JP2989031B2 - Method and apparatus for removing hydrocarbon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a gas or a space, and more particularly to a method and an apparatus for collecting and removing hydrocarbons (HC) existing in a gas or a space. About. The removal method and apparatus of the present invention
Hydrocarbons and closed spaces (static space) in various gases such as air in offices, hospitals, or various industries, especially in the semiconductor field
Can be used to remove hydrocarbons. next,
An example is shown below. (1) Removal of hydrocarbons generated in homes, offices, and hospitals or contained in introduced air (gas). (2) Treatment of exhaust gas from various combustion facilities. (3) Exhaust gas treatment of automobiles. (4) Removal of hydrocarbons generated in clean rooms and their surroundings or in introduced air (gas) in the semiconductor industry, the pharmaceutical industry, the food industry, the agriculture and forestry industry, the medical industry, and the precision machine industry. Storage box in clean room,
Removal of hydrocarbons in carrier boxes and transport spaces. In addition, removal of hydrocarbons generated in the operation of handling solvents and solvents.

[0002]

2. Description of the Related Art The prior art will be described by taking air purification in a clean room in the semiconductor industry as an example. The conventional clean room air cleaning method or its apparatus can be roughly classified into: (1) a mechanical filtration method (for example, a HEPA filter); and (2) a high-voltage charged and conductive filter for electrostatically collecting fine particles. Although there is a method (eg, HESA filter), these methods are all aimed at removing fine particles (particulate matter), and have a drawback that they are not effective in removing gaseous pollutants such as hydrocarbons. . Each of these also has the following disadvantages in removing fine particles.

[0003] That is, in the mechanical filtration system, it is necessary to use a fine filter in order to increase the cleanliness (class) of the air. In this case, the pressure loss is high, and the increase in the pressure loss due to clogging is also caused. Not only is the life of the filter short, the maintenance, management or replacement of the filter is not only troublesome, but also it is necessary to stop the work during the replacement of the filter, and it takes a long time to return. However, there is a disadvantage that the production efficiency is poor. In order to increase the cleanliness of the air, the number of ventilations (the number of air circulations by a fan) is also increased, but in this case, there is a disadvantage that the power cost is high.

In the method of electrostatically collecting fine particles, a high voltage of, for example, 15 to 70 kv is required for the preliminary charging section, so that the apparatus becomes large, and safety and maintenance are reduced. There was a problem. H. C. As a method for removing methane, a combustion decomposition method, a catalytic decomposition method, an adsorption removal method, an O ₃ decomposition method and the like are known. However, these methods use low concentrations of H.I. contained in the air introduced into the clean room. C. It has no effect on removal. In clean rooms, low concentrations of H.I. C. Is also a problem as a pollutant. In addition, various solvents (eg, alcohols, ketones, etc.) generated in operations in the clean room also pose a problem as pollutants.

[0005]

SUMMARY OF THE INVENTION In a clean room, an H. elegans is used. C. Can cause a decrease in the productivity (yield) of semiconductor products (eg, damage to the product circuit due to deposition on the product surface), so it is necessary to remove them together with ordinary fine particles (particulate matter). I have. The inventor of the present invention has proposed an ordinary method for removing fine particles as an ultraviolet irradiation method or a radiation irradiation method using a photoelectron emitting material as described later. Therefore, an object of the present invention is to solve the above problems and to provide a method and an apparatus capable of efficiently removing low-concentration hydrocarbons with a simple apparatus.

[0006]

In order to achieve the above object, according to the present invention, when removing hydrocarbons present in a space, the hydrocarbons are irradiated with ultraviolet rays and / or radiation to form fine particles of the hydrocarbons. A method for removing hydrocarbons, which comprises removing charged particles by a filter or collecting the charged fine particles after being charged by photoelectrons. In order to achieve the above and other objects, according to the present invention, a hydrocarbon atomizing unit having an ultraviolet and / or radiation irradiation source, a collecting unit having a filter for collecting the fine particles, Alternatively, the present invention provides a hydrocarbon removing device, comprising at least a charging unit for charging the fine particles with photoelectrons and a collecting unit for collecting the charged fine particles.

