JP2917773B2 - High frequency heating element with catalytic function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses high-frequency energy to heat and raise the temperature to catalytically decompose harmful substances such as hydrocarbons and carbon monoxide in exhaust gas discharged from internal combustion engines such as automobiles. The present invention relates to a high-frequency heating element.

[0002]

2. Description of the Related Art In recent years, pollution caused by exhaust gas has become a problem, and in automobiles using gasoline as a fuel, emission regulations of hydrocarbons, carbon monoxide, and nitrogen compounds contained in the exhaust gas have been increasing. One of the purification methods for these pollutants is a post-treatment method using a catalyst. A typical catalyst is to control the air-fuel ratio to near the stoichiometric air-fuel ratio to oxidize hydrocarbons and carbon monoxide and reduce nitrogen oxides. At the same time, there is a catalytic body (three-way catalyst) that converts it into harmless carbon dioxide, water vapor, and nitrogen.

[0003] The catalyst is a monolithic carrier of cordierite containing silica, alumina and magnesia as main components at 300 to 400 cells / inch2, or a metal carrier (metal carrier) obtained by corrugating an iron-chromium-aluminum alloy. Is provided with a coating layer called a wash coat composed of fine particles such as alumina having a large surface area, or an oxide film layer of the metal carrier, and the coating layer or the oxide film layer is formed of platinum, palladium, rhodium, or the like. It is configured to carry noble metal fine particles, and exhibits a catalytic function by heating exhaust gas.

Recently, an electric heater system has been studied in which an electric current is directly applied to the metal carrier to rapidly heat the catalyst body in order to exert a catalytic function in a short time.

[0005]

However, the above conventional configuration has the following problems.

That is, the conventional catalyst requires the catalyst layer to have a temperature of 350 ° C. or higher in order to exert the catalytic function. It took about one minute, and until then, there was a problem that harmful exhaust gas was directly discharged to the atmosphere.

[0007] Further, a heater-type catalyst body that rapidly heats by energizing the metal carrier improves the temperature rising speed as compared with a catalyst body that is heated only by the exhaust gas, but has a large heat capacity of the metal carrier, so that it takes an extremely short time. In addition, there is a problem that large power is required to raise the temperature, and there is a problem that reliability such as an electrical insulator is lacking.

The present invention solves the above-mentioned problem, and has a catalytic function of reducing harmful substances such as hydrocarbons and carbon monoxide in exhaust gas discharged when starting an engine of an automobile or the like by using high-frequency heating. It is intended to provide a high-frequency heating element.

[0009]

In order to achieve the above object, a high-frequency heating element having a catalytic function according to the present invention is a high-frequency absorbing material made of a high-frequency absorbing material which absorbs high-frequency energy and generates heat on a support made of a plurality of ceramic fibers. A high-frequency absorber having a layer formed thereon and a catalyst supported on the high-frequency absorption layer, and a carrier layer formed of ceramic fine particles formed on a support made of a plurality of ceramic fibers and a catalyst supported on the carrier layer. Two separate structures with the catalyst body
It consists Zotai, fluid the high frequency absorption such as an exhaust gas
After passing through the body, it passes through the catalyst body .

Further, the high-frequency heating element having a catalytic function of the present invention comprises a high-frequency absorber having a plurality of high-frequency absorbing fibers for absorbing high-frequency energy and generating heat, and a supporting member comprising a plurality of ceramic fibers. A carrier layer made of ceramic fine particles is formed on the body, and a catalyst body carrying a catalyst on the carrier layer is composed of two separate structures, and a fluid such as exhaust gas passes through the high frequency absorber.
After that, it passes through the catalyst body .

[0011]

In the above configuration, when high-frequency energy is supplied to the high-frequency heating element (high-frequency absorber and catalyst body) having the catalytic function of the present invention, the high-frequency absorption layer (high-frequency absorbing material) constituting the high-frequency absorber is provided. from consisting) or high-frequency absorption fibers absorb high frequency energy formic, is heated by heat conversion. It is simultaneously heated to a temperature at which the catalyst carried on the catalyst and catalyst medium carried on the high frequency absorbing layer or high-frequency absorption fibers described above functions as a catalyst, carbon monoxide in the exhaust gas discharged from automobiles And hydrocarbons are decomposed by the heated catalyst and converted into harmless carbon dioxide gas and water vapor.

Fluid such as exhaust gas passes through the high frequency absorber.
After passing through the catalyst body, the catalyst body
Adhesion of sulfur etc. contained in exhaust gas is suppressed,
Poisoning of the catalyst due to poison can be prevented, and catalyst life
Can be improved.

Further , since the high-frequency absorber and the catalyst body have a skeleton composed of a support made of fibers of a ceramic material, the weight is reduced and the heat capacity can be reduced as compared with a conventional catalyst body. Further, the high-frequency absorber and the catalyst
The body is composed of these two separate structures,
The high-frequency absorber heated by the frequency becomes smaller and lighter,
This can be heated to a high temperature in a short time and its heat energy
Efficient transmission of lugi to the catalyst using the flow of exhaust gas
can do. Also, as described above, the catalyst body
Since the amount is small, the temperature can be raised to a temperature that functions as a catalyst in a short time.

Further, since the high-frequency absorber carries a catalyst, the high-frequency absorber also causes a catalytic reaction.
And the purification performance of a fluid such as exhaust gas can be improved .

Further, since the specific surface area can be increased by forming the carrier layer on the support made of the ceramic fibers constituting the catalyst, the catalytic activity at low temperatures is increased, and the time for functioning as a catalyst is reduced. It can be further shortened.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partial sectional view of a high-frequency heating element having a catalytic function according to an embodiment of the present invention. In FIG. 1A, reference numeral 1 denotes a high-frequency absorber, and a high-frequency absorbing layer 3 made of a high-frequency absorbing material 3 that absorbs high-frequency energy and generates heat is formed on a support 2 made of a plurality of ceramic fibers. The layer carries a catalyst 4 for decomposing harmful substances in the exhaust gas. In FIG. 2B, reference numeral 5 denotes a catalyst body, and a support layer 2 made of ceramic fine particles 6 having an increased specific surface area is formed on a support 2 made of ceramic fibers made up of a plurality of ceramic fibers as shown in FIG. In addition, the same catalyst 4 as shown in FIG. The high-frequency heating element having a catalytic function of the present invention is composed of a high-frequency absorber and a catalytic body.
One separate consists of structures of, after the fluid such as the exhaust gas passes through the high <br/> frequency absorber 1, to pass through the catalyst 5
You are.

FIG. 2 shows a partial cross-sectional view and an external view of a support 2 made of ceramic fibers constituting the high-frequency absorber 1 and the catalyst 5 shown in FIG. In FIG. 1A, reference numeral 7 denotes a ceramic fiber, and the support 2 is constituted by a twisted yarn obtained by bundling a plurality of ceramic fibers 7. FIGS. 7B and 7C show a structure in which the support 2 is made of a non-woven fabric obtained by weaving the twisted yarn shown in FIG. FIGS. 7B and 7C show examples of plain weave, but various weaves such as satin weave, leno weave, blade, rope, and tape are possible. Further, the support 2 is not limited to the woven fabric, but may be a nonwoven fabric such as paper or mat.

The high-frequency absorption layer and the carrier layer are desirably formed on a support 2 made of ceramic fibers formed in an arbitrary shape, but each of the ceramic fibers 7 or ceramic fibers 7 forming the support 2 is preferably formed. It is also possible to form in advance a twisted yarn composed of: The support 2, the high-frequency absorbing material 3 forming the high-frequency absorbing layer, and the ceramic fine particles 6 forming the carrier layer are bonded with an inorganic binder, and the catalyst 4 is supported by bonding with the inorganic binder or immersion and drying of the catalyst solution. Is done.

The ceramic fiber 7 is desirably a ceramic material having excellent heat resistance. In particular, a material mainly containing at least one of alumina, silica and zirconia is used.

High frequency absorbing material 3 excellent in high frequency absorbing characteristics
As a semiconductor material, zinc, copper, manganese, cobalt, iron, tin, titanium, oxides containing silicon as a main component, carbides, at least a complex oxide such as a perovskite-type complex oxide containing the metal One type is applied. It is not clear why the semiconductor material is excellent in absorbing and generating heat of high-frequency energy, but it is considered that the semiconductor material has conductive and dielectric properties suitable for absorbing high-frequency energy. In particular, by applying silicon carbide as the high-frequency absorbing material, more excellent high-frequency energy absorption / heating characteristics, heat resistance in an exhaust gas atmosphere, and chemical stability can be realized.

The ceramic fine particles 6 constituting the carrier layer are formed to improve the dispersibility of the supported catalyst 4 and increase the catalytic activity (enlargement of the specific surface area), and have excellent heat resistance. This applies to at least one of silica, alumina, zirconia, and ceria.

The catalyst 4 for decomposing harmful substances is platinum,
Palladium, noble metals of rhodium, copper, manganese, oxides of cobalt, perovskite-type composite oxides,
At least one of these applies.

The inorganic binder is not particularly limited, but is preferably a colloidal particle of alumina, silica, zirconia or the like having excellent heat resistance and adhesiveness.

The high frequency absorber 1 is manufactured as follows. A slurry made of an inorganic binder and a solvent (usually water) is prepared in the high frequency absorbing material 3 and the support 2 made of ceramic fibers is immersed in the slurry, or the slurry is brush-coated on the support 2 made of ceramic fibers. High-frequency absorbing material 3
And a high-frequency absorption layer formed by adhering an inorganic binder to the mixture, followed by drying or firing. Next, a catalyst solution in which the metal catalyst 4 or a metal compound containing the catalyst 4 is dispersed (or dissolved) is prepared, and the support 2 made of the ceramic fiber on which the high-frequency absorption layer is formed is immersed in the catalyst solution. Alternatively, the catalyst solution is applied on the high frequency absorption layer by spraying or the like, and then dried or fired. The composition of the slurry is the required high frequency absorbing material 3
The amount is appropriately set according to the amount of the inorganic binder capable of maintaining the adhesion amount and the adhesive strength of the resin, the operation at the time of the immersion treatment, and the like. Alternatively, the catalyst 4 may be prepared by adding a predetermined amount to the slurry composed of the high-frequency absorbing material 3, the inorganic binder and the solvent in advance, and supporting the catalyst 4 simultaneously with the formation of the high-frequency absorbing layer.

On the other hand, the catalyst body 5 is manufactured as follows. A slurry comprising ceramic fine particles 6 such as silica or alumina, an inorganic binder and a solvent (usually water) is prepared, and the slurry is mixed with a support 2 made of ceramic fibers.
Or by applying the slurry to a support 2 made of ceramic fibers by brushing or spraying to form a carrier layer made of ceramic fine particles 6, and then drying or firing. Next, a metal catalyst 4,
Alternatively, the metal compound containing the catalyst 4 is dispersed (or dissolved).
After preparing the catalyst solution, the support 2 made of ceramic fibers having the carrier layer formed thereon is immersed in the catalyst solution, or the catalyst solution is applied on the carrier layer by spraying or the like, and then dried or dried. Bake. Catalyst 4
Alternatively, a predetermined amount may be previously added to a slurry composed of the above-mentioned ceramic fine particles 6, an inorganic binder, and a solvent, and the catalyst 4 may be supported simultaneously with the formation of the carrier layer.

When the catalyst 4 is a metal oxide, the loading of the catalyst is carried out as follows. A slurry made of the catalyst 4, the inorganic binder and the solvent is prepared, and the support 2 made of ceramic fibers is immersed in the slurry or applied by brushing or spraying, and then dried or fired.

Next, the function and effect of the high-frequency heating element having a catalytic function of the present invention will be described using an exhaust gas purifying apparatus as an example.

FIG. 3 shows the high-frequency absorber 1 and the catalyst 5 of the present invention.
1 shows an example of an apparatus for purifying exhaust gas discharged from an automobile provided with a high-frequency heating element 8 having a catalytic function constituted by the following. In the figure, an exhaust pipe for discharging exhaust gas of an internal combustion engine 9, 10 is a heating chamber provided in the middle of the exhaust pipe, the high frequency heating member 8 having a catalytic function of the present invention the fluid is a high frequency of the exhaust gas After passing through absorber 1,
It passes through the catalyst body 5 . 11 is a heating room 10
Is a support member for supporting the high-frequency heating element 8 having a catalytic function, which is accommodated in the housing. The supporting member 11 has a heat insulating function between the outer periphery of the high-frequency heating element 8 having the catalytic function and the inner wall of the heating chamber 10. Doubles as well. Reference numeral 12 denotes a high-frequency oscillator for generating high-frequency energy to be supplied to the heating chamber 10, and a high-frequency oscillator 13 for transmitting high-frequency energy generated from the high-frequency oscillator 12 to the heating chamber 10. 14 and 15 are heating chambers 10
This is a high-frequency shielding means that is limited to a metal plate having a large number of punched holes or a metal honeycomb structure having a large number of through holes.

