JP2013094699A - Filter medium for mist separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter medium for mist separators which can raise oil trapping and drainage performance, can improve oil or water trapping efficiency and can reduce pressure loss caused by clogging.SOLUTION: A filter medium 15 used in an oil mist separator 10 includes an aggregate of fibers and is so constituted as to remove oil or water in a blow-by gas. The filter medium 15 is constituted in a way that high density fiber layer 18 upstream of the gas flow to trap oil or water is laminated with a low density fiber layer 19 downstream to drain the oil or the water trapped in the high density fiber layer 18. The high density fiber layer 18 and the low density fiber layer 19 are constituted in a way that the forms of the fibers each exhibit oil or water trapping ability and its drainage ability. For example, the high density fiber layer 18 is made of crimped fibers and the low density fiber layer 19 is made of straight fibers.

Description

  The present invention is used, for example, in an oil mist separator for separating oil mist from blow-by gas generated in an engine, and improves the oil mist capturing efficiency and can reduce pressure loss due to clogging. It relates to filter media.

  When the automobile engine is operated, blow-by gas containing unburned gas leaks into the crankcase. If this blow-by gas is discharged as it is, the load on the environment is large, and therefore a system has been implemented in which the blow-by gas is returned to the intake manifold for combustion. In this case, since oil mist is contained in the blow-by gas, an oil mist separator that separates the oil mist has been conventionally used.

  This type of oil mist separator is described in Patent Document 1, for example. That is, this oil mist separator is composed of a case in which an inflow hole and an outflow hole are formed, and a filter element disposed in the case and having a filter medium part, and the filter medium part has a surface coated with a fluororesin or a silicone resin. It is made up of filtered filter media.

  Further, Patent Document 2 discloses an antifouling filter used by being attached to a ventilation fan or a range hood. This antifouling filter is made of a fiber sheet containing fibers having a fiber diameter of 5 μm or more and less than 35 μm, and the surface of the fibers has oil repellency due to the oil repellency treatment or the properties of the fibers themselves.

JP 2004-255230 A JP 2009-15669 A

  In the oil mist separator having the conventional configuration described in Patent Document 1, since the surface of the filter medium is coated with fluororesin or silicone resin, the oil mist contained in the gas passing through the surface of the filter medium is repelled and oil It becomes easy to grow as a droplet, and the separation efficiency of oil mist can be improved. However, when the surface of the filter medium is subjected to an oil repellency treatment with a fluororesin or a silicone resin, the oil mist can be made into oil droplets on the fiber surface, but it cannot be expected that the oil droplets are positively drained. Furthermore, increasing the fiber density of the filter medium part to increase the separation efficiency of the oil mist or increasing the thickness of the filter medium part does not improve drainage, but also increases the pressure loss in the filter medium part. There was a problem of inviting.

  On the other hand, in the conventional antifouling filter described in Patent Document 2, a non-oil-repellent fiber layer is provided on the air inflow side and an oil-repellent fiber layer is provided on the air outflow side. For this reason, there has been a problem that there is a concern that the oil drop becomes a film due to the non-oil-repellent fiber on the air inflow side, resulting in clogging and an increase in pressure loss.

  Accordingly, an object of the present invention is to provide a filter medium for a mist separator that can improve both oil and water trapping properties and drainability, and can reduce pressure loss due to clogging. It is in.

  In order to achieve the above object, the filter medium for a mist separator according to the invention of claim 1 is a filter medium made of an aggregate of fibers and used for a mist separator for removing oil or water from gas. A high-density layer of fibers that capture oil or water is stacked on the upstream side of the gas flow, and a low-density layer of fibers that drain oil or water captured by the high-density layer is stacked on the downstream side. In addition, the high-density layer and the low-density layer are characterized in that the fiber shapes are formed so as to express oil or water trapping properties and drainage properties, respectively.