[0007] In the above-mentioned removing apparatus, the hydrocarbon atomizing portion and the charged portion of the fine particles can be further integrated, and the hydrocarbon atomizing portion, the charged portion of the fine particles, and the collecting portion of the charged fine particles can be further integrated. Can also be integrated. In the above-mentioned removal of hydrocarbons, a hydrocarbon gas is converted into a condensable substance by irradiating ultraviolet rays and / or radiation into a space in which the hydrocarbons are present, and the hydrocarbon gas is converted into fine particles or the fine particles are activated. It is changed into a substance (a substance having high reactivity), and the changed particulate matter is collected and removed by being removed by a filter or charged by photoelectrons. In the above method, the fine particles are charged by irradiating the photoelectron emitting material with ultraviolet rays and / or radiation to emit photoelectrons and use the photoelectrons. The charging of the fine particles is preferably performed in an electric field.

Next, various constituent members of the present invention will be described in detail. The microparticulation unit is a part that converts hydrocarbons (HC) in the space into fine particles (condensable substance or fine particles and an active substance). C. , And the irradiation source is H. C. Can be converted into fine particles or fine particles and an active substance. In addition to ultraviolet irradiation, electromagnetic waves, lasers, and radiations are applicable fields, target processing. C. Preliminary tests can be carried out as appropriate for the components, concentrations, equipment scales, shapes, economics, etc. to select and use. The irradiation causes H. in the space. C. Is H. C. Is converted into a particulate substance (condensable substance) or a particulate substance and an active substance depending on the type and coexisting substance. For example, H. C. Irradiates a gas mixture containing toluene, alkane (i-pentane), and olefin (propylene) with ultraviolet light to produce a carboxylic acid or carbonyl compound (condensable substance or active substance)
Is generated. In the conversion to fine particles (fine particle formation),
Irradiation sources having a wavelength of 260 nm or less, preferably 245 nm or less are effective, and ultraviolet and / or radiation irradiation is usually suitably used in terms of effect and operability.

[0009] The ultraviolet light source is H. C. Can be converted into fine particles (conversion to fine particles or condensable substances or conversion to fine particles and an active substance). C. Preliminary tests can be carried out as appropriate depending on the type of and coexisting substances. Of these, those that generate oxygen active species (active radicals) such as active oxygen and OH radicals are preferable depending on the application field. Usually, a mercury lamp and a hydrogen discharge tube (deuterium lamp) can be used as a light source of ultraviolet rays. The UV light source is H.I. C. It is preferable to use a compound having a plurality of wavelengths that cause different effects depending on the type of the compound and the coexisting substance. For example, a mercury lamp has a wavelength of ozone generation (one of the starting substances for generating oxygen activated species),
It is preferable because a wavelength for decomposing the ozone and promoting the generation of the oxygen active species can be additionally provided, and a wavelength for charging the fine particles described later can be used together.

As radiation, α-rays, β-rays, γ-rays and the like are used, and as irradiation means, radioactive isotopes such as cobalt 60, cesium 137, strontium 90, or radioactive waste produced in a nuclear reactor and For example, a method using a radioactive material that has been appropriately processed and processed as a radiation source, a method using a nuclear reactor as a direct radiation source, a method using a particle accelerator such as an electron beam accelerator, and the like are used. When irradiating an electron beam with an accelerator, high-density irradiation can be performed by performing at a low output, which is effective. The acceleration voltage is 500 kV or less, preferably 50 kV to 300 kV. In the micronization section, H. C. Depending on the type and coexisting substance of the above, the above-mentioned irradiation converts it into a particulate substance (condensable substance) or a particulate substance and an active substance (highly reactive substance) and converts it into a form that is easy to handle (process). .

Next, the charged portion of the fine particles is a portion that applies the charge of the harmful gas which has been finely divided, and its configuration is shown in FIG. 2, which is a major feature of the present invention. Regarding the charging of the fine particles by the photoelectrons and the removal of the charged fine particles described later, there are various proposals by the present inventors, and they can be used as appropriate. The following are the main proposals. 1. JP-A-61-1
No. 78050 (PS Patent 4,750,917),
2. JP-A-62-244459,3. JP-A-63-7
No. 7557,4. JP-A-63-100955; JP-A-2-8638,6. JP-A-2-10034,
7. 7. Japanese Patent Application No. 1-120564,8. Japanese Patent Application No. 1-155
857, 9. Japanese Patent Application No. 2-278123,10. Japanese Patent Application No. 2-295423.

