JPH0233406B2 - DENJIFUIRUTAA - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in electromagnetic filters for removing magnetic contaminants from fluids.

Conventionally, electromagnetic filters have been used to remove magnetic contaminants such as iron from the cooling water used in large quantities in nuclear and thermal power applications to prevent corrosion of pipes and clogging of piping elements.

As shown in Fig. 1, the electromagnetic filter has a diameter of 600 to 2000 φ, in which a magnetic generating coil 1 wound with a large number of dry or water-cooled conductors is arranged on the outer periphery.
Spherical or piece-shaped magnetic grains 3 with fluid flow gaps are provided inside the non-magnetic (SUS) pipe 2 to adsorb magnetic contaminants in the cooling water 4.

However, when we examine the magnitude of the magnetic field (magnetic flux density) inside the coil 1, we find that in the radial direction r ₀ of the coil 1, as shown in Figure 2a, the inner surface of the coil is the largest and the coil center O is the smallest, as shown in Figure 2b. Become.

Further, in the axial direction _l0 of the coil 1 as shown in FIG. 2a, the coil center O is the maximum and the coil end is the minimum as shown in FIG. 2c.

Therefore, the attraction force is greater on the inner surface of the coil where the magnetic grains 3 are strongly magnetized and is smaller at the center of the coil, and the attraction force is also smaller at the ends of the coil than in the center, resulting in a biased phenomenon. The cooling water flowing through the center of the coil, that is, the center of the pipe 2, tended to pass through the filter without removing iron and the like. This tendency becomes more pronounced as the inner diameter of the coil becomes larger compared to the height of the coil.

The present invention has been made in view of the above-mentioned conventional problems, and is constructed by providing a streamlined non-magnetic capsule in the fluid flow direction at the center of magnetic grains corresponding to the center of the coil, so that the fluid can be controlled by a magnetic field. The fluid is made to flow only toward the inner surface of the coil where the fluid has a large diameter, thereby improving the removal rate of magnetic contaminants in the fluid.

Embodiments of the invention will now be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, an annular magnetic field generating coil 1 is arranged on the outer periphery of the non-magnetic pipe 2, and inside the pipe 2 corresponding to the magnetic field generating coil 1,
A group of iron balls 3, which are magnetic particles, are provided.

At the center of the iron ball group 3 corresponding to the center of the coil 1, that is, at the center of the piping 2, there are
As shown in the figure, a streamlined non-magnetic capsule 5 is provided in the direction of flow of the cooling water 4, and the capsule 5 includes a pair of magnetic discs 7, 7 having fluid passage holes 6,..., 6.
The iron ball group 3 is supported vertically and fixed to the inner wall of the pipe 2, and is held between the pair of magnetic discs 7 by a ball holder 12.

The capsule 5 is made of SUS (non-magnetic material), for example.
Accordingly, a conical upper part 5b and a conical lower part 5c are integrally molded on a cylindrical body part 5a, making the interior hollow.
The overall shape is streamlined.

Since the center portion occupies a small proportion of the internal cross-sectional area of the pipe 2, the loss resistance of the cooling water 4 does not increase significantly even if the capsule 5 is provided.

When the capsule 5 is installed in the center of the piping 2, as shown in Fig. 8, if the minimum magnetic flux density required for treatment is 0.2 ^T (2000 Gauss), if the capsule 5 is installed in the shaded area, the cooling water 4 does not pass through the center where the magnetic field is small, but flows only toward the inner surface of the coil where the magnetic field is large, so that the adsorption of magnetic contaminants is promoted and the removal rate is improved.

This is shown in FIGS. 9a and 9b of the conventional device without the capsule 5, and in FIG. 10a of the present application with the capsule 5,
A comparison with FIG. 10b is shown. Further, in the case where a central magnetic field reinforcing coil 9, which will be described later, is provided, the state of a composite magnetic field c of a magnetic field a caused by the coil 1 and a magnetic field b caused by the coil 9 is shown in FIGS. 10a and 10b.

