JP2001349215A - Exhaust emission control device for sticking/decomposing nox to/by adsorbent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To purify exhaust gas by reacting and extinguishing a particulate substance scavenged by a filter and NOX captured by an adsorbent by using plasma energy in this exhaust emission control device. SOLUTION: This exhaust emission control device is provided with the filter 3 arranged in a easing 2 and sticking the adsorbent composed of zeolite for capturing the NOX in the exhaust gas, a pair of electrically mutually insulated and mutually separately arranged electrodes respectively arranged on both surfaces of the filter 3 and a plasma generator 1 for generating plasma by impressing high voltage between the electrodes, and captures the NOX in the exhaust gas by the adsorbent, and puts the NOX in a radical state by making the plasma generated by the plasma generator 1 act on the NOX, and decomposes the NOX into N2 and O2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is particularly, the NO _X contained in the exhaust gas discharged from a diesel engine is captured by the adsorbent, the NO _X in the radical state trapped NO _X in plasma energy, etc. The present invention relates to an exhaust gas purification device that decomposes.

[0002]

2. Description of the Related Art Conventionally, an exhaust gas treatment apparatus for treating exhaust gas of an engine has a large filter area provided in an exhaust pipe, a heating coil provided in the filter, and a particulate matter such as carbon contained in the exhaust gas. The particulate matter is deposited on the front of the filter and collected, and then the particulate matter deposited on the filter is heated by energizing the heating coil to burn and burn the particulate matter, thereby regenerating the filter. .

For example, a diesel particulate filter device disclosed in Japanese Utility Model Laid-Open Publication No. 1-144427 passes exhaust gas through a filter body, and the filter body collects particulates such as carbon and smoke in the exhaust gas. When particulates accumulate in the filter body and clog the filter, shut off the flow of exhaust gas to the filter body and switch to the flow of exhaust gas to another filter body. From the downstream side of the clogged filter body It blows in air and heats the filter body to incinerate the clogged particulates.

[0004]

The exhaust gas discharged from a diesel engine contains carbon, unburned fuel, H
It contains particulate substances such as C and SO _{X. The} particulate substances are carbon, hydrocarbon, S
A composite of O _X such, its size is small from the very large particles, specifically, 40Myuemu～0.1Myuemu
In many cases, about 20 μm, and these sizes are dispersed in the exhaust gas. In particular,
Among the sizes of the particulate substances, those having a small particle size of 2.5 μm or less have been problematic in that they adversely affect the human body such as asthma in the environment.

[0005] However, when the particulate particulate matter is collected by the diesel particulate filter device, even if the particulate matter is collected in the intersection space between the fibers, NO _X contained in the exhaust gas is a gas. There, NO _X is will pass through the filter, also,
At present, it is not possible to completely collect all SPM with a filter and purify exhaust gas. How to capture NO _X from exhaust gas and how to decompose the captured NO _X Is a major problem in preventing air pollution.

[0006] Further, when the particulate matter collected by the diesel particulate filter is heated to about 600 ° C or more in the presence of oxygen, it can react with oxygen and easily burn and incinerate. In an atmosphere where the exhaust gas flows, a blow-off phenomenon occurs, and it is difficult to completely heat and incinerate the particulate matter. In addition, in order to continuously collect particulate matter using a diesel particulate filter, it is necessary to regenerate the filter by oxidizing and eliminating the particulate matter, and how to remove the particulate matter collected by the filter is determined by the atmosphere. It is also a major problem in preventing pollution.

By the way, plasma is a discharge current,
This is a phenomenon caused by positive and negative charged particles moving freely between gases. When the positive and negative electrons collide with an object, the material is radicalized by the excitation or separation of the electrons in the material, and is easily separated or reacted. Therefore, the diesel particulate filter has a cylindrical structure that is folded in a fold form using a filter body that is made of laminated ceramic fibers with insulating material on the outside and conductive properties on the inside, and wire mesh holding material on both sides. When the wire mesh on both sides of the filter body is composed of electrodes, and high frequency and high voltage are applied,
Plasma can be generated between both electrodes.

[0008]

[Means for Solving the Problems An object of the invention is to solve the above problem, to adhere the adsorbent comprising a zeolite to trap NO _X in the fiber material composed of a material such as ceramic fiber A filter is constructed, and both sides of the filter are sandwiched between electrodes such as a wire mesh, and the electrodes are used as electrodes to form a plasma generator. A high voltage is applied between the electrodes by high frequency or direct current to generate plasma. colliding the positive and negative electrons to fine particles trapped in the filter while decomposing NO _X trapped in the adsorbent by use of energy, excitation to the particulate material, to cause a phenomenon of dissociation, it is radicalized An object of the present invention is to provide an exhaust gas purifying apparatus for purifying exhaust gas by promoting the reaction with oxygen to react and oxidize particulate matter.

