JP2013111572A - Filter medium for gas removal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a requirement for removing a pollutant gas such as an alkaline gas or an acidic gas contained in the atmosphere in addition to conventional removal of dust particles in building air conditioning, and air conditioning systems in hospital facilities and clean rooms along with recent environmental change.SOLUTION: A filter medium for gas removal is made by attaching an ion-exchange group and a reaction group with a method such as graft polymerization, a chemical liquid impregnation method and the like to a laminated filter base material which is prepared by attaching an adhesive medium of a binder, a fused fiber or adhesive powder to nonwoven or woven fabric constituted of a synthetic fiber or a glass fiber and a natural fiber of 0.3-50 μm in fiber diameter and 0.1-1.0 mm in thickness to laminate a micro-fine fiber layer of 0.01-0.5 μm in fiber diameter, and to unite the nonwoven or woven fabric with the micro-fine fiber.

Description

  The present invention relates to an air filter gas removal filter medium capable of simultaneously removing dust particles contained in the air-conditioning air and atmospheric air and pollutant gases such as alkaline gas and acid gas.

  Along with recent environmental changes, air conditioning systems for building air conditioning, hospital facilities, clean rooms, etc. require removal of pollutant gases such as alkaline gas or acid gas contained in the atmosphere in addition to conventional dust particle removal. It has come to be.

  In general, in an air filter, the fiber density of a filter medium is increased to maintain a higher collection efficiency. On the other hand, when the fiber density of the filter medium is increased, a phenomenon occurs in which the pressure loss of the filter medium increases and the passing air volume decreases.

  Therefore, as a method for increasing the amount of passing air and reducing the pressure loss, a method is adopted in which the filter medium is folded into a pleated shape and the area of the filter medium is widened by using a separator or the like. The following methods have been tried to provide not only the function of removing dust particles but also the function of removing gas.

(1) A method of providing a deodorizing function by attaching or impregnating a deodorizing material to a filter medium.
(2) A method in which a filter having a deodorizing action is installed before or after the filter unit so as to have a removing function and a deodorizing function.

  However, in the method described above, in the case of (1), there is a problem that the pressure loss of the filter medium itself becomes high and the amount of passing air is reduced, and in the case of (2), an installation space for installation is required. There was a problem. In addition, there are problems that both processing and assembly are complicated and the cost is high.

  The present invention has been made in view of the above circumstances, and an object thereof is an air filter unit comprising a gas removal filter medium having a dust particle removal function and a gas removal function at an air conditioning intake of a building, hospital facility, clean room or the like. Through this air filter unit, we tried to maintain a comfortable indoor environment.

  Next, an object of the present invention is to enable energy saving while using a gas removal filter medium having a greatly reduced pressure loss while maintaining a dust removal efficiency equivalent to or higher than that of a conventional filter medium, and to save energy. The service life is long.

  Furthermore, the object of the present invention is to use a gas removal filter medium having an adsorption function while maintaining a dust removal efficiency equivalent to or higher than that of a conventional filter medium. This makes it possible to remove pollutant gases such as solid particles and radioactive iodine.

  Furthermore, an object of the present invention is to provide a gas removal filter medium in which the lifetime of the harmful substance collection / removal function and the filtration function is almost the same.

  The first solving means of the present invention is that the fiber diameter is 0.3 to 50 μm and the thickness is 0.1 to 1.0 mm of synthetic fiber, nonwoven fabric or woven fabric made of glass fiber, natural fiber, etc., binder, molten fiber or Adhesive powder adhesive medium is attached, a superfine fiber layer having a fiber diameter of 0.01 to 0.5 μm is laminated, and graft polymerization or chemical solution is applied to the laminated filter base material in which the nonwoven fabric or woven fabric and the superfine fiber are integrated. It is an object of the present invention to provide a gas removal filter medium to which an ion exchange group or a reactive group is added by a technique such as an attachment method.