  A filter medium for a mist separator according to a second aspect of the present invention is the filter according to the first aspect, wherein the high-density layer is composed of crimped fibers and the low-density layer is composed of straight fibers. And

  The filter medium for a mist separator according to a third aspect of the present invention is the invention according to the first aspect, wherein the high-density layer is composed of thin fibers having a fiber diameter of 5 to 15 μm, and the low-density layer has a fiber diameter. It is comprised by 20-30 micrometers thick fiber, It is characterized by the above-mentioned.

  The filter medium for a mist separator according to a fourth aspect of the present invention is the filter medium according to the first aspect, wherein the high-density layer is composed of fibers having an irregular cross section other than a circular cross section, and the low density layer is a fiber having a circular cross section. It is characterized by comprising.

  The filter medium for a mist separator according to claim 5 is characterized in that, in the invention according to claim 1, the high-density layer is composed of short fibers and the low-density layer is composed of long fibers. To do.

  A filter medium for a mist separator according to a sixth aspect of the present invention is the filter according to the first aspect, wherein the high-density layer is formed by intertwining fibers vertically and horizontally, and the low-density layer is a fiber extending in one direction. It is characterized by being intertwined.

  A filter medium for a mist separator according to a seventh aspect of the present invention is the invention according to any one of the first to sixth aspects, wherein the fibers of the high-density layer and the fibers of the low-density layer are entangled. It is characterized by being.

  The filter medium for a mist separator according to an eighth aspect of the present invention is the invention according to any one of the first to seventh aspects, wherein the high-density layer is subjected to a water / oil repellent treatment and has a low density. The density layer is characterized by being subjected to hydrophilic lipophilic treatment.

According to the present invention, the following effects can be exhibited.
In the filter medium for a mist separator of the present invention, a high-density layer of fibers capturing oil or water on the upstream side of the gas flow, and a fiber that drains oil or water captured by the high-density layer on the downstream side. The low-density layer is laminated. The high-density layer and the low-density layer are formed so that the fiber shape can express oil or water capture and drainage, respectively. For this reason, for example, when blow-by gas hits the filter medium, oil or water in the blow-by gas is trapped on the fiber surface forming the high-density layer, and the trapped oil or water moves downstream to move the low-density layer. It reaches the fiber surface to be formed, descends along the fiber surface, and is drained.

  Therefore, according to the filter medium for a mist separator of the present invention, it is possible to improve the oil or water capturing ability and drainability, improve the oil or water capturing efficiency, and reduce the pressure loss due to clogging. The effect that it can aim at can be exhibited.

The schematic sectional drawing which shows the oil mist separator provided with the filter medium in one Embodiment of this invention. Sectional drawing which shows the filter medium of a two-layer structure typically. (A) is a schematic front view which shows the high-density layer formed with the crimped fiber, (b) is a schematic front view which shows the low-density layer formed with the straight fiber. (A)-(e) is a non-circular sectional view of the fiber which forms a high-density layer, (f) is a circular sectional view of the fiber which forms a low-density layer. (A) is a schematic front view which shows the high-density layer knitted at random, (b) is a schematic front view which shows the low-density layer knitted with the fiber. (A) is sectional drawing which shows the effect | action of a high density layer typically, (b) is sectional drawing which shows the effect | action of a low density layer typically.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, a housing 12 of an oil mist separator 10 is supported on a cylinder head cover 11 of an automobile engine. A blow-by gas inflow hole 13 is opened at one end of the housing 12, and a blow-by gas outflow hole 14 is opened at the other end. A cylindrical filter medium 15 for separating oil (oil mist) or water (water mist) from blow-by gas is supported in the housing 12. The filter medium 15 is composed of an aggregate of fibers formed of a polyester resin such as polyethylene terephthalate resin (PET).

  The filter medium 15 will be described. As shown in FIG. 2, the filter medium 15 is formed by laminating an upstream high-density layer 18 having a high fiber density and a downstream low-density layer 19 having a low fiber density by a nonwoven fabric as an aggregate of fibers 16 and 17. Configured. The high-density layer 18 forms the shape of the fiber 16 so that oil or water scavenging properties are expressed well, while the low-density layer 19 forms the shape of the fiber 17 so that oil or water drainage is expressed. Form. In addition, the arrow in FIG.1 and FIG.2 shows the flow direction of blow-by gas.

