JP2009041879A - Filter duct and air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further reduce the weight of a filter duct and improve its shape stability while securing its particle collection performance. <P>SOLUTION: The filter duct has a bag-like fiber array laminate 101 provided with an opening portion from which gas flows in, such that the gas flowing into the inside from the opening flows out to the outside through the fiber array laminate 101. The fiber array laminate is formed by laminating a plurality of fiber array layers 101A to 101D in which fibers 103A to 103D are arranged approximately linearly in one direction, where some fiber array layers 101A, 101C and the others 101B, 101D are laminated such that the fiber stretching directions 105A to 105D are mutually orthogonal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a filter duct and an air conditioning system, and more particularly to a structure of the filter duct.

  Conventionally, a filter called a filter duct or a sock filter is known. The filter duct is a filter formed by forming a thin filter medium into an elongated bag shape having one end opened and the other end closed. The opening of the filter duct is connected to an air supply means such as a fan or a blower via an air supply chamber, a duct or the like. When a predetermined air volume is supplied from the air supply means, the internal pressure of the filter duct becomes higher than the external pressure due to the pressure loss of the filter medium. As a result, the filter duct expands to assume a tubular shape and retains its shape. In this specification, such a function that the filter duct maintains its shape by the internal pressure is referred to as a shape maintaining function. Air is filtered by a filter medium, and clean air from which dust is removed is supplied to the surroundings. Such a filter does not have a limited air outlet like a conventional metal duct, and air is uniformly supplied from the entire outer surface of the filter. There is an advantage that can be supplied in. For this reason, filter ducts are used as part of air conditioning systems in many facilities such as hospitals, libraries, semiconductor factories, etc., mainly in food processing factories.

Conventionally, a woven fabric has been used as a filter medium for a filter duct, but the structure becomes thick and heavy in order to ensure particle collection performance. Then, the filter duct comprised from the filter medium which laminated | stacked the melt blown nonwoven fabric and the spun bond nonwoven fabric is proposed (patent document 1).
JP-A-10-272316

  The filter duct maintains its own shape by the internal pressure, thereby securing a contact area with the outside, that is, an air outflow area. Therefore, the shape maintaining function is an essential function for securing an air outflow area. However, if the weight of the filter duct is too large, it is necessary to apply a considerable internal pressure to overcome the dead weight and maintain the shape retention function, leading to an increase in operating cost due to an increase in fan power and an early deterioration of the filter duct. . The filter duct described in Patent Document 1 uses a non-woven fabric as a filter medium, but the basis weight (weight per unit area) tends to increase due to the fact that the fibers are bent or oriented in a random direction. It is not necessarily optimal for weight reduction. Further, since the fiber is bent, the fiber is easily stretched when subjected to internal pressure, and as a result, the outer diameter and length of the filter duct itself are likely to fluctuate. Since the filter duct is usually supported by a support, if the outer diameter or length changes, a relative displacement occurs between the filter duct and the support, causing damage.

  It is an object of the present invention to provide a filter duct that ensures particle collection performance, further reduces weight and improves shape stability, and an air conditioning system using such a filter duct.

  The filter duct of the present invention has a bag-like fiber array laminate having an opening through which gas flows, and the gas flowing into the inside from the opening flows out to the outside through the fiber array laminate. . The fiber array laminate is formed by laminating a plurality of fiber array layers in which fibers are arranged substantially linearly in one direction, and some fiber array layers and other fiber array layers are perpendicular to each other in the fiber stretching direction. It is laminated so that.

  Such a fiber array laminate has a small fiber array layer and is suitable for weight reduction. Further, since the fibers are laminated so that the fiber drawing directions are orthogonal to each other, it is easy to adjust the area of the opening generated by the intersection of the fibers. Since the area of the opening is closely related to the size of the particles that can pass through, the desired particle collection performance can be easily realized by adjusting the particle diameter and arrangement pitch of the fibers. Furthermore, unlike conventional nonwoven fabrics in which the fibers are bent, the fibers are arranged in a straight line, so that the elongation of the fibers when the internal pressure of the filter duct rises is suppressed, and excellent shape stability is exhibited.

  The air conditioning system of the present invention has the above-described filter duct and air supply means connected to the opening.

  As described above, according to the present invention, it is possible to provide a filter duct that ensures particle collection performance, further reduces weight and improves shape stability, and an air conditioning system using such a filter duct. .

