JPS58137418A - Filter material for filter - Google Patents

Abstract

PURPOSE:To obtain a filter material for a filter capable of purifying contaminated water stably in high reliability, by filling a casing with a diffusion bonded magnetic stainless fiber to increase the strength of the filter material. CONSTITUTION:A casing 20 is filled with a magnetic stainless steel fiber 22 and, after said fiber is degreased with trichloroethylene, it is subjected to intermetallic diffusion bonding in a vacuum heating furnace and thereafter cooled rapidly. Thus obtained filter material is free from the outflow of a metal fiber piece even if filtration and backwashing are repeated compared to a filter material with a conventional structure because of intermetallic diffusion bond and the lowering of filtering capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION Misfire 1 (1j is porous 411.filtration j+IJ, relates to FILKU 111 filtration material that filters pollutants using the body, and particularly relates to a filtration material for a filter that is good for lightning and magnetic filter devices. .

Electromagnetic filter devices are used to remove minute corrosion products from the water in the primary system of thermal and nuclear power plants.

In this electromagnetic filter device, a ferromagnetic porous filter material with 11
4 I'm bored. This porous filter material has a ferrite type, a martensitic type, or a mixture of ferrite and austenite phases, which are made by machines such as cutting and cutting, or wire drawing processes such as wire drawing and bundle drawing. Two-phase magnetic stainless steel fibers are used. These magnetic stainless steel fibers have a typical diameter of several 11 m to several 100/1 m or less, and can be filled irregularly into a filter casing, or aggregated into a web and stacked to a constant layer height to form a filter layer. This is intended to remove fine IIS products from the system water at the Bukha Nuclear Power Plant.

However, with this filter material using magnetic stainless steel fibers, the magnetic stainless steel material is subjected to intense cold working during the manufacturing process, so the toughness of the material is reduced by *L7, and in addition, there are many particles on the surface of the fibers. Since the unprocessed scratches remain, these processing scratches are the cause of stress. For this reason, these stainless steel fibers break due to the fluid force of the water to be treated and the impact fluid force during backwashing (7).There is a problem that they flow out into the treated water.In addition, these stainless steel fibers have a significant decrease in fatigue strength due to a decrease in toughness. Due to the fluid force applied to the stainless steel fibers during continuous use during long-term filtration and backwashing cycles, the fibers may undergo fatigue rupture at multiple locations or undergo elastic yielding as a whole. The fiber layer becomes compacted.As a result, the pressure loss of the filter material suddenly increases, resulting in water delivery failure, or the filter becomes clogged due to the presence of non-alloy. A discontinuous filling direction is formed, causing channeling of the fluid to be treated, which deteriorates filtration and backwashing performance.This channeling occurs when the filter is compacted and the water permeation resistance of a part of the filter increases. , becomes noticeable.

In consideration of the above facts, the present invention aims to obtain a filtration material for a filter that can stably and reliably purify system water.

In the filter medium according to the present invention, the strength of the filter medium is increased by loading magnetic stainless steel fibers that are diffusion-bonded to each other into the casing.

An actual MIi example of the present invention will be described below with reference to the drawings.

The electromagnetic filter device shown in FIG.
4 is placed. This filter material 14 is magnetized by the magnetic force of an electromagnetic coil 16 placed outside the canister, and is
, B, contaminated water flows in from the lower canister 12, is filtered by a filter medium 14, and is sent out from the upper canister 10 as shown by arrow B.

In addition, the code|symbol 8 in the figure shows a pole piece.

FIG. 2 shows the filter medium 14, in which a cylindrical casing 20 is loaded with magnetic stainless steel fibers 22. As shown in FIG.

The circular casing 20 is SUS /+30)I>t
Fl (outer diameter 3 C1ttn using r, plate thickness) The cylinder is 11° rounded to a height l 5 cqn, and the average line fJ is produced by IJI machining into the inside of this cylindrical casing 20.
It is loaded with magnetic stainless steel fibers of 30 μm SUS4 knee < 0 (ferrite type) at an average filling rate of 5%. After loading this stainless steel fiber into a cylindrical casing, it was degreased with trichlorethylene, and further heated to 6 degrees of air 10' + mnHg (tolerance range 10') in a vacuum heating furnace.
-'~10'gtl'& ), temperature 1] 50℃ (
Tolerance range: 10,500-1,200℃), processing time: 1 hr
(Tolerance range: 05 to 3 hours) The metal was diffusion bonded, and then it was rapidly cooled.

Through this heat treatment in the vacuum furnace, the magnetic stainless fibers 22 in the casing receive compressive force during filling at the mutual contact portion of the fibers, and as shown in FIG. They are strongly bonded through interatomic bonds. As shown in FIG. 4, metal-to-metal diffusion bonding is also achieved at the contact portion between the inner periphery of the circular casing 2o and the magnetic stainless steel fiber 22.

The results of comparing the filter material of this example created in this way with a filter material with a conventional structure, that is, a filter material in which metallic fibers are simply filled into the cylinder at the same filling rate without performing metal-to-metal diffusion bonding, are shown in the fifth section. , 6 will be explained below.

