JP2014023999A - Bag-like filter, streamer-type filter, and method of making filter medium for bag-like filter - Google Patents

Abstract

[PROBLEMS] To provide a bag-shaped filter, a blow-off filter, and a method for producing a filter material for a bag-shaped filter capable of suppressing breakage of glass fiber wool or a glass fiber sheet as a filter medium while maintaining pressure loss and the like in the conventional manner. provide.
A bag-like filter includes a net-like net member, and a sheet-like cotton fiber layer that is integrated with the net member and laminated on the net member by fibers entangled with the net yarn of the net member. The filter medium formed by overlapping the pair of laminated materials in the filter medium and the filter medium formed in a bag shape by overlapping the mesh members so that the mesh members face inward And a yarn material that connects the facing portions at a plurality of locations so that the portions to be separated do not separate from each other by a predetermined distance or more. Laminate with a cotton-like fiber layer laminated on a mesh member is produced by entanglement and attachment of glass fibers made by melting glass raw material in a gas flow flowing in one direction to the mesh member being conveyed Is done.
[Selection] Figure 1

Description

  The present invention relates to a bag-shaped filter, a streamer-type filter, and a method for producing a filter material for a bag-shaped filter.

  Conventionally, a windsock-type filter has been used for supply and exhaust in a nuclear facility. When the function as an air filter is completed, the windsock filter can be folded and stored or incinerated, and thus has better handleability than a pleated air filter. When the bag filter captures radioactive material, the folded stream filter is isolated in the storage room and stored for a long time. For this reason, it is excellent in installation workability and operability as compared with a pleated air filter that uses a spacer or the like to fold the filter medium into a zigzag shape and maintain the zigzag shape.

As a bag-like filter, there is known a bag-like filter that prevents the glass fiber sheet as a base material of the filter medium from coming into direct contact with the air flow, prevents the glass fiber from being peeled off by the air current, and increases the life of the filter medium. (Patent Document 1).
Specifically, the bag-like filter has a reinforcing sheet attached to both the upstream side and the downstream side with respect to the airflow of the glass fiber filter material sheet, and the two glass fiber filter material sheets are overlapped on one side edge. A bag-shaped filter medium is used in which the other side edges are sandwiched between covering cloths and further sewn with a thread from the covering cloth to form a bag.

  Moreover, as a bag-like filter, a mesh-like reinforcing material is integrated on the entire surface of the glass fiber of a filter medium formed in a bag shape by arranging glass fiber wool inside and a non-woven fabric on the outer surface of the glass fiber wool. There is also known a filter configured to be fixed (for example, using an adhesive or the like) (Patent Document 2).

JP 2011-161429 A Japanese Utility Model Publication No. 5-44214

  However, the bag-shaped filter in Patent Document 1 has a structure capable of suppressing the breakage of the glass fiber sheet (sheet-like cotton-like fiber layer), but improves the filter characteristics (its pressure loss, collection efficiency, life, etc.). It ’s difficult. And in the bag-like filter in the above-mentioned patent document 1 and patent document 2, when used in an air conditioner with a large processing air volume, the difference in wind speed is partially large due to the wind speed distribution on the filter medium surface, and the turbulent flow becomes severe, A flutter phenomenon may occur locally, and the surface of the filter medium may become fluffy and lose its performance as a filter medium at an early stage.

  Therefore, in order to solve the conventional problems, the present invention eliminates the damage of the sheet-like cotton-like fiber layer in the filter medium while maintaining the filter characteristics (its pressure loss, collection efficiency, life, etc.). It aims at providing the preparation methods of the bag-shaped filter which can be suppressed more, a streamer type filter, and the filter medium for bag-shaped filters.

One embodiment of the present invention is a bag-shaped filter. The bag-like filter includes a net-like net member, and a sheet-like cotton-like fiber layer that is integrated with the net member by being entangled with the net yarn of the net member and laminated on the net member. A pair of laminated materials, a filter medium formed by being overlapped so that the mesh members face inward, and
A thread material that connects the facing portions at a plurality of locations so that the facing portions of the filtering media formed by overlapping the pair of laminated materials in the filtering media are not separated by a predetermined distance or more.

  It is preferable that the said cotton-like fiber layer is a layer formed by spraying glass fiber on the said net | network member.

  Furthermore, it is preferable that the bag-like filter has a support layer that supports the cotton-like fiber layer and transmits flowing air, and the support layer is provided in the outermost layer of the filter medium.

Another aspect of the present invention is a windsock filter. The windsock filter is
A rectangular outer frame member;
A plurality of inner frame members arranged and locked in one direction on the outer frame member; and the bag-like filter fixed to each of the plurality of inner frame members;
Is provided.