  Hereinafter, a filter duct and an air conditioning system of the present invention will be described in detail with reference to the drawings. FIG. 1 is a conceptual diagram showing an embodiment of an air conditioning system of the present invention. The figure (a) is a plan view of the building where the air conditioning equipment is arranged, the figure (b) is a sectional view along the line bb in the figure (a), and the figure (c) is a filter. FIG. 3 shows a perspective view of a duct and an air supply chamber. The air conditioning system 1 targets the space 2 for air conditioning. A plurality of filter ducts 3 a to 3 d are arranged near the ceiling 14 of the space 2. As will be described later, each of the filter ducts 3a to 3d is composed of an elongated bag-like fiber array laminate 101, and exhibits an elongated tubular shape when the inside is pressurized with air. Air is made to flow out through the fiber array laminate 101. One ends of the filter ducts 3a to 3d (bag-like fiber array laminate 101) are openings 4a to 4d, and the other ends are closing portions 5a to 5d. The filter ducts 3a to 3d are connected to the air supply chamber 6 through the openings 4a to 4d. The air supply chamber 6 is connected to a fan 7 serving as an air supply means provided in an adjacent space 9 through a duct 8. An air intake 10 is provided in the space 9 to introduce air from the outside. The air intake 10 is connected to a fan coil unit 12 that adjusts air temperature and humidity via a duct 11, and the fan coil unit 12 is connected to the fan 7. The space 2 is provided with air discharge ports 13a and 13b.

  The air taken in from the air intake 10 is adjusted to an appropriate temperature and humidity by the fan coil unit 12, sent to the air supply chamber 6 by the fan 7, and passes through the openings 4a to 4d to the filter ducts 3a to 3d. Sent inside. The air supplied into the space 2 from the filter ducts 3a to 3d is discharged to the outside from the air discharge ports 13a and 13b. As shown in FIG. 1C, the filter ducts 3a to 3d are expanded by the internal pressure, and maintain a shape extending in a substantially horizontal direction by the above-described shape holding function. Therefore, there is no problem even if there is no support at the time of operation, but the internal air escapes at the time of non-operation and the shape maintaining function is lost. Therefore, in order to prevent the filter ducts 3a to 3d from drooping when not in operation, the filter ducts 3a to 3d are held horizontally by beams 16 provided in the vicinity of the ceiling 14 via suspensions 15 provided at several locations.

  FIG. 2 is a partially exploded perspective view of the fiber array laminate constituting the filter duct. The fiber array layer is drawn with a slight curve, the left-right direction in the figure is the circumferential direction of the filter duct, and the front-depth direction in the figure is the major axis direction of the filter duct. The fiber laminate 101 is formed by laminating a plurality of fiber arrangement layers in which fibers are arranged in one direction. Although four fiber array layers 102A, 102B, 102C, and 102D are shown in the figure, the number of layers to be stacked can be appropriately determined according to the application. The fiber array layers 102A, 102B, 102C, and 102D are thermocompression bonded together to form a single fiber laminate 101 as a whole.

  FIG. 3 is an enlarged partial perspective view showing a part of the fiber array layer. Although only the fiber array layers 102A and 102B are shown in the figure, the other fiber array layers have the same configuration. As shown in the figure, the fiber array layer 102A is an aggregate of a large number of continuous long fibers 103A extending in parallel and linearly to each other. Similarly, the fiber array layer 102B is an aggregate of a large number of continuous long fibers 103B extending in parallel and linearly to each other. A gap 106 is formed by the orthogonal fiber array layers 102A and 102B. The gap 106 functions as an air passage, and particles larger than the gap 106 are captured by the fiber laminate 101. The fibers 103A and 103B may be folded in the middle or laminated in two or more layers. The fiber array layer 102A can be made from thermoplastic resins such as polyethylene, polypropylene, polyester, polyamide, polyvinyl chloride resin, polyurethane, and fluorine resin, and modified resins thereof. Resins by wet or dry spinning means such as polyvinyl alcohol resins and polyacrylonitrile resins can also be used. The same applies to the fiber array layer 102B. The diameter of each of the fibers 103A and 103B is, for example, about 10 μm, but a fiber having an arbitrary diameter can be made by changing the spinning conditions. For this reason, adjustment of particle collection performance is easy. The fiber array layers 102A and 102B are laminated so that the stretching direction 105A of the fibers 103A of the fiber array layer 102A and the stretching direction 105B of the fibers 103B of the fiber array layer 102B are orthogonal to each other. The stretching direction 105C of the fibers 103C of the fiber array layer 102C is orthogonal to the stretching direction 105B of the fibers 103B of the fiber array layer 102B. Similarly, the extending direction 105D of the fibers 103D of the fiber array layer 102D is orthogonal to the extending direction 105C of the fibers 103C of the fiber array layer 102C. The direction of the fibers in the fiber array layer does not need to be orthogonal to each other between adjacent fiber array layers, and two or more fiber array layers having the same stretching direction may be provided continuously.

