Metal laminate, dust collector, and method for manufacturing a metal laminate

Abstract

One of the objectives of the present invention is to provide a metal laminate and a method for manufacturing a metal laminate that achieve multiple performance characteristics in a laminate having a filtration layer, particularly by suppressing malfunctions due to clogging and enabling efficient backwashing. [Solution] To solve the above problems, the present invention provides a metal laminate and a method for manufacturing the same, comprising a base layer made of metal fiber cloth, a filtration layer made of metal fiber nonwoven fabric, and a surface layer made of metal fiber nonwoven fabric, wherein the surface layer is the outermost layer, the diameter of the metal fibers in the surface layer is larger than the diameter of the metal fibers in the filtration layer, the layer structure is coarser than that of the filtration layer, and the layer structure of the filtration layer is denser than that of the surface layer. According to this invention, the entire laminate is made of metal fibers, and a laminate with excellent metallic properties can be obtained. Furthermore, by setting the diameter of the metal fibers used in each layer and the layer structure, solid particles in the material to be filtered cannot penetrate into the filtration layer, and the occurrence of problems due to clogging can be suppressed.

Description

Technical Field

[0001] The present invention relates to a metal laminate and a method for manufacturing the metal laminate. The present invention also relates to a dust collector using the metal laminate.

Background Art

[0002] A laminate formed by laminating structures made of fibrous materials is easier to have higher performance than a structure made of a single layer and is utilized in various fields. In particular, a laminate having a filtration layer is widely known for use as a dust collection filter (filter cloth) for collecting suspended particles in a gas.

[0003] Regarding a laminate having a filtration layer, although the required performance may vary depending on the properties of the filtration object and the conditions during the filtration process, generally, it is required to have properties such as heat resistance, durability, high strength, flexibility, and low pressure loss. For example, Patent Document 1 discloses a laminate (molded filter) composed of a filtration layer made of a heat-resistant short fiber aggregate and a support layer made of a metal mesh, and the filtration layer and the support layer are integrated by a thermosetting resin impregnated or adhered to the support layer. It is described that PTFE, which is one of the organic fibers, is particularly preferable as the heat-resistant short fiber.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the laminate described in Patent Document 1, by providing a support layer made of a metal mesh for a filtration layer made of a heat-resistant material, the heat resistance and strength of the laminate are enhanced. However, on the other hand, problems regarding flexibility remain. Furthermore, in the laminate described in Patent Document 1, a thermosetting resin is used to integrate the filtration layer and the support layer. Depending on the usage conditions, separation of the filtration layer and the support layer may occur due to the deterioration of the thermosetting resin, leaving a problem regarding durability.

[0006] In conventional laminates, including those described in Patent Document 1, it is generally considered preferable to use metal fibers rather than organic fibers to achieve properties such as heat resistance and high strength, while organic fibers are preferable to organic fibers to achieve properties such as flexibility and low pressure drop. However, if the entire laminate is made of organic fibers, problems remain in terms of heat resistance and strength, and in combinations of dissimilar materials (organic fibers and metal meshes), as in the laminate described in Patent Document 1, layer separation may occur, posing challenges in terms of durability.

[0007] Therefore, the object of the present invention is to provide a metal laminate and a method for manufacturing a metal laminate that, in a laminate having a filtration layer, does not impair any of the performance characteristics such as heat resistance, durability, high strength, flexibility, and low pressure drop, in particular suppresses the occurrence of problems due to clogging and enables efficient backwashing, as well as to provide a dust collector that is easy to maintain and capable of high-performance processing. [Means for solving the problem]

[0008] As a result of diligent research into the above-mentioned problems, the inventors have found that by making the entire laminate out of metal fibers and specifying the fiber diameter and layer structure of the metal fibers used in each layer, the performance of the laminate is improved, and in particular, the occurrence of malfunctions due to clogging is suppressed and efficient backwashing operations become possible. Furthermore, by using this metal laminate as a dust collection filter, it is possible to obtain a dust collection device that is easy to maintain and capable of high-performance processing, thus completing the present invention. In other words, the present invention is a metal laminate, a dust collector, and a method for manufacturing a metal laminate, characterized by the following:

[0009] The metal laminate of the present invention, which solves the above problems, comprises a base layer made of a cloth of metal fibers, a filtration layer made of a nonwoven fabric of metal fibers, and a surface layer made of a nonwoven fabric of metal fibers, wherein the surface layer is laminated so that it is the outermost layer, and the surface layer is characterized in that the diameter of the metal fibers is larger than the diameter of the metal fibers of the filtration layer, the layer structure is coarser than that of the filtration layer, and the layer structure of the filtration layer is denser than that of the surface layer. According to this characteristic, by making the entire laminate out of metal fibers, it becomes possible to obtain a laminate with excellent metallic properties (heat resistance, high strength, flexibility). Furthermore, by using a metal fiber cloth as the base layer, this base layer becomes a "foundation" on which the metal fiber nonwoven fabric is interwoven and embedded, and can be used as a dust collection filter. Moreover, it becomes possible to make the laminate high strength. Furthermore, because the layer structure of the filtration layer is "more dense" than the surface layer, when the material to be filtered (e.g., exhaust gas containing dust) passes through the laminate, it is possible to suppress the penetration of solid particles (e.g., dust) within the material to be filtered into the interior of the filtration layer. In other words, it is possible to suppress the occurrence of malfunctions due to clogging and to easily create and maintain a low pressure loss state. Furthermore, by providing a surface layer in the outermost layer using metal fibers with a larger fiber diameter than the metal fibers forming the filtration layer and a coarser layer structure than the filtration layer, it becomes possible to improve the protective function of the filtration layer (pre-coat layer retention function for powders, etc.) and enhance the detachability of solid particles after they have been collected in the laminate. In other words, it becomes possible to maintain the performance of the laminate and perform efficient backwashing operations on the laminate.

[0010] Furthermore, one embodiment of the metal laminate of the present invention is characterized in that the fiber diameter of the metal fibers in the surface layer is 4 to 100 μm. This feature improves the protective function of the filtration layer (pre-coat layer retention function for powders, etc.), enhances the detachability of solid particles after they are collected in the laminate, and also contributes to improving the dust collection efficiency of solid particles within the object being filtered by forming a layer structure based on fiber diameter. As a result, it becomes possible to achieve both low pressure loss and improved dust collection efficiency in metal laminates.

[0011] Furthermore, one embodiment of the metal laminate of the present invention is characterized in that the basis weight of the filtration layer is greater than the basis weight of the surface layer. This characteristic means that in a metal laminate, the area formed as a filtration layer is larger than the area formed as a surface layer. As a result, it becomes easier to suppress malfunctions caused by clogging in the metal laminate as a whole, and to create and maintain a low pressure loss state.

[0012] Furthermore, in one embodiment of the metal laminate of the present invention, the filtration layer and / or surface layer are formed by a water flow entanglement method. This characteristic means that when non-woven or laminated metal fibers, there is no need to use materials other than metal fibers, and since no mechanical contact occurs with the metal fibers during the non-woven fabrication process, it is possible to create a metal laminate that does not impair the properties inherent in the metal (especially heat resistance and high strength). Furthermore, although the structure of each layer in the metal laminate differs, unlike conventional laminates made of organic fibers and metal fibers, it is not a combination of dissimilar materials such as metal and non-metal, so it is possible to strongly integrate them without using binders or other components, and it also has the effect of making separation between layers less likely.

[0013] Furthermore, one embodiment of the metal laminate of the present invention further comprises a back layer made of a nonwoven fabric of metal fibers, characterized in that the back layer is laminated so as to be the outermost layer opposite to the surface layer. This feature allows for the protection of the base material layer, which is not highly resistant to external forces such as friction, by providing a back layer on the outermost layer opposite the surface layer that the object to be filtered first comes into contact with. In particular, when the metal laminate (back layer side) comes into contact with the retainer that holds the metal laminate, the back layer acts as a buffer. This makes it possible to prevent damage and wear to the metal laminate.

[0014] Furthermore, the dust collection device of the present invention, which solves the above problems, is characterized by comprising the above-mentioned metal laminate. This characteristic allows for the use of a metal laminate as a dust collection filter without compromising any of its performance characteristics, such as heat resistance, durability, high strength, flexibility, and low pressure loss. In particular, it suppresses malfunctions caused by clogging and enables efficient backwashing. This makes it possible to create a dust collection device that is easy to maintain and capable of high-performance processing.

[0015] Furthermore, the present invention provides a method for manufacturing a metal laminate to solve the above problems, comprising: a filter layer forming step of forming a filter layer made of a nonwoven fabric of metal fibers; a surface layer forming step of forming a surface layer made of a nonwoven fabric of metal fibers; and a lamination step of laminating the filter layer and the surface layer on a base layer made of a cloth of metal fibers such that the surface layer becomes the outermost layer, wherein the surface layer is characterized in that the fiber diameter of the metal fibers is larger than the fiber diameter of the metal fibers of the filter layer, the layer structure is coarser than that of the filter layer, and the layer structure of the filter layer is denser than that of the surface layer. According to this characteristic, by making the entire laminate out of metal fibers, it becomes possible to obtain a metal laminate with excellent metallic properties (heat resistance, high strength, flexibility). Furthermore, by using a metal fiber cloth as the base layer and laminating a metal fiber nonwoven fabric onto this base layer, lamination using the base layer as a "foundation" becomes possible, facilitating the formation of each layer (filtration layer and surface layer) made of nonwoven fabric. The resulting metal laminate can then be used as a dust collection filter and can be made highly strong. Furthermore, because the layer structure of the filtration layer is "denser" than the surface layer, the resulting metal laminate can suppress the penetration of solid particles (e.g., dust, etc.) from the material to be filtered (e.g., exhaust gas containing dust, etc.) into the filtration layer when the material passes through the laminate. In other words, the resulting metal laminate can suppress the occurrence of malfunctions due to clogging and facilitate the formation and maintenance of a low pressure loss state. Then, on the outermost layer, a surface layer using metal fibers with a fiber diameter larger than that of the metal fibers forming the filtration layer and a layer structure coarser than that of the filtration layer is provided. For the obtained metal laminate, it becomes possible to improve the function related to the protection of the filtration layer (precoat layer holding function for powders, etc.) and enhance the peelability of solid particles after being collected on the laminate. That is, for the obtained metal laminate, it becomes possible to improve the durability of the laminate and perform an efficient backwashing operation on the laminate.

