JPS6344004B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic separation device, particularly for purification of various system water and wastewater of steel works, boiler water, cooling water, and various system water of thermal power plants, nuclear power plants, etc.
The present invention relates to a magnetic separation device suitable for purifying wastewater, etc.

Conventionally, as this type of magnetic separation device, one having the configuration shown in the sectional view of FIG. 1 is known.

As shown in FIG. 1, magnetic particles contained in the fluid are stored in a filter housing 1 having an inlet 1a and an outlet 1b for the fluid to be treated.
An overlayer 2 is attached which traps magnetically.
This overlayer 2 is formed of a substantially porous magnetic overmedium (matrix) and is adapted to be magnetized by an annular coil 3 provided on the outer periphery of the filter housing 1. In order to make the magnetic field formed in the overlayer 2 uniform, an inlet side magnetic pole member 4 is provided on the inflow surface, and an outlet side magnetic pole member 5 is provided on the outflow surface, and in order to improve the return efficiency of magnetic flux, A return frame 6 as a return yoke is provided so as to surround the outside of the annular coil 3. The input and output magnetic pole members 4 and 5 are generally made of a ferromagnetic material, such as magnetic steel materials such as SS41, SB42, and SUS430.

In a magnetic separation device configured in this way,
The magnetic flux density distribution in the flow direction in the overlayer 2 is as shown in FIG. 2b, and a substantially uniform magnetic field is formed. Capturing performance of magnetic particles contained in the fluid to be treated is proportional to the magnetic flux density directly applied to the matrix portion, assuming that the matrix type of the overlayer 2 is the same and the treatment flow rate is constant. Furthermore, if the magnetic particles are ferromagnetic, the magnetization is saturated at a magnetic flux density of about 1 to 3 kg, so that the applied magnetic flux density of 1 to 3 kg is sufficient for trapping. On the other hand, in the case of weakly magnetic or paramagnetic particles, the induced magnetization of the particles themselves is weak, so in order to improve the capture performance, the magnetic field must be as strong as possible, and generally a magnetic field of 5KG or more is created. It's getting old.

However, in general, the fluid to be treated often contains a mixture of ferromagnetic particles and weak or paramagnetic particles, and the set magnetic field is selected to be 5KG or more to target weak or paramagnetic particles that are difficult to capture. has been done. However, when such a strong magnetic field is used, ferromagnetic particles are trapped in the surface layer of the front part of the matrix, resulting in the formation of a cake-like layer.
Once this cake layer is formed, weak or paramagnetic particles are not sufficiently trapped inside;
This has the disadvantage that the pressure loss of the fluid is increased due to the cake layer.

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to
Magnetic separation can suppress the formation of a cake layer due to ferromagnetic particles when passing through a fluid containing a mixture of strong, weak, or paramagnetic particles, and can efficiently capture weak or paramagnetic particles as well. The goal is to provide equipment.

The present invention has an intensity distribution in which the magnetic field formed in a superlayer made of a magnetic supermedia has an intensity distribution that gradually increases from the inflow face of the fluid to be treated to the outflow face of the superlayer. The object of this invention is to suppress the formation of a cake layer due to ferromagnetic particles and to improve the trapping efficiency of weakly or paramagnetic particles.

More specifically, by applying a material with lower magnetization (i.e., lower magnetic permeability) than the conventional material for forming the input side magnetic pole member of the overlayer to increase the magnetic resistance of the input side magnetic pole member, By reducing the magnetic flux density of the superlayer inflow part and using a material with a higher magnetization (that is, a higher magnetic permeability) equal to or preferably higher than that of the conventional material for forming the exit side magnetic pole member, the superlayer outflow can be reduced. The objective is to increase the magnetic flux density at the superlayer inflow surface to the outflow surface, thereby forming a trapping zone having a magnetic field strength distribution corresponding to the magnetism of the trapped particles from the superlayer inflow surface to the outflow surface.

The following description will be made based on the illustrated embodiments of the present invention shown in FIGS. 3a to 6a. It should be noted that these figures show single cross-sections, and the same reference numerals as those in the conventional example shown in FIG.

The embodiment shown in FIG. 3a differs from the conventional example shown in FIG. 1 in that the inlet magnetic pole member 7 is made of a substantially non-magnetic SUS304 material. In all of the embodiments, including the conventional example, the inner diameter of the filter housing 1 is 400 mm, the interval between the magnetic pole members 7 and 5 on the inlet and outlet sides is 185 mm, and the overlayer 2 is made of cut wool of SUS430 material (average Wire diameter
70 μm) × filling rate 5%, number of turns of circular coil 3 is 198
Turn, excitation current is 456A.

In the first embodiment configured in this way,
Even under the same excitation conditions as in the conventional example, the magnetic resistance of the entrance magnetic pole member 7 is increased, so that the magnetic flux density in the flow direction of the overlayer 2 has a distribution as shown by the solid line A shown in FIG. 3b. When a magnetic flux density gradient as shown in the figure is formed, the magnetic flux density at the superlayer inflow part is low, so even if ferromagnetic particles are inflowed, they are captured by the internal flux over the range of 1 to 3 kg as shown in the figure. No strong cake layer is formed. In addition, weakly magnetic or paramagnetic particles are trapped in the strong magnetic flux density region from the middle to the outflow portion of the superlayer 2. In other words, by forming a magnetic flux density distribution having a gradient in the flow direction, particles with different magnetic properties are separated and captured by the internal filter in each effective magnetic flux density region.