  The fibers 103A, 103B, 103C, and 103D of the fiber array layers 102A, 102B, 102C, and 102D do not bend in directions other than the stretching directions 105A, 105B, 105C, and 105D, and do not face random directions. It has extremely high linearity and directionality. Therefore, even if a tensile force is applied in the fiber drawing direction, the fiber is hardly stretched. On the other hand, since almost no resistance force is generated against the tensile force in the direction orthogonal to the fiber stretching direction, when each of the fiber array layers 102A, 102B, 102C, 102D is provided alone, These fiber array layers are freely deformed. For example, when the fiber array layer 102A is provided alone, it hardly deforms with respect to the tensile force in the stretching direction 105A, but freely deforms with respect to the tensile force in the direction orthogonal to the stretching direction 105A. In the present embodiment, the fiber array layers 102A, 102B, 102C, and 102D are provided in a laminated manner, and the fibers 103A and 103C of the fiber array layers 102A and 102C are stretched in directions 105A and 105C (hereinafter collectively referred to as a first direction). The fibers 103B and 103D of the fiber array layers 102B and 102D extend in the extending directions 105B and 105D (hereinafter collectively referred to as the second direction S2. The second direction S2 is the first direction). Is perpendicular to S1). Thus, by laminating the fiber array layer so that the fiber drawing directions are orthogonal to each other, large strength and deformation resistance are generated against the tensile force from any direction.

Table 1 is a table showing the correspondence between the basis weight and the fragile air permeability in some examples. The fragile air permeability and the particle collection performance are in an inversely proportional relationship, and the fragile air permeability can be used as one index indicating the particle collection performance. In each example, the basis weight is in the range of 10 to 40 g / m ² , and the corresponding fragile air permeability of the fiber array laminate is in the range of 50 to 500 cm ³ / cm ² · sec. The smaller the basis weight, the lower the pressure loss of the fiber array laminate, and the fragile permeability increases. Therefore, when capturing particles having a fine particle size, it is desirable to use a fiber array laminate having a larger basis weight.

  As described above, in the fiber array laminate of the present embodiment, continuous long fibers extending in a straight line are stacked so that the stretching directions are orthogonal to each other. From these characteristics, the following advantages can be obtained.

  (1) The fiber array laminate of this embodiment can be easily reduced in weight while ensuring strength and particle collection performance. That is, in the filter duct of the prior art, the fibers are bent at random, and many fibers that do not generate tension but are deformed even when subjected to a tensile force are included. That is, the fibers that can effectively bear the tensile force have been limited. On the other hand, in this embodiment, since the fiber is extended | stretched linearly, each fiber can bear a tensile force effectively. This means that it can withstand the same level of tensile force with a small amount of fiber (weight), that is, it is easy to reduce the weight while ensuring the same strength. Further, in the filter duct of the prior art, the desired particle collection performance is ensured by complex entanglement of the fibers, but in this embodiment, the gap 106 that prevents the passage of particles by the fibers being orthogonal to each other. (See FIG. 3), that is, making "eyes". For this reason, the particle | grain capture | acquisition part can be formed very efficiently.

When the melt-blown nonwoven fabric of conventional filter duct reinforced with spun-bonded nonwoven fabric, a trapping layer for melt-blown nonwoven those 100 g / m ² about basis weight of about 40 g / m ² as a spunbonded nonwoven fabric is a reinforcement layer having a basis weight It is conceivable as an example to use the above. In this case, the total basis weight is 140 g / m ² . When Frazier permeability is used as an index indicating the particle collection performance, in this embodiment, the same Frazier permeability can be obtained with a basis weight of 10 to ²⁰ g / m ² , which is about 1/10 of the conventional technology. It is possible to reduce the weight.

  Specifically, the weight reduction of the filter duct has the following advantages. First, it is necessary to apply a certain amount of internal pressure to the filter duct in order to realize the shape maintaining function. Since the filter duct of the present embodiment has a lightweight structure, it can easily overcome the weight of the filter duct even with a small internal pressure, so that the shape maintaining function can be easily realized. This leads to a reduction in power costs for fans and the like (reduction in operating costs) and a longer life of the filter duct. Next, when a filter duct is used in an environment such as a clean room or a semi-clean room, high performance is always required, so that the fiber array laminate needs to be frequently replaced. Since the filter duct of this embodiment is lightweight, replacement work is easy. Even when the used fiber array laminate is discarded, the weight is reduced due to its light weight. Furthermore, the fiber array laminate of the present embodiment is characterized in that it is easy to fold and thin because the fibers are aligned, which is advantageous not only for weight reduction but also for volume reduction.