Effects of the Invention

[0016] According to the present invention, in a laminate having a filtration layer, without impairing any of the properties such as heat resistance, durability, high strength, flexibility, and low pressure loss, it is possible to provide a metal laminate that can suppress the occurrence of problems due to clogging in particular and enable an efficient backwashing operation, a method for manufacturing the metal laminate, and a dust collector that is easy to maintain and can perform high-performance processing.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic explanatory view of a metal laminate according to the first embodiment of the present invention. [Figure 2] It is a schematic explanatory view showing the structure of a dust collector according to the first embodiment of the present invention. [Figure 3] It is a schematic explanatory view of a metal laminate according to the second embodiment of the present invention.

Modes for Carrying Out the Invention

[0018] Hereinafter, embodiments of a metal laminate, a dust collector, and a method for manufacturing a metal laminate according to the present invention will be described in detail with reference to the drawings. Note that the metal laminate, dust collector, and method for manufacturing a metal laminate described in the embodiments are merely examples for explaining the metal laminate, dust collector, and method for manufacturing a metal laminate according to the present invention, and are not limited thereto.

[0019] 〔First Embodiment〕 [Metal Laminate] Figure 1 is a schematic diagram illustrating the structure of the metal laminate 10 in the first embodiment of the present invention. As shown in Figure 1, the metal laminate 10 in this embodiment comprises a base layer 20, a filtration layer 30, and a surface layer 40, and is laminated so that the surface layer 40 is the outermost layer. Although Figure 1 shows the metal laminate 10 with the base layer 20, filtration layer 30, and surface layer 40 laminated in that order, it is not limited to this, and for example, it also includes laminates with the filtration layer 30, base layer 20, and surface layer 40 laminated in that order. In the following description, the metal laminate 10 in this embodiment will mainly be described in which a base layer 20, a filtration layer 30, and a surface layer 40 are laminated in that order, as shown in Figure 1.

[0020] In this embodiment, the metal laminate 10 uses metal fibers as the material constituting each layer. That is, the entire metal laminate 10 is made of metal fibers. This makes it possible to obtain a laminate with excellent metallic properties (heat resistance, high strength, flexibility). Furthermore, in this embodiment, the metal laminate 10 is constructed in which all layers are made of metal fibers, and the layer structure and the fiber diameter of the metal fibers used differ for each layer. This results in a laminate that does not compromise any of the multiple properties (heat resistance, durability, high strength, flexibility, and low pressure drop) that are often trade-offs and difficult to achieve simultaneously in conventional laminates. The details of each configuration are described below.

[0021] <Base material layer> The base layer 20 is made of a metal fiber cloth and supports the other layers (filtration layer 30 and surface layer 40), as well as serving as the foundation for forming the filtration layer 30 and surface layer 40. In this embodiment, the base material layer 20 may be a cloth (woven fabric) obtained by directly weaving metal fibers, or a cloth (woven fabric) obtained by weaving organic fibers with metal plated on its surface. However, from the viewpoint of heat resistance, a cloth (woven fabric) obtained by directly weaving metal fibers is preferred. By using this base material layer 20, it becomes possible to obtain a metal laminate 10 that possesses not only the properties of metal (heat resistance, high strength) but also the properties of cloth (woven fabric) (flexibility). In other words, it becomes possible to achieve both high strength and flexibility, properties that tend to be a trade-off in conventional laminates. Furthermore, as will be described later, the fact that the base layer 20 is made of a metal fiber cloth facilitates the formation of the other layers (filtration layer 30 and surface layer 40) and the strong integration of the metal laminate 10.

[0022] The metal fibers forming the base layer 20 are not particularly limited. Examples include stainless steel fibers, titanium fibers, tungsten fibers, nickel fibers, aluminum fibers, copper fibers, and brass fibers. The metal fibers used may be used individually or in combination. In particular, stainless steel fibers are preferred as the metal fibers due to their availability and durability (corrosion resistance).