Further, the pair of magnetic disks 7, 7 are connected to the coil 1.
Since a good magnetic circuit is formed with respect to the coil 1, the bending of the magnetic flux at the end of the coil can be corrected, and the magnetic field in the radial direction and the axial direction of the coil 1 can be made uniform.

This is compared to the conventional figure 12a without the magnetic disk 7,
FIG. 12b is compared with FIGS. 13a and 13b of the present application in which the magnetic disk 7 is provided.

On the other hand, as shown in FIG.
A central field strengthening coil 9 can be provided in the center of the interior 8 of.

If the coil 9 is used in combination with the magnetic field generating coil 1, the magnetic field at the end of the coil will be strengthened.

In addition, as shown in FIG. 7, a non-magnetic capsule 5
A pair of central magnetic field reinforcing coils 10 and 11 can be provided on both sides of the center of the interior 8 of.

The coils 10 and 11 are the magnetic field generating coil 1.
When used in combination with this, the magnetic field at both the ends of the coil and the center of the coil is strengthened.

When installing the central magnetic field reinforcing coil 9 inside the capsule 5, as shown in FIG.
and the lead wire 16 through the packing 15.
Either a split structure in which the lead wire 16 is drawn out, or an integrated structure in which the capsule 5 is fixed to the pipe 17 and the lead wire 16 is drawn out, as shown in FIG. 14b, may be adopted.

Note that the shape, position, number, etc. of the central magnetic field reinforcing coils 9, 10, 11 can be changed as appropriate.

As is clear from the above explanation, the present invention
Since a streamlined non-magnetic capsule is provided at the center of the magnetic particles, which corresponds to the center of the coil in an electromagnetic filter, it is possible to direct the fluid toward the inner surface of the coil where the magnetic field is large, without significantly increasing the loss resistance of the fluid. The removal rate of magnetic contaminants in the fluid can be improved.

In addition, since only a capsule is provided, the structure is extremely simple and inexpensive, and furthermore, it can be applied to existing electromagnetic filters with only a slight modification.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional electromagnetic filter, Figure 2 is a cross-sectional view of a conventional electromagnetic filter.
Figure a is a cross-sectional view of the magnetic field generating coil, Figure 2 b is a graph showing the magnitude of the magnetic field in the radial direction, Figure 2 c is a graph showing the magnitude of the magnetic field in the axial direction, and Figure 3 is a graph according to the present invention. 4 is a perspective view of the capsule, FIG. 5 is a plan view of FIG. 4, FIGS. 6 and 7 are sectional views of the electromagnetic filter with a central magnetic field strengthening coil, and FIG. 8 is a sectional view of the electromagnetic filter. Magnetic flux density diagram of piping,
Figures 9a and 9b, Figures 10a and 10b,
Figures 11a and 11b are explanatory diagrams of the relationship between the coil and magnetic flux density, Figures 12a and 12b, and Figures 13a and 13b are diagrams showing the relationship between the magnetic disk and magnetic flux density, respectively. FIG. 14a and FIG. 14b are sectional views of the capsule mounting structure, respectively. DESCRIPTION OF SYMBOLS 1...Magnetic field generating coil, 2...Nonmagnetic piping, 3...Iron ball group, 4...Cooling water, 5...Nonmagnetic capsule, 6...Fluid hole, 7...Magnetic disc, 8...Interior, 9, 10, 1
1...Central magnetic field reinforcement coil.

Claims (1)

[Claims] 1. Spherical or piece-shaped magnetic grains with a fluid circulation gap are provided inside a non-magnetic pipe in which a magnetic field generating coil is arranged on the outer periphery, and the magnetic grains are magnetized by the coil, An electromagnetic filter for adsorbing magnetic contaminants in a fluid, characterized in that a non-magnetic capsule is provided in the fluid flow direction at the center of the magnetic grains corresponding to the center of the coil. 2. Claim 1, characterized in that the capsule is supported by a pair of magnetic discs having fluid passage holes, and the magnetic grains are held between the pair of magnetic discs. electromagnetic filter. 3. The electromagnetic filter according to claim 1 or 2, wherein the capsule has a built-in central magnetic field reinforcing coil.