  (2) The fiber array laminate of this embodiment is excellent in dimensional stability. In the conventional structure, there are many bent portions of the fiber, and the bent portion tends to be linearly deformed by receiving a tensile force, so that the filter duct itself may be greatly deformed. On the other hand, in this embodiment, since the fiber is extended linearly, there is little room for the fiber to stretch and high dimensional stability is exhibited. For this reason, a filter duct does not deform | transform excessively during driving | operation, relative displacement with a support (suspender 15) is suppressed, and it contributes to the damage prevention of a filter duct or a support.

  (3) The fiber array laminate of the present embodiment is less contaminated with fiber piece waste. In a conventional filter duct using a nonwoven fabric, a melt blown nonwoven fabric in which fibers are substantially cut is used, so that there is a problem in that fiber scraps are scattered from the filter duct. However, since the fiber array laminate of continuous long fibers according to this embodiment does not generate such section waste, it is particularly excellent as a filter duct for clean rooms and semi-clean rooms that do not like the generation of such section waste.

  As described above, the filter duct of the present embodiment has various merits, but the fiber array laminate itself can be subjected to processing such as antibacterial, antifungal, and deodorant.

  Next, the manufacturing method of the fiber laminated body demonstrated above is demonstrated. FIG. 4 shows a schematic view of a production apparatus used for producing the fiber array layer. The fiber array layer manufacturing apparatus 21 includes a spinning unit 22 mainly composed of a meltblown rice 24 and a conveyor 25, and a stretching unit 23 composed of stretching cylinders 26a and 26b, take-up nip rollers 27a and 27b, and the like. ing. The melt blown rice 24 has a large number of nozzles 28 arranged at the tip (lower end) in a direction perpendicular to the paper surface (only one is shown in the figure). A large number of fibers 31 are formed by the molten resin 30 fed from a gear pump (not shown) being extruded from the nozzle 28. Air reservoirs 32a and 32b are provided on both sides of each nozzle 28, respectively. High-pressure heated air heated to a temperature higher than the melting point of the resin is sent to the air reservoirs 32a and 32b, and is ejected from slits 33a and 33b communicating with the air reservoirs 32a and 32b and opening at the tip of the melt blown die 24. As a result, a high-speed air flow substantially parallel to the extrusion direction of the fibers 31 extruded from the nozzle 28 is generated. The fiber 31 extruded from the nozzle 28 is maintained in a meltable state that can be drafted by the high-speed airflow, and the fiber 31 is drafted by the frictional force of the high-speed airflow, thereby reducing the diameter of the fiber 31. The temperature of the high-speed airflow is set to 80 ° C. or higher, desirably 120 ° C. or higher, than the spinning temperature of the fiber 31. In the method of forming the fiber 31 using the melt blown rice 24, the temperature of the fiber 31 immediately after being extruded from the nozzle 28 can be made sufficiently higher than the melting point of the fiber 31 by increasing the temperature of the high-speed airflow. Therefore, the molecular orientation of the fiber 31 can be reduced.

  A conveyor 25 is disposed below the melt blown rice 24. The conveyor 25 is wound around a conveyor roller 29 and other rollers that are rotated by a drive source (not shown), and the fibers extruded from the nozzles 28 by driving the conveyor 25 by the rotation of the conveyor roller 13. 31 is conveyed rightward in the drawing.

  The fiber 31 flows along a high-speed airflow that is a flow in which high-pressure heated air ejected from the slits 33a and 33b on both sides of the nozzle 28 is merged. The high-speed air current flows in a direction substantially perpendicular to the conveying surface of the conveyor 25 by the high-pressure heated air ejected from the slits 33a and 33b.

  A spray nozzle 35 is provided between the melt blown rice 24 and the conveyor 25. The spray nozzle 35 sprays mist-like water into a high-speed air stream, whereby the fibers 31 are cooled and rapidly solidified. A plurality of spray nozzles 35b are actually installed, but only one is shown in FIG. The fluid ejected from the spray nozzle 35 is not necessarily required to contain moisture or the like as long as the fiber 31 can be cooled, and may be cold air.