Another embodiment of the present invention is a method for producing a filter material for a bag-like filter. The production method is as follows:
Transporting a net-shaped net member;
A cotton-like fiber layer laminated on the mesh member by forming glass fibers by melting the glass raw material in a gas flow flowing in one direction, and entangled the glass fibers with the mesh member being conveyed. Producing a pair of laminates having
Of the pair of laminated materials, the mesh members are overlapped so as to face inward, and the opposing portions facing the inner side of the filter medium by the overlapping of the pair of laminated materials are not separated from each other by a predetermined distance or more. And connecting the parts to be performed at a plurality of locations.

  According to the method for producing the bag-shaped filter, the blow-off type filter, and the filter medium for the bag-shaped filter, the sheet-shaped cotton fiber layer that is the filter medium while maintaining the filter characteristics (its pressure loss, collection efficiency, life, etc.) Can be suppressed from conventional products.

It is a figure which shows schematic structure of the windsock-type filter which is one Embodiment of the windsock-type filter of this invention. It is a figure which shows the structure of a part of streamer type filter shown in FIG. (A), (b) is a figure which shows the structure of the bag-shaped filter of this embodiment. It is a figure which shows the structure of the net | network member of this embodiment, a cotton-like fiber layer, and a support layer. (A), (b) is the photograph which shows the state which a part of conventional cotton-like fiber layer peeled and the thickness became thin. It is a figure which shows typically the system which performs the method of forming a cotton-like fiber layer in the net | network member of this embodiment. (A), (b) is a figure which shows the cross-sectional structure of the bag-shaped filter of a comparative example and a prior art example.

Hereinafter, the method for producing the bag-shaped filter, the blow-off filter, and the filter medium for the bag-shaped filter of the present invention will be described in detail.
FIG. 1 is a diagram showing a schematic configuration of a windsock filter 10 which is an embodiment of the windsock filter of the present invention. FIG. 2 is a diagram showing a configuration of a part of the windsock filter 10.

(Flower type filter)
As shown in FIG. 1, the windsock filter 10 is a filter unit in which a large number of bag-like filters are arranged. The streamer filter 10 includes an outer frame member 12, a plurality of inner frame members 14, and a plurality of bag-like filters 16.
The outer frame member 12 has a rectangular shape and is made of steel or the like.
The inner frame member 14 forms a rectangular frame and is made of steel or the like. As shown in FIG. 2, the size of the inner frame member 14 is determined so as to correspond to the size of the opening of the bag-like filter 16. The bag-shaped filter 16 is attached to the inner frame member 14 so that the edge on the circumference of the opening of the bag-shaped filter 16 is in contact with the outer periphery of the inner frame member 14. Accordingly, the plurality of inner frame members 14 to which the bag-like filter 16 is attached are arranged and locked to the outer frame member 12 in one direction. At this time, the adjacent inner frame members 14 are fastened with screws 14 a through through holes provided in the inner frame member 14. Thereby, the bag-like filter 16 is fixed to the inner frame member 14. Furthermore, the portions of the inner frame members 14 arranged in a row that are in contact with the outer frame members 12 are fixed to the outer frame member 12 by screws or the like (not shown).
In this way, the windsock filter 10 as shown in FIG. 1 is produced.

(Bag-like filter)
FIGS. 3A and 3B are diagrams showing the configuration of the bag-like filter 16. The bag-like filter 16 has a filter medium including a net member 20, a cotton-like fiber layer 22, and a support layer 24. This filter medium is configured by laminating a net member 20, a cotton-like fiber layer 22, and a support layer 24. The net member 20 and the cotton-like fiber layer 22 are prepared in advance as a laminated material. The pair of laminated materials are overlapped so that the net members 20 face inward and the support layer 24 faces outward so that a bag-shaped filter medium is formed so that the pair of laminated materials has a bag shape. The shape of the bag-shaped filter medium is maintained by sewing the mesh member 20 and the cotton-like fiber layer 22 constituting the pair of laminated materials and the support layer 24 with the peripheral sewing threads 18a, 18b, and 18c. Furthermore, the overlapped facing portions are connected by the thread material 26a at a plurality of locations so that the facing portions of the inwardly facing filter media formed by overlapping the pair of laminated materials are not separated by a predetermined distance or more. ing.

