JPH02265614A - High gradient magnetic separation apparatus with continuously altering flow speed - Google Patents

Abstract

PURPOSE:To efficiently capture magnetic particles in a fluid by forming flowing routes of a fluid to be treated in the way that the cross section of the flowing route is expanded gradually in the proceeding direction and gradually lowering the flowing speed of the fluid to be treated which passes a filter element. CONSTITUTION:Filter elements 18 of a ferromagnetic material 19 are placed in flowing routes 15, 17, 16 for a fluid to be treated so as to form magnetic fields in the flowing routes and magnetic particles floating in the fluid are attracted and removed by the highly grading magnetic field formed around the magnetic material. The flowing routes for the fluid are formed in the way that the cross sections of the routes are extended gradually toward proceeding direction of the fluid and the speed of the fluid passing the filter elements is lowered gradually. As a result, fine particles with small specific magnetic susceptibility can be efficiently separated and removed in a proper treatment rate and an apparatus for the treatment can be small and economical.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a high gradient magnetic separation device that can effectively collect magnetic particles contained in a fluid.

(b) Prior Art Conventionally, there is a high gradient magnetic separation apparatus for the above purpose described in Japanese Patent Publication No. 59-43208.

The internal structure of the high gradient magnetic separation apparatus according to FIGS. 8 to 1θ is shown.

As shown, N! A non-magnetic cell 53 is arranged in the space between the ff151 and the S magnet 8ii52. An inlet 54 and an outlet 55 are provided in each of the two.

Further, in the filter space formed within the non-magnetic cell 53, a large number of ferromagnetic thin wires 56 are arranged parallel to the flow direction of the processing fluid.

These ferromagnetic thin wires 56 are arranged at equal intervals,
They are densely arranged and parallel to each other.

With this configuration, a high gradient magnetic field is formed around the ferromagnetic thin wire 56, and very small particles can be adsorbed and removed.

By the way, the performance of the above-mentioned high gradient magnetic separation device is generally as follows.
It is expressed by the following equation (1) using the effective length Le.

Le-(L/a)(Vm/Vo) ・ ・
・ (1) Here, L,! =a is the effective length and radius of the ferromagnetic thin wire, Vo is the flow rate of the treated water, and V- is the following formula (2
) is the magnetic velocity given by

V+*= (2/9) (Zp ・MS-He・b
”/ 7/ ・a)・・・・(2) In the above formula (2), χ and b are the relative magnetic susceptibility and radius of the magnetic fine particles, Ms is the saturation magnetic flux density of the ferromagnetic III wire, and ■.

is the strength of the applied magnetic field, and η is the viscosity coefficient of the fluid with respect to the particles.

In other words, the larger the value of Le, the better the performance as high gradient magnetic separation.

(c) Problem to be Solved by the Invention However, in order to separate and remove fine particles with an extremely small J-specific magnetic susceptibility, it is necessary to use (+) (2), an extremely large magnetic field gradient, and therefore a sufficiently thin ferromagnetic wire. However, it is difficult to produce such ferromagnetic thin wires, and
Manufacturing costs increase.

■It is necessary to increase the applied magnetic field H0 or to increase the effective length of the ferromagnetic thin wire, that is, to increase the length of the filter, but if these elements are increased or lengthened, the magnetic field generator will become very large, making it difficult to manufacture. High cost and detour.

(2) It is necessary to lower the flow rate v0 of the treated water, but this lowers the flow rate of the treated water, which lowers the throughput and lowers the cost performance of the separation and removal device.

An object of the present invention is to provide a high gradient magnetic separation device that can solve the above problems.

(d) Means for Solving the Problems The present invention provides a filter element made of a ferromagnetic material in a flow path of a processing fluid, forms a magnetic field in the flow path, and creates a magnetic field around the ferromagnetic material. In a high-gradient magnetic separation device for adsorbing and removing magnetic fine particles suspended in a processing fluid using a high-gradient magnetic field formed in The present invention relates to a high gradient magnetic separation apparatus characterized in that the flow rate of the processing fluid passing through the filter element is gradually reduced.

In addition, in the above configuration, the shape of the filter element is
(2) It can be cylindrical or a shape obtained by cutting out a part of a cylinder such as an annular shape or a sector; (2) It can be spherical or a shape obtained by cutting out a part of a sphere such as a cone or a pyramid.

