JP2019025422A - Dust collection filter cloth and bag filter - Google Patents

Abstract

To provide a dust collection filter cloth and a bag filter having heat resistance, durability and flexibility and achieving low pressure loss compatible with a high dust collection rate.SOLUTION: A dust collection filter cloth comprises: a base material layer made of an inorganic fiber cloth involving a plain weave or twilled stainless steel wire; and a laminate layer being disposed on one surface or both surfaces of the base material layer containing an organic fiber or an inorganic fiber having a fiber diameter of 2-30 μm with a basis weight of 200-1,800 g/m2 or a stainless steel metal fiber having a fiber diameter of 2-30 μm with a basis weight of 10-30 g/m2. The base material layer and the laminate layer are integrated by needling and a heat resistant binder is coated on both surfaces.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dust collection filter cloth and a bag filter.

  A bag filter obtained by sewing a dust collecting filter cloth into a cylindrical shape is installed in the dust collecting device in a state of covering a cylindrical retainer. Exhaust gas containing dust generated from steelworks etc. is sent into the dust collector and passed through the dust collection filter cloth that constitutes the bag filter from the upstream side (outside) to the downstream side (inside) and purified. Exhaust gas is released into the atmosphere. If the dust in the exhaust gas is continuously collected by the filter cloth, the filter cloth will be clogged and the dust collection capacity will be reduced. To regenerate the dust collection capacity of the dust collection filter cloth, for example, spray compressed air, etc. from the downstream side (inner side) to the upstream side (outside) of the dust collection filter cloth at regular intervals, and collect it on the filter cloth. Remove the dust.

  Bag filters used at sites where high-temperature gas containing dust is discharged, such as at steel manufacturing sites, are required to have heat resistance. As a method for treating high-temperature exhaust gas, a cooling facility is installed in front of the dust collector to cool the high-temperature exhaust gas, and then the exhaust gas is treated with a room temperature specification bag filter made of organic fibers. There is a method of directly treating high-temperature exhaust gas using a bag filter made of a metal material or a ceramic molding material.

  The former method is disadvantageous in terms of energy saving because it requires cooling equipment. Therefore, for example, by using a bag filter made of a metal material having high heat resistance such as stainless steel, it becomes possible to directly process high-temperature exhaust gas. However, the bug filter is weakly compatible with bug filters used in existing dust collectors. Further, the bag filter causes high pressure loss and high price. Further, the bag filter causes a decrease in the dust collection rate with respect to dust due to problems with the workability of the material and the diameter of the stainless steel. Therefore, there is a need for a dust collection filter cloth and a bag filter that combine heat resistance, durability, and flexibility, and that enable low pressure loss and a high dust collection rate.

  Patent Document 1 comprises a glass woven fabric base fabric made of yarn obtained by twisting metal wires into glass fibers, and a web containing glass fibers and heat-resistant organic fibers arranged on one or both sides of the base fabric. In addition, a needle felt formed by integrating a base fabric and a web is described. This needle felt can be used at medium temperature and has excellent mechanical properties.

  Patent Document 2 is composed of a surface layer composed of inorganic fibers having a fiber diameter of 0.1 μm to 30 μm, an intermediate layer containing ceramic nanofiber fibers having a fiber diameter of 0.01 μm to 0.7 μm, inorganic fibers and a metal cloth. A heat-resistant dust collection filter cloth having a base material layer is described. This dust collection filter cloth combines heat resistance, durability, and flexibility, and is expected to have a low pressure loss and a high dust collection rate.

Japanese Patent Laid-Open No. 2006-84554 JP 2017-29907 A

  The present inventors have found that the conventional heat-resistant dust collection filter cloth has room for improvement with respect to heat resistance, durability, flexibility, pressure loss, and dust collection rate.

  Accordingly, an object of the present invention is to provide a dust collection filter cloth and a bag filter that have both heat resistance, durability, and flexibility, and that achieve both low pressure loss and high dust collection rate.