[0009] The present invention, the filter adhering the adsorbent comprising a zeolite to trap NO _X in the exhaust gas is arranged in a casing incorporated in an exhaust pipe in which the exhaust gas flows discharged from the engine, of the filter A pair of electrodes, which are electrically insulated from each other and are spaced apart from each other, and a plasma generator for generating a plasma between the electrodes by applying a high DC voltage between the electrodes; The N in the exhaust gas depends on the adsorbent.
The O _X capture, the said plasma generated by a plasma generating apparatus by acting on the NO _X by the NO _X in the radical state, the NO _X to N ₂ and O consists of _two be decomposed into the exhaust gas purifying device About.

[0010] The adsorbent is composed of zeolite and / or a material obtained by adding Cu, Pt and / or Ti to the zeolite, and the NO _X is trapped in pores of the zeolite.

[0011] The plasma generating apparatus, wherein the NO _X is captured more than a predetermined amount, wherein the NO _X rearwardly disposed the NO _X than the predetermined amount detected by the sensor of the filter is collected in the adsorbent It is operated intermittently or continuously in the closed state.

The filter is composed of randomly stacked S
iC, Si_ThreeN_FourNon-conductive heat-resistant ceramic fibers such as
Aluminum wire on the surface of the ceramic fiber material wire
_TwoO _Three, SiO_TwoAdsorbent by glass adhesive etc.
Are attached in an uneven manner.

The filter detects that the amount of the collected particulate matter has reached a predetermined amount or more by a pressure sensor, and generates a high-power plasma based on this signal, and the particulate matter collected by the filter is detected. The curable substance is reacted and oxidized.

The filter is formed in a honeycomb structure from a ceramic porous body or a metal plate whose surface is insulated and coated, and the adsorbent is irregularly attached to the surface of the ceramic porous body or the metal plate. Is connected so that a current supply line is inserted into the upstream opening and another current supply line is inserted into the downstream opening, and the current supply line is coated so as to generate plasma.

The filter is capable of collecting particulate matter contained in the exhaust gas, and the particulate matter collected by the filter is reduced or oxidized by the plasma.

In the case where the filter is formed of a metal honeycomb, the metal honeycomb has the adsorbent adhered on its surface, and a wire serving as an electrode is disposed in a honeycomb hole at an upstream opening. The negative side of the DC power supply is loaded on the wire, and the positive side is loaded on the honeycomb.

[0017] The electrode is composed of wire mesh, said between the wire mesh by a plasma generating device subjected the DC potential of the high-voltage NO _X removal, high voltage, high frequency power supply is applied for the particulate material removal, the The plasma is generated in a filter.

[0018] The between the electrodes 30v~400v is applied as a NO _X removing voltage by the plasma generation device and, 5k as particulate matter removal voltage
AC voltage v~25kv is applied, radicalized the NO _X by acting on the NO _X which the plasma generated between the electrodes is attracted to the suction member attached to said filter between said electrodes Then, the particulate matter attached to the filter is radicalized.

The power generated by a generator provided in the engine is used as a power source for generating a high voltage at a high frequency applied to the electrodes by the plasma generator.

Since this exhaust gas purifying device is constructed as described above, when a high frequency intermittent DC voltage is applied between the electrodes on both sides of the filter, an ion sheath is provided between the electrodes on the negative side and the electron sheath is provided on the positive side. sheath motion, since a plasma state occurs continuously in the middle section, particulate material fine particles trapped in the NO _X and filter trapped adsorbent, NO _X receives the electronic supply, NO ^- of radical state (free radicals, free radical) and, NO ^- is NO because of instability ^- is decomposed into N ₂ and O _2. ^{NO + e → NO - 2NO -} → N 2 + O 2

In addition, high frequency and high voltage AC power
The particulate matter is radicalized and easily reacted, and is oxidized to CO ₂ and H ₂ O and disappears. For example,
When the wire mesh is configured as a heater, heat in the wire mesh propagates and ignites the SPM and black carbon. However, as in the present invention, when the wire mesh is configured as an electrode to generate plasma, electron motion is generated. As a result, the vibration caused by the mixture of positive and negative ions gives energy to the SPM and reacts, so that the particulate matter is oxidized reliably. Further, once the particulate matter reacts and oxidizes, it reacts with O ₂ in the exhaust gas, C is oxidized, and HC is also oxidized. In this state, C,
HC, the NO _X coexist, the following reaction occurs. 2NO + CH → N ₂ + H ₂ O + CO 2CO + O ₂ → 2CO ₂ As described above, in other words, NO is reduced.