[0023] <Filtration layer> The filtration layer 30 is made of a nonwoven fabric of metal fibers and has a denser layer structure than the surface layer 40, which will be described later. In this embodiment, the filtration layer 30 is preferably made of a nonwoven fabric of metal fibers having a specific range of fiber diameters, and more specifically, it is formed by using metal fibers having a fiber diameter of 1 to 8 μm and forming them into a nonwoven fabric. By using metal fibers with an extremely fine fiber diameter of 1 to 8 μm as the filtration layer 30, the resulting layer structure becomes denser. When the material to be filtered (e.g., exhaust gas containing dust) passes through the metal laminate 10, it is possible to suppress the penetration of solid particles, especially those up to about 10 μm in diameter, into the filtration layer 30. Here, the fact that solid particles do not penetrate into the filtration layer 30 means that malfunctions caused by blockage (clogging) of the metal laminate 10 by solid particles can be suppressed. In addition, since the permeability of the filtration layer 30 is less likely to decrease, it becomes easier to form and maintain a low pressure drop state for the metal laminate 10 as a whole.

[0024] The metal fibers forming the filtration layer 30 are not particularly limited. Examples include stainless steel fibers, titanium fibers, tungsten fibers, nickel fibers, aluminum fibers, copper fibers, and brass fibers. Furthermore, the metal fibers used may be used individually or in combination. In particular, stainless steel fibers are preferred as the metal fibers due to their availability and durability (corrosion resistance).

[0025] Furthermore, it is preferable that the basis weight of the filtration layer 30 be greater than that of the surface layer 40. This results in a larger area in the metal laminate 10 that is formed as the filtration layer 30 than that formed as the surface layer 40. As a result, the performance of the filtration layer 30 is more strongly exhibited in the metal laminate 10 as a whole, making it easier to suppress malfunctions due to clogging and to form and maintain a low pressure loss state. The specific numerical value of the basis weight of the filtration layer 30 is not particularly limited. For example, 50 g / m 2 ~400g / m 2 One possible solution is to...

[0026] As for the means of forming the filtration layer 30, known means of non-woventing fibers can be used. While methods using binders (adhesives) (resin bonding method, chemical bonding method) are known as general methods for non-woven fabrication of fibers, it is preferable to use a binder-less method for forming the filtration layer 30 (means for non-woven fabrication of metal fibers) in this embodiment. This eliminates the need to use materials other than metal fibers when non-woven fabrication and lamination of metal fibers, and makes it possible to create a metal laminate 10 that does not impair the properties (especially heat resistance and high strength) caused by the properties of the metal.

[0027] As for the means of forming such a filtration layer 30 (means for non-woven metal fibers), for example, there are methods of fusing the fiber raw materials by heat (thermal bonding method), mechanical manipulation of the fiber raw materials (puncture with a needle), or methods of entangling the fibers by applying pressure using water pressure (needle punching method, water flow entanglement method). Among these, the water flow entanglement method is particularly preferred.

[0028] The water entanglement method involves spraying a high-pressure water stream onto the fiber raw material, causing the fibers to entangle due to the resulting pressure load. In addition to being binder-less, the water entanglement method avoids mechanical contact with metal fibers during the nonwoven fabrication process. Therefore, it suppresses the occurrence of defects due to damage to the metal fibers or the nonwoven fabrication means, and allows for the creation of a metal laminate that does not impair the properties inherent in the metal (especially heat resistance and high strength). Furthermore, although the structure of each layer in the metal laminate 10 differs, unlike conventional laminates consisting of organic fibers and metal fibers, it does not involve a combination of dissimilar materials such as metal and nonmetal. Therefore, it is possible to firmly integrate the materials without using binders or other components, and it also has the effect of making separation between layers less likely.

[0029] <Surface layer> The surface layer 40 is made of a nonwoven fabric of metal fibers and has a layer structure that is coarser than the filtration layer 30 described above. Furthermore, the surface layer 40 is formed by using metal fibers having a larger fiber diameter than the metal fibers used in the filtration layer 30, and forming them into a nonwoven fabric. Moreover, the surface layer 40 is laminated so as to become the outermost layer of the metal laminate 10. By using metal fibers with a larger fiber diameter than those used in the filtration layer 30 as the surface layer 40, the resulting layer structure is coarser than that of the filtration layer 30. Furthermore, since the surface layer 40 is the outermost layer, when the material to be filtered (for example, exhaust gas containing dust) passes through the metal laminate 10, it first passes through the surface layer 40. Therefore, it becomes possible to select, to a certain extent, the solid particles in the material to be filtered that come into contact with the filtration layer 30, thereby suppressing the deterioration of the performance of the filtration layer 30 due to contact with solid particles (for example, reduced durability, malfunctions due to clogging, and increased pressure loss). In other words, the protective function of the filtration layer 30 (function of retaining the pre-coat layer of powder, etc.) is improved. Furthermore, because the layer structure formed by the surface layer 40 is coarser than that of the filtration layer 30, and because larger solid particles among the material to be filtered remain on the surface layer 40, it is possible to improve the detachability of solid particles after they have been collected on the metal laminate 10. In other words, efficient backwashing of the metal laminate 10 becomes possible. At this time, the detachability of solid particles can be further improved by smoothing the surface structure of the surface layer 40.