FIG. 4 shows the configuration of the net member 20, the cotton-like fiber layer 22, and the support layer 24.
The net member 20 is formed by arranging a plurality of glass fibers twisted and bundled in a lattice shape. The net fiber of the net member 20 is, for example, 2.5 to 3.0 dtex. The length of one side (mesh size) of the rectangular shape in which the mesh fibers are arranged in the mesh member 20 is 3 to 7 mm, for example, to maintain the durability of the cotton-like fiber layer 22 described later for a long period of time. It is preferable in that the function of the air filter can be maintained, and further, the cotton-like fiber layer 22 is integrated to form a laminated material. The net shape of the net fiber is not limited to the lattice shape, but may be a triangular shape, a hexagonal shape, or the like, and the net shape of the net fiber is not limited.

The cotton-like fiber layer 22 is made of glass fiber wool and has a diameter of 0.5 to 3.0 μm, for example. The thickness of the cotton fiber layer 22 is, for example, 5 to 10 mm. The cotton-like fiber layer 22 has a function of collecting particles (average 0.7 μm) in the air. The collection efficiency of the cotton-like fiber layer 22 is preferably 70% or more (particles having an average of 0.7 μm). Moreover, it is preferable that the pressure loss of the cotton-like fiber layer 22 is 100 Pa or less. The basis weight of the cotton-like fiber layer 22 is preferably 7 to 10 kg / m ² , for example.
Such glass fiber wool is integrated with the net member 20 and laminated on the net member 20 by the glass fiber wool being entangled with the net yarn of the net member 20.

The support layer 24 supports the cotton-like fiber layer 22. The support layer 24 is made of a nonwoven fabric made of vinylon, polypropylene, polyester, or a glass net. The support layer 24 does not have a function of collecting particles (average 0.7 μm) in the flowing air, and the pressure loss is substantially zero. It is not integrally joined to the adjacent cotton-like fiber layer 22 and is only partially fixed to the cotton-like fiber layer 22 and the net member 20 by the thread material 26a. The support layer 24 can support the cotton-like fiber layer 22 even if it is not integrally joined to the cotton-like fiber layer 22 (even if not integrally joined to the laminated material).
In addition, the net member 20 described above does not have a collection function like the support layer 24, and the pressure loss is substantially zero.

  Thus, in the filter medium, the cotton-like fiber layer 22 is not fixed to the mesh member 20 using an adhesive, and the glass fiber wool of the cotton-like fiber layer 22 is entangled with the mesh yarn of the mesh member 20. The mesh member 20 is integrated and laminated on the mesh member 20. The cotton-like fiber layer 22 includes a binder for fixing between the fibers so that the glass fiber wool is entangled with the net yarn of the net member 20. Conventionally, in the method of fixing the cotton-like fiber layer 22 to the net member 20 using an adhesive or the like, which has been used for laminating the cotton-like fiber layer 20 to the net member 20, the cotton-like fiber layer 22 is Since it is partially compressed and fixed, the bulk of the cotton-like fiber layer 22 is reduced. As a result, the collection efficiency and pressure loss of the cotton-like fiber layer 22 are easily affected. For this reason, in this embodiment, the glass fiber wool of the cotton-like fiber layer 22 is entangled with the mesh yarn of the mesh member 20 so as to be integrated with the mesh member 20 and laminated on the mesh member 20.

  In the filter medium, the net member 20 is provided on the inner surface where a pair of laminated materials are overlapped. The glass fiber wool of the cotton-like fiber layer 22 is fluffed by the wind pressure of the air, and further the glass fiber wool is partially made of the cotton-like fiber layer. It is because it peels from 22 and becomes thin, and cannot function as a filter medium. 5 (a) and 5 (b) are photographs showing a state in which a part of the cotton-like fiber layer is peeled and thinned in a conventional bag-like filter without a net member. By providing the net member 20, glass fiber wool fluffing and partial detachment from the cotton-like fiber layer 22 can be suppressed without increasing pressure loss. From the standpoint of more effectively exerting the effect of the mesh member 20, the interval between the meshes (rectangular shapes) in which the mesh fibers are arranged is preferably 3 to 7 mm.

FIG. 6 is a diagram schematically showing a system 30 that executes the method of forming the cotton-like fiber layer 22 on the mesh member 20.
The system 30 mainly includes drive rollers 32a, 32b, and 32c, a wire mesh belt 34, a glass filament 36, a gas burner 38, and a dryer 40.
The wire mesh belt 34 is wound around the drive rollers 32a, 32b, and 32c, and the wire mesh belt 34 is moved in the arrow direction by the rotation of the drive rollers 32a, 32b, and 32c.
A glass filament 36 and a gas burner 38 are provided on the upstream side of the wire mesh belt 34 in the conveying direction. The dryer 40 is provided on the downstream side in the conveyance direction of the wire mesh belt 34.

