JPH02303505A - High gradient magnetic separator of continuously changing flow velocity - Google Patents

Abstract

PURPOSE:To allow the sepn. and removal of magnetic fine particles having a small specific magnetization rate with the adequate treatment amt. by uniformly distributing the treating fluid passing the inflow side of a filter element consisting of a ferromagnetic body to uniformly lower the flow velocity of the inflow side. CONSTITUTION:The filter element 18 consisting of the ferromagnetic material is disposed in a main flow passage P1 for the treating fluid and a magnetic field is formed in the main flow passage P1 to adsorb and remove the magnetic fine particles suspended in the treating fluid by the high-gradient magnetic field formed around the ferromagnetic material. A pretreating flow passage P2 is provided in the front part of the main flow passage P1 and the sectional area of the flow passage is so formed as to increase gradually in the progressing direction in the pretreating flow passage P2 to lower the flow velocity of the treating fluid passing the element 18. In addition, the main flow passage P1 is so formed to such shape as to decrease the sectional area of the flow passage gradually in the progressing direction to increase the flow velocity on the outflow side past the element 18. As a result, the magnetic fine particles having the small specific magnetization rate are separated away with the adequate treatment atm.

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. 9 to 11 is shown.

As shown in the figure, a non-magnetic cell 53 is arranged in the space between the N magnetic pole 51 and the S magnetic pole 52, and the non-magnetic cell 53 forms a filter space for removing particulates therein. At the same time, an inlet 54 and an outlet 55 are provided at the lower and upper portions, respectively.

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.

And those ferromagnetic wires! 56 are arranged closely and parallel to each other at equal intervals.

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 e.

Le= (L/a)(Vs/Vo)...(1
) Here, L and a are the effective length and radius of the ferromagnetic thin wire, respectively, vO is the treated water flow rate, and V is the magnetic velocity given by the following equation (2).

V■-(2/9)(Xs・Ms・H*・b”/
v ・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 wire, H6 is the strength of the applied magnetic field, and η is the viscosity coefficient of the fluid for particles.

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

(c) Problems to be Solved by the Invention However, in order to separate and remove fine particles with extremely low specific magnetic susceptibility, from equations (1) and (2), ■ an extremely large magnetic field gradient, and therefore a sufficiently thin ferromagnetic wire must be used. 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 increase the effective length of the ferromagnetic m-ray, that is, increase the length of the filter, but if these elements are increased or lengthened, the magnetic field generator will become very large. , manufacturing cost increases.

■It is necessary to lower the treated water flow rate V, but for this purpose, the cross-sectional area of the flow path must be widened, and in rectangular cells, the treated fluid flowing in from the inlet must be distributed uniformly in the filter space. Moreover, since the cell becomes larger, the manufacturing cost of the device increases.

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 the main flow path of a processing fluid to form a magnetic field in the main flow path, and to create 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 The cross-sectional area of the channel is formed so as to gradually expand in the direction of travel, and on the inflow side of the main channel,
The flow rate of the processing fluid passing through the filter element is reduced, and the shape of the main flow path is formed so that the cross-sectional area of the flow path gradually decreases in the advancing direction, and the flow rate is increased on the outflow side after passing through the filter element. The present invention relates to a high-gradient magnetic separation device in which the flow rate changes continuously, characterized in that the flow rate changes continuously.

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 a ring or a sector; (2) It can be spherical, or a shape obtained by cutting out a part of 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, a pretreatment flow path is provided in the front part of the main flow path, and the cross-sectional area of the flow path is formed so as to gradually expand in the direction of movement, so that the pretreatment flow path passes through the inflow side of the filter element. By uniformly distributing the processing fluid and uniformly reducing the flow velocity on the inlet side, it is possible to treat an appropriate amount of fine particles with extremely low specific magnetic susceptibility using magnetic field strength that can easily be generated and conventional ferromagnetic stainless steel wire. It can be separated and removed depending on the amount.

On the other hand, later on, the shape of the main flow path was formed so that the cross-sectional area of the flow path gradually decreased in the traveling direction, and the flow velocity was increased on the outflow side after passing through the filter element, so the diameter of the flow path outlet was changed. By matching the diameter of the water supply pipe on the downstream side, the treated water can be quickly supplied to the desired location.