According to the first aspect of the present invention, a base material layer comprising a plain-woven or twill-woven stainless steel wire-containing inorganic fiber felt;
The basis weight of 200 to 1800 g / m2 of inorganic fibers having a fiber diameter of 2 to 30 μm, or 10 to 30 g / m2 of stainless steel metal fibers having a fiber diameter of 2 to 30 μm, disposed on one side of the base material layer. Comprising a laminate layer including the basis weight of
A dust collecting filter cloth in which the base material layer and the laminated layer are integrated by needling and coated with a heat-resistant binder on both surfaces is provided.

  The dust collection filter cloth according to the first aspect of the present invention may further comprise a surface layer made of alumina silica fibers having a fiber diameter of 0.3 to 20 μm and fixed to the laminated layer side by a heat-resistant binder. Good.

  According to the 2nd aspect of this invention, the bag filter which sewed the dust collection filter cloth which concerns on a 1st aspect is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the dust collection filter cloth and bag filter which combine heat resistance, durability, and a softness | flexibility and are compatible with a low pressure loss and a high dust collection rate are provided.

Sectional drawing which shows an example of the dust collection filter cloth which concerns on 1 aspect of this invention. Sectional drawing which shows the other example of the dust collection filter cloth which concerns on 1 aspect of this invention. FIG. 10 illustrates an example of a bug filter according to one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same referential mark is attached | subjected to the component which exhibits the same or similar function through all the drawings, and the overlapping description is abbreviate | omitted.

FIG. 1 is a cross-sectional view illustrating an example of a dust collection filter cloth according to one embodiment of the present invention.
A dust collection filter cloth 1 shown in FIG. 1 includes a base material layer 2 and a laminated layer 3 arranged on one side of the base material layer 2. The base material layer 2 and the laminated layer 3 are integrated by needling, and both surfaces of the dust collecting filter cloth 1 are coated with a heat resistant binder 4.

  The base material layer 2 is a layer made of an inorganic fiber felt 6 containing a stainless steel wire (SUS wire) 5 that is plain-woven or twill-woven.

  The material of the inorganic fibers constituting the inorganic fiber felt 6 used for the base material layer 2 is, for example, glass, silica, ceramics, carbon, or a mixture thereof, and does not include refractory ceramic fibers (RCF). The material of the inorganic fiber constituting the inorganic fiber felt 6 is appropriately selected according to the exhaust gas temperature range assumed in the field. The fiber diameter of this inorganic fiber is, for example, 5 to 13 μm. Moreover, the fiber length of this inorganic fiber is 30 to 100 mm, for example. The basis weight of the inorganic fiber felt 6 is, for example, 100 to 600 g / m2.

  The kind of stainless steel wire 5 used for the base material layer 2 is not particularly limited, and can be appropriately selected in consideration of heat resistance and workability. The diameter of the stainless steel wire 5 is, for example, 50 to 300 μm, preferably 50 to 200 μm, and more preferably 100 to 180 μm. The stainless steel wire 5 is woven into the inorganic fiber felt 6 by plain weave or twill weave. The basis weight of the stainless steel wire 5 is, for example, 10 to 30 g / m 2, preferably 15 to 25 g / m 2, and more preferably 16 to 23 g / m 2.

  By weaving the stainless steel wire 5 into the inorganic fiber felt 6, the strength of the base material layer 2 can be improved. Further, by providing the base material layer 2 on the downstream side of the dust collecting filter cloth 1, it is possible to improve the strength of the entire filter cloth against the inflowing exhaust gas and prevent friction with the retainer. That is, the durability of the entire filter cloth can be improved. The basis weight of the base material layer 2 is, for example, 500 to 1500 g / m2. The thickness of the base material layer 2 is, for example, 0.3 to 2.5 mm.