  The second solving means of the present invention is such that a binder, a molten fiber or an adhesive powder adhesive medium is attached to the surface of the thin layer of the ultrafine fiber of the multilayer filter substrate of the solving means 1, and the fiber diameter is 1 to 100 μm, A gas removal filter medium in which a non-woven fabric or a woven fabric having a thickness of 0.05 to 1.5 mm is dry-fixed and integrated with a laminated filter base material to which an ion exchange group or a reactive group is added by a technique such as graft polymerization or chemical solution deposition. Is to provide.

  Here, the nonwoven fabric or woven fabric of the laminated filter substrate can be organic fibers such as polyester fibers, polyamide fibers, polyethylene fibers, rayon, polypropylene fibers, glass fibers, and pulp fibers. These may be used alone or in combination of two or more.

  As a method for forming these nonwoven fabrics or woven fabrics, a method using a wet papermaking method, a dry method, a spunbond method, a melt blow method, an electrospinning method, or the like is used.

  As an adhesive medium for the laminated filter substrate, a binder, molten fiber, adhesive powder, or the like is used. As the binder, an organic binder, an inorganic binder, or a mixed binder obtained by mixing is used. An acrylic resin is preferably used. As the molten fiber, a fiber having a core-sheath structure is used. Further, resin powder having a low softening point is used as the adhesive powder.

  The ultrafine fiber of the laminated filter substrate refers to a fiber having a single fiber diameter in the range of 0.01 to 0.5 μm, and the form may be a fibrous form, It is not particular. The material constituting the ultrafine fiber is not particularly limited, and examples thereof include polyester, polyamide, polyolefin, polyphenylene sulfide (PPS), and the like. Examples of the polyester include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polylactic acid (PLA). Examples of polyamide include nylon 6 (N6), nylon 66 (N66), nylon 11 (N11), and the like. Examples of the polyolefin include polyethylene (PE), polypropylene (PP), and polystyrene (PS). In addition to the above materials, it is of course possible to use phenol resins, polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polyethersulfone (PES), polysulfone, fluorine-based polymers and their derivatives.

  The super extra fine fiber layer used in the present invention is composed of the super extra fine fibers as described above, but the super extra fine fibers are preferably not in a bundle but in a state in which the extra extra fine fibers are dispersed. This is because the ultrafine fiber has a slip flow effect that improves the fluid flow and lowers the pressure loss.

  The ultrafine fiber layer is produced by an electrospinning method. Thus, since the super extra fine fiber layer manufactured by the electrospinning method has sufficient strength when used in combination with the base material, it is excellent in processability of various filters. The electrospinning method is a conventionally known method, and is a method of drawing and fiberizing by applying an electric field to a spinning solution supplied from a nozzle or the like.

  Subsequently, the ultrafine fibers layered can be formed by laminating the fiberized ultrafine fibers on a nonwoven fabric or a woven fabric. The nonwoven fabric or woven fabric is not particularly limited as long as it can collect ultra-fine fibers and can maintain the workability and strength of the filter.

  The production of a laminated filter substrate that exhibits a high-efficiency dust collection function with low pressure loss is made by synthetic fiber or glass fiber having a fiber diameter of 0.3 to 50 μm and a thickness of 0.1 to 1.0 mm, or natural fiber. An electric field that forms a stretched ultra-fine fiber by applying an electric field to the spinning material supplied from a nozzle or the like on a non-woven fabric or woven fabric made of fibers, etc. A laminated filter base material in which the non-woven fabric or woven fabric and the ultra-fine fiber are integrated is formed by laminating the ultra-fine fiber layer of 0.01 to 0.5 μm by a spinning method or a melt spinning method.

  Furthermore, another form of the multilayer filter base material is that a binder, molten fiber or adhesive powder adhesive medium is attached to the surface of the ultrafine fiber layer of the multilayer filter base material, the fiber diameter is 1 to 100 μm, and the thickness is 0.00. It is a laminated filter medium in which a non-woven fabric or woven fabric having a thickness of 05 to 1.5 mm is fixed by drying, or is simply physically stacked and integrated.