Therefore, according to this example, even if a fluid containing a mixture of strong, weak, or paramagnetic particles is passed through, the formation of a cake layer due to ferromagnetic particles is suppressed, and the weak or paramagnetic particles are efficiently well captured,
Furthermore, there is an effect that overperformance is stabilized without increasing pressure loss.

Note that it is desirable that the gradient of the magnetic flux density distribution formed in the overlayer 2 corresponds to the ratio of ferromagnetic particles contained in the fluid to be treated. For example, when the content of ferromagnetic particles is small, The material of the entrance magnetic pole member is nickel, and the magnetic flux density gradient is
It is effective to use the one shown by the broken line B in Figure b. By the way, the magnetization of nickel is as described above.
It is about 1/3 of SS41, SB42, and SUS430.

Furthermore, in the above embodiments, the material of the incoming magnetic pole member has lower magnetization than that of the outgoing magnetic pole member, and a predetermined magnetic flux density gradient is formed in the overlayer. The inlet magnetic pole member 8 may be formed of a composite plate of a thin ferromagnetic member 8a and a non-magnetic member 8b, as shown in FIG. 4a. According to this, the magnetic flux density distribution shown in FIG. 4b is formed. Similarly, as shown in FIG. 5a, the inlet magnetic pole member 9 may simply have a smaller magnetic path cross-sectional area to increase the magnetic resistance, and the magnetic flux density distribution in this case is as shown in FIG. 5b. It becomes like this.

Furthermore, if weak or paramagnetic particles are contained in a relatively larger amount than ferromagnetic particles, the sixth
As shown in FIG. a, it is advantageous to insert and arrange a ferromagnetic intermediate magnetic member 10 between the overlayers 2. In other words, as shown in Fig. 6b, the magnetic field at the superlayer inflow section has a predetermined gradient to trap ferromagnetic particles, and a uniform high magnetic field is formed between the intermediate and exit magnetic pole members. The aim is to effectively and stably capture weak or paramagnetic particles.

As explained above, according to the present invention, the generation of a cake layer due to ferromagnetic particles is suppressed, and weak or paramagnetic particles are efficiently captured. Even if the fluids to be treated are mixed, it is possible to stably capture and pass through with low pressure loss and high efficiency.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the conventional example, Figures 2 a and b are the 1st
FIG. 3A is a cross-sectional view of an embodiment of the present invention;
3b is a diagram of the magnetic flux density in the overlayer of the embodiment shown in FIG. 3a, FIG. 4a, FIG. 5a, and FIG. FIG. 4b, FIG. 5b, and FIG. 6b are diagrams of the magnetic flux density in the superlayer for the embodiments shown in FIGS. 4a, 5a, and 6a, respectively. 1... Filter housing, 2... Overlayer, 3
... Annular coil, 5 ... Outgoing magnetic pole member, 6... Return frame, 7, 8, 9, 11... Incoming magnetic pole member, 10... Intermediate magnetic pole member.

Claims (1)

[Scope of Claims] 1. A cylindrical housing forming a flow path for a fluid to be treated, and an overlayer made of a substantially porous magnetic material installed in the housing and passing through the fluid;
an inlet magnetic pole member and an outlet magnetic pole member respectively arranged to coincide with the inflow and outflow surfaces of the overlayer; an annular coil located outside the housing and wound around the outer periphery of the overlayer; In a magnetic separation device comprising a magnetic pole member and a return path yoke formed to enclose the overlayer and the annular coil, the magnetic field formed in the overlayer is A magnetic separation device characterized in that magnetic pole members are formed and arranged so that the intensity distribution gradually increases from the inflow face to the outflow face. 2 In the invention described in claim 1,
A magnetic separation device characterized in that the magnetic resistance of the input side magnetic pole member is made larger than that of the output side magnetic pole member. 3 In the invention described in claim 1,
An intermediate magnetic pole member is provided in the overlayer to face the output magnetic pole member and made of the same material as the magnetic pole member, and the magnetic resistance of the input magnetic pole member is formed to be larger than that of the output magnetic pole member. A magnetic separation device featuring: 4. In the invention according to claims 1 to 3, the magnetic separation is characterized in that the incoming magnetic pole member is made of a non-magnetic material, and the outgoing magnetic pole member is made of a ferromagnetic material. Device. 5. In the invention according to claims 1 to 3, the magnetic separation is characterized in that the input side magnetic pole member is formed from a material whose plate thickness is thinner than the plate thickness of the output side magnetic pole member. Device. 6. In the invention according to claims 1 to 3, the input magnetic pole member is formed from a composite material of a magnetic material and a non-magnetic material, and the output magnetic pole member is formed from a ferromagnetic material. A magnetic separation device characterized by: