Kanazawa University

Kazuo Bessho

Sotoshi Yamada

Masato Enokizono

A converged magnetic flux type electro-magnetic pump in which plural circular conductor plates provided with slits reaching peripheries from central holes in the plates and plural exciting spiral coils are alternately stacked with respect to each other and individually surrounded by magnetic frames. A high density traveling magnetic flux is generated by eddy currents concentrated around the central holes of the circular conductor plates in response to the application of a multiphase alternating voltage in a non-magnetic pipe passing through the central holes with a cylindrical iron core inserted in the pipe, so as to convey high temperature molten metal such as molten sodium used for refrigerating a high speed breeder reactor. The thickness of the central portions of the circular conductor plates is greater than the remainder of the plates, so as to form a radial T-shaped cross-section. Eddy currents concentrated in the central portions of the circular conductor plates are dispersed in the axial direction by increasing the thickness thereof, so as to prevent local overheating and to increase the applied voltage, effective magnetic flux and output thrust and hence improve the efficiency and molten metal conveyance.

Converged magnetic flux type intense magnetic field electro-magnetic pump

A conventionally arranged multilayered eddy current type intense AC magnetic field generator is remarkably improved only by intercrossing frame-shaped iron cores with alternately multilayered structure of exciting coils and conductor plates for inducing eddy currents, so as increase the impedance of the exciting coils as well as to increase the mutual inductance thereof with the conductor plates. As a result, the desired intense AC magnetic field can be efficiently and continuously generated with evidently reduced electric power.

Multilayered eddy current type power-saved intense AC magnetic field

In circular conductor plates having radial slits alternately stacked with spirally wound coils continuously connected in order and supplied with comparatively low frequency AC current, eddy currents generated in peripheral direction are concentrated along the radial slits around central holes of the conductor plates, so as to induce concentrated AC magnetic fluxes in those holes. As a result, an intense AC magnetic field can be efficiently obtained by a comparatively small driving AC current in comparatively low frequency range.

Eddy current type multilayered coil for generating intense AC magnetic

Five-legged core type frequency triplo-multiplier

The disclosed coil is for a strong AC magnetic field generator with coaxially laminated eddy-current carrying conductor disks each of which disks have a central hole and a radial slit. Each turn of the coil consists of an annular conductor plate disposed between adjacent disks and each turn is insulated from the adjacent conductor disks by insulation rings inserted between the annular conductor plate and the adjacent conductor disks. The annular conductor plate and the insulating rings in each turn of the coil have radial slits. The slits in one coil turn are aligned in a radial direction, but the slits of adjacent coil turns are angularly displaced with respect to the central hole of the conductor disk. A slitted end of the annular conductor plate of each coil turn is connected to that of the immediately neighboring coil turn through the radial slits of the conductor disk and the insulation ring.

Laminated coil for an eddy-current type strong AC magnetic field

The disclosed strong magnetic field generator has a number of concentric conductor circular plates, central portions thereof being unified, each of which plates has a radial slit so as to have open sidewalls. Exciting coils are mounted between each of the concentric circular plates respectively, so as to induce an eddy current in each of the conductor circular plates in a peripheral direction. A conductor circular plate forming the unified central portions of the concentric circular plates has a central hole and a radial slit extending from the central hole to each of the slits of the concentric circular plates and connected with each other at a periphery thereof, while the central hole is placed at the center of all of the concentric circular plates and while all of the radial slits are aligned in a longitudinal direction. Thus, the path of eddy current in each circular plate is closed through sidewall portions of the radial slit and the central hole, and hence the eddy currents of all the concentric circular plates are superposed at the sidewall portion of the central hole for generating an extremely strong magnetic field in the central hole.

Multilayered-eddy-current-type strong magnetic field generator

The disclosed strong magnetic field generator has a number of concentric conductor cylinders, each of which has a longitudinal slit so as to have an open sidewall. Exciting coils are mounted on the cylinders to induce an eddy current in each cylinder in a circumferential direction. A conductor plate with a central hole and a radial slit extending from the central hole to an open end at its periphery is connected to the concentric cylinders while placing the central hole at the center of all the cylinders and while aligning the longitudinal slits of all the cylinders with each other along the radial slit. Thus, the path of eddy current in each cylinder is closed through sidewall portions of the radial slit and the central hole, and the eddy currents of all the cylinders are superposed at the sidewall portion of the central hole for generating a very strong magnetic field there.

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Kanazawa, Japan

Kazuo Bessho