This exhaust gas purifying device is provided with the above-mentioned filter.
NO_XThe adsorbent that captures
When high frequency and high voltage are applied between the electrodes of the generator,
The generation of a plasma state between the electrodes, that is, a plasma flow of 5
Excited in the state of high-frequency current of ~ 25KV,
(E^-), Ionized substances (e⁺) Is generated continuously
You. NO contained in exhaust gas_XIs an unstable composition
Adsorption of granular zeolite in the atmosphere and electron transfer
Decomposed by the supply, but further positrons e in the plasma stream
⁺, Negative electron e^-Received, NO_XBecomes a radical state,
N_Two, O_TwoEasily disassembled.

[0023] That is, zeolite functions as an adsorbent since it has pores, the NO _X adsorbed i.e. trapped in the air hole, in the radical state is reacted over plasma trapped NO _X, if ask decomposed again zeolites ready having an empty pores becomes possible to adsorb the NO _X contained in the exhaust gas subsequently. The NO _x removal rate of zeolite is, for example, about 40%, but if NO _x captured by plasma energy is decomposed,
NO _X can always capture, it is possible to purify the exhaust gas.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exhaust gas purifying apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing an embodiment of an exhaust gas purifying apparatus according to the present invention, FIG. 2 is a schematic explanatory view showing a relationship between a filter of a DPF apparatus and a plasma generator, and FIG. 3 is a voltage applied to the plasma generator. FIG. 4A is a schematic explanatory view showing a pulse voltage in one direction, FIG. 4B is a schematic diagram showing a constant voltage, FIG. 4 is a circuit diagram showing a high-frequency oscillator in the plasma generation circuit of FIG. 1, and FIG. 1 is a circuit diagram showing an interrupter in the plasma generation circuit of FIG. 1, FIG. 6 is an explanatory view showing a ceramic fiber material constituting a filter and wire meshes on both sides, and FIG. 7 is an adsorbent attached to the ceramic fiber material wire of FIG. FIGS. 8A and 8B show a honeycomb structure constituting a filter, FIG. 8A is a perspective view showing a honeycomb structure in which electrodes are provided, and FIG. 8B is a perspective view showing a structure of a wire constituting the electrodes. 9 is the honeycomb structure of FIG. Explanatory view showing a state in which the adsorbent is attached to the honeycomb unit that is made of ceramics porous body, and 10 8
FIG. 4 is an explanatory diagram showing a state in which an adsorbent is attached to a honeycomb portion having a honeycomb structure formed of a metal plate.

In this exhaust gas purifying apparatus, a filter 3 is disposed in a casing 2 incorporated in an exhaust pipe 23 for discharging exhaust gas from a combustion chamber constituting an engine. The filter 3 captures particulate particulate matter (SPM) suspended in the exhaust gas, reacts and oxidizes the particulate matter, and partially oxidizes and disappears.
Is supported by a support bar 24 on the inlet 12 side, and the outlet 1
The three sides are supported by a shielding plate 17 provided with a through hole 22 in the central part closing the filter end. Filter 3 is
The upstream exhaust gas passage 14 and the downstream exhaust gas passage 15 are arranged in the casing 2 incorporated in the exhaust pipe 23.

The filter 3 is, for example, formed as an annular filter as a whole from a laminated fiber filter folded in a fold shape, the upstream end face of which is closed by a shielding plate 16 and the downstream side is formed in the center. The downstream end face of the filter is closed by a shielding plate 17 in a state where the passage 22 is aligned with the downstream side exhaust gas passage 15. Therefore,
Exhaust gas flowing through the exhaust pipe 23 passes through the filter 3 through the passage between the inlet 12 and the support bar 24 and the upstream exhaust gas passage 14 on the outer peripheral side of the filter 3, and passes through the filter 3 on the inner peripheral side. 15, and then from the outlet 13 to the exhaust pipe 23. When the exhaust gas discharged from the engine passes through the filter 3, carbon (C), unburned fuel, HC, S
Particulate material O _X and the like are collected.