Since the fiber shape in each layer of the high-density layer 18 and the low-density layer 19 can take various shapes, those fiber shapes will be described in order in the following [A] to [G].
[A] As shown in FIG. 3 (a), the high-density layer 18 is composed of crimped fibers 16a, and as shown in FIG. 3 (b), the low-density layer 19 is composed of straight fibers 17a. it can. Since the crimped fibers 16a are formed in a twisted state, oil or water is easily captured by the crimped fibers 16a when reaching the surface of the crimped fibers 16a forming the high-density layer 18. Therefore, the high-density layer 18 can express high oil or water trapping properties.

  On the other hand, since the straight fibers 17a extend almost straight, when the oil or water reaches the surface of the straight fibers 17a forming the low-density layer 19, the length direction or peripheral surface of the fibers along the surface of the straight fibers 17a. It becomes easy to flow down in the direction along. Therefore, the low density layer 19 can express high drainage.

Accordingly, the filter medium 15 works by linking the trapping function of the high-density layer 18 and the drain function of the low-density layer 19, and can significantly increase the oil or water trapping efficiency and greatly reduce the pressure loss. it can.
[B] The high-density layer 18 is composed of thin fibers 16 having a fiber diameter of 5 to 15 μm, and the low-density layer 19 is composed of thick fibers 17 having the same basis weight as the high-density layer 18 and a fiber diameter of 20 to 30 μm. can do. By using the thin fibers 16 with the same basis weight, the contact area with the oil or water is increased, so that the chance of the oil or water hitting the thin fibers 16 is increased, and the surface of the fibers 16 is easily captured. For this reason, the high-density layer 18 can express the high trapping property of oil or water.

  On the other hand, by using the thick fibers 17, oil droplets captured by the high-density layer 18 on the upstream side and having a large diameter are sufficiently received and easily descend along the surface of the fibers 17. For this reason, the low density layer 19 can express the high drainability of oil or water.

The larger the difference between the fiber diameter of the fibers 16 of the high-density layer 18 and the fiber diameter of the fibers 17 of the low-density layer 19, the more significant the difference between the two effects. Since the balance with the drainage of 19 may be impaired, the above ranges are appropriate.
[C] The high-density layer 18 can be constituted by the fibers 16 having an irregular cross section other than the circular cross section, and the low-density layer 19 can be constituted by the fibers 17 having a circular cross section. The fiber 16 having a modified cross-section has a larger contact area with oil or water than the fiber 17 having a circular cross-section, and the probability that the oil or water hits the fiber 16 having a modified cross-section increases and is easily trapped on the surface of the fiber 16. Therefore, the high-density layer 18 can express high oil or water trapping properties.

  On the other hand, since the fiber 17 having a circular cross section has no protrusions around it and is smooth and straight, oil or water attached to the surface of the fiber 17 easily flows down along the surface of the fiber 17. Accordingly, the low density layer 19 can exhibit a high drainage property of oil or water.

  For example, as shown in FIG. 4A, it is possible to form the cross-sectional cross-section as the fiber 16 having an odd-shaped cross section, and form the capturing protrusions 16b on all sides. The trapping protrusions 16b extending in all directions enhance the trapping property when oil or water reaches the surface of the fiber 16 having a deformed cross section of the high-density layer 18. As shown in FIG. 4 (b), it is possible to form the cross-sectionally star-shaped fibers 16 as irregularly shaped fibers 16 and to form a large number of capturing protrusions 16b from the periphery thereof. As shown in FIG. 4C, the fiber 16 having an irregular cross section can be formed into a flat shape by forming an elliptical cross section. As shown in FIGS. 4D and 4E, the fiber 16 having an irregular cross section can be formed in a rhombus cross section or a hexagon cross section.

