JPH08318144A - Diffuser - Google Patents

Abstract

PURPOSE: To provide a diffuser excellent in toughness as well as in both strength and air permeability and capable of being easily connected to a diffuser main body. CONSTITUTION: In this diffuser provided with a gas flow passage 102 for introducing gas to be diffused into a diffuser main body 101 from the gas source side, and the diffusing gas into liquid to be diffused from the gas flow passage 102 through a diffusing part 103 installed in the specified part of the diffuser main body 101, the diffusing part 103 comprises a metal porous body obtained by a forming treatment process containing a hot hydrostatic pressure pressurization sintering treatment in which metal powder material is sintered in a heated state under hydrostatic pressure pressurization, and provided with a lot of holes generated during the treatment process and penetrating between the surface and the back surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air diffuser which is used, for example, in the lower part of a membrane separation device in a septic tank or for ejecting air, oxygen or the like in water such as a pond. More specifically, the present invention relates to an apparatus, and more specifically, includes a gas flow path that guides a gas to be diffused from a gas source side into an air diffuser body, and an air diffuser provided at a specific portion of the air diffuser body. The present invention relates to an air diffuser configured to diffuse gas from a gas flow path into a liquid to be diffused.

[0002]

2. Description of the Related Art In such an air diffuser, the gas to be diffused is dispersedly discharged from the inside of the air diffuser into the liquid to be diffused through an air diffuser. Conventionally, porous ceramics or synthetic resins have been used to form the air diffuser.

[0003]

However, when ceramic is used to form the air diffuser, although the pressure resistance strength is relatively high, it is difficult to obtain air permeability, so a large amount of power is required for the air diffuser and the air diffuser is used. There is a problem in that the ceramic is likely to be cracked or chipped due to the vibration generated during the operation. Further, in the case of ceramics, since it is difficult to make the pore diameters uniform, it is difficult to diffuse air with uniform bubbles. Further, it is necessary to hermetically connect the ceramic air diffuser to the air diffuser main body that is generally made of metal. In this case, it is necessary to configure this connection with a relatively complicated structure. There was a problem. On the other hand, when using synthetic resin, the pressure resistance is low, so
It was difficult to use in deep water and its life was short due to oxidation by ultraviolet rays. Therefore, an object of the present invention is to obtain an air diffuser which is excellent in both pressure resistance and air permeability and is also excellent in toughness, and which can be easily connected to the air diffuser body. Especially.

[0004]

To achieve the above object, the air diffuser according to the present invention is characterized in that the metal powder material is sintered in a heated state under hydrostatic pressure. The diffuser is composed of a porous metal body having a large number of holes which are obtained through a forming process including a hydraulic pressure sintering process and which are generated in the forming process and penetrate between the front and back surfaces. Further, in the air diffuser according to claim 1, the metal porous body has a first step of pressure-molding the metal powder to obtain a powder preform, and the powder preform obtained in the first step. Is obtained through a second step of carrying out the hot isostatic pressing sintering treatment to the above, and in the second step,
In the hole existing in the powder preform and penetrating the front and back of the powder preform, the hydrostatic pressure medium used in the hot isostatic pressing process is allowed to enter, and the treatment is performed. What is obtained is preferable. This is a characteristic configuration of the air diffuser according to claim 2. Further, in the air diffuser according to claim 1, the metal porous body is filled with the metal powder in a mild steel capsule, degassed and sealed, and subjected to the hot isostatic pressing sintering treatment. It is preferably obtained by heat treatment while being stored in a mild steel capsule. This is a characteristic configuration of the air diffuser according to claim 3. The action and effect are as follows.