This exhaust gas purifying device is particularly suitable for casing
NO 2 in the exhaust gas_XTo capture
The adsorbent 52 (FIGS. 7, 9, and 10) made of olilite is
Sandwich the attached filter 3 and filter 3 from both sides
High voltage is applied between the electrodes of the wire mesh 4, 6, etc.
Having a plasma generator 1 for generating plasma in
NO in exhaust gas by the adhering material 52_XCapture the plasm
Plasma generated by the laser generator 1_XActs on
Let me know_XTo a radical state, NO_XTo N _TwoAnd O_Two
It is characterized by being decomposed into.

As shown in FIG. 6, for example, the filter 3 is electrically insulated from each other on both sides of the ceramic fiber material 5, and constitutes a pair of electrodes spaced apart from each other. And wire meshes 4 and 6. The ceramic fiber material 5 constituting the filter 3 is
It is made of a non-conductive heat-resistant fiber material such as SiC or Si ₃ N ₄ which is randomly laminated. As shown in FIG. 7, the wire 51 constituting the ceramic fiber material 5 has an A surface on the wire 51.
The adsorbent 52 is attached in an uneven shape by an adhesive such as l ₂ O ₃ or SiO ₂ .

As shown in FIGS. 8 to 10, the filter 3 can be formed in a honeycomb structure from a ceramic porous body 53, and an adsorbent 52 is attached to the surface of the ceramic porous body 53 in an uneven manner. Ceramic porous body 5
Reference numeral 3 denotes a power source of the battery when made of a conductive material.
A plasm can be generated by applying a voltage from 8. As shown in FIG. 8, when the filter 3 is configured to have a honeycomb structure, an assembled wire rod 56 that forms an electrode in each honeycomb hole formed in the ceramic porous body 53.
Are inserted one by one. The assembly of the wire 56 is shown, for example, in FIG.

As shown in FIG. 9, when the ceramic porous body 53 is made of a non-conductive material, a conductive plate or wire 57 constituting an electrode is attached to the surface of the ceramic porous body 53. Plas can be generated by applying a voltage from a battery power supply 28. Alternatively, as shown in FIG. 10, the filter 3 is formed in a honeycomb structure from a metal plate 54, and the adsorbent 52 is attached to the surface of the metal plate 54 constituting an electrode in an uneven shape. In this embodiment, the metal plate 5
A plasm can be generated by applying a voltage from the battery power supply 28 to the power supply 4.

The adsorbent 52 is made of zeolite and / or a material obtained by adding Cu, Pt and / or Ti to the zeolite. Zeolite has a Soraana to that organization, the NO _X contained in the exhaust gas trapped in the pores of the zeolite, even if the temperature changes in the exhaust gas is generated has the function of maintaining the state ing.

The plasma generating device, NO in the exhaust gas by the NO _X sensor 55 provided at the rear of the filter 3
_{When X} reaches a predetermined amount or more, the adsorbent 52 is in a full state in which NO _X cannot be adsorbed.
It is assumed that _X is trapped in a predetermined amount or more, and the filter 3 is operated intermittently or continuously when particulate matter is trapped in a predetermined amount or more. The plasma generator can detect, for example, a state in which a predetermined amount of particulate matter is collected in the filter 3 by the pressure sensors 9 and 11 and control the controller 10 to operate at that time. ,Also,
Condition NO _X is captured a predetermined amount or more to the adsorbent 52, by setting the elapsed time such as 1 hour timer may be operated plasma generating apparatus at that time. The electrodes are composed of, for example, wire meshes 4 and 6 as shown in FIG. 6. A high-voltage DC potential is applied between the wire meshes 4 and 6 by a plasma generation circuit 1 of a plasma generator. Generate. Alternatively, as shown in FIG. 9, the electrode is constituted by a conductive porous plate provided on the surface of the ceramic porous body 53. Alternatively, as shown in FIG. 10, the electrode is composed of a porous metal plate 54, and the adsorbent 52 is attached to the surface of the porous metal plate 54.

The controller 10, a state in which a predetermined amount or more of the NO _X detected by the NO _X sensor 55 installed in the rear of a predetermined time and / or filter 3, which is predetermined by the timer has been trapped in the filter 3 And / or intermittently or continuously applying plasma power generated by the plasma generator in response to the particulate matter detected by the pressure sensors 9 and 11 provided in the filter 3 exceeding a predetermined trapping amount. Control so that the As shown in FIG. 3 (A) or (B), the carbon of the particulate matter collected in the filter body 5 becomes a conductor, and the carbon which has become the conductor is placed between the wire nets 4 and 6 in FIG. When a one-way high pulse voltage V shown in FIG. 3A or a constant voltage V shown in FIG. 3B is applied and a change occurs in the frequency, a dielectric phenomenon occurs. Is heated and incinerated.