The respective configurations will be described. The photoelectron emitting material may be any material that emits photoelectrons by irradiating ultraviolet rays, and a material having a small photoelectric work function is preferable. Ba, Sr, Ca, Y, G
d, La, Ce, Nd, Th, Pr, Be, Zr, F
e, Ni, Zn, Cu, Ag, Pt, Cd, Pb, A
1, C, Mg, Au, In, Bi, Nb, Si, Ta,
Any of Ti, U, B, Eu, Sn, P, and W, or a compound or alloy or a mixture thereof is preferable, and these are used alone or in combination of two or more. As the composite material, a physical composite material such as amalgam can be used.

For example, compounds include oxides, borides and carbides, and oxides include BaO, SrO, and Ca.
O, Y ₂ O ₅ , Gd ₂ O ₃ , Nd ₂ O ₃ , ThO ₂ , Z
rO ₂ , Fe ₂ O ₃ , ZnO, CuO, Ag ₂ O, La
₂ O ₃ , PtO, PbO, Al ₂ O ₃ , MgO, In _{2
O 3, BiO, NbO, YB} 6 is to include BeO, also _{borides, GdB 6, LaB 5, NdB} 6, CeB
₆ , BuB ₆ , PrB ₆ , ZrB _{2 and the} like, and further, as carbides, UC, Zrc, TaC, TiC, Nb
C and WC. In addition, brass, bronze,
Phosphor bronze, alloy of Ag and Mg (Mg is 2 to 20 wt.
%), An alloy of Cu and Be (Be is 1 to 10 wt%), an alloy of Ba and Al, and an alloy of Ag and Mg, an alloy of Cu and Be, and an alloy of Ba and Al. Alloys are preferred. The oxide can also be obtained by heating only the metal surface in air or oxidizing it with a chemical.

Still another method is to heat before use,
An oxide layer can be formed on the surface to obtain a stable oxide layer over a long period of time. As an example, an oxide film can be formed on the surface of an alloy of Mg and Ag in steam at a temperature of 300 to 400 ° C. under a temperature condition, and this oxide film is stable for a long period of time. Further, as already proposed by the inventor, a photoelectron emitting material having a multi-layered structure can be suitably used (Japanese Patent Application No. 1-155857).
Further, a substance capable of emitting photoelectrons in the form of a thin film can be added to an appropriate base material and used. This example is an example in which Au is added on a glass base material in the form of a thin film. These materials may be used in any shape such as a plate shape, a pleated shape, a curved surface shape, and a net shape, but a shape having a large ultraviolet irradiation area and a large air contact area is preferable.

The emission of photoelectrons from the photoelectron emitting material can be effectively implemented by appropriately using a reflecting surface, a curved reflecting surface, etc., as already proposed by the present inventor (Japanese Patent Application Laid-Open No. Sho 63). -100955 publication). The shape of the photoelectron emitting material and the shape of the reflecting surface vary depending on the shape and structure of the device, the desired efficiency, and the like, and can be determined as appropriate.

The type of the ultraviolet light may be any as long as the photoelectron emitting material can emit photoelectrons by the irradiation.
Usually, a mercury lamp, a hydrogen discharge tube, a xenon discharge tube, a Lyman discharge tube and the like can be appropriately used. Depending on the field of application, those having a bactericidal (sterilizing) action are also preferred. The type of the ultraviolet ray can be appropriately determined depending on the application field, work content, application, economy, and the like. For example, in the biological field, it is preferable to use far ultraviolet rays in combination from the viewpoints of sterilization and efficiency. For example, it is preferable to use a germicidal lamp (254 nm is the main wavelength) because a germicidal (sterilizing) action is added to the charge of the present invention. Any ultraviolet light source can be used as long as it emits ultraviolet light, and it can be appropriately selected and used depending on the application field, the shape, structure, effect, economy, etc. of the device.

The charging of the fine particles by photoelectrons is efficiently performed by irradiating the photoelectron emitting material with ultraviolet light in an electric field. The present inventor has already proposed charging in an electric field (eg, JP-A-61-178050,
JP-A-62-244459, Japanese Patent Application No. 1-120.
No. 563). The electric field of the present invention is 0.1 V / cm to 5 kV.
/ Cm and the preferred electric field strength is
Preliminary tests and examinations can be made as appropriate based on the shape, scale, effect, economy, etc. of the device, and the value can be determined. For example, a weak electric field may be used for purifying an enclosed space such as a storage box, but a relatively strong electric field is used in various industries where a large amount of processing gas is used.