(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 FIGS. 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.
At the same time, a magnetic circuit can be formed.

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

The return frame 10 has upper and lower walls 10a,
Upper and lower donut-shaped permanent magnets 11 and 12 are attached to the inner surface of 10b, respectively, and both permanent magnets 11° and 12
A filter cart 13 in the form of a thick disc for adsorbing and removing magnetic fine particles 22 (see FIGS. 7 and 8), which will be described later, is interposed in the gap between them.

The filter cartridge 13 has a main flow path PI, which will be described later, formed inside thereof, and an annular fluid inflow portion 14 is connected to the outer peripheral portion of the filter cartridge 13 for communication.

A return frame 10 is provided in the fluid inflow portion 14.
An annular fluid outflow portion 17b forming the lower part of the pretreatment device B disposed on the upper portion of the pretreatment device B is connected thereto.

That is, in the present embodiment, the pretreatment device B connects the lower end of the fluid inflow pipe 16 to the inflow side portion 17a of the hollow conical flow rate reduction portion 17 whose diameter gradually increases downward; The fluid outflow section 17b of the flow rate reduction section 17 is connected in communication with the annular fluid inflow section 14 provided on the peripheral wall of the filter cartridge I3.

As shown in FIG. 3, the flow rate reduction section 17 gradually expands the cross-sectional area of the annular pretreatment flow path pg defined by the outer circumferential wall 17c and the inner circumferential wall 17d downward.

Further, the inner circumferential wall 17d is fixed to the outer circumferential wall by a fixed guide 17e.

With this configuration, the treated water flowing into the high gradient magnetic separation device A from the fluid inflow pipe 16 first has a cross-sectional area of the pre-treatment channel pt, as shown in FIGS. 2 and 3.
Due to the significant difference between the inflow and outflow sides, the flow rate is significantly reduced by the flow rate reduction section 17, and the flow rate is at a minimum at the fluid inlet section 14 of the filter cartridge 13.

Thereafter, the treated water will flow into the main flow path P1 in the filter cartridge 13 at the minimum flow rate.

Next, regarding the internal configuration of the filter cartridge 13,
This will be explained with reference to FIGS. 1, 5, and 6.

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

5 and 6. Each filter element 18 is
As shown in the figure, a large number of ferromagnetic thin wires 19 are arranged radially in all directions of 360°, and the cross-sectional area of the main flow path P1 formed between the ferromagnetic thin wires 19 is from the outer peripheral edge of the filter element 18. It gradually becomes smaller towards the center.

With this configuration, the speed of the processing fluid flowing into the main flow path P1 of each filter element 18 from the pretreatment device B is as follows.
First, the velocity is the lowest at the outer periphery of the filter element 18, and then gradually becomes faster as it flows from the outer periphery toward the inside of the filter element 18.

In other words, in the flow of treated water in the filter cartridge 13, the flow velocity at any point in each filter element 18 in which the ferromagnetic wires 19 are arranged radially changes constantly.
Compared to the flow velocity near the outer periphery, the flow velocity near the center increases in inverse proportion to the radius.

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 central angle of the ferromagnetic thin wires 19 is coarse in the center and gradually denser toward the outer periphery.

On the other hand, an opening 20 is provided in the center of the lower wall 10b of the return frame 10, and a fluid outflow pipe 21 extends inside the return frame 10 by passing through the opening 20 in the vertical direction. The opening 21a formed at the end is
It is communicatively connected to the center portion of the lower surface of the filter cartridge 13 .

Next, the principle of fine particle adsorption and removal of the high gradient magnetic separation bag MA according to the present invention having the above configuration will be explained with reference to FIGS. 7 and 8 while comparing it with the case of a conventional device.

In FIG. 7 (X-Z sectional view), the magnetic field is applied in the X direction, and the processing fluid containing the magnetic particles 22 flows in the Y direction. (In other words, it flows from the back of the page to the front.) In FIG. 7, 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 2 , and the magnetic fine particles 22 move along a trajectory as 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 22 in the X-Z cross section between the present invention and the prior art.

