JPH0687995B2 - Air cleaning method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a particulate matter and an acidic gas, an alkaline gas and a gas stream containing an odorous gas from the particulate matter and the acidic gas, an alkaline gas and an odorous gas. The present invention relates to a method and an apparatus for removing air, and more particularly to an air cleaning method and an apparatus for homes, businesses, hospitals and the like.

[Conventional technology and its problems]

In the conventional air cleaning method and its device, removal of particulate matter and removal of So ₂ , H ₂ SNOx, HCl, HNO ₃ , NH ₃ , O ₃ , various solvents, solvents and mercaptans, sulfides, thiophene, etc. Gaseous pollutants such as malodorous substances and tar-like substances were removed using separate removing devices.

The methods for removing particulate matter in the air are roughly classified into (1) mechanical over-method (2) electrostatic charging of high-voltage particles for collection of particles and electrostatic-filter collection method. But,
Each of these methods has the following drawbacks.

That is, (1) In the mechanical overpass method, it is necessary to use a filter having fine meshes in order to improve the cleanliness of the air, but in this case, the pressure loss is high, and the pressure loss due to clogging is also remarkable. However, it has the drawback of a short filter life, and has no effect on the removal of gaseous pollutants.

(2) The electrostatic filter system requires electric power, requires maintenance and safety, and is completely ineffective in removing gaseous pollutants.

On the other hand, the removal of gaseous pollutants has been carried out by passing air through a filling section filled with an adsorbent such as activated carbon.

The removal of these particulate matter and gaseous pollutants from the air was carried out by separate methods or devices, so that the device became complicated and large, and the maintenance and management were troublesome. Atsuta

[Object of the Invention]

An object of the present invention is to provide a method and an apparatus capable of simultaneously removing particulate matter in the air and gaseous pollutants such as acidic gas, alkaline gas and odorous gas.

[Structure of Invention]

The present invention includes (1) a cation exchange filter and an anion obtained by precharging particulate matter contained in the air in advance and then graft polymerizing an ion exchanger onto the fibrous material. A method of contacting an ion exchange filter (hereinafter simply referred to as an ion exchange filter) including an exchange filter to collect charged particles and simultaneously remove gaseous pollutants.

And (2) An air purifying device comprising a pre-charging unit for charging particulate matter by at least discharge and / or friction and an ion exchange filter unit on the air flow path from the air intake port to the air discharge port.

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an air purifier that performs precharging by friction charging.

The polluted air 1 in the room is sucked while the coarse particles are removed by the fan 2 by the fan 2.

The fine particles are collided with the triboelectric substance 4 by the fan 2 and are charged with static electricity.

The charged fine particles and pollutant gases such as SO ₂ and odorous gas in the room are collected by the ion exchange filter 5, and the air 6 of high cleanliness is discharged.

The triboelectrifying substance 4 may be any substance as long as it gives a charge to the fine particles by friction. A substance having a negative triboelectrification order is preferable, and polytetrafluoroethylene, polytrifluorochloroethylene, polyvinyl chloride, chlorinated polyether, polyethylene, sulfur, polyacrylonitrile, natural rubber, butadiene acrylonitrile copolymer, polychlorobutadiene, epoxy Resin, polyvinyl butyral and polyethylene glycol tetraphthalate are preferred. These may be used alone or in combination of two or more.

The shapes of these materials used are plate-like, pleated-like, net-like, etc. in a flow in a normal flow, countercurrent or an intermediate state thereof, and the application of the device
It can be appropriately selected depending on the shape, structure, desired effect, and economy.

In order to effectively carry out the pre-charging, it is preferable that the cross section of the pre-charging section is narrower than the cross section of the ion exchange filter section in order to increase the linear velocity.

Next, the ion exchange filter used in the present invention will be described in detail.

As the ion exchange filter 5, any ion exchange filter can be used as long as it can collect charged particulate matter and acidic gas, alkaline gas and odorous gas from the gas stream.