[0030] The metal fibers forming the surface layer 40 are not particularly limited. Examples include stainless steel fibers, titanium fibers, tungsten fibers, nickel fibers, aluminum fibers, copper fibers, and brass fibers. Furthermore, the metal fibers used may be used individually or in combination. In particular, stainless steel fibers are preferred as the metal fibers due to their availability and durability (corrosion resistance).

[0031] The fiber diameter of the metal fibers in the surface layer 40 can be set to 4 to 100 μm. In this case, the surface layer 40, with its layered structure formed based on the fiber diameter of the metal fibers, improves the dust collection efficiency for solid particles within a certain particle size range. This makes it possible to achieve both low pressure loss and improved dust collection efficiency in a metal laminate.

[0032] As mentioned above, it is preferable that the basis weight of the surface layer 40 be smaller than that of the filtration layer 30. The specific numerical value of the basis weight of the surface layer 40 is not particularly limited. For example, 20 g / m 2 ~200g / m 2 One possible solution is to...

[0033] As for the means of forming the surface layer 40, known means of non-woventing fibers can be used, similar to the means of forming the filtration layer 30 described above. For example, methods using a binder (adhesive) (resin bonding method, chemical bonding method) may be used, but it is preferable to use a binder-less method, such as one that fuses the fiber raw materials by heat (thermal bonding method), one that entangles the fibers by mechanical manipulation of the fiber raw materials (puncture with a needle), or one that entangles the fibers by pressure loading with water pressure (needle punching method, water flow entanglement method). This eliminates the need to use materials other than metal fibers when non-woventing or laminating metal fibers, and makes it possible to create a metal laminate 10 that does not impair the properties of the metal (especially heat resistance and high strength). Furthermore, similar to the means for forming the filtration layer 30 (means for making metal fibers into a nonwoven fabric) described above, the water flow entanglement method is particularly preferred as the means for forming the surface layer 40 (means for making metal fibers into a nonwoven fabric).

[0034] [Method for manufacturing metal laminates] The method for manufacturing the metal laminate in this embodiment comprises a filter layer formation step of forming a filter layer 30 made of a nonwoven fabric of metal fibers, a surface layer formation step of forming a surface layer 40 made of a nonwoven fabric of metal fibers, and a lamination step of laminating the filter layer 30 and the surface layer 40 on a base layer 20 made of a cloth of metal fibers such that the surface layer 40 becomes the outermost layer. The order in which each step is performed is not particularly limited.

[0035] An example of a method for manufacturing a metal laminate in this embodiment will be described below. First, a filter layer formation step is performed to form a filter layer 30 made of a nonwoven fabric of metal fibers. At this time, it is preferable that the fiber diameter of the metal fibers forming the filter layer 30 be 1 to 8 μm. Specific examples of the filtration layer formation step include those selected from the above-described means for forming the filtration layer 30 (means for non-woven metal fibers), with those based on the water flow entanglement method being particularly preferred. Furthermore, while the filtration layer 30 may be formed independently, it is preferable to arrange metal fibers (fiber diameter 1-8 μm) for forming the filtration layer 30 on the base layer 20 and to perform the formation of the filtration layer 30 and the lamination (entanglement) of the base layer 20 and the filtration layer 30 by the water flow entanglement method. In other words, it is preferable to perform part of the filtration layer formation step and the lamination step simultaneously. As a result, the metal fibers of the filtration layer 30 are entangled and embedded in the gaps between the metal fibers in the base layer 20, making it possible to create a binder-less structure and suppress layer separation (increasing durability).

[0036] Next, a surface layer formation step is performed to form a surface layer 40 made of a nonwoven fabric of metal fibers. At this time, the fiber diameter of the metal fibers is larger than that used in the filtration layer formation step. For example, the fiber diameter of the metal fibers forming the surface layer 40 can be 4 to 100 μm. Specific examples of the surface layer formation step include those selected from the above-described means for forming the surface layer 40 (means for non-woven metal fibers), with those based on the water flow entanglement method being particularly preferred. Furthermore, while the surface layer 40 may be formed independently, it is preferable to place metal fibers (fiber diameter 4-100 μm) for forming the surface layer 40 on the filtration layer 30, where the base layer 20 and the filtration layer 30 are already laminated, and to perform the formation of the surface layer 40 and the lamination (entanglement) of the filtration layer 30 and the surface layer 40 by the water flow entanglement method. In other words, it is preferable to perform part of the surface layer formation step and the lamination step simultaneously. As a result, the metal fibers of the surface layer 40 become entangled with the layer structure (gaps between metal fibers) in the filtration layer 30, making it possible to create a binder-less structure and suppress layer separation (increasing durability).