  The mesh member 20 is placed on the metal mesh belt 34 that is moved by the drive rollers 30a, 30b, and 30c, and is moved and conveyed. At this time, the tip portion of the glass filament 36 (filament diameter 0.3 mm) is melted by the high-temperature and high-pressure combustion gas from the gas burner 38, and the glass filament 36 becomes fine glass fiber wool and is moved by the metal belt 34. 20 is sprayed on. A liquid binder 42 is supplied to the gas flow when the glass fiber wool flows toward the mesh member 20. As a result, the fiberglass wool is entangled with the mesh member 20 to form the cotton-like fiber layer 22.

An air inlet (not shown) is provided inside the wire mesh belt 34, and the air inlet creates a negative pressure atmosphere so as to suck the gas flow that has passed through the mesh member 20. The glass fiber wool that has passed through the net of the wire mesh belt 34 is sucked and collected.
On the mesh member 20 conveyed by the wire mesh belt 34, the glass fiber wool is entangled with the mesh fibers of the mesh member 20 and gradually adheres, whereby the cotton-like fiber layer 22 is formed. The reticulated fiber layer 22 is gradually cooled while being conveyed, while being conveyed to the dryer 40 and dried.
Thus, the glass fiber wool is entangled with the mesh fibers of the mesh member 20 to form the cotton-like fiber layer 22 integrated with the mesh member 20. The fabric weight of the cotton-like fiber layer 22 is performed by controlling the conveyance speed of the wire mesh belt 34 and the flow rate of the gas for blowing the glass fiber wool.

That is, in the method of producing the filter medium having the net member 20, the cotton-like fiber layer 22, and the support layer 24, first, the net-like net member 20 is conveyed by the metal net belt 34. At this time, glass fiber wool 36 is melted in a gas flow flowing in one direction to form glass fiber wool, and this glass fiber wool is adhered to the mesh member 22 being conveyed, thereby forming a mesh. A pair of laminated materials having a cotton-like fiber layer 22 laminated on the member is produced.
Next, of the pair of laminated materials, the pair of laminated materials are overlapped using equipment (not shown) so that the net member 22 faces inward, and due to this overlapping, the facing portions facing inward are not separated by a predetermined distance or more. In this way, the opposing portions are connected at a plurality of locations by the thread material 26a. The opposing portions are connected from the outermost support layer 24 by a thread material 26a.
Furthermore, the edge part except the part used as the opening part of a bag among the edges of a pair of laminated | stacked laminated material is sewn with a thread | yarn using the apparatus which is not shown in figure, and is made into a bag shape.
In this way, the bag-shaped filter medium is produced.
[Experimental example]

In order to investigate the effect of the filter material for bag-like filter of this embodiment, the blow-off filter shown in FIG. 1 was produced and the presence or absence of peeling of the cotton-like fiber layer used for the filter material was examined.
The produced windsock filters are Comparative Examples 1 and 2 and Example 1.
Example 1 is a form shown in FIG. 3, in which the glass fiber wool of the cotton-like fiber layer 22 is entangled with the mesh yarn of the mesh member 20 and integrated with the mesh member 20. In Example 1, a mesh member 20 made of glass fiber having a thickness of 0.5 mm and a mesh size of 5 mm was used. The cotton-like fiber layer 22 has a basis weight of 45 g / m ² and a thickness of 7 mm. The collection efficiency (particles having a diameter of 0.7 μm) of the cotton-like fiber layer 22 is 85 to 90%, and the pressure loss is 30-40 Pa. The support layer 24 was a non-woven fabric made of polyester having a basis weight of 40 g / m ² and a thickness of 0.5 mm.
In Comparative Example 1, as shown in FIG. 7A, the cotton-like fiber layer 22 is placed on the inner side and the support layer 24 is placed on the outer side, and the portions of the filter media that face each other are connected with the yarn material 26a at a plurality of locations. It is a configuration. In Comparative Example 1, the same cotton-like fiber layer 22 and support layer 24 of Example 1 were used.
As shown in FIG. 7B, Comparative Example 2 has the same layer configuration as that of Example 1, but is a form in which the net member 20 and the cotton-like fiber layer 22 are fixed and integrated with an adhesive. In Comparative Example 2, the same mesh member 20, cotton-like fiber layer 22 and support layer 24 of Example 1 were used.

  Whether or not the cotton-like fiber layer 22 is peeled off by blowing air at a wind speed of 6.2 m / sec and a wind speed of 7.75 m / sec for a long time using such a blow-off type filter using a filter medium for an air filter. I investigated. The wind speed of 6.2 m / sec and the wind speed of 7.75 m / sec are respectively twice and 2.5 times the normally used wind speed. The presence or absence of peeling of the cotton-like fiber layer 22 was judged by visually observing the surface of the filter medium every time 1 hour passed.