When the engine of a gasoline-powered vehicle starts, exhaust gas containing harmful substances such as carbon monoxide and hydrocarbons discharged from the engine flows through an exhaust pipe 9 into a high-frequency heating element 8 having a catalytic function. On the other hand, at the same time as or immediately before the start of the engine, the high-frequency oscillator 12 generates high-frequency energy according to a command from a control unit (not shown). When this high-frequency energy is transmitted to the heating chamber 10 through the waveguide 13, the high-frequency absorber 1 (actually, the high-frequency absorbing material 3 constituting the high-frequency absorbing layer formed on the support 2) Is absorbed and converted to heat.
The exhaust gas passing through the high-frequency absorber 1 heated at the same time
Catalyst 5 is disposed adjacent the flow is heated pressurized. When the high frequency absorber 1 and the catalyst 4 carried on the catalyst 5 has reached a temperature that serves as a catalyst, oxygen and reaction of carbon monoxide and hydrocarbons are harmful substances in the exhaust gas in the exhaust gas is decomposed into water vapor and carbon dioxide is harmless to. The harmless exhaust gas passes through the muffler and is exhausted to the atmosphere through the exhaust pipe 9.

The exhaust gas contains a sulfur compound.
Catalytic activity gradually decreases as sulfur compound reacts with catalyst
(Poisoned). In the present invention, the exhaust gas passes through the high-frequency absorber 1 .
After passing through the catalyst body 5,
The compound adheres to the high frequency absorber 1. Therefore, touch
The adhesion of the sulfur compound to the medium 5 is suppressed , and the catalyst can be prevented from being deteriorated due to poisoning.
Can be improved.

Example 1 Twisted yarn obtained by bundling 1000 continuous fibers of silica (ceramic fiber) having a diameter of 15 μm as a support 2 made of ceramic fiber was plain-woven at a driving number of 10 (twisted yarn) / inch for both warp and weft yarns. A high frequency absorber 1 was produced using the woven fabric (diameter 90 mm), silicon carbide whiskers as the high frequency absorbing material 3 constituting the high frequency absorbing layer, and platinum as the catalyst 4 for decomposing harmful substances. Further, a catalyst body 5 was prepared using the same woven fabric as the support 2, alumina as the ceramic fine particles 6 constituting the carrier layer, and platinum as the catalyst 4 for decomposing harmful substances. Note that alumina sol was used as the inorganic binder. Above high frequency absorber 1
And the catalyst body 5 are superimposed on each other, and the exhaust gas
Passes through the high frequency absorber 1 and then through the catalyst 5
The high-frequency heating element 8 having a catalytic function is configured as shown in FIG.
Exhaust gas purification device (high frequency power consumption 1.5kW)
In a heating chamber 10 with an exhaust gas amount of about 300 l / mi
n, an engine (displacement: 2000 cc) was operated at an exhaust gas temperature of 300 to 350 ° C., and the purification performance of hydrocarbons by a hydrocarbon analyzer was evaluated. was gotten.

When noble metals such as rhodium and palladium and metal oxides of copper, manganese, iron and cobalt were used as the catalyst 4 in place of platinum, a purification rate of 45 to 80% was obtained after 30 seconds of high frequency power supply. Was.