[0034] Between the electrodes, 5
voltage kv~25kv is applied, the plasma generated between the electrodes causes the radicalized the NO _X acts to the NO _X adsorbed in the adsorbent 52 that is attached to the filter 3 between the electrodes. The power generated by the generator provided in the engine is used as a power source for generating a high voltage at a high frequency applied to the electrodes by the plasma generator 1.

When exhaust gas flows through the filter 3, the controller 10 collects particulate matter from the pressure sensor 9 provided upstream of the filter 3 and the pressure sensor 11 provided downstream thereof, and In response to the operation state of the engine from the rotation sensor 18 and the load sensor 19, the state of generation of plasma by the plasma generator is adjusted, and control is performed so that the particulate matter is oxidized and eliminated by reaction. In particular, when the engine load is at a partial load or when the cooling water temperature is low immediately after the start, the controller 10 applies plasma to the wire meshes 4 and 6 of the electrodes of the plasma generator to generate plasma, thereby promoting the reaction of the particulate matter. , Promotes oxidation of HC and decomposes NO _X into N ₂ and O ₂ to purify exhaust gas.

This exhaust gas purifier is configured as described above, and the particulate matter contained in the exhaust gas is collected by the filter 3 and the particulate matter collected by the filter 3 is collected by the plasma generator. The particulate matter is reacted and oxidized by the plasma generated by the plasma to disappear, and the filter is regenerated. That is, C and HC which are components of the particulate matter collected by the ceramic fiber material 5 react with the radical state O ^{* of} O ₂ contained in the exhaust gas by the reaction of the plasma electrons, and
Reacts oxidized to CO _2, HC reacts oxidized to CO ₂ and H ₂ O. These reactive oxidations are preferably generated intermittently in a state where the particulate matter is collected in the filter 3 by a predetermined amount or more, but may be generated constantly. In this exhaust gas purifying apparatus, the particulate matter collected by the filter 3 is turned into a radical state by the collision of electrons generated by plasma, and the particulate matter is oxidized by the auxiliary action and disappears. Is done.

Further, the NO _X contained in the exhaust gas by the adsorbent 52 made of zeolite supported on the filter 3 to capture a high voltage trapped NO _X between the electrodes such as wire mesh 4,6 When applied, the electrons move in the filter 3 to make NO _x into a radical state, which is decomposed into N ₂ and O ₂ . That is, the high voltage applied between the electrodes is 5 kv to 25 kv.
v, which causes a charge reaction to occur in NO _x trapped in the zeolite and causes a decomposition into N ₂ and O ₂ when applied in a direct current manner. Alternatively, a high voltage is applied between the electrodes to generate a high-frequency plasma of 1MH _Z ~15MH _Z are, the electronic cross state by the plasma in the filter 3, a radical state NO ^* to the NO _X trapped in the zeolite (NO ^- or NO ⁺ ) and is easily decomposed into N ₂ and O ₂ . These reactive oxidations are NO
It is preferable that _X is generated intermittently in a state where a predetermined amount or more of _X is captured by the zeolite adsorbent 52 of the filter 3, but it is also possible to generate _X constantly.

As shown in FIG. 6, the filter 3 is made of a felt body formed by randomly laminating non-conductive ceramic fibers having excellent heat resistance and corrosion resistance.
And wire meshes 4 and 6 containing Ni, Cr and the like, which are heat-resistant and corrosion-resistant and are fixed by sandwiching both sides of the filter body 5. The filter 3 is, for example, formed into a predetermined shape having a pleated cylindrical shape as a whole, and is formed into a shape having a large surface area.
It may be formed in a shape such as a flat plate or a wave. The material constituting the filter 3 is, for example, SC coated with SiC.
i ₃ N _4, and / or SiC (SiC-O, Si- T
i-C-O, Si-C) is formed of a non-woven fabric obtained by randomly laminating ceramic fibers and fibers obtained by coating carbon or alumina with SiC. The fiber diameter of the ceramic fibers is, for example, about 5 to 15 μm. The height is 30-150m
m. The ceramic fiber material laminated in a felt shape is formed, for example, to have a thickness of about 3 to 5 mm.

The wire nettings 4 and 6 constituting the electrodes are coated insulatively by ceramic coating or enamelling, and are prevented from being energized by the particulate matter collected by the filter 3. In addition, wire mesh 4,
Numerals 6 are stacked such that the vertical and horizontal lines intersect, and are alternately connected at a part of the intersection of the vertical and horizontal lines so that no voltage difference occurs between the vertical and horizontal lines.