On the other hand, as shown in FIG. 4 (f), even if the number of the fibers 17 having a circular cross section is the same as that of the fibers 16 having an irregular cross section, the surface area is small, so that the fibers 17 substantially function as the low density layer 19. .
[D] The high-density layer 18 can be composed of short fibers, and the low-density layer 19 can be composed of long fibers. The short fibers are arranged in an irregular direction in the high-density layer 18 and easily get entangled. Therefore, the chance of coming into contact with oil or water increases, and the oil or water is easily trapped on the surface of the fibers 16. For this reason, the high-density layer 18 can express the high trapping property of oil or water.

On the other hand, the oil or water attached to the surface of the long fiber easily flows down along the surface. For this reason, the low density layer 19 can express high drainage.
[E] The high-density layer 18 can be configured so that the fibers 16 are intertwined vertically and horizontally, and the low-density layer 19 can be configured to be intertwined with fibers extending in one direction. As shown in FIG. 5A, by configuring the fibers 16 to be entangled vertically and horizontally, the probability of collision of oil or water with the fibers 16 in the thickness direction of the high-density layer 18 is increased. Therefore, the high-density layer 18 can express high oil or water trapping properties.

On the other hand, as shown in FIG. 5 (b), the fibers 17 are entangled with the fibers extending in one direction, so that the oil or water attached to the fibers easily descends along the surface of the fibers 17 due to its gravity. Therefore, the low density layer 19 can express high drainability of oil or water.
[F] The fibers 16 of the high-density layer 18 and the fibers 17 of the low-density layer 19 can be entangled. As the entanglement means, for example, a needle punch method is used, and the fibers 16 of the high-density layer 18 and the fibers 17 of the low-density layer 19 are entangled by performing needle punching in a state where the high-density layer 18 and the low-density layer 19 are overlapped. Can be made. By configuring in this way, the oil or water captured by the high-density layer 18 can easily move to the low-density layer 19 side. Therefore, the oil or water is smoothly drained by the low density layer 19 and the drainability can be improved.
[G] The fiber 16 forming the high-density layer 18 can be subjected to water / oil repellent treatment, and the fiber 17 forming the low-density layer 19 can be subjected to hydrophilic / lipophilic treatment. By performing the water / oil repellent treatment on the fiber 16, the oil or water grows and is captured in a spherical shape on the surface of the fiber 16, and the captured oil or water easily moves to the low density layer 19 side. That is, as shown in FIG. 6A, the oil or water 20 reaching the high-density layer 18 is formed into a spherical shape on the surface of the fiber 16 based on the water / oil repellency of the fiber 16, and the sphere gradually becomes larger. The diameter is increased and the material moves to the low density layer 19 side.

  Examples of the water / oil repellent used in the water / oil repellent treatment include fluorine compounds and silicone compounds. As the water / oil repellent treatment method, the fiber 16 is immersed (dipped) in the water / oil repellent to form a water / oil repellent film on the surface of the fiber 16, or the water / oil repellent is chemically treated by graft polymerization or the like. And the like. In this case, the water / oil repellent can be dissolved in an organic solvent.

  On the other hand, by subjecting the fibers 17 to hydrophilic / lipophilic treatment, oil or water that has moved from the high-density layer 18 has affinity to the surface of the fibers 17 of the low-density layer 19 and flows down the surface of the fibers 17 and is drained. That is, as shown in FIG. 6B, the oil or water 20 that has moved from the high-density layer 18 to the low-density layer 19 has a affinity for the surface of the fiber 17 of the low-density layer 19 and is downward along the surface of the fiber 17. Dripping and flowing down.

  Examples of the hydrophilic lipophilic agent used for the hydrophilic lipophilic treatment include polyester alkylene glycol copolymer resins. Examples of the hydrophilic / lipophilic treatment method include a method of immersing the fiber 17 in a hydrophilic lipophilic agent to form a hydrophilic / lipophilic film on the surface of the fiber 17.

  About the high-density layer 18 and the low-density layer 19 described in the above [A] to [G], the thickness, density, etc. of the high-density layer 18 and the low-density layer 19 according to the properties of the gas passing through the filter medium 15. Can be set as appropriate.