Furthermore, in (1) above, the ferromagnetic thin wires constituting the filter element, which have a cylindrical shape or a shape obtained by cutting out a part of a cylinder, are arranged radially along the radial direction of the cylinder; Another feature is that the ferromagnetic thin wires constituting the filter element, which has a shape obtained by cutting out a part of a sphere, are arranged radially along the radial direction of the sphere.

(E) Functions and Effects In the present invention, the shape of the wave path of the processing fluid is formed so that the cross-sectional area of the flow path gradually expands in the traveling direction, and the flow velocity of the processing fluid passing through the filter element is gradually reduced. Therefore, we provide a compact and inexpensive high-gradient magnetic separation device that can separate and remove fine particles with extremely low specific magnetic susceptibility at an appropriate throughput using easily generated magnetic field strength and conventional ferromagnetic stainless steel wire. can do.

(f) Examples The present invention will be specifically described below based on examples shown in the attached drawings.

1 to 4 show the specific structure of the high gradient magnetic separation apparatus A according to this embodiment.

In Figures 1 and 2, 10 is a return frame made of soft iron or the like, and permanent magnets 11 and 12, which will be described later, are used.
At the same time, a magnetic circuit can be formed.

In this embodiment, the return frame 10 is formed of disk-shaped upper and lower walls 10a and a lob, and a cylindrical peripheral wall 10c.

Then, the return frame IO has its upper and lower walls ]Oa,
Upper and lower permanent magnets 11 and 12 in the form of dona knots are attached to the inner surface of 10b, respectively, and both permanent magnets II.

A filter cartridge 13 in the form of a thick inner disk is interposed in the gap between the filter cartridges 12 and 12 for adsorbing and removing magnetic fine particles 20 (see FIGS. 5 and 6), which will be described later.

Further, an opening 14 is provided in the center of the upper wall 10a of the return frame 10, and a fluid inflow pipe 15 extends inside the return frame 10 by passing through the opening 14 in the vertical direction. The opening 15a formed at the end is
It is connected in communication with the central part of the L blood of the filter cartridge 13.

On the other hand, a plurality of fluid outflow pipes 16 are connected to the peripheral wall of the filter cartridge 13 .

The present invention is 8. Substantially, the filter cartridge 13
The gist is in the internal structure of.

That is, in this embodiment, as shown in FIG. 1, the filter cartridge 13 includes a hollow cylindrical filter container 17 made up of thin disc-shaped upper and lower walls and a thin peripheral wall, and a hollow cylindrical filter container 17 that includes a hollow cylindrical filter container 17 that includes thin disc-shaped upper and lower walls and a thin peripheral wall. It consists of a large number of disc-shaped filter elements (or filter modules) 18 arranged in a stacked manner.

As shown in FIGS. 3, 4, and 5, each filter element 18 includes a large number of ferromagnetic thin wires 19 at 36.
0'' are arranged radially in all directions, and the cross-sectional area of the flow path P formed between the ferromagnetic thin wires 19 is the same as that of the filter element 1.
It gradually becomes thicker from the center of 8 toward the outer periphery.

With this configuration, the speed of the processing fluid flowing into each filter element 18 becomes gradually slower as it flows from the center of the filter element 18 toward the outer periphery.

In other words, in the flow of treated water in the filter cartridge 13, the flow velocity at any point in each filter element 8 in which the ferromagnetic thin wires 19 are arranged radially changes, and the flow velocity near the outer periphery is lower than the flow velocity near the center. will decrease in inverse proportion to.

However, in order to make the space factor of the ferromagnetic wires 19 per unit volume of the filter element 18 substantially the same in the radial direction, the ferromagnetic wires 19 are arranged radially in multiple stages. That is, the density per unit center of the ferromagnetic thin wires 19 is coarse in the center and gradually denser toward the outer periphery.

Next, the principle of adsorption and removal of particulates in the high gradient magnetic separation apparatus A according to the present invention having the above configuration will be explained with reference to FIGS. 5 and 6, while comparing it with the conventional apparatus.