The plasma generating apparatus generates plasma by, for example, the plasma generating circuit 1, and the upstream wire mesh 4 is generated from an AC generator by a high-frequency oscillator 20 having a power source, that is, a battery 28, and an interrupter 21. In order to control the high voltage, it is connected to an AC generator, and the downstream wire mesh 6 is connected to the earth side of the transformer. The voltage generated by the AC generator is boosted to a predetermined high voltage by a transformer, rectified by a rectifying coil, and then the interrupter 21 is controlled by the output of the high-frequency oscillator 20.
A high-frequency, high-voltage controlled by the interrupter 21 is applied between the upstream wire mesh 4 and the downstream wire mesh 6, and the ceramic fiber material 5 of the filter body between the upstream wire mesh 4 and the downstream wire mesh 6 Plasma is generated in the region of. The AC generator is composed of, for example, two types of low-power-side generators and high-power-side generators in which the number of windings wound around the stator core is changed to be large or small. A generator is used (for example, see Japanese Patent Application No. 2000-113915, which is an application filed by the present applicant).

The high frequency oscillator 20 oscillates a high frequency by a high frequency oscillation circuit shown in FIG. 4, for example, and the voltage from the power supply 28 is adjusted by the variable resistor 35.
The base voltage is input to the base of the transistor 26 through the crystal oscillator 27 through the RC circuit 29. When a base voltage is input to the base of the transistor 26, the current from the power supply 28 passes through the transistor 26, and a high frequency is output from the capacitor 33 as an output signal 34 from the terminal. In the high frequency oscillation circuit shown in FIG. 4, reference numerals 30, 31, and 32 denote capacitors, reference numeral 37 denotes a capacitor with a diode, and reference numerals 38, 39, and 40.
Is resistance.

An interrupter 21 for interrupting the high frequency generated by the high frequency oscillator 20 is formed, for example, in a high frequency interrupting circuit shown in FIG. In the high-frequency interrupting circuit, the current from the power supply 36 is output from the terminal 44 through the transistor 41. The output signal 34 output from the high-frequency oscillation circuit of the high-frequency oscillator 20 is applied to the input 50 of the high-frequency intermittent circuit and is input as the base voltage of the transistor 42. The power supply 36 includes an AC generator, a transformer, and a rectifier coil. When the base voltage is input to the transistor 42, the base voltage is input to the transistor 41, and the high voltage from the power supply 36 passes through the transistor 41 and the high voltage is output at a high frequency from the electrode terminal 44. The electrode terminals 44 correspond to the upstream wire mesh 4 and the downstream wire mesh 6 of the electrode. In the high-frequency interrupting circuit of FIG.
Reference numeral 3 denotes a transistor, and reference numerals 45, 46, 47, 49
Is resistance. That is, the voltage output from the alternator is adjusted to a high voltage by a transformer and a rectifying coil, and the high voltage is controlled by a high-frequency output signal controlled by an interrupter 21, and the upstream wire mesh 4 and the downstream wire mesh 6 are controlled. And a plasma is generated.

The power generated by a generator provided in the engine is used as a power source for generating a high voltage at a high frequency applied to the upstream electrode 4 and the downstream electrode 6 in the plasma generator. The power of the generator is made high by a transformer in the plasma generator 1, the high voltage is rectified by a rectifier coil, and the power transistors 41, 42, 4 are turned on / off by a signal transmitted from a high frequency oscillator 20.
The power is turned into alternating power by the output of the interrupter 21 having a high frequency 3, and a high frequency, high voltage is applied to the upstream wire mesh 4 of the electrode and the downstream wire mesh 6 of the electrode through the electrode terminals 7, 8 to generate plasma.

In the engine incorporating the exhaust gas purifying device, the fuel injection timing is delayed so that the NO _X
And has the property of increasing the generation of HC. In this exhaust gas purifying apparatus, NO _X and HC react in plasma generated between the wire mesh 4 of the electrode and the wire mesh 6 of the electrode to reduce the generation of NO _X.