As the ion exchange filter, a net-like, woven or fibrous porous polymer support having an ion exchanger supported by graft polymerization is used, and these can be appropriately produced by a known method.

As the ion exchanger, an anion exchanger or a cation exchanger can be used, but usually both are mixed at an appropriate ratio and used.

As the support, polyethylene, polypropylene, polybutylene, a polymer of an aliphatic unsaturated hydrocarbon such as polybutene, polystyrene, a polymer of an aromatic hydrocarbon such as poly α-methylstyrene, an alicyclic group such as polyvinylcyclohexane Polymers of hydrocarbons, copolymers of these hydrocarbons, polytetrafluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymers, tetrafluoroethylene-hexafluoropropylene copolymer Coalescing,
A fluorine-containing unsaturated hydrocarbon polymer such as a vinylidene fluoride-hexafluoropropylene copolymer or a copolymer thereof is used.

Further, polyvinyl alcohol, polyamide, polyester, cellulose, wool, silk or a mixture thereof can be used.

These supports are used as a porous support, and the shape thereof may be such that the contact area with the gas flow is wide and the resistance is low. For example, a suitable thin film cloth, preferably a net shape, etc. An appropriate shape such as a woven or fibrous shape is used.

The porosity of the porous support is 10 to 95%, preferably 50 to 85%. The shape, thickness and porosity of the porous support can be appropriately determined depending on the shape of the device, the material used, the structure, the expected effect and the like.

The ion exchanger that can be used in the present invention is not particularly limited, and various cation exchangers or anion exchangers can be used.

For example, a cation exchange group-containing exchanger such as a carboxyl group, a sulfonic acid group, a phosphoric acid group or a phenolic hydroxyl group, an anion such as a primary to tertiary amino group, a quaternary ammonium group, a sulfonium group or a phosphonium group. Examples thereof include an ion-exchange group-containing exchanger, and a polymerization-type or condensation-type homogeneous or heterogeneous ion-exchanger containing both the positive and anion ion-exchange groups.

As a typical example, acrylic acid, methacrylic acid, or styrene, halomethylstyrene, acyloxystyrene,
Styrene compounds such as hydroxystyrene, aminostyrene, vinylbenzenesulfonic acid, vinylpyridine, 2-
Polymers of monomers having a cation or anion exchange group such as methyl-5-vinylpyridine, 2-methyl-5vinylimidazole, acrylonitrile, or sulfuric acid, chlorosulfonic acid, or sulfonic acid, or a group that can be converted into the same, or Copolymers of these monomers with monomers having two or more double bonds such as divinylbenzene, trivinylbenzene, butadiene, ethylene glycol divinyl ether, ethylene glycol dimethacrylate, or polyethylene, polyvinyl fluorocarbon ether or polytetra Ion exchangers obtained by introducing positive and / or anion ion-exchange groups into the polymers obtained by graft-polymerizing styrene onto fluoroethylene, or by converting them into ion-exchange groups, tetrafluoroethylene, chloro There ion exchanger consisting of a copolymer of perfluorovinyl monomer having a group capable of exchanging the vinyl monomer and the ion exchange groups or ion exchange groups such as Li fluoroethylene.

The method for supporting the ion exchanger on the support is not particularly limited and may be a known method.

For example, ultraviolet rays or α rays, β rays, electron beams, γ
Irradiation of ionizing radiation such as rays, oxygen, ozone,
Treatment with an oxidizing agent such as chlorosulfonic acid, hydrogen peroxide, benzoyl peroxide, peracetic acid, etc., or a method of grafting a monomer after carrying out a treatment of two or more of these, or supporting an ion exchanger, or supporting After irradiating the body (for example, polyethylene) with ionizing radiation, an aqueous solution of acrylic acid and / or methacrylic acid is reacted to obtain a graft polymer, which is treated with an aqueous sodium hydroxide solution.