  Next, the production of a gas removal filter medium that has a high-efficiency dust collection function while exhibiting a low pressure loss and that exhibits the function of adsorbing polluted gases is performed using α-rays, β-rays, and γ-rays on the laminated filter substrate. Radiation (reaction initiation species) is generated by irradiation with radiation such as X-rays and electron beams. The laminated filter substrate after the irradiation is immersed in a polymerizable monomer-containing solution, and the polymerizable monomer is graft-polymerized on the laminated filter substrate fiber. As a result, the polymerizable monomer is bound to the fiber as a graft polymerization side chain. The resulting fiber having a polymerizable monomer as a side chain is contact-reacted with a compound having an anion exchange group or a cation exchange group, whereby an ion exchange group is introduced into the polymerizable monomer of the graft polymerized side chain, and finally A product is obtained. Further, a gas removal filter medium can be produced by impregnating, attaching and drying a solution having a reactivity with a gas or a particulate removal material. Therefore, when such a product comes into contact with a pollutant gas such as an alkaline gas or an acid gas in the air, the ultrafine fiber having a large surface area comes into contact with the gas and efficiently comes into contact with the product. It will be excellent.

  Examples of the polymerizable monomer include vinyl sulfonic acid, styrene sulfonic acid, vinyl pyridine acrylic acid, methacrylic acid, arylamine, and chloromethyl sulfonic acid, which are appropriately selected depending on the necessity of a cation exchange group and an anion exchange group. And are not limited to these ranges.

  As the impregnation reaction solution, potassium hydroxide, potassium carbonate, sulfuric acid, amine or the like is used.

  The gas removal filter medium is formed by laminating a superfine fiber layer having a fiber diameter of 0.01 to 0.5 μm on a nonwoven fabric or woven fabric provided with an ion exchange group or a chemical, and the nonwoven fabric or woven fabric and the superfine fiber. The structure which combined these may be sufficient.

  And the production of a functional filter that has a high-efficiency dust collection function while exhibiting a low pressure loss and a function of adsorbing polluted gas, folds the gas removal filter medium in a zigzag shape, It is manufactured by sandwiching a separator or bead-like adhesive between pleated filter media and attaching it airtightly with an adhesive in the outer frame.

  When the gas removal filter medium is used as a filter pack, it is preferable that a binder is applied to the surface of the thin layer of the ultrafine fibers of the gas removal filter medium, and the non-woven fabric is dried and fixed, so that they are arranged integrally. However, the present invention is not limited to this and may be used in any manner.

  And when using as a filter pack, it attaches in the state with the airtightness to the cell type filter frame which attached the sealing material inside.

  In another form, a gas removal filter medium or the like in which the embosses protruding on the front surface and the embosses protruding on the back surface are alternately formed in the width direction is folded in a zigzag shape so that the protruding embosses are in contact with each other. It is manufactured and airtightly attached to the outer frame with an adhesive.

  The operation of the above problem solving means is as follows.

  First, the gas to be treated is sucked into the gas removal filter medium by the operation of the air filter. Then, NOx, SOx, ammonia gas and the like contained in the gas to be processed that have passed through the gas removal filter medium are collected and adsorbed by the gas removal filter together with the solid particles, and are discharged as clean air.

  Furthermore, the layer thickness and amount of the removal material attached to the filter substrate surface can be changed according to the nature and amount of harmful substances contained in the gas to be treated. The removal function and the filtration function work well and the service life is almost at the same time, which solves the problem that one of the functions is lost as soon as in the prior art and a new gas removal filter medium must be replaced.

  In addition, the replacement frequency of the gas removal filter medium is reduced, so that the replacement work is not time-consuming and stable performance can be obtained over a long period of time, thereby reducing cost.

  Furthermore, in the case of particulate removal material attachment, since the binder is fixed on the surface of the gas removal filter medium on the dust collecting side, the particulate removal material does not adhere to the cleaned air discharge side. For this reason, the removing material is not peeled off from the air filter medium and scattered in the purified air. Therefore, the cleaning air is not contaminated by the removing material.