The controller 10 generates plasma between the upstream wire mesh 4 and the downstream wire mesh 6 in response to the collection of particulates of a predetermined amount or more in the filter 3, and generates the plasma. The particulate matter trapped in the filter body 5 between the metal wire 4 and the downstream wire mesh 6 is controlled so as to regenerate the filter body 5 by heating and burning. The amount of particulates collected in the filter 3 is determined by a pressure sensor 9, 1 for detecting exhaust gas pressure by a controller 10.
The pressure ratio of the pressure detected in step 1 can be calculated or can be detected by a sensor or the like that detects the flow resistance of the filter. When the filter body 5 is regenerated, although not shown, the exhaust gas that has been purified from the downstream side of the filter 3 and that has been released to the atmosphere and has a constant pressure is recirculated to the upstream side by a pump to supply oxygen for regeneration. The particulate matter collected in the filter 3 can be heated and incinerated by the plasma generated in the upstream wire mesh 4. Further, although not shown, it is also possible to arrange a pair of filters 3 side by side so as to switch between a DPF device for collecting particulate matter and a filter for regeneration.

The controller 10 includes the rotation sensor 1
The amount of particulate matter generated in the exhaust gas generated by the engine changes according to the engine speed detected at 8 and the operating state of the engine load detected by the load sensor 19. The plasma generator 1 is controlled in accordance with the amount and the amount of the collected particulate matter in the filter 3 to control the state of plasma generation, and the particulate matter in the exhaust gas is always satisfactorily burned. To play. Further, the plasma generators 1 and 25 are applied to the metal meshes 4 and 6 of the electrodes to generate plasma when the engine load is a partial load and when the temperature of the cooling water immediately after the start is low, thereby promoting the burning of the particulate matter. , Promotes the oxidation of HC and reduces NO _x to N ₂
And O ₂ to purify the exhaust gas.

[0047]

[Effect of the Invention] exhaust gas purifying device according to the invention, which is configured as described above, the carrier an adsorbent comprising a zeolite to trap NO _X contained in exhaust gas discharged from a diesel engine since deposited on the filter, NO _X is trapped in the pores of the zeolite, the captured NO _X becomes radical state by intermittently or continuously plasma energy or charge reaction occurs, the N ₂ and O ₂ Decomposed. When the trapped NO _X is decomposed, the vacancies of the zeolite are emptied, and the NO _X contained in the subsequent exhaust gas is trapped again. Further, the fibrous material of the filter of the carrier collects the particulate matter, reacts and oxidizes the collected particulate matter using plasma energy, and disappears, thereby regenerating the filter. Therefore,
Particulate material trapped in the filter, in particular, react oxide particulates substances 0.25μm following small particle size in question by the plasma energy, the NO _X trapped in the empty hole of the zeolite adsorbent N ₂ and O ₂
It can be decomposed into clean exhaust gas and does not cause environmental pollution, which may damage health.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of an exhaust gas purifying apparatus according to the present invention.

FIG. 2 is a schematic explanatory diagram showing a relationship between a filter of a DPF device and a plasma generator.

FIGS. 3A and 3B are schematic explanatory diagrams showing a relationship between voltages applied to a plasma generator, where FIG. 3A shows a pulse voltage in one direction and FIG. 3B shows a constant voltage.

FIG. 4 is a circuit diagram showing a high-frequency oscillator in the plasma generator of FIG.

FIG. 5 is a circuit diagram showing an interrupter in the plasma generator of FIG.

FIG. 6 is an explanatory view showing a ceramic fiber material and a wire mesh on both sides constituting a filter.

FIG. 7 is an explanatory view showing an adsorbent attached to the ceramic fiber material wire of FIG. 6;

FIG. 8 shows a honeycomb structure constituting a filter;
(A) shows a honeycomb in which electrodes are arranged,
(B) is a perspective view showing a structure of a wire constituting an electrode.

FIG. 9 is an explanatory view showing a state in which an adsorbent is attached to a honeycomb portion in which the honeycomb structure of FIG. 8 is formed of a porous ceramic body.

FIG. 10 is an explanatory view showing a state in which an adsorbent is attached to a honeycomb portion in which the honeycomb structure of FIG. 8 is formed of a metal plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Plasma generator 2 Casing 3 Filter 4 Upstream wire mesh 5 Ceramic fiber material 6 Downstream wire mesh 10 Controller 14 Upstream exhaust gas passage 15 Downstream exhaust gas passage 51 Fiber wire 52 Adsorbent 53 Ceramic porous body 54 Metal plate 55 NO _X sensor 56, 57 wire rod (electrode)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 53/34 ZAB B01J 20/34 E 4G066 53/56 F01N 3/02 301A 53/81 301B 53/74 321E B01J 20/34 321A F01N 3/02 301 3/18 B B01D 53/34 ZAB 321 129A 129C 3/18 F term (reference) 3G090 AA02 AA03 BA01 CA01 DA04 DA18 DA20 EA01 3G091 AA18 AB09 AB13 DA14 BA00 DA01 DA04 CB DB10 EA01 EA03 EA32 EA33 GA04 GA05 GA06 GB01X GB09Y GB10X GB17X HA36 HA37 HA42 4D002 AA12 AC10 BA04 BA05 BA06 BA07 BA14 CA07 DA21 DA23 DA25 DA45 EA07 4D019 AA01 BA02 BA05 BB03 BC05 BC12 JA03 JA08 TA06 TA11 4G066 AA02C AA20D AA22D AA42C AA51C AA61B AA72C AE16B AE17B BA05 BA07 BA22 CA28 DA02 FA15 GA18