Figures 5 and 6 show raw water containing Fe2O3 with an average grain size of 17zm], OOppl), which was filtered in an upward flow at a magnetic field strength of 3 KG and a treatment line speed of 400 m/hr for 1 hour, then the magnetic field was removed, and the treatment line was filtered. This figure shows the change in removal rate for each filtration and backwash cycle and the change in pressure loss of the filter medium when backwashing is carried out in a downward flow for 10 seconds at a speed of 2000 m/hr. Arrow C in the figure indicates the backwashing. Indicates processing time.

As is clear from Figures 5 and 6, in conventional filter media, metal fiber fragments flow out during each cycle of filtration and backwashing, which accumulates and completely reduces the filling rate. is compacted and the initial differential pressure of the filter medium increases after about 5,000 cycles or more. As a result, the final differential pressure after the 1-hour filtration cycle also rises rapidly, resulting in insufficient backwashing and reduced filtration performance. However, the filtration fee in this example is each gold,
Since the rutted fibers are firmly diffusion bonded to each other, there is no outflow of metal fiber pieces, and even after approximately 5,000 filtration cycles, stable filtration work is possible in the same way as in the initial state.

Furthermore, conventional filter media can be used approximately 5,000 times! After the cycles L and -1-, channeling flow along the inner wall surface of the container containing the filtration medium tends to occur due to the increase in pressure loss, which also reduces the filtration performance, but in this example, magnetic stainless steel Since the fibers 22 are also diffusion bonded to the inner circumference of the cylindrical casing 20, channeling flow can be prevented.

Next, FIGS. 7 to 9 show second to fourth embodiments of the present invention, in which unitized filter media 114, 214, . 314
are shown respectively. These filter media are also
Filter material in Example 19] Casing 20 in the same way as in 4.
Diffusion-bonded magnetic stainless steel fibers 22 are loaded inside.

Among these, the filter material 11.4 in Fig. 7 has a hexagonal planar shape.
The filtration material 214 in FIG. 8 is fan-shaped, and the filtration material 314 in FIG.
It is rectangular in shape, and a large-mouth layer (about 50 cr in diameter) is made by combining multiple unitized filter media.
2) can be configured.

The filter media 114.2], 4.3]1 in the second to fourth embodiments configured as J: are also diffusion-bonded with the magnetic stainless steel fibers 22 to each other and to the inner periphery of the casing 2o. Effects similar to those of the embodiment can be obtained.

Next, FIG. 10 shows a fifth embodiment of the present invention.

In the filter medium 4 in this embodiment 1+11, stoppers 28 are provided in several stages at the middle part of the cylindrical casing 20 in the height direction, and extended band metals 30 are passed to these stoppers. Magnetic stainless fibers 22 similar to those in each of the above embodiments are filled between these expanded metals, but these magnetic stainless fibers are divided into upper, middle, and lower stages by expanded metals 30. Metal fibers with different filling rates and wire diameters are loaded in each stage. These magnetic stainless steel fibers 2
2 is also diffusion bonded in the same manner as in each of the above embodiments.

As a result, it is possible to create a porous filter material in which the filling rate and wire diameter are varied in the height direction of the hollow layer using the filter material 414 in this example, and when the particles in the water to be treated have a wide particle size distribution. It is possible to create a porous filter material having a wire diameter and a filling rate suitable for each particle size, and it is possible to improve filtration and backwashing efficiency.

Note that this cylindrical casing 20 is also covered with expanded metal 30 at its upper and lower ends to prevent the magnetic stainless fibers 22 from falling off. It should be noted that the extracted ξ metals of the upper end and lower end can of course be applied to each of the first to fourth embodiments.

As explained above, the filter medium according to the present invention has the excellent effect of stably and reliably purifying contaminated water because the casing is loaded with diffusion-bonded magnetic stainless steel fibers.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an electromagnetic coil device to which the filter material of the present invention is applied; Fig. 4 is an enlarged perspective view showing the diffusion bonding state of the magnetic stainless steel fiber and the cylindrical casing, Fig. 5 is a diagram showing the degree of change in removal rate with respect to filtering time, 20...・Casing, 2z...Magnetic stainless steel fiber. ) Figure 8 I)') Figure 10

Claims (4)

[Claims] (1) A filtration material for a filter, characterized in that magnetic stainless steel fibers are loaded into a caning and the magnetic stainless steel fibers are bonded to each other by diffusion bonding. (2) The magnetic stainless steel carrier is 00μ, -)-00μ
A filtration material for a filter according to Claim No.], characterized in that: m. (3) The magnetic stainless steel fiber f1 has a light J rate [~20
% range+! The filtration material for a filter according to claim 11r1 or 2, characterized in that it is loaded into a caning at point Ii. (4) The filtration material for a filter according to any one of claims 1 to 3, wherein the magnetic stainless steel fibers are diffusion bonded to the inner surface of the can.