Next, the magnetic fine particles 22 in the X-Y cross section
Fig. 8 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 22 in the prior art is shown by a dashed line, and the locus of the magnetic fine particles 22 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 22 are attracted to the ferromagnetic wire 19 is different from the effective magnetic line length 21 according to the prior art. It is interesting that it is much shorter than the length 12.

In other words, since the long rectangular cells are filled with filters, the flow rate of the processing fluid flowing through the filter space is constant at all positions from the vicinity of the inlet to the outlet.

On the other hand, in the present invention, the main flow path P from the fluid supply pipe 16 to the filter element 18 is
The flow velocity of the treated water flowing into the filter element 18 is significantly reduced at the outer periphery of the filter element 18, so that the magnetic fine particles 22 can be adsorbed at a location where the effective length of the ferromagnetic wire 19 is short.

Therefore, the magnetic fine particle adsorption/removal range 1 according to the present invention is as follows:
Compared to the conventional magnetic particle adsorption/removal box Ml & It, the particle adsorption/removal range per τ of the magnetic wire 19 is
As shown by the two-dot chain line in FIG. 8, a significant improvement can be achieved.

Thereafter, the treated water from which the magnetic particles have been removed as described above flows toward the center within the filter element 18, but in the process, the flow velocity is increased and the water is connected to the water supply pipe downstream of the device. The fluid is quickly delivered to a desired location through the fluid outflow pipe 21.

In addition, in the above-described embodiment, permanent magnets 11 and 12 were used to form a magnetic field, but the invention is not limited to this, and i! A magnetic field can also be formed using a magnet, a superconducting magnet, or the like.

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 material 11!1119 is: ■Cylindrical or a shape obtained by cutting out a part of a cylinder, such as an annular shape or a fan shape, ■A shape obtained by cutting out a part of a cylinder such as a cylindrical shape, or ■A shape cut out from a part of a cylinder such as a spherical shape or a cone or a pyramid. It can be made into a shape.

Furthermore, in (1) above, the ferromagnetic wires 19 forming the filter element 18 are arranged radially along the radial direction of the cylinder, and in (2) the ferromagnetic wires [19 forming the filter element 1B] are arranged radially along the radial direction of the cylinder. They can also be arranged radially along the direction.

The ferromagnetic thin wire 19 constituting the filter element of the magnetic separation device A is made by etching a thin ferromagnetic plate or by
It may be processed by punching so that thin wire portions remain, or it may be a non-magnetic thin plate printed with a ferromagnetic material. 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 the drawing]

FIG. 1 is a cross-sectional front view of a high gradient magnetic separation apparatus according to the present invention, FIG. 2 is a cross-sectional view taken along line 1-1 in FIG. 1, and FIG. 3 is a cross-sectional view taken along line ■-■ in FIG. Fig. 4 is a cross-sectional view taken along line ■-■ in Fig. 1, Fig. 5 is a perspective view of the filter element, Fig. 6 is a partially enlarged perspective view of the filter element, and Fig. 7
8 and 8 are explanatory diagrams of the adsorption principle of magnetic fine particles, and FIG. 9 is a perspective view showing the conceptual configuration of a conventional high gradient magnetic separation device.
Figure 1O is the same cross-sectional side view, Figure 11 is Figure 10 IV-I.
It is a cross-sectional view taken along the V line. In the figure, A: High gradient magnetic separation device PI: Main flow path Pt: Pretreatment flow path 10: Return frame 11: Permanent magnet 12: Permanent magnet 13: Filter cartridge 14: Opening 16; Fluid inlet pipe 18: Filter element 19: Ferromagnetic thin wire 21: Fluid outflow pipe 22: M fine particles

Claims (1)

[Claims] 1. A filter element made of a ferromagnetic material is disposed in the main flow path of the processing fluid to form a magnetic field in the main 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, a pre-treatment channel is provided at the front of the main channel, and the cross-sectional area of the channel is set in the direction of travel. The flow rate of the processing fluid passing through the filter element is reduced on the inflow side of the main flow path by gradually expanding, and the shape of the main flow path is such that the cross-sectional area of the flow path gradually decreases in the direction of movement. 1. A high gradient magnetic separation device in which a flow rate changes continuously, characterized in that the flow rate is increased on the outflow side after passing through a filter element. 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.