[0005]

In the air diffuser according to the first aspect of the present invention, the air diffuser is composed of a metal porous body obtained by a process including a so-called HIP sintering method (hot isostatic pressing process). Parts are used. Since such a porous metal body is superior in strength to, for example, a conventional synthetic resin porous body, it is excellent in shape retention and durability. Further, in the metal porous body obtained through such HIP sintering treatment, pores communicating between the front and back surfaces of the molded body are more likely to be formed than in the conventional general sintered body. The reason for this is that, for example, in the conventional sintering process, in order to obtain a predetermined strength along with the sintering, it is necessary to use a metal powder having a nonuniform particle shape and a shape far from a spherical shape. On the other hand, in the HIP sintering process, since the sintering is effective, it is possible to obtain a predetermined strength by sintering particles having a relatively constant particle shape and a nearly spherical shape. This is because the pores formed between the particles are continuously formed between the front and back surfaces of the material. Therefore, it is possible to easily obtain such a porous metal body having a high open porosity (a high proportion of pores which are communicated with the outer surface of the material and can be used as, for example, a circulation pore for air diffusion). In addition, since the diameters of the formed holes can be made uniform, an air diffuser having holes suitable for the purpose of air diffusion can be obtained. Furthermore, since this air diffuser is a porous metal body obtained through the HIP sintering process, it can be connected to the metallic air diffuser body by welding. Therefore, it is possible to obtain, for example, an air diffuser having a relatively high airtightness and a strong connection structure, which is strong against vibration.

Next, an air diffuser according to claim 2 will be described. To obtain such a metal porous body,
This is formed through the first step and the second step. In the first step, a powder preform is obtained from a metal powder that is a material for obtaining a metal porous body, and the powder preform is subjected to HIP sintering treatment. In processing,
In the state where the hydrostatic medium is allowed to enter the holes penetrating the front and back of the powder preform as well (for example, without storing the powder preform in the evacuated mild steel capsule) Then, it is put into a hydrostatic medium and treated. By doing so, the so-called open pores (holes connected to the outer surface) can be processed while maintaining the pore state, and a metal porous body having a high open porosity and relatively high strength can be obtained. . Therefore, with this product, it is possible to obtain an air diffuser which is preferable in terms of ventilation performance (sufficient air diffusion can be performed with a small air pressure) and durability.

Next, an air diffuser according to claim 3 will be described. To obtain such a metal porous body,
Store the metal powder in a vacuum-evacuated mild steel capsule,
First, a HIP sintering process is performed. Then, after the treatment, the processed product in a state of being contained in the mild steel capsule is heat-treated. H
As described above, the IP-sintered product has characteristics of high open porosity, but it is possible to obtain a product having relatively high strength by heat treatment while maintaining this state. result,
A metal porous body having a high open porosity and relatively high strength can be obtained. Therefore, with this product, it is possible to obtain an air diffuser which is preferable in terms of ventilation performance (sufficient air diffusion can be performed with a small air pressure) and durability.

[0008]

According to the air diffuser of the first aspect,
Both the pressure resistance and air permeability are excellent, and the toughness is also excellent, so that a simple connection structure can be obtained with the air diffuser body. Furthermore, in the air diffuser according to claim 2, when a metal porous body is obtained, holes that penetrate through the front and back of the material are surely obtained, and while ensuring the flow performance of the diffused fluid, It has become possible to obtain an air diffuser excellent in strength. Further, in the air diffuser according to the third aspect, it is possible to obtain the air diffuser excellent in strength while ensuring the flow performance of the air diffused fluid.

[0009]

EXAMPLE An example in which the air diffuser D of the present application is applied to the septic tank 100 will be described below with reference to the drawings. Septic tank 10
As shown in FIG. 1, 0 is configured so that the water to be treated is advected from the upstream side to the precipitation separation tank N, the flow rate adjustment tank B, and the membrane separation tank E in the order listed, and a partition W is provided between the tanks. It is partitioned.

The sedimentation separation tank N receives the raw water flowing in from the inflow port I as water to be treated, and separates solid matters such as solid matter precipitated from the treated water and scum generated on the liquid surface while In addition, the liquid component of the raw water is naturally admitted to the flow rate adjusting tank B, and anaerobic bacteria that anaerobically decompose the water to be treated are grown inside. In addition, F in the figure is an advection pipe in which an opening F1 is provided in the center portion in the width direction of the precipitation separation tank N so that mainly liquid components are admitted to the flow rate adjusting tank B from raw water.