Also, by irradiating radiation instead of irradiating ultraviolet rays, the fine particles are similarly charged, and the same effect can be obtained. Irradiation can be carried out in the same manner as has already been proposed by the present inventor (JP-A-62-24459). Since the charge by photoelectrons is charged with high efficiency even with fine ultrafine particles (eg, <0.1 μm), the collection and removal of the fine particles can be performed efficiently. The charging of the fine particles can be performed by increasing the particle diameter of the fine particles upon charging. Increase the particle size of the fine particles,
The inventor has already proposed a charging method (Japanese Patent Application No. 1-120564), and the method can be used for charging fine particles appropriately depending on the application field. Next, the charged fine particle collecting unit is a part for collecting and removing charged fine particles, and a well-known method and apparatus can be applied as appropriate.

That is, any material for collecting charged fine particles can be used as long as it can collect charged fine particles. Generally, a dust collecting plate (dust collecting electrode) or an electrostatic filter method in a normal charging device is used. However, a wool-like substance such as steel wool or tungsten wool is used as an electrode (wool-like electrode material). A structure in which the collecting portion itself forms an electrode is also effective. Electret materials can also be suitably used. Further, an ion exchange filter (fiber) already proposed by the present inventor is also effective depending on the application field. The ion exchange filter is preferable depending on the field of application because it can collect coexisting active substances, harmful gases, odorous gases, and the like which are difficult to collect by the present charging method. The ion-exchange filter is composed of active substances and condensable H.O. generated by irradiation of ultraviolet rays to HC in the space. C. It is effective for trapping water and is preferable in some fields of application. For example, carboxylic acid generated by irradiation of toluene with ultraviolet light, or inert H. C. There is collection of aldehydes generated by UV irradiation on the surface.

The ion exchange filter is practically preferable because it can collect acidic gas, alkaline gas, odorous gas and the like in addition to the collection of charged fine particles. The type, amount and ratio of the anion exchange filter and the cation exchange filter to be used depend on the charged state and the concentration of the charged fine particles in the gas or the type and concentration of the accompanying acidic gas, alkaline gas, odorous gas, etc. It can be determined as appropriate. For example, an anion exchange filter is effective for collecting negatively charged fine particles and acidic gas, and a cation exchange filter is effective for collecting positively charged fine particles and alkaline gas. The amount of filter used and its ratio correspond to the concentration and concentration ratio of the substance to be collected, and the amount corresponding to these, considering the application field, shape, structure, effect, economy, etc. of the device It may be determined appropriately. These trapping materials can be used singly or in combination of two or more depending on the application field, device scale, shape, economy, and the like. this house,
H. C. Depending on the type of H. C. In the case where an active substance is generated from, it is preferable to use an ion exchange filter (fiber) because it is effective.

[0021]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. Embodiment 1 An air cleaning method using a clean bench in a clean room using an ultraviolet irradiation method, that is, a method in which only a part of a work area is kept at a high degree of cleanliness, will be described with reference to FIG. In the clean room 1, coarse particles of the outside air introduced from the pipe 2 are filtered by the pre-filter 3, and the temperature of the air with the air taken out from the air outlet 4 of the clean room 1 is passed through the fan 5 through the air conditioner 6. The air is circulated and supplied with the fine particles removed by the HEPA filter 7 while controlling the humidity and humidity.
It is kept at about 000.

A clean bench 11 is provided in the clean room 1 to collect and remove trace hydrocarbons (HC) and fine particles (particulate matter) in the clean room 1. H. in clean room 1 C. The cause of
H. in the outside air introduced from the pipe 2 C. (Presumed to be mainly due to automobiles) and H.C. C. It is estimated from. The clean bench 11 is mainly composed of a fine particle forming section 8, a fine particle charging section 9, and a charged fine particle collecting section 1.
0 on the work table 13. C. Is supplied, and high-purity (class 10) air from which coexisting fine particles are also removed is supplied.