(1) By using a gas removal filter medium using ultrafine fibers, the pressure loss of the filter medium itself can be reduced, and the passing air volume can be secured.
(2) By using ultrafine fibers for the filter substrate, the specific surface area can be increased, and the gas removal performance can be effectively enhanced.
(3) Since the gas removal filter medium has a dust removal function and a gas removal function, it is possible to reduce the installation space and the installation cost by using one filter that has been manufactured separately.
(4) By laminating ultrafine fibers on various substrates, gas removal filter media suitable for various applications can be produced.
(5) Since a gas removal filter medium in which a nonwoven fabric or a woven fabric is integrated on the surface of a thin layer of superfine fibers, the superfine fiber layer is not damaged or peeled off and scattered. It can be processed into various shapes by changing.
(6) Capturing harmful substances collected on the gas removal filter medium stably over a long period of time by attaching ion exchange groups and reactive solutions to the filter base material on the front and back surfaces according to the purpose and amount. Can do. Therefore, harmful substances collected by the gas removal filter medium can be efficiently collected and removed, and the safety and performance are high.
(7) The layer thickness of ion exchange groups and reactive solutions can be changed according to the type, nature, and amount of harmful substances contained in the gas to be treated, so it can remove and remove harmful substances. Since the functional life is almost the same period, the function of the gas removal filter medium can be fully utilized.
(8) Since the particulate removal material is attached to the dust collecting surface and back substrate of the gas removal filter medium by transfer of a roller or the like, the gas removal filter medium can be manufactured by an easy means. .
(9) It is possible to reliably attach the removal material to the gas removal filter medium and provide a low-cost filter medium.
(10) Since the type, nature, and layer thickness of the removal material to be attached to the surface of the gas removal filter medium are changed, the pressure loss of the air filter medium is controlled, and unnecessary clogging inside the filter medium is reduced. The life of the filter media can be extended.
(11) Although the conventional particulate removal material has large particles and there is a limit to the pleating process, by using this gas removal filter medium, it is possible to pleat from the prefilter to the medium performance filter, the HEPA filter, and the ULPA filter. it can.

Schematic which shows the panel type pre filter using the gas removal filter medium of this invention. Schematic which shows the automatic update type air filter which uses the gas removal filter medium of this invention. Schematic which shows another Example of the automatic update type air filter using the gas removal filter medium of this invention. The schematic diagram which shows the blow-off type air filter which uses the gas removal filter medium of this invention is shown. Schematic which shows another Example of the blow-off type air filter which uses the gas removal filter medium of this invention. Schematic which shows the flange type medium performance filter which uses the gas removal filter medium of this invention. Schematic which shows the box type medium performance filter which uses the gas removal filter medium of this invention. Schematic which shows the double flange type | mold semi-HEPA filter which uses the gas removal filter medium of this invention. Schematic which shows the double flange type HEPA filter using the gas removal filter medium of this invention. The schematic diagram of the functional filter which shows the box type HEPA filter which uses the gas removal filter medium of this invention. The schematic of the functional filter which shows the flange type ULPA filter which uses the gas removal filter medium of this invention. Schematic of the functional filter pack using the gas removal filter medium of the present invention.

  Hereinafter, the shape of various filters using a gas removal filter medium will be described with reference to FIGS.

  FIG. 1 shows a panel type pre-filter, where the joining parts of the filter medium 1 and the outer frame 2 are all bonded and have excellent durability, and a uniform pleat gap and peak height are maintained by a wire mesh and fingers bonded to the back side of the filter medium 1. Since dust can be collected evenly by the entire filter medium 1, there is no sudden increase in pressure loss, and it has the characteristics of an unprecedented long life. Moreover, because it is ultralight and compact, replacement work is easy, and used filters can be discarded after being compressed and reduced in volume. The material of the filter medium 1 is a gas removal filter medium, and the material of the outer frame 2 is a card board.