The flow rate adjusting tank B comprises a metering device 1a and a transfer pump 1b, and temporarily stores the liquid component of the water to be treated, which has naturally advected from the precipitation separating tank N, and the membrane separating tank. It is formed so that it can be transferred to E substantially quantitatively via the transfer pipe 1c.

The membrane separation tank E is for purifying the water to be treated by filtering it with a plurality of flat membranes M as filtration membranes.
In the membrane separation tank E, aerobic bacteria that aerobically decompose the organic components of the water to be treated are grown. Further, with the flat membrane M installed in the tank, an air diffuser D is provided below the flat membrane M to supply bubbles to prevent sludge and the like from adhering to the surface of the flat membrane M. . Therefore, by performing an air diffusion operation from the air diffusion device D, oxygen can be supplied to the aerobic bacteria and the surface of the flat membrane can be washed to maintain the membrane separation performance of the flat membrane M at a high level.

The flat membrane M as a filtration membrane is shown in FIGS.
As shown in FIG.
The filtration membrane member 6 made of polyethylene is adhered and formed on both surfaces of the resin-made support plate 5, and the nozzle 4 communicating with the treated water conducting portion 3 is continuously provided. By suctioning from the nozzle 4 in the state of being immersed in the water, the water to be treated passes through the filtration membrane member 6, and sludge and the like in the water to be treated are removed by the filtration membrane member 6 to highly purify the water. The treated water can be taken out. Here, the filtration membrane member 6 is an ultrafiltration membrane having a pore size of 0.3 μm or less, and by selecting a membrane having such a pore size, it is possible to prevent intra-membrane contamination for long-term use, It enables long-term maintenance-free operation.

The nozzle 4 includes a suction pump P and a water collecting pipe 8
The water to be treated (referred to as membrane-permeable water) subjected to the membrane separation by the flat membrane M is sent to the outside of the septic tank by operating the suction pump P.

As shown in FIG. 2, the air diffuser D is provided with a gas passage 102 having a pump 9 for introducing a gas to be diffused into the air diffuser body 101 from the atmosphere which is a gas source. The gas passage 1 is provided through an air diffuser 103 provided at a specific portion (upper surface portion of the main body) of the air diffuser body 101.
From 02, gas (specifically, air) is diffused into the liquid to be diffused (water to be treated in the membrane separation tank E). This air diffuser 103 is a hot isostatic pressing sintering process (H) in which a metal powder material is sintered under a hydrostatic pressure in a heated state.
It is composed of a metal porous body which is obtained through a molding treatment process including an IP sintering treatment) and which is formed in the treatment process and has a large number of holes penetrating between the front and back surfaces. The air diffuser 103 described above
The air diffuser body 101 is hermetically connected by welding. The air diffuser 103 is a flat plate-shaped member as shown in the drawing. The metal porous body that constitutes the air diffuser 103 has a first step of obtaining a powder preform by press forming a metal powder, and a first step. It is obtained through a second step of performing hot isostatic pressing treatment on the powder preform obtained in step 1.
In the process, the processing is performed by allowing the intrusion of the hydrostatic medium used in the hot isostatic pressing process into the holes existing in the powder preform and penetrating the front and back of the powder preform. Obtained. This manufacturing process is the same as the process for obtaining the specimens 1 to 5 belonging to the first group described below.