As another method, there is a method of supporting the ion exchanger through a polymerized layer (adhesive layer) having a high affinity with the ion exchanger. In this method, first, a monomer is graft-polymerized on a support to form an adhesive layer with an ion exchanger. As the monomer for forming the adhesive layer, a monomer whose polymer has a high affinity or adhesiveness to the ion exchanger is used. Examples of such a monomer include an olefin monomer such as propylene, a vinyl halide monomer such as vinyl chloride, a styrene derivative, a monomer having a nitrile group such as acrylonitrile, a diene monomer such as butadiene, vinyl acetate,
There are monomers with acid ester groups such as ethyl acrylate.

These monomers are graft-polymerized on the support by means such as irradiation with ionizing radiation and / or treatment with an oxidizing agent. That is, after pretreating the support by these means,
Polymerization may be performed by impregnating the monomer solution to be grafted, or in the case of ultraviolet rays or radiation, irradiation may be performed with the support impregnated with the monomer solution. Next, the support is made to support the ion exchanger. This method is carried out as follows, for example, though it depends on the type of ion exchanger and the manufacturing method thereof. Initially, the support is impregnated with the raw material monomer mixture of the ion-exchanger before it is condensed, and the monomer mixture is allowed to be condensed (condensed) after the impregnation, or partially pre-compressed. Heavy (shrink) coalescing as it is,
Alternatively, if necessary, it is dissolved in an appropriate solvent to impregnate the support, and after the impregnation, the weight (contraction) is completed.

The feature of this method is that since the support has a graft polymer having a high affinity with the ion-exchanger-forming monomer, the adhesive layer of the support is changed by the monomer mixture or its initial weight (condensation). It swells or dissolves and is sufficiently impregnated. As a result of the subsequent polymerization of the monomer mixture or its initial weight (condensation), a structure is obtained in which the polymer is intimately integrated with the support via the graft polymerization layer.

When the polymer impregnated into the support and polymerized does not have sufficient ion-exchange groups, cation- or anion-exchange groups are subsequently introduced by known means to obtain an ion-exchange filter.

In this way, an ion exchange filter is produced, and a fibrous or woven anion exchange filter and a cation exchange filter are obtained.

The type, filling amount, and ratio of the anion exchange filter and cation exchange filter to be used are appropriately determined depending on the charge state and concentration of the charged fine particles in the gas flow, or the type and concentration of pollutants and malodorous substances in the gas flow. You can

For example, an anion exchange filter is effective for collecting negatively charged fine particles and acidic gas such as H ₂ S, and a cation exchange filter is effective for collecting positively charged fine particles and alkaline gas such as NH ₃ . In addition, the filling amount and its ratio are determined by the device shape,
It may be appropriately determined in consideration of the structure, pressure loss and the like. As a standard, an anion exchange filter 40 (V / V%) and a cation exchange filter 60 (V / V%) may be used.

In the description with reference to the drawings, the filter 5 downstream of the precharging section is used.
Although the method of using the ion exchange filter has been described above, it goes without saying that the coarse filter 3 can be similarly used.

For example, when the concentration of pollutant gas or tar substances is high, it is preferable to use an ion exchange filter also for the filter 3 because the maintenance on the downstream side becomes easy.

The location where the ion exchange filter is used can be appropriately determined depending on the shape and structure of the apparatus, desired effect, economical efficiency and the like.

When discharging is used as the precharging method, a known method can be used. The discharge is normally positive and the fine particles are positively charged.

When the fan material is a triboelectrification material, or when a film made of the same material as the triboelectrification material is attached to the fan, the triboelectrification body 4 shown in the drawing can be omitted.

Example 1 An ion exchange filter manufactured by the following means was tested using the air purifier shown in FIG.

Triboelectric material; Polytetrafluoroethylene film 1.
6 m ^{2 was} used.

Filling ratio: Anion exchange filter 40%, Cation exchange filter 60% Generated gas: Incense smoke (average particle size 0.2 to 0.5 μm), 50 mg / m
The H ₂ S and NH ₃ were added which become 10ppm respectively ^3.