[0037] Furthermore, if the filtration layer 30 and the surface layer 40 are formed independently in the filtration layer formation step and the surface layer formation step, the lamination step may involve not only integrating all layers using a nonwoven fabrication method of metal fibers, but also using a method to fix the layers stacked on the base layer 20 in the order of filtration layer 30 and surface layer 40. More specifically, this could involve placing the stacked layers of base layer 20, filtration layer 30, and surface layer 40 inside a frame or housing and fixing them in place with a locking mechanism or the like.

[0038] As described above, the metal laminate 10 in this embodiment is a metal laminate in which the entire laminate is made of metal fibers and the fiber diameter of the metal fibers used is specified, and without impairing any of the performance characteristics such as heat resistance, durability, high strength, flexibility, and low pressure drop, it suppresses the occurrence of malfunctions due to clogging in particular and enables efficient backwashing operations.

[0039] The metal laminate 10 of this embodiment is suitably used as a dust collection filter for removing and recovering solid particles within a material to be filtered. Furthermore, since the layer structure of the filtration layer 30 and surface layer 40 of the metal laminate 10 of this embodiment allows for the entry, exit, and retention of gases, it is also suitably used as various thermal insulation materials (for example, thermal insulation materials for automobiles).

[0040] [Dust collector] Figure 2 is a schematic diagram illustrating the structure of the dust collector 1 in the first embodiment of the present invention. As shown in Figure 2, the dust collector 1 in this embodiment includes a dust collection unit 2 for separating and recovering solid particles S in the gas G1 to be treated, and is connected to the dust collection unit 2 by a line L1 for introducing the gas G1 to be treated and a line L2 for discharging the treated gas G2 after treatment by the dust collection unit 2. Furthermore, a dust collection filter and retainer 3 are arranged inside the dust collection section 2 to separate solid particles S from the gas G1 to be treated, and a metal laminate 10 is used as this dust collection filter.

[0041] <Gas to be treated> The gas to be treated G1 is not particularly limited as long as it mainly contains solid particles S. However, as described above, the metal laminate 10 used as a dust collection filter in the dust collector 1 in this embodiment is a laminate with excellent metallic properties (especially heat resistance and high strength), and is suitable for processing under high-temperature conditions. Therefore, suitable examples of the gas to be treated G1 include, for example, high-temperature exhaust gas from steelmaking electric furnaces or waste furnaces.

[0042] <Dust Collection Unit> The dust collection unit 2 only needs to separate and recover solid particles S from the gas G1 to be treated using a dust collection filter (metal laminate 10), and its detailed structure is not particularly limited. Specifically, it can be a known structure related to cyclone dust collectors, bag filter dust collectors, etc. Figure 2 shows an example of the structure of a so-called bag filter dust collector, but is not limited to this.

[0043] Line L1 is piping for introducing the gas to be treated G1 into the dust collection unit 2. The material and shape of the piping are not particularly limited, as long as it can withstand the temperature of the gas to be treated G1. Line L2 is a pipe for discharging the treated gas G2 from the dust collection unit 2 to the atmosphere. The material and shape of the pipe are not particularly limited, as long as it can withstand the temperature of the treated gas G2. The treated gas G2 from line L2 is subjected to appropriate treatment (not shown) before being discharged to the atmosphere.

[0044] The retainer 3 supports the metal laminate 10, which acts as a dust collection filter, and has the function of maintaining the dust collection effect. Although Figure 2 shows the retainer 3 as cylindrical, it is not limited to this. At this time, the metal laminate 10 is attached to the retainer 3 such that the surface layer 40 of the metal laminate 10 is the first to come into contact with the gas G1 to be treated introduced from line L1.

[0045] The gas G1 to be treated, introduced into the dust collection unit 2, passes through the metal laminate 10 from the surface layer 40 side, thereby separating the solid particles S. The separated solid particles S are then recovered from the bottom of the dust collection unit 2 and discharged outside the system. Meanwhile, the treated gas G2 from which the solid particles S have been separated is discharged outside the system via a line L2 located above the dust collection unit 2.

[0046] Furthermore, the dust collector 1 in this embodiment includes means for backwashing the metal laminate 10 (not shown). For example, this can be done by spraying high-pressure air from the retainer 3 side toward the base material layer 20 of the metal laminate 10. This makes it possible to brush off solid particles S that have been collected on the metal laminate 10.

[0047] In the dust collector 1 of this embodiment, a metal laminate 10 is used as a dust collection filter without compromising any of its properties, such as heat resistance, durability, high strength, flexibility, and low pressure drop, and in particular, it suppresses malfunctions caused by clogging and enables efficient backwashing. Therefore, it is possible to create a dust collector that is easy to maintain and capable of high-performance processing.

[0048] [Second Embodiment] [Metal laminate] Figure 3 is a schematic diagram illustrating the structure of the metal laminate 11 in a second embodiment of the present invention. As shown in Figure 3, the metal laminate 11 in this embodiment comprises a base layer 20, a filtration layer 30, a surface layer 40, and a back layer 50, with the back layer 50 being laminated so as the outermost layer opposite the surface layer 40. Here, the same aspects as in the first embodiment will be omitted from the explanation.