That is, in the clean bench 11, a small amount of H.O. C. Air having a cleanliness (class) of about 10,000 containing air is sucked by a fan (not shown), and short-wave ultraviolet rays are irradiated on the introduced air by the atomizing section 8 to thereby introduce H.V. C. Are atomized.
Next, the fine particles are efficiently charged by photoelectrons generated from a photoelectron emitting material to be described later in the fine particle charging unit 9 to become charged fine particles, and the charged fine particles are collected by the rear charged particle collecting unit 10.
The work table 13 is collected and removed by H.
C. It is kept in free high-purity air. The loading and unloading of instruments, products, etc. to and from the workbench 13 in the clean bench 11
This is performed by a movable shutter 12 provided on a clean bench 11.

In the clean bench 11, which is a feature of the present invention, H.O. C. FIG. 2 shows the outline of the fine particle forming section 8, the fine particle charging section 9, and the charged fine particle collecting section 10 for removal, which will be described below. That is, a fan (not shown)
H. aspirated by H. C. After being filtered by a pre-filter (not shown), the air 14 containing H. mainly comprises an ultraviolet lamp 15. C. Ultraviolet light of a low wavelength is irradiated in the microparticulation unit 8. Here, H. in air is used. C. Are converted into fine particles 16 by ultraviolet irradiation. H. C. The fine particles 16 converted from are charged together with the normal fine particles 17 already existing in the introduced air 14 in the fine particle charging section 9 to become charged fine particles 18. The fine particle charging section 9 mainly includes an ultraviolet lamp 19, a photoelectron emitting material (here, a material in which Au is added in a thin film shape on a glass material surface) 20, and an electrode material 21 for setting an electric field. Release material 20
Irradiation of ultraviolet rays from the ultraviolet lamp 19 generates photoelectrons 22, and the photoelectrons effectively charge the microparticles 16 and 17 to become charged microparticles 18, which are formed of a charged microparticle collecting material at the rear. Collected in the collecting part 10. 23 is an ultraviolet transmitting material. 24, H.
C. Is clean dust-free air from which air has been removed.

In the examples shown in FIGS. 1 and 2, the fine particle forming section 8, the fine particle charging section 9, and the charged fine particle collecting section 10 are individually installed. The functions can be appropriately integrated depending on the effect, economy, etc., or can be installed and implemented at an appropriate position. For example, (1) the fine particle forming section 8 and the fine particle charging section 9 are integrated, (2) the fine particle charging section 9 and the collecting section 10 are integrated, and further (3) the fine particle forming section 8 and the charging section 9, All the collecting units 10 can be integrated. Above,
Selection of the irradiation source of the atomizing unit 8 and the charging unit 9 and the collection material of the charged fine particles, and the above-described atomizing unit 8, charging unit 9, and collecting unit 10
Investigation is made as appropriate depending on the application field, the shape, structure, effect, economy, etc. of the application, the presence or absence of integration, the type of integration (which function is integrated), and the preliminary test. Can be decided.

To describe an example of a general form, in the case of a large-scale processing, radiation or ultraviolet rays are used as an irradiation source, and the micronizing unit 2, the charging unit 3, and the collecting unit 4 are individually arranged as shown in FIG. Installed in That is, in a large-scale processing, it is practically important to keep the running cost of the apparatus low because of a large processing amount. For this purpose, it is preferable to operate each component under optimal conditions. Further, the collecting unit 10 is made independent so that the collected fine particles can be appropriately discharged, so that a long-time continuous operation can be performed. In such a case, a dust collecting plate (a dust collecting electrode) is preferably used for collecting the charged fine particles.

Next, as a small scale, there is a storage box (storage) for wafers and liquid crystals in the semiconductor field. In this case, it is preferable to use an ultraviolet ray as an irradiation source, and to perform all of the microparticulation part, the charged part of the fine particles, and the collection part of the charged fine particles in one part. That is, in a field where the throughput is small, it is practically preferable that the apparatus is made compact (miniaturized). Therefore, all functions are performed in one box. In this case, the particles are charged (photoelectron emission) at the wavelength at which the particles are usually formed into fine particles, and the collection and removal of the charged particles are performed by installing the charged particle collecting material on or around the electrode material for setting the electric field. I do.