  An elliptical airflow vibration mechanism 34 is provided in a region near the melt blown rice 24 where high-speed airflow is generated by the slits 33a and 33b. The airflow vibration mechanism 34 rotates in the direction of the arrow A around an axis 34a that is substantially orthogonal to the conveyance direction D of the fibers 31 on the conveyor 25, that is, substantially parallel to the width direction of the fiber array layer to be manufactured. Be made. In general, when a wall exists in the vicinity of a high-speed jet of gas or liquid, the jet tends to flow near the direction along the wall surface, which is called the Coanda effect. The airflow vibration mechanism 34 changes the flow direction of the fibers 31 using this Coanda effect. In the case of FIG. 4, when the elliptical long axis of the airflow vibration mechanism 34 coincides with the direction of the high-speed airflow (vertical direction in the drawing), the fibers 31 fall almost vertically toward the conveyor 25. When the airflow vibration mechanism 34 rotates 90 degrees around the axis 34a and the elliptical long axis of the airflow vibration mechanism 34 is orthogonal to the direction of the high-speed airflow, the fibers 31 are in the transport direction D (right side in the figure) of the conveyor 25. At this time, the displacement is maximized. When the airflow vibration mechanism 34 further rotates around the shaft 34a, the position where the fibers 31 drop onto the conveyor 25 periodically moves in the front-rear direction with respect to the transport direction D. In other words, the solidified fibers 31 are accumulated on the conveyor 25 while being swung in the vertical direction, and are partially folded in the vertical direction and continuously collected to form continuous long fibers.

  The fibers 31 collected on the conveyor 25 are transported in the transport direction D by the conveyor 25, nipped by the stretching cylinder 26a and the pressing roller 36 heated to the stretching temperature, and transferred to the stretching cylinder 26b. Thereafter, the fiber 31 is nipped between the stretching cylinder 26b and the pressing rubber roller 37, transferred to the stretching cylinder 26b, and is in close contact with the two stretching cylinders 26a and 26b. In this way, the fibers 31 are sent while being in close contact with the drawing cylinders 26a and 26b, so that the fibers 31 become a web in which the adjacent fibers 31 are fused together while being partially folded in the vertical direction.

  The web obtained by being in close contact with the drawing cylinders 26a and 26b is further taken up by take-up nip rollers 27a and 27b (the take-up nip roller 27b in the subsequent stage is made of rubber). The peripheral speed of the take-up nip rollers 27 a and 27 b is larger than the peripheral speed of the stretching cylinders 26 a and 26 b, whereby the web is stretched in the longitudinal direction and becomes the longitudinally stretched fiber array layer 38. In this way, the stretchability of the filaments can be further improved by stretching the spun web in the machine direction. When the fiber 31 is sufficiently quenched, the fiber 31 having a small stretching stress and a high elongation is formed. This is realized by spraying mist-like water from the spray nozzle 35 as described above and including the mist-like liquid in the high-speed airflow. In the fiber array layer formed by the method described above, the directions of the fibers are aligned in one direction.

  The fiber array layered body described above is completed by sequentially laminating and thermocompression-bonding the fiber array layers thus manufactured so that the fiber directions are orthogonal to each other.

It is a conceptual diagram which shows one Embodiment of the air conditioning system of this invention. It is a partial disassembled perspective view of the fiber arrangement | sequence laminated body which comprises a filter duct. It is a fragmentary perspective view which expands and shows a part of fiber arrangement layer. It is the schematic of the manufacturing apparatus used for preparation of a fiber arrangement | sequence layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioning system 2,9 Space 3a-3d Filter duct 4a-4d Opening part 5a-5d Closure part 6 Air supply chamber 7 Fan 8,11 Duct 10 Air intake 12 Fan coil unit 13a, 13b Air exhaust port 101 Fiber laminated body 102A, 102B, 102C, 102D Fiber array layer 103A, 103B, 103C, 103D Fiber 105A, 105B, 105C, 105D Stretching direction 106 Gap S1 First direction S2 Second direction

Claims (4)

Having a bag-like fiber array laminate with an opening through which gas flows,
The gas flowing into the inside from the opening is made to flow out through the fiber array laminate,
The fiber arrangement laminate is formed by laminating a plurality of fiber arrangement layers in which fibers are arranged substantially linearly in one direction, and some of the fiber arrangement layers and the other fiber arrangement layers are drawn from the fibers. Laminated so that the directions are orthogonal to each other,
Filter duct. ^2. The filter duct according to claim 1, wherein the fiber array laminate has a fragile air permeability in a range of 50 to 500 cm ³ / cm ² · sec and a basis weight in a range of 10 to 40 g / m ² .   The filter duct according to claim 1, wherein the filter duct has an elongated tubular shape when the inside is pressurized with the gas. The filter duct according to any one of claims 1 to 3,
An air supply means connected to the opening;
Having an air conditioning system.

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