In Comparative Example 1, peeling of the cotton-like fiber layer 22 was confirmed 2 hours after the start of the experiment at a wind speed of 6.2 m / second (twice the normal wind speed).
In Comparative Example 1, peeling of the cotton-like fiber layer 22 was confirmed 1 hour after the start of the experiment at a wind speed of 7.75 m / sec (2.5 times the normal wind speed).
In contrast, in Comparative Example 2, peeling of the cotton-like fiber layer 22 was not confirmed even after 5 hours from the start of the experiment at a wind speed of 6.2 m / sec (twice the normal wind speed). At 7.75 m / sec (2.5 times the normal wind speed), peeling of the cotton-like fiber layer 22 was confirmed 6 hours after the start of the experiment.

In Example 1, at a wind speed of 6.2 m / sec (twice the normal wind speed), peeling of the cotton-like fiber layer 22 was not confirmed even after 5 hours had elapsed since the start of the experiment. Even at a wind speed of 7.75 m / sec (2.5 times the normal wind speed), peeling of the cotton-like fiber layer 22 was not confirmed even after 10 hours from the start of the experiment.
From this, it turns out that this embodiment can suppress the damage by peeling of glass fiber wool, a glass fiber sheet, etc. which are filter media. Further, since the support layer 24 and the net member 20 do not affect the pressure loss, the filter characteristics can be maintained.

In this embodiment, since the cotton-like fiber layer 22 is a layer formed by spraying glass fibers on the mesh member 20, the cotton-like fiber layer 22 is compressed as compared with the case of fixing using an adhesive. Therefore, it is difficult to affect the collection efficiency and pressure loss.
Moreover, since the support layer 24 which supports the cotton-like fiber layer 22 and permeate | transmits the flowing air is provided in the outermost layer of the filter medium, peeling of the cotton-like fiber layer 22 can be suppressed further.
In the method for producing a filter material for a bag-like filter, cotton laminated on the net member 20 is obtained by entangled and adhering glass fibers produced by melting a glass raw material in a gas flow flowing in one direction to the net member 20 being conveyed. Since the fiber-like fiber layer 22 is formed, the cotton-like fiber layer 22 can be easily formed on the net member 20.

  As mentioned above, although the manufacturing method of the bag-shaped filter of this invention, a windsock type filter, and the filter medium for bag-shaped filters was demonstrated in detail, this invention is not limited to the said embodiment, In the range which does not deviate from the main point of this invention, various Of course, improvements and changes may be made.

DESCRIPTION OF SYMBOLS 10 Blow-off type filter 12 Outer frame member 14 Inner frame member 16 Bag-like filter 18a, 18b, 18c Peripheral sewing thread 20 Mesh member 22 Cotton-like fiber layer 24 Support layer 26a Thread material 30 System 32a, 32b, 32c Drive roller 34 Wire mesh belt 36 Glass filament 38 Gas burner 40 Dryer 42 Binder

Claims (5)

A bag-like filter,
A pair of laminated materials including a net-shaped net member and a sheet-like cotton-like fiber layer that is integrated with the net member by being entangled with the net yarn of the net member and laminated on the net member, A filter medium formed by overlapping the mesh members so as to face inward;
A thread material that connects the facing portions at a plurality of locations so that the facing portions of the filtering media formed by overlapping the pair of laminated materials in the filtering media are not separated by a predetermined distance or more. Bag-like filter.   The bag-like filter according to claim 1, wherein the cotton-like fiber layer is a layer formed by spraying glass fibers on the mesh member.   Furthermore, the bag-shaped filter of Claim 1 or 2 which has the support layer which supports the said cotton-like fiber layer and permeate | transmits the flowing air, and the said support layer is provided in the outermost layer of the said filter medium. A streamer filter,
A rectangular outer frame member;
The bag shape according to any one of claims 1 to 3, which is fixed to each of the plurality of inner frame members arranged in one direction and locked to the outer frame member, and the plurality of inner frame members. Filters,
A windsock-type filter comprising: A method for producing a filter medium for a bag-like filter,
Transporting a net-shaped net member;
A cotton-like fiber layer laminated on the mesh member by forming glass fibers by melting the glass raw material in a gas flow flowing in one direction, and entangled the glass fibers with the mesh member being conveyed. Producing a pair of laminates having
Of the pair of laminated materials, the mesh members are overlapped so as to face inward, and the opposing portions facing the inner side of the filter medium by the overlapping of the pair of laminated materials are not separated from each other by a predetermined distance or more. And a step of connecting parts to be connected at a plurality of locations.

Images