JPS588229B2 - Kanjiyouchiyokusengatadenjipump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a yoke in an electromagnetic pump.

As is well known, electromagnetic pumps create a moving magnetic field linearly, similar to the principle of an induction motor, and attempt to transport liquid metal to be transported in one direction by the induced electromagnetic action.

Figure 1 shows a conventionally used annular linear induction electromagnetic pump (referred to as ALIP type).As is clear from Figure 2, in this ALIP type electromagnetic pump, the cross section of the liquid metal flow path is usually annular. The outer duct 3 is supported on the inner duct 1 by the rim 6 to form a liquid metal flow path 2 between the two ducts, and a predetermined gap is provided between the outer duct 3 and the outer duct 3 in the circumferential direction. An iron core 8 is provided which is laminated on the iron core 8.

A coil insertion groove is formed in this iron core 8, and a doughnut-shaped winding 7 excited by multiphase alternating current is housed in the groove so as to generate a moving magnetic field 9 in the flow direction 10 of the flow path 2.

Further, inside the inner duct 1, a yoke 5 formed of iron plates laminated in the circumferential direction is housed.

In the ALIP type electromagnetic pump having the above configuration, when the winding 7 is excited with multiphase alternating current, the magnetic flux path (magnetic path) of the magnetic field induced in the winding 7 is shown by the broken line 4 in FIG. In the iron core part 8, it passes parallel to the liquid metal direction, in the iron core tooth part and the liquid metal flow path part 2, it passes perpendicularly, and further in the yoke part 5 housed inside the inner duct 1, it passes in parallel.

As described above, the liquid metal interlinks with the magnetic path 4, and a continuous closed loop current flows in the circumferential direction within the annular shape.

The interaction between this induced current and the moving magnetic field creates a force in the same direction as the moving magnetic field, and this force causes the liquid metal to move.

However, in an electromagnetic pump having such a configuration, the yoke iron core 5 has a yoke structure formed of laminated iron plates, so the distribution of the laminated iron plates is uneven on the outer periphery facing the liquid metal flow path, and is uneven. The magnetic flux distribution along the annular cross-section of the flow path is not uniform, resulting in a pulsating distribution.

For this reason, even if the induced current in the liquid metal is constant, the distribution of the generated force is not uniform.

Therefore, since the flow velocity distribution is different, local flow turbulence occurs in the flow path, resulting in greater fluid loss than in the case of uniform flow, and the efficiency of the pump decreases.

In addition, in this laminated core type, the liquid metal is at a relatively high temperature (300
℃ to 600℃), the yoke core itself is exposed to high temperatures, and the cores may peel off from each other due to magnetic vibrations, making it impossible to expect the yoke core to integrate, resulting in a decrease in mechanical strength. , the noise is loud due to the magnetic vibration caused by the alternating magnetic field.

In addition, ALIP type electromagnetic pumps are generally very long in length compared to the diameter of the yoke core, and are made by laminating thin iron plates in the circumferential direction.
Fixing it in place has poor workability and is inconvenient in terms of increasing work efficiency and reducing costs.

The present invention has been made in view of the above points, and has a yoke structure that uniformizes the magnetic flux distribution interlinking with the induced current in the annular liquid metal, thereby increasing the flow rate of the liquid metal in the annular flow path. It is an object of the present invention to provide an annular linear induction electromagnetic pump that can make distribution as uniform as possible and reduce liquid loss within a duct.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is exactly the same as FIG. 1 and FIG. 2 except for the structure of the yoke core 5, and the same parts are denoted by the same reference numerals and the explanation thereof will be omitted.

That is, in the present invention, the yoke 5 of the electromagnetic pump is made by mixing iron powder of a specific particle size, which has been refined into powder, and an organic and inorganic hardening binder (binder) in a predetermined ratio, as shown in FIG. It is integrally molded into a cylindrical shape under high pressure, and then
00° C.).

This powdered iron core has the characteristics that its magnetic permeability has no directionality, its core loss is relatively small, and it can be formed into any shape.

