JP3701569B2 - Filter element and manufacturing method thereof - Google Patents

Description

【００１８】
【表２】

【００１９】
【発明の効果】
本発明によれば、極めて簡単に、低い集塵効率の多孔質フィルタエレメントを低い通気圧力損失状態で高い集塵効率を有する多孔質フィルタエレメントに変えることができると共に、帯電防止機能及び非粘着性も付与した多孔質フィルタエレメントを得ることができる。
更に、フィルタエレメントの表面に形成された多孔性表層に含まれる加硫フッ素は、引張り時の伸びが大きいので粉塵を払い落とす際に行なわれる逆洗パルスにおいて、フィルタエレメントの変形に多孔性表層が十分追従でき当該多孔性表層の表面にクラック等が発生する心配がない。
【図面の簡単な説明】
【図１】本発明のフィルタエレメントの一例を示す模式的な部分断面図。
【符号の説明】
１ 樹脂粒子
１１ 空隙の孔径
２ フッ素ゴムの加硫物よりなる多孔性表層
２１ 多孔性表層の孔径
３ フッ素樹脂
４ 導電性物質[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter element incorporated in a dust collector that separates and collects particles from a dust-containing gas, for example, a dust collector for collecting products and protecting the environment in a factory, and in particular, has a low ventilation pressure loss and high dust collection. The present invention relates to a filter element which has both functions of efficiency and has an antistatic function and good dust releasability when dust deposited on the surface of the filter element is removed, and a method for manufacturing the same.
[0002]
[Prior art and its problems]
Conventionally, for the purpose of collecting powder and dust generated in factories and the like, filter elements that have been made porous by communicating synthetic resin powder and forming voids have been used.
[0003]
The dust filtering performance of the filter element depends on the size of the pore diameter of the porous body, but the size of the pore diameter varies depending on the particle size of the resin powder as a raw material.
For example, in a filter element that is sintered and molded using a resin powder having a large particle size as a raw material, the pore diameter of the voids is large, so that powder with a large particle size is filtered, but the particle size Small powders cannot be filtered through, resulting in a filter with low dust collection efficiency.
[0004]
On the other hand, if the filter element is made by sintering using resin powder with a small particle size as the raw material, the pore diameter of the voids will be small, so that powder with a small particle size will also be filtered, but with high pressure loss It becomes the filter of.
Also, when trying to keep the pressure loss low by using a raw material with a small particle size of the resin powder, it is necessary to reduce the wall thickness of the filter element, which reduces the strength of the filter element and makes it practical. Lack.
Furthermore, when pulverizing commercially available pellets or powder bodies to obtain a raw material for the filter element, it is difficult to obtain a powder having a small particle diameter.
[0005]
In the above-described method for manufacturing a filter element by the sintering method, a filter element satisfying both functions of low pressure loss and high dust collection efficiency is obtained by optimizing the pore diameter of the pores of the porous body constituting the filter element. It was technically difficult to manufacture.
[0006]
Further, as another problem, the filter element may cause dust explosion due to the charge generated between the dusts, and in order to prevent this, the antistatic property is often imparted to the surface of the filter element.
Furthermore, although dust accumulated on the surface of the filter element is removed by a backwashing pulse that is appropriately performed, the filter element is often required to have antistatic property or non-adhesiveness in order to improve releasability.
[0007]
Conventionally, as a method for imparting antistatic properties to the surface of a filter element, for example, a conductive powder such as carbon or metal is mixed in advance with a resin powder, and then the mixture is sintered to produce a filter element. Or by previously kneading resin powder and conductive powder such as carbon or metal to produce a resin in which a conductive substance is dispersed, and then crushing the resin to obtain a pulverized product. A method of manufacturing a filter element by sintering is used.
[0008]
However, in the former method for the purpose of imparting antistatic properties, the conductive material is dropped from the sintered resin powder, or the conductive material existing between the sintered resin powders Since the contact between each other is weakened, there is a problem that the mechanical strength of the filter element is extremely lowered.
Also in the latter method for the purpose of imparting antistatic properties, the conductive material present in the sintered resin powder weakens the contact between the sintered resin powders, so that the mechanical strength of the filter element is reduced. There was a problem of extreme reduction.
[0009]
[Means for solving the problems]
The present invention seeks to provide a filter element having a low pressure loss and high dust collection efficiency, which has solved the above-mentioned problems, and also has an antistatic function and non-adhesiveness, and a method for producing the same. 1) A filter element characterized in that a porous surface layer of a fluororubber vulcanizate is formed on the surface of a filter element having voids obtained by sintering resin particles.
2) The filter element according to 1) above, wherein the porous surface layer comprises a vulcanized product of fluororubber and a fluororesin.
3) The filter element according to 1) above, wherein the porous surface layer is made of a vulcanizate of fluororubber and a conductive material having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less. .
4) The filter according to 1) above, wherein the porous surface layer is composed of a vulcanized product of fluororubber, a fluororesin, and a conductive material having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less. Is an element.
5) A porous surface layer is formed by applying and drying a suspension of fluoro rubber and fluoro rubber vulcanizing agent on the surface of a filter element having voids obtained by sintering resin particles in advance. A method for manufacturing a filter element.
6) The method for producing a filter element according to 5) above, wherein the suspension comprises fluororubber, a vulcanizing agent for fluororubber, and a fluororesin.
7) The filter according to 5) above, wherein the suspension comprises a fluororubber, a vulcanizing agent for fluororubber, and a conductive substance having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less. It is a manufacturing method of an element.