Example 2 Twisted yarn obtained by bundling 1000 continuous fibers of alumina (ceramic fiber) having a diameter of 12 μm as a support 2 made of ceramic fiber was plain-woven at a driving number of 10 (twisted yarn) / inch for both warp and weft yarns. A high-frequency absorber 1 was manufactured using the woven fabric (diameter 90 mm), zinc oxide whiskers as a high-frequency absorbing material 3 constituting a high-frequency absorbing layer, and platinum as a catalyst 4 for decomposing harmful substances. Further, the same woven fabric as above and the ceramic fine particles 6 constituting the carrier layer are used as the support 2.
Of zirconia and platinum as a catalyst 4 for decomposing harmful substances, a catalyst 5 was prepared. Note that alumina sol was used as the inorganic binder. Above high frequency absorber 1
And the catalyst body 5 are superimposed on each other, and the exhaust gas
Passes through the high frequency absorber 1 and then through the catalyst 5
The high-frequency heating element 8 having a catalytic function is configured as shown in FIG.
Exhaust gas purification device (high frequency power consumption 1.5kW)
In a heating chamber 10 with an exhaust gas amount of about 300 l / mi
n, an engine (displacement: 2000 cc) was operated so that the exhaust gas temperature became 300 to 350 ° C., and the purification performance of hydrocarbons by a hydrocarbon analyzer was evaluated. was gotten.

As the high-frequency absorbing material 3 constituting the high-frequency absorbing layer, oxides of copper, manganese, cobalt, titanium, tin and iron, mixtures thereof, and one or more of these metals are used instead of zinc oxide whiskers. Including complex oxides,
When using a compound of titanium-silicon-carbon-oxygen,
After 30 seconds of high-frequency power supply, a purification rate of 60 to 75% was obtained.

When silica or ceria was used instead of zirconia as the ceramic fine particles 6 constituting the carrier layer, a purification rate of 65 to 75% was obtained after 30 seconds of high frequency power supply.

On the other hand, when no high-frequency energy was supplied in Example 2, the purification rate after 30 seconds was about 5%. The high-frequency absorber 1 not supporting the catalyst 4 has a purification rate of about 5 to 1 after 30 seconds as compared with the catalyst supporting the high-frequency absorber 1.
0% lower results were obtained.

As described above, by applying the high-frequency heating element 8 having a catalytic function of the present invention to an exhaust gas purifying apparatus, excellent purifying performance can be obtained. This is because the high-frequency absorber 1 and the support 2 serving as the skeleton of the catalyst 5 are made of ceramic fibers 7, so that the weight is lower than that of the conventional catalyst made of cordierite carrier , and the heat capacity is reduced to about 1/3 or less . be able to. Further contact with high frequency absorber 1
Since the medium 5 is separate, it is heated with high-frequency energy.
High frequency absorber 1 becomes smaller and lighter,
The frequency absorber 1 can be heated to a high temperature,
The lugi is efficiently transmitted to the catalyst 5 using the flow of exhaust gas.
Can be reached. Further, as described above, the heat capacity of the catalyst body 5 is also low.
Since it is small, raise the temperature to a temperature that functions as a catalyst in a short time.
Can be

Further, by supporting the catalyst 4 on the high frequency absorber 1, the purification rate of hydrocarbons can be improved.
This is because the high-frequency absorbing layer made of the high-frequency absorbing material 3
, The high-frequency absorber 1 also has a catalytic function, and the catalyst 4
Is heated directly by the high-frequency energy, so that the temperature can be raised more quickly to the temperature that functions as a catalyst.

In the above-described embodiment, the high-frequency heating element 8 having the catalytic function of the present invention has the high-frequency absorber 1 and the catalyst 5 stacked five each, but the number of stacked layers is not particularly limited. Instead, it is appropriately designed in an optimal state according to the pressure loss, heat capacity, and catalyst performance required for the high-frequency heating element.

In the embodiment, the exhaust gas passage uses a lattice formed of warp and weft yarns of a woven fabric. However, the present invention is not limited to this structure. The exhaust gas passage may be formed by a gap between the woven fabric and the woven fabric.

Although a woven fabric is used as the support 2 in the embodiment, the present invention is not limited to the woven fabric, but may be a paper or mat made of ceramic fibers 7 or a twisted yarn obtained by bundling a plurality of ceramic fibers 7. Nonwoven fabric such as is also used as the support 2.