[0049] Figure 3 shows a metal laminate 11 in which the back layer 50, base layer 20, filtration layer 30, and surface layer 40 are stacked in that order. However, it is not limited to this configuration, and for example, a laminate in which the back layer 50, filtration layer 30, base layer 20, and surface layer 40 are stacked in that order is also included. In the following description, the metal laminate 11 in this embodiment will mainly be described in which the layers are stacked in the order of back layer 50, base material layer 20, filtration layer 30, and surface layer 40, as shown in Figure 3.

[0050] <Back layer> The back layer 50 is made of a nonwoven fabric of metal fibers and is laminated in the metal laminate 10 so as to be the outermost layer on the opposite side from the surface layer 40. The base layer 20, which is made of metal fibers, is a collection of fibers and therefore has flexibility, but it does not have high durability against external forces such as friction. Therefore, by providing a back layer 50 on the outermost layer opposite the surface layer 40, the base layer 20 is no longer directly subjected to external forces such as friction, and the durability of the metal laminate 10 can be increased.

[0051] In particular, when using the metal laminate 10, it is desirable that the back surface layer 50 functions as a cushioning material without impairing the performance of the metal laminate 10 when in contact with a holder for holding the metal laminate 10 (for example, a retainer 3 in the dust collector 1). For example, the back layer 50 is made of metal fibers having a larger fiber diameter than the metal fibers used in the filtration layer 30, similar to the surface layer 40 described above, and the resulting layer structure is made coarser than that of the filtration layer 30, thereby providing a certain function as a buffering material.

[0052] The metal fibers forming the back layer 50 are not particularly limited. Examples include stainless steel fibers, titanium fibers, tungsten fibers, nickel fibers, aluminum fibers, copper fibers, and brass fibers. Furthermore, the metal fibers used may be used individually or in combination. In particular, stainless steel fibers are preferred as the metal fibers due to their availability and durability (corrosion resistance).

[0053] The fiber diameter of the metal fibers in the back layer 50 can be set to 4 to 100 μm. In this case, the back layer 50 can fully perform its function as a cushioning material due to its layered structure formed based on the fiber diameter of the metal fibers.

[0054] The basis weight of the back layer 50 is not particularly limited, but as mentioned above, it is preferable to set it so that it functions sufficiently as a cushioning material. Furthermore, there are no particular limitations on the specific numerical value of the basis weight of the backing layer 50. For example, 50 g / m² 2 ~400g / m 2 One possible solution is to...

[0055] As for the means of forming the back layer 50, known means of non-woventing fibers can be used, similar to the means of forming the filtration layer 30 and the surface layer 40 described above. For example, methods using a binder (adhesive) (resin bonding method, chemical bonding method) may be used, but it is preferable to use a binder-less method, such as one that fuses the fiber raw materials by heat (thermal bonding method), one that entangles the fibers by mechanical manipulation of the fiber raw materials (puncture with a needle), or one that entangles the fibers by pressure loading with water pressure (needle punching method, water flow entanglement method). This eliminates the need to use materials other than metal fibers when non-woventing or laminating metal fibers, and makes it possible to create a metal laminate 10 that does not impair the properties of the metal (especially heat resistance and high strength). Furthermore, similar to the means for forming the filtration layer 30 and the surface layer 40 (means for non-woven metal fibers) described above, the water flow entanglement method is particularly preferred as the means for forming the back layer 50 (means for non-woven metal fibers).

[0056] [Method for manufacturing metal laminates] The method for manufacturing the metal laminate in this embodiment comprises a filter layer forming step of forming a filter layer 30 made of a nonwoven fabric of metal fibers, a surface layer forming step of forming a surface layer 40 made of a nonwoven fabric of metal fibers, a back layer forming step of forming a back layer 50 made of a nonwoven fabric of metal fibers, and a lamination step of laminating the filter layer 30, surface layer 40, and back layer 50 on a base layer 20 made of metal fiber cloth such that the surface layer 40 and back layer 50 become the outermost layers, respectively. The order in which each step is performed is not particularly limited.

[0057] The manufacturing method for the metal laminate in this embodiment is modified from the manufacturing method for the metal laminate described above by adding a step of forming a back layer 50 (back layer formation step), and changing the lamination step to a step of laminating three layers (filtration layer 30, surface layer 40, and back layer 50) onto the base layer 20.