In the first embodiment, collection and collection of fine particles (hydrocarbons converted into fine particles or condensable substances)
In this example, the removal is performed by applying a charge with photoelectrons, but as another means, the fine particles can be collected and removed using a filter or an adsorbent. The fine particles are generally ultrafine particles. The fine particles generated from ordinary hydrocarbons have a particle size of about 0.01 to 0.05 μm, and as described above, the fine particles have higher activity than ordinary fine particles (eg, inorganic substances) or are active substances. The feature is that it coexists with Any filter may be used as long as it can collect the above-mentioned fine particles. Generally, a filter of a filtration system, for example, a HEPA filter, a ULPA filter, an electrostatic filter, a filter using an electret material, or an ion exchange filter (fiber) is used. Of these, HEPA filters, ULPA filters, and ion-exchange filters are usually preferred because of their simplicity and high effect.

In particular, an ion exchange filter is preferable because it has a high effect on collecting and removing active substances as described above. Depending on the field of use, an adsorbent such as activated carbon can also be used as appropriate. Adsorbents such as activated carbon are preferred depending on the field of application because they can collect coexisting active substances and harmful gases which are difficult to collect by the present charging method, similarly to ion exchange filters.
Whether the collection / removal of fine particles is performed by applying a charge by photoelectrons or performed by an adsorbent filter may be appropriately selected depending on the application field, apparatus scale, shape, effect, economy, etc., or may be performed in combination. it can. Of these, charge collection / removal by photoelectrons and / or collection / removal by a filter are preferable because of their high effects. Further, in this example, an example in which the present invention is applied to the clean bench 11 in the clean room 1 is described. However, the outside air introduced into the clean room 1 (or the introduced gas such as the air conditioner 6 and the HEPA filter 7 in FIG. , Various storage boxes in a clean room, a carrier box, and transport space. C. The same can be applied to the removal. Here, H. C. Is described as gaseous, but mist H.
C. (Eg, condensable HC, oily fume, oily H.
C. In the case of (1), since the charging is performed in the charging section 9 in the same manner, the collection is performed in the same manner. H. micronized C. Or mist H. C.
Is considered to be in a form that easily interacts with coexisting fine particles (ultrafine particles) and an active substance (highly reactive substance), condenses, and is easily charged. H. C. Since the effect of the coexisting substance increases with the coexisting substance, the coexisting substance can be appropriately added and carried out.

Example 2 The following gas mixture was sealed in the apparatus shown in FIG. 3 (specified below), and the mixture was irradiated with ultraviolet rays to measure the hydrocarbon concentration. Gas components: Toluene: 1 ppm, i-pentane: 1 ppm, NOx: 0.1 ppm, SOx:
0.05 ppm, moisture: 55% (RH) Ultraviolet lamp 31; Mercury lamp Photoemission material 34; Cu-Zn with Au added in a thin film form. Electric field: 50 V / cm Measurement of hydrocarbon; gas chromatograph Further, in FIG. 3, 32 is an ultraviolet reflecting surface, 33 is an electric field electrode material and a collecting material, and 35 is an ultraviolet transmitting glass material. Results The residual ratio was calculated from the concentration relative to the initial concentration, and is shown in FIG.
After 1 hour, the gas in the apparatus was analyzed by mass spectrometry. As a result, the content of hydrocarbons was 0.1 ppm or less. In addition, when the same operation was performed without ultraviolet irradiation and the hydrocarbon concentration in the device was examined, 90% or more thereof was measured (detected).

Example 3 The same gas mixture as in Example 2 was similarly irradiated with ultraviolet rays, and after 45 minutes, the gas mixture was passed through the following filter to measure the hydrocarbon concentration. The results are shown in Table 1 below. Filter; ULPA filter Ion exchange filter (anion type) Measurement; Concentration of toluene and i-pentane by gas chromatography Measurement of hydrocarbon by mass spectrometry

[Table 1]

[0032]

According to the present invention, the following effects can be obtained. 1. In removing hydrocarbons, the hydrocarbons are exposed to ultraviolet light and / or
Or, by irradiation, the hydrocarbon is converted into fine particles (converted to a condensable substance), and the form becomes easy to handle (easily processed). In addition, since a part was converted into an active substance (a substance having high reactivity) such as aldehydes, the form became easy to handle. 2. In removing the hydrocarbon, by performing charging with photoelectrons subsequent to the above 1, fine ultrafine particles (for example, <
(0.1 μm), the particles easily became charged fine particles, and the particles were easily collected and removed. Since the charging by photoelectrons is uniform and highly efficient, the handling of the charged fine particles is facilitated. Since the charged particles are substantially uniform, collection / removal and handling of the charged fine particles are facilitated.
-By using a more appropriate charged particle collecting material, charged particles could be easily collected and removed. 3. The use of ultraviolet radiation and / or radiation, to the radiation, it is possible to have multiple actions of charged action of conversion action and fine particles to fine particles acting as an active substance of hydrocarbon (hydrocarbon In some cases, the device can be compact and inexpensive, depending on the field of application, since the conversion of fine particles into an active substance, the charging of the generated fine particles, and the charging of previously existing fine particles (particles) can be performed in one box.