In FIG. 5 (X-Z sectional view), the magnetic field is applied in the X direction, and the processing fluid containing the magnetic particles 20 flows in the Y direction. (In other words, it flows from the back to the front of the paper.) In FIG. 5, a distortion of the magnetic field occurs near the ferromagnetic wire 19, and the magnetic fine particles 2 floating in the processing fluid
A magnetic attraction force acts on the magnetic particles 20, and the magnetic fine particles 20 move along the trajectory shown by the solid arrow, and are finally attracted to the magnetic wire 19.

That is, there is no difference in the adsorption trajectory of the magnetic fine particles 20 in the X-Z cross section between the present invention and the prior art.

Next, the magnetic fine particles 20 in the X-Z cross section are the ferromagnetic thin wires 1.
Fig. 6 shows the trajectory until it is adsorbed by 9.

In this case, the flow direction of the processing fluid is from the top to the bottom of the page.

The locus of the magnetic fine particles 20 in the prior art is shown by a dashed line, and the locus of the magnetic fine particles 20 in the present invention is shown by a broken line.

As shown in the figure, there is a clear difference between the present invention and the prior art, and the effective magnetic line length 21 according to the present invention until the magnetic fine particles 20 are attracted to the ferromagnetic thin wire 19 is different from the effective magnetic line length 21 according to the prior art. Length 2. It can be seen that it is considerably shorter than .

In other words, when the initial flow velocity of the processing fluid is the same, in the prior art, the flow velocity is constant at all positions from the inlet on the center side of each filter element 18 to the outlet on the outer peripheral edge side.

In contrast, in the present invention, the flow velocity at any position decreases inversely proportional to the distance traveled by the processing fluid from the inlet on the center side of the filter element 18 with respect to the initial flow velocity. The magnetic fine particles 20 can be attracted at a location where the effective length of the magnetic thin wire 19 is short.

Therefore, the magnetic particulate adsorption/removal range cap according to the present invention has a particulate adsorption/removal range per magnetic wire 19 as shown by the two-dot chain line in FIG. can be significantly improved.

In the above-described embodiment, permanent magnets 11 and 12 were used to form a magnetic field, but the present invention is not limited thereto (the magnetic field may also be formed using an electromagnet, a superconducting magnet, etc.).

In addition, it is preferable to use a ferromagnetic stainless steel wire as the ferromagnetic thin wire 19 in consideration of corrosion etc. However, it is not limited to stainless steel wire in any way, and may be made of other materials as long as it has ferromagnetism. It is also possible to use a line consisting of

In addition, the shape of the filter element 18 formed by the ferromagnetic thin magnetic wire 19 is: (1) cylindrical shape or a shape in which a part of a cylinder is cut out, such as an annular shape or a fan shape; (2) a spherical shape or a shape in which a part of a sphere such as a cone or a pyramid is It can be cut out.

Furthermore, in the above, the ferromagnetic thin wires 19 forming the filter element 18 are arranged radially along the radial direction of the cylinder, and in They can also be arranged radially along. [Hereinafter, a high gradient magnetic separation bag WLA having the structure shown in FIGS. 1 to 3 was actually manufactured and an experiment was conducted.

First, the specific configuration and specifications of the device A will be explained.

Permanent magnet 11.12 (Nd-
Pa-B system, residual magnetic flux density Br-12,000 (G),
Coercive force Hc-11,000 (Oe), energy product (B
- [1) wax = 35 (MGOe)), as shown in Fig. 1, the different poles are faced with three air gaps, and the periphery is surrounded by a return frame 10 made of soft iron to form a magnetic circuit. .

At that time, the magnetic field strength generated in the gap between the permanent magnets 11 and 12 was about 5,500G.

A filter container 17 made of acrylic resin, which is a non-magnetic material, is placed in the gap, and inside the filter container 17, 25 filter membranes 18 as shown in FIG. 4 are placed.
The filter elements 18 were assembled in a laminated state.

The shape and dimensions of each filter element 18 are the outermost diameter -2
00mmφ, innermost diameter -20mmφ, and between them, the outer diameter of the first stage is -80mmφ, the outer diameter of the second stage is -140mφ, and the outer diameter of the third stage is - the outermost diameter. It was arranged in three stages.

Each stage is made of ferritic stainless steel with an outer diameter of 100/711φ and has a saturation magnetic flux density Ms (-1
, 77) were arranged radially with a space factor of 6%.

The fluid inlet 15 is provided at the center of the upper surface of the return frame 10, and the fluid outlet 16 is provided at the center of the upper surface of the return frame 10.
Twelve pieces were provided on the circumferential surface of 0 at intervals of 30° in the circumferential direction.