The air diffuser 103 provided in the air diffuser D is
It is obtained through so-called hot isostatic pressing sintering (HIP sintering). Therefore, the air diffuser 103 is stronger in strength than the conventional metal sintering method.
It has good characteristics as an air diffuser with many open pores communicating between the surfaces of the material. Hereinafter, the sample configured as the air diffuser 103 will be described. Specimens can be divided into two groups according to their forming method. Less than,
The first group and the second group will be described separately. 1 First group Specimens belonging to this group are manufactured through two steps. In manufacturing, the first step, which is a step typified by a so-called CIP method, for pressure-molding a metal powder material to obtain a powder preform, and the powder preform obtained in the first step It is manufactured through a second step in which hot isostatic pressing is performed. Then, in this second step, the powder preform is left naked and placed in the hydrostatic medium for treatment. Therefore, in this step, the hydrostatic medium is allowed to enter the holes existing in the powder preform and penetrating the front and back of the powder preform, and the process proceeds. Such a hole can maintain its open state, and as a result, a metal sintered body having a high open porosity can be obtained. Table 1 shows the production conditions and physical properties of the specimens belonging to this group. Each sample will be described below. Using the following metal powder as a raw material, it is enclosed in a rubber mold and CIP-molded to form a powder preform (first step). Then, the powder preform was placed in a HIP device and subjected to a sintering treatment (second step) to obtain metal porous bodies No. 1 to 5.

Stainless steel powder: SUS 310S equivalent, atomized powder (C:
0.02, Si: 1.0, Mn: 0.1, Cr: 18.3, Ni: 10.8.%) Alloy tool steel powder: SKD 61 equivalent, atomized powder (C: 0.3
8, Si: 0.9, Mn: 0.01, Cr: 5.25, Ni: 1.20, V: 1.0.%)

Specimens Nos. 1 to 5 are inventive examples, and No. 1
Reference numeral 1 is a comparative example obtained by heating and sintering a powder preform in a vacuum atmosphere. In the table, the value in the "Pore size distribution" column is the maximum pore size (μm), the value in the "Degassing property" column is the pressure (Kgf / cm ² ) required for air permeation, and the "Bending strength" column is Shows the measurement results of 3-point bending strength (Kgf / mm ² ) by the bending test method of JIS B 1601 (span distance: 30 mm). As shown in Nos. 1 to 3, the metal porous body obtained by HIPing the powder preform has a higher degassing property as compared with the metal porous body No. 11 of the comparative example. It has a strength far exceeding that of .11. Especially No.
No. 2 has achieved extremely high strength. No. 4 is a comparative example
While maintaining the same strength as No. 11, it has a large pore size, high open porosity, and higher gas permeability. Also N
Although o.5 has different metal materials, it has high open porosity, degassing property and improved strength, and the difference from Comparative Example No. 11 is obvious.

[0019]

[Table 1]

The large number of through-holes extending between the front and back surfaces of the materials in Specimens 1 to 5 is clear from the fact that the ratio of open porosity / porosity is higher than that in the comparative example.

1 Second Group Specimens belonging to this group are also manufactured through two steps. In the production, a hot isostatic pressing sintering process corresponding to the above-mentioned second step is first performed, and the product obtained by this process is heat-treated to obtain a desired product. In the hot isostatic pressing sintering process belonging to this group, the metal powder is deaerated and hermetically sealed in a mild steel capsule. Then, after this treatment, the treated product is heat-treated in a heating furnace while being kept in a mild steel capsule. The feature of the hot isostatic pressing sintering process in this method is that the process time is selected to be shorter than that in the case where the above-mentioned one belonging to the first group is obtained, and the process is performed only for this process. There is something happening. Table 2 shows the production conditions and physical properties of the test pieces belonging to this group. Each sample will be described below. The following metal powder is used as a raw material, filled into a mild steel capsule, degassed and sealed (1 × 10 ⁻² Torr), and then placed in a HIP device for preforming. Then, the capsules, as they are, are placed in a heating furnace and heat-treated. After the treatment, the capsule is removed by machining to obtain a porous metal body.