[0058] An example of a method for manufacturing a metal laminate in this embodiment will be described below. For example, a back layer formation step is performed in the same manner as the filtration layer formation step and surface layer formation step described above to form a back layer 50 made of a nonwoven fabric of metal fibers. In this case, the fiber diameter of the metal fibers is larger than that used in the filtration layer formation step. For example, the fiber diameter of the metal fibers forming the back layer 50 can be 4 to 100 μm. Specific examples of the back layer formation step include those selected from the means for forming the back layer 50 described above (means for non-woven metal fibers), with those based on the water flow entanglement method being particularly preferred. Furthermore, while the back layer 50 may be formed independently, it is preferable to place metal fibers (fiber diameter 4-100 μm) for forming the back layer 50 on the base layer 20, where the base layer 20, filtration layer 30, and surface layer 40 are already laminated, and then perform the formation of the back layer 50 and the lamination (entanglement) of the back layer 50 and the base layer 20 by the water flow entanglement method. In other words, it is preferable to perform part of the back layer formation step and the lamination step simultaneously. As a result, the metal fibers of the back layer 50 become entangled in the gaps between the metal fibers in the base layer 20, making it possible to create a binder-less structure and suppress layer separation (increasing durability).

[0059] [Dust collector] In this embodiment, an example of a dust collection device is one in which the above-described metal laminate 11 is used as a dust collection filter in the dust collection device 1 shown in the first embodiment.

[0060] In particular, in this embodiment, the metal laminate 11 has a back layer 50 on the outermost layer opposite to the surface layer 40 that the object to be filtered (the gas to be treated G1) first comes into contact with. This allows the back layer 50 to function as a buffer when the metal laminate 11 (back layer 50 side) comes into contact with the retainer 3 that holds the metal laminate 11. This prevents damage and wear to the metal laminate 11 when used in the dust collector 1.

[0061] The embodiments described above illustrate examples of the metal laminate, dust collector, and method for manufacturing the metal laminate according to the present invention. The metal laminate, dust collector, and method for manufacturing the metal laminate according to the present invention are not limited to the embodiments described above, and the metal laminate, dust collector, and method for manufacturing the metal laminate according to the embodiments described above may be modified without changing the gist of the claims.

[0062] In this embodiment of the dust collector, a metal laminate serving as a dust collection filter is shown attached to a retainer, but the invention is not limited to this configuration. Because the metal laminate in this embodiment uses a cloth made of metal fibers as the base layer, it is highly flexible and easy to process. Therefore, it is easy to create a dust collection filter with a known structure, and it offers excellent compatibility with existing dust collection filters. Specifically, examples include making the metal laminate in this embodiment into an envelope shape or a suspended type. [Industrial applicability]

[0063] The metal laminate and method for manufacturing the metal laminate of the present invention are suitably used in high-performance laminates and their manufacture. In particular, they are suitably used as metal laminates and methods for manufacturing the same that suppress the occurrence of problems due to clogging and enable efficient backwashing operations without impairing any of the properties such as heat resistance, durability, high strength, flexibility, and low pressure drop. Furthermore, the dust collector of the present invention is suitably used as a dust collector that is easy to maintain and capable of high-performance processing. In particular, it is suitably used for dust collection of high-temperature exhaust gases. [Explanation of Symbols]

[0064] 1...Dust collector, 2...Dust collection section, 3...Retainer, 10,11...Metal laminate, 20...Base layer, 30...Filtration layer, 40...Surface layer, 50...Back layer, G1...Gas to be treated, G2...Processed gas, L1,L2...Lines, S...Solid particles

Claims

1. A base layer made of metal fiber cloth, A filter layer made of a nonwoven fabric of metal fibers, It comprises a surface layer made of a nonwoven fabric of metal fibers, The aforementioned surface layer is laminated so that it becomes the outermost layer. The surface layer has a metal fiber diameter that is larger than that of the metal fiber in the filter layer, and its layer structure is coarser than that of the filter layer. A metal laminate characterized in that the layer structure of the filtration layer is denser than that of the surface layer.

2. The metal laminate according to claim 1, characterized in that the fiber diameter of the metal fibers in the surface layer is 4 to 100 μm.

3. The metal laminate according to claim 1 or 2, characterized in that the basis weight of the filtration layer is greater than the basis weight of the surface layer.

4. The metal laminate according to claim 1 or 2, characterized in that the filtration layer and / or the surface layer are formed by a water flow entanglement method.

5. It further comprises a back layer made of a nonwoven fabric of metal fibers, The metal laminate according to claim 1 or 2, characterized in that the back surface layer is laminated such that it becomes the outermost layer on the opposite side from the surface layer.

6. A dust collector comprising a metal laminate as described in claim 1 or 2.

7. A filter layer forming step in which a filter layer made of a nonwoven fabric of metal fibers is formed, A surface layer forming step in which a surface layer made of a nonwoven fabric of metal fibers is formed, The process includes a lamination step of laminating the filtration layer and the surface layer on a base layer made of metal fiber cloth, such that the surface layer becomes the outermost layer. The surface layer has a metal fiber diameter that is larger than that of the metal fiber in the filter layer, and its layer structure is coarser than that of the filter layer. A method for manufacturing a metal laminate, characterized in that the layer structure of the filtration layer is denser than that of the surface layer.

Images