  FIG. 2 shows an automatic renewal type air filter in which a long-sized gas removal filter medium 1 is intermittently wound by a timer or a pressure loss of the filter medium is detected. The filter medium 1 has a mat shape and has a very high restoring force and flexibility. Moreover, although the filter medium 1 having a length of 20 m is a compact roll having a diameter of about 30 cm, it returns to a thickness of 50 cm on the filtration surface and collects dust over the entire thickness instead of surface filtration, so that the dust holding capacity is extremely large. It has become.

  FIG. 3 makes it possible to process a large volume in a limited space by taking advantage of the automatic update type air filter shown in FIG. 2 and further zigzag the filtration surface of the filter medium 1.

  FIG. 4 shows a blow-off type air filter that is attached to a metallic honeycomb header frame 4 with a bag-shaped filter medium 3 obtained by sewing a gas removal filter medium in a bag shape. The bag-shaped filter medium 3 is composed of six filter pockets having a depth of 890 mm. And with high collection rate and low pressure loss, the dust holding capacity is extremely large and very compact.

  Fig. 5 shows a blow-off type air filter in which a bag-like filter medium 3 is attached to a slit-type header frame 5 made of metal. All the pockets swell with low filtration resistance. The filter medium becomes an effective filtration surface to every corner. Dust is collected over the entire filter medium. As a result, an increase in pressure loss is extremely slow.

6 shows that the gas removal filter medium 1 is zigzag-folded in a metal outer frame 6 and a corrugated aluminum separator 7 is inserted between the filter medium 1 so that the filter medium 1 and the outer peripheral surface of the outer frame 6 are sealed with a sealing material. This is a flange-type filter integrated with a certain characteristic.
The filter medium 1 is a non-woven fabric or woven fabric 1A made of glass fiber, synthetic fiber or natural fiber having a fiber diameter of 0.3 to 50 μm and a thickness of 0.1 to 1.0 mm, and an adhesive medium of binder, molten fiber or adhesive powder. The fiber diameter is 1 to 100 μm and the thickness is 0.05 to 1. This is a gas removal filter medium obtained by laminating ultrafine fiber layers 1B having a fiber diameter of 0.01 to 0.5 μm and integrating the nonwoven fabric or woven fabric 1A and the ultrafine fiber layer 1B.

  FIG. 7 is a modification of the flange type filter of FIG. 6 and shows a box type filter in which a plywood frame 8 is used instead of the metal outer frame 6.

  FIG. 8 shows that the gas removal filter medium 1 is zigzag-folded in a metal outer frame 9, and a corrugated aluminum separator 7 is inserted between the filter media 1 to apply the filter medium 1 and the inner peripheral surface of the outer frame 9 with an adhesive. Thus, it is a double flange type quasi-HEPA filter integrated with airtightness.

  FIG. 9 shows that the gas removal filter medium 1 is folded in a zigzag shape in a metal outer frame 10, the corrugated aluminum separator 7 is interposed between the filter medium 1, and the filter medium 1 and the inner peripheral surface of the outer frame 9 are sealed with a sealing material. Is a double flange type HEPA filter integrated with each other. The filter medium 1 is a non-woven fabric or woven fabric 1A made of glass fiber, synthetic fiber or natural fiber having a fiber diameter of 0.3 to 50 μm and a thickness of 0.1 to 1.0 mm, and an adhesive medium of binder, molten fiber or adhesive powder. The fiber diameter is 1 to 100 μm and the thickness is 0.05 to 1. This is a gas removal filter medium in which an ion exchange group is added to a laminated filter base material obtained by laminating ultrafine fiber layers 1B having a fiber diameter of 0.01 to 0.5 μm by a technique such as graft polymerization.

  FIG. 10 shows a filter pack formed by folding the gas removal filter medium 1 into a plywood outer frame 11 in a zigzag shape, and holding a thread-like resin 12 between the filter mediums to keep the distance of the filter medium 1 constant. This is a box-type HEPA filter integrated with a sealing material on the inner peripheral surface of the frame 11.