Next, the operation of the filter medium 15 for the oil mist separator 10 configured as described above will be described.
Now, as shown in FIG. 1, the blow-by gas that has flowed into the filter medium 15 from the inflow hole 13 passes through the filter medium 15. At this time, the filter medium 15 is configured by laminating a high-density layer 18 on the upstream side and a low-density layer 19 on the downstream side, and the high-density layer 18 and the low-density layer 19 have a fiber shape that is high in oil or water 20, respectively. It is formed so as to express trapping properties and high drainage properties. For this reason, in the high-density layer 18 of the filter medium 15, much of the oil or water 20 in the blow-by gas is trapped on the surface of the fiber 16, and then the captured oil or water 20 rides on the gas flow of the blow-by gas and becomes a low-density layer. 19 moves to the low density layer 19 and flows down along the surface of the fiber 17. Therefore, the filter medium 15 composed of two layers of the high-density layer 18 and the low-density layer 19 can facilitate the capture of the oil or water 20 and can smoothly drain the captured oil or water 20.

  After the oil or water 20 in the blow-by gas is captured in the filter medium 15 and subsequently drained, the blow-by gas flows out from the outflow hole 14. The gas flowing out from the outflow hole 14 is sent to the intake system of the engine.

The effects exhibited by the filter medium 15 for the oil mist separator 10 according to the embodiment described in detail above will be collectively described below.
(1) The filter medium 15 for the oil mist separator 10 of the present embodiment includes an upstream high-density layer 18 and a downstream low-density layer 19 laminated, and the high-density layer 18 and the low-density layer 19 are each oil. Or it is comprised so that the high capture | acquisition property and high drain property of the water 20 may be expressed. For this reason, the oil or water 20 in the blow-by gas is captured on the surface of the fiber 16 of the high-density layer 18, and the captured oil or water 20 reaches the surface of the fiber 17 of the low-density layer 19 and descends the surface of the fiber 17. And drained.

Therefore, according to the filter medium 15 for the oil mist separator 10 of the present embodiment, it is possible to improve the trapping and draining properties of the oil or water 20, improve the trapping efficiency of the oil or water 20, and The effect of reducing pressure loss due to clogging can be exhibited.
(2) The high density layer 18 is composed of crimped fibers 16a, and the low density layer 19 is composed of straight fibers 17a. For this reason, the oil or water 20 in the blow-by gas is easily entangled with the crimped fibers 16a, and the trapping property can be improved. On the surface of the straight fibers 17a, the oil or water 20 is likely to descend along the surface, and the drainage property Can be improved.
(3) The high density layer 18 is composed of thin fibers 16 having a fiber diameter of 5 to 15 μm, and the low density layer 19 is composed of thick fibers 17 having a fiber diameter of 20 to 30 μm. Therefore, in the high density layer 18, the portion where the oil or water 20 comes into contact with the fibers 16 can be increased to improve the trapping property, and in the low density layer 19, the oil or water 20 easily flows down on the surface of the fibers 17, Can be improved.
(4) The high-density layer 18 is composed of fibers 16 having an irregular cross section other than a circular cross section, and the low-density layer 19 is composed of fibers 17 having a circular cross section. Therefore, the surface area of the fiber 16 having the irregular cross section can be increased, the oil or water trapping property can be improved, and the oil or water can be smoothly lowered on the surface by the fiber 17 having the circular cross section. Can be improved.
(5) The high density layer 18 is composed of short fibers, and the low density layer 19 is composed of long fibers. Accordingly, the oil or water 20 can be captured well by the short fibers, and the oil or water 20 can be easily guided down the surface by the long fibers, thereby improving the drainability.
(6) The high-density layer 18 is configured by intertwining fibers 16 vertically and horizontally, and the low-density layer 19 is configured by intertwining fibers extending in one direction. For this reason, in the high-density layer 18, the opportunity for oil or water to collide with the fibers 16 can be increased, and the trapping property can be improved. Drainability can be improved.
(7) The fibers 16 of the high-density layer 18 and the fibers 17 of the low-density layer 19 are entangled. In this case, the oil or water 20 captured by the high-density layer 18 can be efficiently moved to the low-density layer 19 side by the entanglement of the fibers 16, and the drainage can be further promoted.
(8) The high density layer 18 is subjected to water / oil repellent treatment, and the low density layer 19 is subjected to hydrophilic / lipophilic treatment. Therefore, in the high-density layer 18, the oil or water 20 grows in a spherical shape on the surface of the fiber 16, and the trapping efficiency can be increased. In the density layer 19, the oil or water 20 easily flows down with affinity to the surface of the fiber 17, and drainage can be improved.
(9) In the filter medium 15 of this embodiment, the high-density layer 18 that expresses high oil or water 20 trapping properties and the low-density layer 19 that expresses high drainage properties are laminated. For this reason, the function of the high density layer 18 and the function of the low density layer 19 work synergistically. Therefore, the filter medium 15 can suppress the increase in ventilation resistance without causing clogging, and can reduce the pressure loss. Can be improved.

