently exited electromagnets installed across the width of a dryer cylinder. As the cylinder, which is a conductor, passes through the magnetic flux lines, eddy currents (which produce heat) are induced in the shell. This heat provides very precise and discrete control of the moisture profile. The eddy current heating produced can be 100 times higher than the input power to the inductor in the 150-mm width band. Commercial tests show that these profilers control the moisture within h-0.3% and increase the machine speed up to 5%-10% [48]. 

Resistive heating When charged particles or atomic elements like electrons in carbon based substances are free to move through the material, the movement induces a current that runs in phase with the electromagnetic field. Comparable to eddy current heating for induction, the pole change of the currents leads to a heat loss. 

Other sources of heat in-flows include mechanical vibrations, sloshing during transport, eddy current heating and Joule heating of measuring instruments. 

Another source of heating can arise from electromagnetic fields causing eddy-current heating in low resistivity materials such as copper, aluminium and superconductors. The answer is to ... 

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