  The laminated layer 3 is made of organic fibers or inorganic fibers having a fiber diameter of 2 to 30 μm in an amount of 200 to 1800 g / m 2 in order to ensure sufficient air permeability while maintaining the strength as a dust collection cloth. Stainless steel (SUS) metal fibers having a basis weight of 2 to 30 μm and a basis weight of 10 to 30 g / m 2 are included. Regarding organic fibers, polyester is particularly preferable. The laminated layer 3 is disposed on one side of the base material layer 2 and has a thickness of 0.7 to 8.0 mm, for example.

  The material of the inorganic fiber used for the laminated layer 3 is, for example, glass, silica, ceramics, carbon, rock wool, or a mixture thereof. The material of the inorganic fiber is appropriately selected according to the exhaust gas temperature range assumed in the field. The fiber diameter of the inorganic fiber used for the laminated layer 3 is 2 to 30 μm, preferably 4 to 15 μm, and more preferably 6 to 12 μm. The fiber length of this inorganic fiber is, for example, 50 to 150 mm. The laminated layer 3 contains the inorganic fiber at a basis weight of 200 to 1800 g / m 2, preferably 200 to 500 g / m 2, more preferably 300 to 450 g / m 2.

  The diameter of the stainless steel wire constituting the stainless steel metal fiber used for the laminated layer 3 is, for example, 2 to 30 μm, preferably 10 to 20 μm. This stainless steel metal fiber has an opening of, for example, 25 to 300 mesh, preferably 50 to 250 mesh, and more preferably 100 to 200 mesh. The laminated layer 3 contains the above-mentioned stainless steel metal fibers in a basis weight of 10 to 30 g / m 2, preferably 15 to 25 g / m 2, more preferably 16 to 23 g / m 2.

  The base material layer 2 and the laminated layer 3 are integrated in a state where the fibers constituting each layer are entangled by needling. Needling can be performed by a known needle punch method.

  A heat-resistant binder 4 is coated on both surfaces of a laminate obtained by integrating the base material layer 2 and the laminate layer 3 by needling. The coating of the heat resistant binder 4 is performed by spraying, for example. By coating the heat-resistant binder 4 on both surfaces of the laminate, the fibers constituting the base layer 2 and the laminate layer 3 can be prevented from falling off.

  The heat resistant binder 4 is an arbitrary inorganic binder or heat resistant organic binder. The heat-resistant temperature of the heat-resistant binder 4 is, for example, 200 to 1000 ° C., preferably 300 to 900 ° C., and more preferably 300 to 800 ° C. A binder having a suitable heat-resistant temperature can be appropriately selected according to the temperature range of the exhaust gas to be removed. The inorganic binder is, for example, silica, alumina, silicon or a composite ceramic powder, preferably silica, alumina or a composite. The heat-resistant organic binder is, for example, silicon, fluorine, imide, or polyphenylene, preferably fluorine resin or polyimide. The amount of the heat-resistant binder 4 coated on both surfaces of the laminate of the base material layer 2 and the laminate layer 3 is not particularly limited as long as the pressure loss of the dust collecting filter cloth does not increase excessively. To 120 g / m2.

  FIG. 2 is a cross-sectional view illustrating another example of the dust collecting filter cloth according to one embodiment of the present invention. A dust collecting filter cloth 1 ′ shown in FIG. 2 further includes a surface layer 7 on the laminated layer 3 side of the dust collecting filter cloth 1 shown in FIG. 1, that is, on the exhaust gas upstream side. Further, a heat-resistant organic binder is used below 300 ° C., and an inorganic binder is used above 300 ° C.

  The surface layer 7 is made of alumina silica fibers having a fiber diameter of 0.3 to 20 μm, and is fixed to the laminated layer 3 side by a heat-resistant binder 4. The alumina silica fiber is a fiber containing alumina at a ratio of 20 to 80% by mass, with the balance being made of silica. The fiber diameter of the alumina silica fiber is typically 0.3 to 20 μm, preferably 1 to 20 μm, more preferably 4 to 15 μm. The fiber length of the alumina silica fiber is, for example, 50 to 150 mm, more preferably 60 to 100 mm. In order to collect fine particles efficiently, fine fibers are effective and the pressure loss is low. However, thick fibers are also required to maintain strength, so the fiber diameter is appropriately selected depending on the purpose of dust collection.