FIG. 4 is a partial sectional view of a high-frequency absorber constituting a high-frequency heating element having a catalytic function according to another embodiment of the present invention. Reference numeral 16 denotes a high-frequency absorber. The high-frequency absorber 16 includes a support 18 made of a plurality of high-frequency absorbing fibers 17 and the catalyst 4 supported on the support 18. The support 18 can be obtained by the same configuration and manufacturing method as the support 2 made of the ceramic fiber described with reference to FIG. That is, a plurality of high-frequency absorbing fibers 17 are bundled to form a twisted yarn, and the twisted yarn is woven into a woven cloth as shown in FIGS.
Is built. As with the support 2 made of ceramic fiber, various weaving methods such as plain weave, satin weave, leno weave, blade, rope, and tape are possible for the high frequency absorber 16 as well. Further, non-woven fabric such as paper and mat can be applied instead of the above-mentioned woven fabric. The difference from the above-described high-frequency absorber 1 is that the high-frequency absorbing fiber 17 can absorb high frequency, and thus does not require the high-frequency absorbing material 3 forming the high-frequency absorbing layer.

The high frequency absorber 16 is used in combination with the catalyst 5 in the same manner as the high frequency absorber 1 described above. You
That is, after the exhaust gas passes through the high-frequency absorber 16,
The high-frequency heating element is configured to pass through the medium 5.

The material of the high-frequency absorbing fiber 17 constituting the high-frequency absorbing body 16 is the same as that of the high-frequency absorbing layer 4 described above. Particularly, compounds of silicon carbide and titanium-silicon-carbon-oxygen which are excellent in high-frequency absorption characteristics and processability as continuous fibers are preferable.

Example 3 A support 18 made of high-frequency absorbing fiber has a diameter of 10 μm.
A woven fabric (diameter 90 mm) obtained by bundling 800 twisted continuous fibers of silicon carbide into a warp yarn and a weft yarn with a driving number of 10 (twist yarn) / inch, and platinum as a catalyst 4 for decomposing harmful substances. The high frequency absorber 16 was produced. The same catalyst body 5 as in Example 1 was used. The five high-frequency absorbers 16 and the five catalyst bodies 5 are superimposed on each other, and the exhaust gas passes through the high-frequency absorber 1.
After passing through, the high-frequency heating element 8 having a catalytic function is constituted so as to pass through the catalyst element 5 and housed in the heating chamber 10 of the exhaust gas purifying apparatus (high-frequency power consumption 1.5 kW) shown in FIG.
Exhaust gas amount about 300l / min, exhaust gas temperature 300 ~
Engine (displacement 2000cc) to reach 350 ° C
Was operated, and the purification performance of hydrocarbons by the hydrocarbon analyzer was evaluated. As a result, a purification rate of about 75% was obtained 30 seconds after the high-frequency power supply.

When a continuous fiber made of a titanium-silicon-carbon-oxygen compound was used as the high-frequency absorbing fiber 17 instead of the silicon carbide continuous fiber,
After 0 seconds, a purification rate of about 70% was obtained.

As described above, even if high-frequency absorbing fibers are used as the high-frequency absorber 16, excellent purification performance can be obtained. Since the heat capacity can be reduced by using the high-frequency absorbing fiber 17 as the high-frequency absorber 16 as in the first and second embodiments, rapid heating becomes possible and the heat can be efficiently transmitted to the catalyst 5. This is because the temperature can be raised more quickly at the temperature that functions as a catalyst, and because the high-frequency absorber 16 also carries the catalyst 4, the temperature can be raised more quickly at the temperature that functions as a catalyst.

The high-frequency heating element 8 having a catalytic function of the present invention 8
When a plurality of high-frequency absorbers 1 or 16 and catalysts 5 are used as in the above embodiment, for example,
They may be arranged alternately one by one or two by two, and are not limited to the embodiments.

The high-frequency heating element 8 having a catalytic function of the present invention can also be used as a means for decomposing oily smoke and odor discharged from a cooker such as an oven microwave oven.

[0051]

As described above, according to the high-frequency heating element having a catalytic function of the present invention, the following effects can be obtained.

(1) It is composed of a separate high-frequency absorber and a catalyst.
The high-frequency heating element formed absorbs high-frequency fluid such as exhaust gas
After passing through the body, it passes through the catalyst body
In the catalyst body is inhibited adhesion such as sulfur contained in the exhaust gas, it is possible to prevent the deterioration of the catalyst due to poisoning, thereby improving the catalyst life.