Porous metal body size: 300 × 300 × 300 mm Stainless steel powder: SUS 310S equivalent, atomized powder (C:
0.02, Si: 1.0, Mn: 0.1, Cr: 18.3, Ni: 10.8.%) Alloy tool steel powder: SKD 61 equivalent, atomized powder (C: 0.3
8, Si: 0.9, Mn: 0.01, Cr: 5.25, Mo: 1.20, V: 1.0.%)

Specimen Nos. 6 to 10 are inventive examples, and No.
12 is a comparative example obtained by heating and sintering a powder compact in a vacuum atmosphere. In the table, the value in the "Pore size distribution" column is the maximum pore size (μm), the value in the "Degassing property" column is the pressure (Kgf / cm ² ) required for air permeation, and the "Bending strength" column is ,
The measurement results of three-point bending strength (Kgf / mm ² ) by the bending test method of JIS B 1601 (span distance: 30 mm) are shown. As shown in Nos. 6 to 8, the metal porous body of the invention example is
Although the porous metal body No. 12 of Comparative Example has almost the same average pore diameter and the like, it has a high open porosity and is excellent in gas permeation, and at the same time, has a high strength that greatly exceeds that of Comparative Example No. 12. It has. Further, like No. 9 and No. 10, it is possible to maintain the mechanical strength equivalent to that of Comparative Example No. 12 while having a large pore diameter and a pore distribution with a high open porosity. The difference with is obvious.

[0024]

[Table 2]

In the test pieces 6 to 10, the large number of through holes extending between the front and back surfaces of the material means that the ratio of open porosity / porosity is
It is also clear from the fact that it is higher than the comparative example. As a result, the air diffuser that employs the metal porous body produced as described above as the air diffuser is excellent in strength, has good air permeability, and is extremely convenient to use.

[Other Embodiments] In the above embodiment, an example in which the air diffuser is used in the septic tank is shown. For example, the water quality of the pond is improved, and the reaction by the air diffusion in the reaction tank under high temperature and high pressure. It can also be used for promotion and the like. Further, in the above-mentioned embodiment, an example in which the metal porous body obtained in the step of passing through the CIP and HIP belonging to the first group is used is shown, but the metal to be heat-treated after the sweet HIP treatment belonging to the second group. The thing obtained through the process of manufacturing a porous body can also be used in this application.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a septic tank equipped with an air diffuser of the present application.

FIG. 2 is a side sectional view of an air diffuser.

FIG. 3 is a diagram showing the structure of a flat membrane.

FIG. 4 is a diagram showing the internal structure of a flat membrane.

[Explanation of symbols]

 101 Air diffuser main body 102 Gas flow path 103 Air diffuser

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Nishi Nishi 1-1-1, Nakamiya Oike, Hirakata-shi, Osaka Prefecture Kubota Hirakata Manufacturing Company (72) Inventor Akira Kosaka 1-1-1, Nakamiya Oike, Hirakata-shi, Osaka No. 1 stock company Kubota Hirakata Factory

Claims (3)

[Claims] 1. A gas flow path (102) for guiding a gas to be diffused from a gas source side into an air diffuser body (101), and a gas diffuser provided at a specific portion of the air diffuser body (101). The gas flow path (10) is provided through the air part (103).
2) A diffusing device for diffusing the above-mentioned gas into a liquid to be diffused, which is a hot isostatic pressing sintering process in which a metal powder material is sintered under a hydrostatic pressure in a heated state. An air diffusing device in which the air diffusing unit (103) is constituted by a metal porous body which is obtained through a molding treatment process including and which is formed in the treatment process and has a large number of holes penetrating between the front and back surfaces. 2. The first step of the metal porous body for pressure-molding the metal powder to obtain a powder preform, and the hot static treatment for the powder preform obtained in the first step. It is obtained through a second step of performing hydraulic pressure sintering treatment, and in the second step, the powder is present in the powder preform,
3. The powder preform is obtained by allowing the intrusion of a hydrostatic medium used in the hot isostatic pressing process into the holes penetrating the front and back of the powder preform and performing the process. Air diffuser. 3. The porous metal body is filled with the metal powder in a mild steel capsule, degassed and hermetically sealed, and subjected to the hot isostatic pressing sintering treatment. After the treatment, the porous metal body is stored in the mild steel capsule as it is. The air diffuser according to claim 1, which is obtained by performing heat treatment.