8) The suspension described above, wherein the suspension is made of a conductive material such that the surface electrical resistivity of the fluororubber, the vulcanizing agent of the fluororubber, the fluororesin, and the filter element is 10 ¹⁰ Ω / sq or less. ) Filter element manufacturing method.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments will be described with reference to the drawings.
FIG. 1 is a schematic partial sectional view showing an example of the filter element of the present invention.
In FIG. 1, 1 is a resin particle, 11 is a pore diameter of a void, 2 is a porous surface layer made of a vulcanized substance of fluorine, 21 is a pore diameter of the porous surface layer, 3 is a fluororesin, and 4 is a conductive substance.
[0011]
In the present invention, as a sintered resin raw material for producing a filter element, resins such as polyethylene, polypropylene, phenol resin, polyethersulfone, polyetherimide, polysulfone, and polycarbonate having an average resin particle size of 50 to 600 μm are used. Particles 1 can be suitably used.
By forming the porous surface layer 2 of the fluororubber vulcanizate on the surface of the filter element having voids obtained by sintering the resin raw material, the pore diameter 11 of the voids formed in the filter element is narrowed. This can control the dust filtration efficiency of the filter element.
By forming the porous surface layer 2 with a raw material containing a vulcanized product of fluororubber and a fluororesin 3, a filter element in which dust filtration efficiency is controlled and non-stickiness is imparted to the surface of the filter element is provided. Obtainable.
The raw material of these porous surface layers 2 is an emulsion in which fluororubber and a vulcanizing agent of fluororubber are dispersed in water, or an emulsion in which three components of fluororubber, fluororubber vulcanizing agent and fluororesin are dispersed in water. It is good to use in the state.
[0012]
By forming the porous surface layer 2 from a raw material containing a vulcanized fluororubber and a conductive material 4 having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less of the filter element, the dust filtration efficiency is improved. It is possible to obtain a filter element that is controlled and has a very low risk of dust explosion.
By forming the porous surface layer 2 from a raw material containing a vulcanizate of fluororubber, a fluororesin 3 and a conductive material 4 such that the surface electrical resistivity of the filter element is 10 ¹⁰ Ω / sq or less, It is possible to obtain a filter element in which dust filtration efficiency is controlled, non-stickiness is imparted to the surface of the filter element, and the risk of dust explosion is extremely small.
The fluororesin 3 and the conductive material 4 are contained in the porous surface layer 2 as shown in FIG. 1 to improve the dust collection efficiency by narrowing the pore diameter 11 of the void to the pore diameter 21 of the porous surface layer. it can.
[0013]
In addition, as a substance to be added to the emulsion liquid in order to give the porous surface layer 2 conductivity, carbon black or conductive whisker powder is preferably used. It is desirable to use an emulsion in which the substance 4 is dispersed.
When the surface electrical resistivity exceeds 10 ¹⁰ Ω / sq, dust is charged and adhesion is likely to occur, and deposition is accelerated, and it becomes difficult to wipe off by backwashing by sending pulsed air in the direction opposite to the filtration direction.
Furthermore, by setting it to 10 ¹⁰ Ω / sq or less, the charge amount between the dust adhering to the surface is reduced, and the danger of dust explosion is eliminated.
[0014]
As a method for producing the filter element of the present invention, a suspension in which fluororubber and a fluororubber vulcanizing agent are suspended on the surface of a filter element having voids obtained by sintering and molding resin particles 1 in advance is used. If necessary, apply an emulsion liquid in which the fluororesin 3 and the conductive material 4 are dispersed so that the surface electrical resistivity is 10 ¹⁰ Ω / sq or less, and then dry the suspension. Then, the manufacturing process of the filter element for forming the porous surface layer 2 may be performed.
The porous surface layer 2 of the vulcanized fluororubber obtained in this way has a good rubber composition due to cross-linking on the filter element side and excellent adhesion, and has a high fluorine content on the surface side and excellent wiping-off property.
[0015]
【Example】
Examples of the present invention will be specifically described below, but the present invention is not limited thereto.
In the present invention, the pore diameter 11 of the resin particles 1 sintered in the filter element is measured by observing the surface of the filter element with a calibrated microscope, and measuring the pore diameter of the void clearly shown on the surface. Is an average value of.
First, ultra high molecular weight polyethylene having an average particle diameter of 200 μm was sintered to form a filter element (No. 1), which is a resin sintered body having voids having an average void diameter 11 of 50 μm and a thickness of 2.5 mm. .
Next, a liquid in which carbon black is dispersed at a mass ratio shown in Table 1 in an emulsion in which the fluororesin 3 and the vulcanized rubber are dispersed in ion-exchanged water is applied to the surface of the resin sintered body. After coating with a liquid amount of 0 g / m ^2, the filter element (No 2) having a porous surface layer 2 was obtained by heating at 150 ° C. for 30 minutes.
[0016]
Table 2 shows the test results of pressure loss measurement, resistivity measurement on the filter element surface, and powder collection performance evaluation of the filter element (No 2) having the porous surface layer 2 and the filter element (No 1) before coating. .
As is clear from Table 2, the filter element (No. 1) before coating was filtered through the filter element in a collection performance test using calcium carbonate powder having an average particle diameter of 4.5 μm. It did not fulfill its function as well.
However, the filter element (No. 2) in which the porous surface layer 2 was provided on the surface of the resin sintered body had good powder collection performance.
Further, in the backwash pulse performed when dust accumulated on the surface of the filter element (2) having the porous surface layer is wiped off, the dust releasability from the surface is extremely higher than that of the filter element (1) before coating. It was good.
[0017]
[Table 1]