(2) Since the high-frequency absorber and the catalyst are composed of a lightweight support made of ceramic fiber or high-frequency absorption fiber , the heat capacity is 1/3 or less of that of a conventional catalyst made of cordierite carrier. It can be. Further, the high frequency absorber 1 and the catalyst body are separate bodies.
Therefore, the high frequency absorber heated by high frequency energy is small,
Lightweight, heats high frequency absorber to high temperature in shorter time
And the heat energy can be used for the exhaust gas flow
And can be efficiently transmitted to the catalyst body. In addition, the catalyst body
As described above, since the heat capacity is small, the temperature can be raised to a temperature that functions as a catalyst in a short time, and excellent purification performance of exhaust gas can be obtained.

(3) Since the catalyst is also supported on the high-frequency absorber, a catalytic reaction occurs in the high-frequency absorber as well.
And the purification performance of the exhaust gas can be further improved.

(4) Since the specific surface area can be increased by forming the carrier layer on the support made of ceramic fibers constituting the catalyst body, the catalytic activity is increased, and the catalytic reaction can be started from a lower temperature. it can. Therefore, the time for functioning as a catalyst can be further reduced,
Excellent exhaust gas purification performance can be obtained.

[0056]

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a high-frequency heating element according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view and an external view of a support constituting the high-frequency heating element of the present invention.

FIG. 3 is a configuration diagram of an exhaust gas purifying apparatus using the high-frequency heating element of the present invention.

FIG. 4 is a partial cross-sectional view of a high-frequency absorber according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency absorber 2 Support made of ceramic fiber 3 High frequency absorbing material 4 Catalyst 5 Catalyst 6 Ceramic fine particles 7 Ceramic fiber 8 High frequency heating element having a catalytic function 16 High frequency absorber 17 High frequency absorbing fiber 18 Support made of high frequency absorbing fiber

Claims (8)

(57) [Claims] 1. A high-frequency absorber formed of a high-frequency absorbing material that absorbs high-frequency energy and generates heat on a support made of a plurality of ceramic fibers and carries a catalyst on the high-frequency absorbing layer. A carrier layer made of ceramic fine particles is formed on a support made of ceramic fibers, and a catalyst body having a catalyst carried on the carrier layer is constituted by two separate structures , and the exhaust gas and the like are formed.
After the fluid passes through the high frequency absorber, it passes through the catalyst.
High-frequency heat generation with a catalytic function so as to pass. 2. A high-frequency absorber formed by supporting a catalyst on a plurality of high-frequency absorbing fibers that absorb high-frequency energy and generate heat, and a carrier layer formed of ceramic fine particles on a support formed of a plurality of ceramic fibers. And a catalyst body having a catalyst supported on the carrier layer.
It consists Zotai, fluid the high frequency absorption such as an exhaust gas
A high-frequency heating element having a catalytic function so that it passes through the catalyst body after passing through the body. 3. A support comprising a plurality of ceramic fibers of a high-frequency absorber and a plurality of ceramic fibers of a catalyst.
The high-frequency heating element having a catalytic function according to claim 1 or 2, wherein the main component of the support is at least one of silica, alumina, and zirconia. 4. The high- frequency heating element having a catalytic function according to claim 1, wherein the high-frequency absorbing material and the high-frequency absorbing fiber constituting the high-frequency absorbing layer of the high- frequency absorbing body are semiconductor materials. 5. The high- frequency absorbing material and the high-frequency absorbing fiber constituting the high-frequency absorbing layer of the high- frequency absorbing body are oxides and carbides containing at least one of zinc, copper, manganese, cobalt, iron, titanium and silicon. 3. A high-frequency heating element having a catalytic function according to 1 or 2. 6. The high- frequency heating element having a catalytic function according to claim 1, wherein the high-frequency absorbing material and the high-frequency absorbing fiber constituting the high-frequency absorbing layer of the high- frequency absorbing body are silicon carbide. 7. The high-frequency heating element having a catalytic function according to claim 1, wherein the main component of the ceramic fine particles constituting the carrier layer of the catalyst is at least one of silica, alumina, zirconia and ceria. 8. The high-frequency heating element having a catalytic function according to claim 1, wherein the high-frequency absorber and the catalyst are formed of a woven cloth having openings through which gas can pass.