Therefore, with the above configuration, when this powder iron core is used as a yoke for an ALIP type electromagnetic pump, the magnetic flux distribution interlinked with the induced current in the liquid metal generated when the winding 7 is excited with multiphase alternating current will be uniform. Therefore, uniform pressure distribution and uniform flow velocity distribution can be realized, and fluid loss can be reduced.

In addition, since the yoke portion is uniform and average, there is no peeling of the yoke steel plate due to temperature or magnetic vibration in the laminated core type, which increases the mechanical strength of the yoke core itself and reduces noise caused by magnetic vibration. can be resolved.

Furthermore, since it is a cylindrical powder core type, it is only necessary to insert the yoke core into the internal duct 1, making the machining work very easy and reducing costs as a result of improving work efficiency.

Moreover, since a binder containing an inorganic hardening binder is used, it can withstand high heat and has a high caking effect.

For example, the liquid metal to be transported, such as liquid sodium, generally has a very high temperature of 300° C. to 600° C., and the yoke core is exposed to high temperatures, but the desired magnetic properties are maintained even in such a case.

It also has the advantage that it is not necessary to compress and heat it in the assembled state or to magnetize it during compression and heating.

In the above embodiment, the yoke core is composed of a single cylindrical piece, but as shown in FIG. Alternatively, the block may be divided into a plurality of segments in the direction of the moving magnetic field as shown in Fig. 6, or the block may be divided into segments in both the direction of the moving magnetic field and the direction perpendicular thereto as shown in Fig. 7. It may be crimped and integrally formed.

That is, even in a yoke structure divided into a plurality of blocks as shown in FIGS. 5, 6, and 7, the relative permeability is Since the device has a large part (gap) where the magnetic coefficient is [1] compared to induction motors, etc., if the powder core is divided into parts and crimped together, the magnetic flux that enters in the radial direction from the outer surface of the yoke core will be uniformly distributed. The structure has magnetic resistance and does not have a major effect on the magnetic circuit.

Therefore, the yoke divided into blocks as shown in FIGS. 5, 6, and 7 has a uniform magnetic flux distribution in the same way as the yoke core shown in FIG. 4, and the same effect can be obtained. Since high-pressure pressing is required when forming powdered iron cores,
Compared to the case of using press equipment for forming a single yoke as shown in Fig. 4, blocks of appropriate size are formed as shown in Figs. Manufacturing a yoke core is more rational in terms of equipment and work, and can reduce costs.

As explained above, the present invention uses a yoke composed of a powder core block as the yoke core of an annular linear induction electromagnetic pump, thereby achieving uniform magnetic resistance, low fluid loss, and high efficiency. It is possible to provide an annular linear induction electromagnetic pump that eliminates inconveniences such as peeling of the yoke core and noise, and that can reduce costs by improving work efficiency.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of a conventional annular linear electromagnetic pump;
The figure is a sectional view taken along the line n-1 in FIG. A perspective view of the powder core yoke, Figures 5 to 7 show other examples of the yoke shown in Figure 4, and Figure 5 shows the powder core in Figure 4 divided into blocks in the direction of the moving magnetic field. Perspective view when
The figure is a perspective view in which blocks are divided in the circumferential direction, and FIG. 7 is a perspective view in which blocks are divided in both the circumferential direction and the moving magnetic field direction. 1... Inner duct, 2... Liquid metal flow path, 3... Outer duct, 4... Magnetic flux path, 5... Joint Iron core, 6... Rim, γ
...Coil, 8...Iron core, 9...
...Moving magnetic field direction, 10...Liquid flow direction.

Claims (1)

[Claims] 1. A rim is provided between the inner and outer ducts arranged in a concentric cylindrical shape to form an annular flow path between the two ducts, and an iron core wrapped with a coil for generating a moving magnetic field is provided on the outer periphery of the outer duct, and It is obtained by mixing binder powder containing iron powder and an inorganic hardening binder in the inner duct so that the magnetic flux distribution is uniform with respect to the annular flow path, molding it under high pressure, and then heat-treating it. 1. An annular linear induction electromagnetic pump characterized in that a yoke core is provided which is made of one powder core block or a combination of a plurality of the powder core blocks and pressure-molded.