Device size: 200 × 200 × 250 mm The generated gas of 5 / min was sucked into the air purifier, and the concentration at the outlet of the ion exchange filter was measured.

If there is no triboelectrified substance, fine particles 21 mg / m ³ , H ₂ S,
NH ₃ <0.1 ppm, tar was 5 mg / m ³ .

Method for producing ion-exchange resin membrane Anion-exchange filter: fibrous polypropylene was irradiated with an electron beam of 20 Mrad in nitrogen, and then immersed in a solution containing a hydroxystyrene monomer and isoprene to carry out a graft polymerization reaction. After the reaction, quaternary amination was performed to obtain an anion exchange membrane.

Cation exchange filter: A fibrous polypropylene was irradiated with an electron beam of 20 Mrad in nitrogen and then immersed in an aqueous solution of acrylic acid to carry out a graft polymerization reaction. After the reaction, it was treated with a sodium hydroxide solution to obtain a cation exchange membrane.

〔The invention's effect〕

1. As a method of collecting particulate matter and acidic gas, alkaline gas, and odorous gas, by using an ion exchange filter, the particulate matter and acid gas, alkaline gas, and odorous gas in the gas stream are It can be removed with high efficiency by the device.

 Tar-like substances in the gas stream can also be removed at the same time.

There is no scattering of collected materials such as collected particles, and steady operation can be continued for a long time.

2. The shape of the ion exchange filter is a woven fabric such as a net,
Alternatively, by using a fibrous form, a practical anion exchange filter and cation exchange filter with low resistance were obtained.

3. As a pre-charging method, discharge or triboelectric charging is performed, and the ion exchanger collects fine particles and the like in the downstream flow, so that pollutants such as fine particles in the gas flow do not actually flow out into the downstream flow. A highly clean gas flow was obtained with a very high efficiency that can be ignored.

4. Selection of charging method (whether discharge or triboelectric charging) and proper use or combination of anion exchange filter and cation exchange filter depending on the concentration and type of particulate matter, gaseous pollutants, tar substances in the air, etc. As a result, the device can be optimized for the purpose of use, the shape of the device, and the economical efficiency.

5. Safer than the conventional electrostatic collection method,
We can provide a compact, multifunctional and economical cleaning device that is easy to maintain and manage.

[Brief description of drawings]

FIG. 1 is a schematic sectional view for explaining an example of the device of the present invention. 1 ... contaminated air, 2 ... fan, 3 ... coarse filter,
4 ... Triboelectric material, 5 ... Ion exchange filter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B03C 3/38 8925-4D

Claims (5)

[Claims] 1. A cation exchange filter and an anion exchange filter obtained by charging particles contained in air by discharge or triboelectric charging, and then graft polymerizing an ion exchanger on a fibrous substance. A method for cleaning air, characterized in that the charged particles are collected through an ion exchange filter consisting of 2. Particles containing triboelectrification in the air,
The method for cleaning air according to claim 1, wherein the method is performed by friction with a substance whose triboelectrification order is negative. 3. Particles that are triboelectrically charged in the air and polytetrafluoroethylene, polytrifluoroethylene, polyvinyl chloride, chlorinated polyether, polyethylene, sulfur, polyacrylonitrile, natural rubber,
The method according to claim 2, which is carried out by friction with one or more substances selected from the group consisting of butadiene acrylonitrile copolymer, polychlorobutadiene, epoxy resin, polyvinyl butyral and polyethylene glycol terephthalate. Air cleaning method. 4. The method for cleaning air according to any one of claims 1 to 3, wherein the ion exchange filter has a woven or fibrous shape. 5. Obtained by graft-polymerizing an ion exchanger on a fibrous substance and a pre-charged part which charges particles by at least discharge and / or friction on an air flow path from an air inlet to an air outlet. An air purifier equipped with an ion exchange filter section consisting of a cation exchange filter and an anion exchange filter.