With this configuration, the processing fluid flows into the filter element 18 of the filter cartridge 13 from the fluid inlet 15, and flows from the center toward the outer periphery within the filter container 17 in which a large number of filter elements 18 are installed. , the fluid is discharged from the fluid outlet 16.

When an untreated fluid in which magnetic fine particles 19 of α-Pe203 with an average particle diameter of lμ− are suspended at a concentration of l(1+g/j!) is treated with the above-mentioned high gradient magnetic separation device A by changing the treatment flow rate. The particulate removal function of is shown in Table 1 below.

Table 1 (Magnetic fine particle separation and removal performance) As is clear from Table 1, the high gradient magnetic separation apparatus A according to the present invention can separate magnetic fine particles 17 with high efficiency (85 to 97%) over a wide flow rate range. It can be removed by adsorption.

The ferromagnetic fine wires constituting the filter element of the magnetic separation device A are those obtained by etching or punching a thin ferromagnetic plate so that a thin wire portion remains, or
A ferromagnetic material may be printed on a non-magnetic thin plate. Alternatively, it may be a net made of magnetic fine wires woven into a cast net shape or a spider web shape.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional front view of a high gradient magnetic separation device according to the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a cross-sectional view taken along line I-1 in Fig. 1, and Fig. 4 is a perspective view of a filter element. Figure 5 is a partially enlarged perspective view of the filter element, Figures 6 and 7 are diagrams explaining the principle of adsorption of magnetic particles, and Figure 8 is a perspective view showing the conceptual configuration of a conventional high gradient magnetic separation device. , FIG. 9 is a cross-sectional side view of the same, and FIG. 1O is a cross-sectional view taken along the line ■-■ in FIG. In the figure, A: High gradient magnetic separation device P: Channel 10: Return frame 11: Permanent magnet 12: Permanent magnet 13: Filter cartridge 14; Opening 15: Fluid inflow pipe 16: Fluid outflow pipe 17: Hollow cylindrical filter container 18: Filter element 19: Ferromagnetic thin wire 20: Magnetic fine particles

Claims (1)

[Claims] 1. A filter element made of a ferromagnetic material is disposed in the flow path of the processing fluid to form a magnetic field in the flow path, and a high gradient magnetic field is formed around the magnetic material. In a high-gradient magnetic separation device for adsorbing and removing magnetic fine particles suspended in a processing fluid, the shape of the flow path of the processing fluid is formed so that the cross-sectional area of the flow path gradually expands in the direction of movement, and the filter element A high-gradient magnetic separation device in which the flow rate changes continuously, characterized in that the flow rate of a processing fluid passing through the process fluid is gradually reduced. 2. The high-gradient magnetic separation in which the flow rate changes continuously according to claim 1, wherein the filter element has a shape such as a cylinder, or a shape obtained by cutting out a part of a cylinder, such as an annular shape or a fan shape. Device. 3. The high-gradient magnetic separation apparatus according to claim 1, wherein the filter element has a shape that is spherical or a shape obtained by cutting out a part of a sphere such as a cone or a pyramid, and the flow velocity changes continuously. 4. The ferromagnetic thin wires constituting the filter element, which has a cylindrical shape or a shape obtained by cutting out a part of a cylinder, are arranged radially along the radial direction of the cylinder.The flow velocity changes continuously. The high gradient magnetic separation apparatus according to claim 2. 5. A claim in which the flow velocity changes continuously, characterized in that the ferromagnetic thin wires constituting the filter element, which are spherical or have a shape obtained by cutting out a part of a sphere, are arranged radially along the radial direction of the sphere. Item 3. High gradient magnetic separation device. 6. The filter element, in which fine ferromagnetic wires are arranged radially, is made by etching or punching a thin ferromagnetic plate so that the fine wire portion remains, or by printing a ferromagnetic substance on a thin non-magnetic plate. 5. The high gradient magnetic separation apparatus according to claim 4, wherein the flow rate changes continuously. 7. The filter element according to claim 4, wherein the filter element in which the magnetic thin wires are arranged radially is made of a mesh of magnetic thin wires woven in a cast net shape or a spider web shape, and the flow velocity changes continuously. Gradient magnetic separation device.