4. In removing the hydrocarbons, the mixture containing the fine particles after the above-mentioned irradiation was passed through a filter, whereby the products were collected and removed, and a highly clean gas or space was formed. 5. When removing hydrocarbons, irradiating the hydrocarbons with ultraviolet rays or radiation causes other harmful gases or odorous substances to coexist (eg, NOx, SOx, tobacco odor components).
Can be collected and removed at the same time, so by collecting and removing fine particles, an ultra-clean gas or space from which hydrocarbons, harmful gases, odorous substances, and fine particles have been removed has been created. 6. In particular, in advanced industries such as the semiconductor industry (although the existence of low-concentration hydrocarbons caused by automobile exhaust gas was a problem), fine particles, harmful gases, and odorous substances coexisting with hydrocarbons could be removed at the same time. Thus, the productivity was improved and it became practically effective. 7. A suitable irradiation source and a method for collecting and removing products can be appropriately selected depending on the application field, the scale of the apparatus, the shape, the effect, the economy, and the like, so that the method can be widely applied to various fields.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a clean room to which the present invention is applied.

FIG. 2 is an explanatory diagram of a fine particle forming section, a charging section, and a collecting section of FIG. 1;

FIG. 3 is a schematic diagram of an apparatus used in Example 2.

FIG. 4 is a graph showing the removal rate of hydrocarbons by irradiation.

[Explanation of symbols]

1: clean room, 2: open air, 3: pre-filter,
4: air outlet, 5: fan, 6: air conditioner, 7:
HEPA filter, 8: micronization section, 9: microparticle charging section, 10: charged microparticle collection section, 11: clean bench,
13: work table, 14: air, 15, 19: ultraviolet lamp, 16, 17: fine particles, 18: charged fine particles, 20: photoelectron emission material, 21: electrode material, 22: photoelectron, 23: ultraviolet transmission material, 24: High clean air

Continuation of the front page (56) References JP-A-47-10108 (JP, A) JP-A-63-54958 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01D 53 / 32 B01D 51/02 B01D 53/72 B03C 3/38

Claims (8)

(57) [Claims] 1. A method for removing hydrocarbons existing in a space, comprising the steps of irradiating ultraviolet rays and / or radiation into fine particles of the hydrocarbons, removing the fine particles by a filter, or charging the fine particles with photoelectrons, and then charging the fine particles. A method for removing hydrocarbons, comprising collecting water. 2. The method for removing hydrocarbons according to claim 1, wherein the wavelength of the fine particles formed by irradiation with ultraviolet rays and / or radiation is 260 nm or less. 3. The method for removing hydrocarbons according to claim 1, wherein the charging of the fine particles by photoelectrons is performed by irradiating the photoelectron emitting material with ultraviolet rays and / or radiation. 4. A method according to claim 1, further comprising at least a hydrocarbon atomizing unit having an ultraviolet and / or radiation irradiation source, a charging unit for charging the fine particles with photoelectrons, and a collecting unit for collecting the charged fine particles. Hydrocarbon removal equipment. 5. The hydrocarbon removing device according to claim 4 , wherein an electric field installation unit is provided in the charging unit for charging the fine particles. 6. The apparatus for removing hydrocarbons according to claim 4 or 5, wherein the a charged portion of the hydrocarbon particulates unit and fine particles are provided integrally. Wherein said that the charged portion and the collector of charged particles is provided integrally apparatus for removing hydrocarbons according to claim 4 or 5, wherein the hydrocarbon particulates portion and microparticles . 8. An apparatus for removing hydrocarbons, comprising at least a hydrocarbon atomizing unit having an ultraviolet and / or radiation irradiation source, and a collecting unit having a filter for collecting the fine particles.