[0018]
[Table 2]

[0019]
【The invention's effect】
According to the present invention, a porous filter element having a low dust collection efficiency can be changed to a porous filter element having a high dust collection efficiency in a low airflow pressure loss state, as well as an antistatic function and non-adhesiveness. It is possible to obtain a porous filter element to which is also applied.
Furthermore, since the vulcanized fluorine contained in the porous surface layer formed on the surface of the filter element has a large elongation when pulled, the porous surface layer is not deformed by the backwash pulse performed when dust is removed. There is no worry that cracks and the like are generated on the surface of the porous surface layer that can be sufficiently followed.
[Brief description of the drawings]
FIG. 1 is a schematic partial sectional view showing an example of a filter element of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Resin particle 11 Pore pore diameter 2 Porous surface layer 21 made of fluoro rubber vulcanizate Porous surface layer pore diameter 3 Fluororesin 4 Conductive substance

Claims (8)

A filter element comprising a porous surface layer of a vulcanizate of fluororubber formed on the surface of a filter element having voids obtained by sintering resin particles. 2. The filter element according to claim 1, wherein the porous surface layer is made of a vulcanizate of fluororubber and a fluororesin. The filter element according to claim 1, wherein the porous surface layer is made of a vulcanizate of fluororubber and a conductive substance having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less. 2. The filter element according to claim 1, wherein the porous surface layer is made of a vulcanizate of fluororubber, a fluororesin, and a conductive material having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less. . A porous surface layer is formed by applying and drying a suspension of fluororubber and a vulcanizing agent of fluororubber on the surface of a filter element having voids obtained by sintering resin particles in advance. A manufacturing method of a filter element characterized by the above. 6. The method for producing a filter element according to claim 5, wherein the suspension comprises fluororubber, a vulcanizing agent for fluororubber, and a fluororesin. 6. The filter element according to claim 5, wherein the suspension is made of a fluororubber, a fluororubber vulcanizing agent, and a conductive material having a surface electrical resistivity of 10 ¹⁰ Ω / sq or less. Manufacturing method. 6. The suspension is made of a conductive material such that the surface electrical resistivity of fluoroelastomer, fluoroelastomer, fluororesin, and filter element is 10 ¹⁰ Ω / sq or less. Filter element manufacturing method.

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