Claims (11)

[Claims] 1. A filter attached an adsorbent comprising a zeolite to trap NO _X in the exhaust gas is an exhaust gas disposed in the integrated casing to an exhaust pipe which flows discharged from the engine, on both sides of the filter A pair of electrodes which are electrically insulated from each other and are spaced apart from each other, and a plasma generator which generates a plasma between the electrodes by applying a high DC voltage between the electrodes;
The adsorbent captures the NO _X in the exhaust gas, and the plasma generated by the plasma generator acts on the NO _X to turn the NO _X into a radical state, thereby converting the NO _X into N ₂ and O _2. Exhaust gas purification device consisting of decomposing into exhaust gas. Wherein said adsorbent is zeolite, and / or Cu in said zeolite, it is made of a material with the addition of Pt and / or Ti, wherein said NO _X consists trapped in the pores of said zeolite Item 2. An exhaust gas purifying apparatus according to Item 1. Wherein the plasma generator, said the NO _X in the adsorbent is captured more than a predetermined amount, wherein the NO _X rear detected by disposed a NO _X sensor a predetermined amount or more filters catching 2. The exhaust gas purifying apparatus according to claim 1, wherein the exhaust gas purifying apparatus is operated intermittently or continuously in a collected state. 4. The filter is made of a non-conductive heat-resistant ceramic fiber material, such as SiC or Si ₃ N ₄ , which is laminated at random, and the surface of the wire of the ceramic fiber material is made of A.
l ₂ O _3, an exhaust gas purifying apparatus according the glass adhesive such as SiO ₂ in claim 1 which comprises the adsorbent is attached to uneven. 5. The filter detects that the amount of the trapped particulate matter has reached a predetermined amount or more by a pressure sensor, and generates a high-power plasma based on the signal, and the trapped particulate matter is collected by the filter. 2. The exhaust gas purifying apparatus according to claim 1, comprising reacting and oxidizing the particulate matter. 6. The filter is formed in a honeycomb structure from a ceramic porous body or a metal plate having a surface coated with an insulating material, and the adsorbent is irregularly attached to the surface of the ceramic porous body or the metal plate.
2. The honeycomb structure according to claim 1, wherein an energizing line is inserted into an upstream opening, another energizing line is inserted into a downstream opening, and the energizing line is coated so as to generate plasma.
An exhaust gas purifying apparatus according to claim 1. 7. The filter according to claim 1, wherein said filter is capable of collecting particulate matter contained in said exhaust gas, and said particulate matter collected by said filter is reduced or oxidized by said plasma. 2. The exhaust gas purifying apparatus according to claim 1. 8. When the filter is formed of a metal honeycomb, the metal honeycomb has the adsorbent adhered on its surface, and a wire serving as an electrode is disposed in a honeycomb hole of an upstream opening. 2. The exhaust gas purifying apparatus according to claim 1, wherein a negative side of a DC power supply is loaded on the wire and a positive side is loaded on the honeycomb. Wherein said electrode is composed of wire mesh, said between the wire mesh by a plasma generating device subjected the DC potential of the high-voltage NO _X removal, high voltage, high frequency power is applied for the particulate material removed 2. The exhaust gas purifying apparatus according to claim 1, further comprising generating the plasma in the filter. Between wherein said electrode 30v~400v is applied as a NO _X removing voltage by the plasma generating apparatus, also, AC voltage 5kv~25kv as particulate matter removing voltage is applied, between the electrodes The generated plasma acts on the NO _x adsorbed on the adsorbent attached to the filter between the electrodes to radicalize the NO _x and radicalize the particulate matter attached to the filter. 7. The exhaust gas purifying apparatus according to claim 6, comprising: 11. The power supply according to claim 1, wherein a power generated by a generator provided in said engine is used as a power supply for generating a high voltage at a high frequency applied to said electrodes by said plasma generator. Exhaust gas purification device.