  The alumina silica fiber can be prepared, for example, by an electrospinning method or a heating spray method. The surface layer 7 made of the alumina silica fiber is fixed to the laminated layer 3 side with a heat-resistant binder. The surface layer 7 is fixed by, for example, laminating alumina silica fibers on the laminated layer 3 side and spraying a heat-resistant binder thereon.

  The heat-resistant binder is an arbitrary inorganic binder or heat-resistant organic binder, similarly to the heat-resistant binder 4 coated on both surfaces of the laminate. A binder having a suitable heat-resistant temperature can be appropriately selected according to the temperature range of the exhaust gas to be removed.

  In addition to the laminated layer 3 side, the surface layer 7 may be further fixed to the back surface side of the base material layer 2, that is, the downstream side of the exhaust gas.

  Since the dust collecting filter cloth described above has a structure in which the base material layer 2 made of the stainless steel 5-filled inorganic fiber felt 6 made of plain weave or twill weave and the laminated layer 3 are integrated, heat resistance and durability are obtained. It is possible to achieve both flexibility and low pressure loss and a high dust collection rate.

  This bag filter made of a dust collection filter cloth has a structure in which a plurality of fiber layers having different fiber diameters and properties are laminated. Therefore, both conventional heat-resistant and flexible metal materials are formed in a mesh shape. Higher dust collection rate than bag filters can be achieved. In addition, the bag filter made of this dust collection filter cloth has both heat resistance and flexibility, so it is less likely to be damaged during dust collection compared to a conventional mold-type bag filter that has been baked and hardened with an inorganic material. Excellent durability.

  Furthermore, since the dust collection filter cloth has flexibility, it is highly workable and has high handling characteristics when the bag filter is attached to and replaced with a retainer in the dust collector. As a result, the work efficiency can be improved and the price of the product can be reduced. In addition, the dust collection filter cloth has the same flexibility as non-heat resistant dust collection filter cloths such as conventional polyester, so it is highly compatible with non heat resistant dust collection filter cloths and uses existing equipment. be able to.

  Since the dust collection filter cloth has excellent heat resistance, use a cooling facility at a site where high-temperature exhaust gas in the temperature range of 250 to 700 ° C that cannot be handled with non-heat resistant dust collection filter cloth is used. This makes it possible to treat exhaust gas and save energy. Furthermore, energy saving can be promoted by secondary use of exhaust heat.

  The dust collecting filter cloth has a surface layer 7 made of alumina silica fibers having a fiber diameter of 0.3 to 20 μm on the laminated layer 3 side (upstream side), or on the laminated layer 3 side and the base material layer 2. You may have on the back side (upstream side and downstream side).

  As the fiber diameter of the alumina silica fiber is reduced, the resistance to the exhaust gas passing through the dust collecting filter cloth can be suppressed. By providing the surface layer 7 on the surface of the dust collecting filter cloth, fine dust such as PM2.5 can be collected without increasing the pressure loss of the entire dust collecting filter cloth. Furthermore, by providing this surface layer 7 on the surface of the dust collection filter cloth, the dust releasability of the dust collection filter cloth can be improved. That is, it is possible to achieve both a low pressure loss and a high dust collection rate. Thereby, the operating energy of the air blower in a dust collector can be suppressed.

  Moreover, since this alumina silica fiber is a material having heat resistance, it is not dissolved by high temperature exhaust gas.

  Therefore, the above dust collection filter cloth has both heat resistance, durability, and flexibility, and can achieve both a low pressure loss and a high dust collection rate.