  FIG. 11 shows that the gas removal filter medium 1 is zigzag-folded in a metal outer frame 13, and a corrugated aluminum separator 7 is inserted between the filter medium 1 and the filter medium 1 and the inner peripheral surface of the outer frame 13 are applied with a sealing material. Thus, the flange-type ULPA filter is integrated with airtightness.

  12 is formed by alternately forming embosses 14 projecting on the surface of the gas removal filter medium 1 and embosses 15 projecting on the back surface in the width direction and folding them in zigzags so that the projecting embosses are in contact with each other. 1 is a perspective view of a filter pack.

  Next, specific examples will be described.

  A binder, molten fiber or adhesive powder adhesive medium is attached to the surface of a nonwoven fabric or woven fabric made of glass fiber, synthetic fiber or natural fiber having a fiber diameter of 0.3 to 50 μm and a thickness of 0.1 to 1.0 mm. After irradiating the filter substrate on which a thin layer of ultrafine fibers having a fiber diameter of 0.01 to 0.5 μm is dried, fixed and integrated, and then irradiated with radiation, a polymerizable single polymer of styrene sulfonic acid or glycidyl acrylate is used. A monomer monomer is contacted to form a cation exchange group or an anion exchange group, respectively. Thereby, a gas removal filter medium having a cation exchange group, that is, an alkali gas adsorption function or an anion exchange group, that is, an acid gas adsorption function is formed.

  The gas removal filter medium is folded in a zigzag shape to form an air filter medium, and a corrugated aluminum separator is inserted between the partition walls of the pleats to form an air filter unit. When the above was mounted on a test duct and tested, the following results were obtained.

Test condition Temperature condition 25 ℃
Humidity condition 65%
Test dust 11 kinds of JIS Z8901 test powder 1
Test gas Ammonia 1000ppm
Hydrogen sulfide 1000ppm
Test and measurement equipment Detector tube

Test results Shown in Table 1

  In this embodiment, one embodiment of the present invention has been described. The present invention is not limited to this embodiment, and the gist of the present invention is not changed at all by various modifications.

  In the industry that handles air conditioning filters, filters having low pressure loss, high collection efficiency, and long-life performance have been conventionally pursued. However, these performances have contradictory performances, making it difficult to create an ideal one. Therefore, the development of air conditioning filters having ideal performance in the filter industry has been attracting attention in recent years due to the development of ultra-fine fibers and the like due to technological development in the textile industry. Therefore, the present invention solves these problems and provides a gas removal filter having a gas removal function while exhibiting the ultrafine fiber effect without regret, having a low pressure loss and high efficiency and long life performance. The present invention is very useful in industry.

DESCRIPTION OF SYMBOLS 1 ... Filter medium 1A ... Nonwoven fabric or woven fabric 1B ... Super extra fine fiber layer 2 ... Outer frame 3 ... Bag-shaped filter medium 4 ... Honeycomb type header frame 5 ... Slit type header frame 6, 9, 10, 13 ... Metal outer frame 7 ... Corrugated aluminum separator 8 ... Plywood frame 11 ... Outer frame made of plywood 12 ... Yarn-like resin 14, 15 ... Embossed

Claims (2)

  A laminated filter in which a superfine fiber layer having a fiber diameter of 0.01 to 0.5 μm is laminated on a nonwoven fabric or woven fabric made of synthetic fiber, glass fiber, natural fiber, etc., and the nonwoven fabric or woven fabric is integrated with the superfine fiber. A gas removal filter medium comprising an ion exchange group and a reactive group added to a base material by a technique such as graft polymerization or chemical solution deposition.   The fiber filter has a fiber diameter of 1 to 100 μm and a thickness of 0.05 to 1.5 mm by attaching an adhesive medium of a binder, molten fiber or adhesive powder to the surface of the thin layer of the ultrafine fiber of the multilayer filter substrate of claim 1. A gas removal filter medium comprising a laminated filter in which a nonwoven fabric or a woven fabric is dry-fixed and integrated with an ion exchange group or a reactive group by a technique such as graft polymerization or chemical solution deposition.

Images