It should be noted that the above embodiment can be modified as follows.
The combination of the configuration of the high-density layer 18 and the configuration of the low-density layer 19 listed in [A] to [G] can be changed as appropriate, or each layer can be configured to have a plurality of layers.

  -As the fiber 17 which comprises the low density layer 19, a highly rigid metal fiber etc. can also be used. In this case, even if oil or water 20 adheres to the surface of the fiber 17, since the metal fiber can maintain its shape, the voids in the low density layer 19 can be retained, and the smoothness of the surface of the metal fiber can be maintained. Oil or water 20 is easily transferred and the drainage of the low density layer 19 can be improved.

The filter medium 15 may be provided between the high-density layer 18 and the low-density layer 19 with one or more medium-density layers having an intermediate fiber density.
The present invention is applied to the filter medium 15 of the oil mist separator 10 provided inside the cylinder head cover 11, the filter medium 15 of the oil mist separator 10 provided alone around the engine, and the oil mist separator 10 in the swash plate compressor used in the air conditioner. It is also possible to embody the filter medium 15 for a mist separator, the filter medium 15 for a mist separator in a ventilation fan, and the like.

  DESCRIPTION OF SYMBOLS 10 ... Oil mist separator, 15 ... Filter medium, 16, 17 ... Fiber, 16a ... Crimped fiber, 17a ... Straight fiber, 18 ... High density layer, 19 ... Low density layer, 20 ... Oil or water.

Claims (8)

A filter medium comprising a collection of fibers and used in a mist separator for removing oil or water from gas,
Constructed by laminating a high-density layer of fibers that capture oil or water on the upstream side of the gas flow and a low-density layer of fibers that drain oil or water captured by the high-density layer on the downstream side. In addition, a filter medium for a mist separator, wherein the high-density layer and the low-density layer are formed so that the fiber shape exhibits oil or water scavenging and draining properties, respectively. The filter medium for a mist separator according to claim 1, wherein the high-density layer is composed of crimped fibers, and the low-density layer is composed of straight fibers. 2. The mist separator according to claim 1, wherein the high density layer is composed of thin fibers having a fiber diameter of 5 to 15 μm, and the low density layer is composed of thick fibers having a fiber diameter of 20 to 30 μm. Filter media. 2. The filter medium for a mist separator according to claim 1, wherein the high-density layer is composed of fibers having an irregular cross section other than a circular cross section, and the low-density layer is composed of fibers having a circular cross section. The filter medium for a mist separator according to claim 1, wherein the high-density layer is composed of short fibers, and the low-density layer is composed of long fibers. 2. The filter medium for a mist separator according to claim 1, wherein the high-density layer is configured by intertwining fibers vertically and horizontally, and the low-density layer is configured by intertwining fibers extending in one direction. . The filter medium for a mist separator according to any one of claims 1 to 6, wherein the fibers of the high-density layer and the fibers of the low-density layer are entangled. The high density layer is subjected to a water / oil repellent treatment, and the low density layer is subjected to a hydrophilic lipophilic treatment. Filter medium for mist separator.

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