  This dust collection filter cloth 1 can be manufactured by the following method, for example. First, the laminated layer 3 is superimposed on one surface of the base material layer 2, and this is integrated by needling. The heat-resistant binder 4 is applied to both surfaces of the laminated body integrated by needling. Thereafter, the surface layer 7 is optionally fixed to the laminated layer 3 side by the heat-resistant binder 4 or to the laminated layer 3 side and the back surface side of the base material layer 2. The structure obtained as described above can be compressed and dried to obtain a dust collecting filter cloth.

  The dust collection filter cloth 1 described above can be used as a bag filter that is installed in a dust collector that sews a cylindrical bag so as to process high-temperature exhaust gas.

  FIG. 3 shows an example of the bug filter 8 according to one embodiment of the present invention, with a part thereof broken. A bag filter 8 shown in FIG. 3 covers a cylindrical retainer 9.

  The bag filter 8 sews the overlapping part of the dust collection filter cloth 1 using inorganic fiber, heat resistant organic fiber, or metal fiber thread alone or in combination. For example, the overlap part of the dust collection filter cloth 1 is sewn. Sewing is carried out using glass yarn on both sides and SUS yarn on the center. By adopting such a sewing method, the strength of the bag filter 8 can be improved.

  The diameter of the glass yarn is, for example, 5 to 50 μm, preferably 7 to 20 μm, more preferably 8 to 15 μm, and a single fiber is twisted into a yarn of 0.3 to 1.0 mm. The diameter of the SUS yarn is, for example, 20 to 70 μm, preferably 30 to 60 μm, more preferably 45 to 55 μm. ing.

  Since this bag filter 8 consists of the dust collection filter cloth 1 mentioned above, it is possible to combine heat resistance, durability, and flexibility, and to achieve both low pressure loss and high dust collection rate.

Dust collection filter cloth (Example) laminated in the order of base material layer, laminate layer, surface layer, dust collection filter cloth (Comparative Example 1) and base laminated in order of base material layer, surface layer, laminate layer A dust collection filter cloth (Comparative Example 2) consisting only of a material layer and a laminated layer was prepared.
For each of the example, comparative example 1 and comparative example 2, the air permeability, dust collection efficiency and heat resistance were measured. These measurement results are summarized in Table 1 below.

  From Table 1, it can be seen that the dust collection filter cloth of the example is excellent in heat resistance and has both a low pressure loss and a high dust collection rate.

  In addition, this invention is not limited to the said embodiment, In the implementation stage, it can change variously in the range which does not deviate from the summary. Further, the embodiments may be implemented in combination as appropriate, and in that case, the combined effect can be obtained. Furthermore, the present invention includes various inventions, and various inventions can be extracted by combinations selected from a plurality of disclosed constituent elements. For example, even if several constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the problem can be solved and an effect can be obtained, the configuration from which the constituent requirements are deleted can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 1,1 '... Dust collection filter cloth, 2 ... Base material layer, 3 ... Laminated layer, 4 ... Heat-resistant binder, 5 ... Stainless steel wire, 6 ... Inorganic fiber felt, 7 ... Surface layer, 8 ... Bag filter, 9 ... Retainer.

Claims (3)

A base layer composed of inorganic fiber cloth with stainless steel wire woven in plain or twill;
An organic fiber such as polyester disposed on one or both surfaces of the base material layer, or an inorganic fiber having a fiber diameter of 2 to 30 μm at a basis weight of 200 to 1800 g / m 2, or a fiber diameter of 2 to 30 μm A laminated layer containing a metal fiber made of stainless steel having a basis weight of 10 to 30 g / m 2,
A dust collecting filter cloth in which the base material layer and the laminated layer are integrated by needling and coated on both sides with a heat-resistant binder.   The dust collecting filter cloth according to claim 1, further comprising a surface layer made of alumina silica fibers having a fiber diameter of 0.3 to 20 µm and fixed to the laminated layer side by a heat-resistant binder. A bag filter, wherein the dust collection filter cloth according to claim 1 or 2 is sewn using inorganic fibers, heat-resistant organic fibers, or metal fibers alone or in combination.