JP2010265850A - Gas purifying device and gas purifying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas purifying device for purifying a gas with a plasma region and a catalyst. <P>SOLUTION: The exhaust emission gas purifying device 1 is disposed in a blast path in which an exhaust gas emitted from a gasoline engine is blasted. Specifically, it is disposed inside an exhaust pipe. The exhaust emission gas purifying device 1 includes a plasma purifying part P1 and a catalyst purifying part C1. The plasma purifying part P1 and the catalyst purifying part C1 are disposed alternately. Since purification is carried out with the plasma region and the photo catalyst alternately in the direction of passage of a gas, purification efficiency is improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gas purification device that purifies gas, and more particularly to a device that purifies gas by a plasma region and a catalyst region.

  An exhaust gas treatment apparatus 100 that is a conventional gas purification apparatus will be described with reference to FIG. The exhaust gas treatment apparatus 100 includes a photocatalyst module 102 into which exhaust gas is introduced, a power supply unit that applies a voltage to the photocatalyst module 102, a voltage detection unit that detects a voltage applied to the photocatalyst module 102, and a current that flows through the photocatalyst module 102. And a control unit that receives detection data from the voltage detection unit and the current detection unit and outputs a control signal to the power supply unit based on the detection data.

  As shown in FIG. 3, the photocatalyst module 102 includes an exhaust pipe 107, a photocatalyst carrier 108 mainly used in the exhaust pipe 107, and discharge electrodes 109 disposed along the front and rear end faces of the photocatalyst carrier 108, 110. The exhaust pipe 107 communicates with the exhaust pipe (not shown) of the automobile engine on the front end opening side, and is connected so that the rear end opening communicates with the muffler (not shown) side.

The photocatalyst carrier 108 is a honeycomb-structured photocatalyst carrier 108 in which a large number of narrow channels 108a through which exhaust gas flows are formed. A photocatalyst such as titanium dioxide (TiO ₂ ) is supported on the inner wall of the narrow channel 108 a of the photocatalyst carrier 108. Specifically, the exhaust pipe 107 and the photocatalyst carrier 108 are formed in, for example, a cylindrical shape, and the narrow channel 108 a of the photocatalyst carrier 108 is set to be parallel to the exhaust gas flow direction of the exhaust pipe 107.

  The discharge electrode 109 is disposed on the front end surface of the photocatalyst carrier 108, and the discharge electrode 110 is disposed on the rear end surface of the photocatalyst carrier 108. The discharge electrodes 109 and 110 have a mesh shape so that exhaust gas can be circulated.

JP 2004-68613 A

  The exhaust gas treatment apparatus 100 described above has the following improvements. In the exhaust gas treatment apparatus 100, by applying a high voltage between the discharge electrodes 109 and 110, harmful components and odor components are decomposed and removed by photocatalytic action by ultraviolet rays generated by plasma discharge. In other words, since purification of exhaust gas relies only on the photocatalytic action, there is a point to be improved that the purification efficiency is not high.

  On the other hand, it is known that plasma itself has a purification action for decomposing and removing harmful components and odor components.

  Then, an object of this invention is to provide the gas purification apparatus which purifies gas by a plasma area | region and a catalyst area | region.

  Means for solving the problems in the present invention and the effects of the invention will be described below.

  The gas purification apparatus according to the present invention is an annular member through which a gas passes, plasma generating means located in the annular member, and plasma generating means having a first electrode and a second electrode, located in the annular member. A gas purifying apparatus comprising catalyst means for purifying the gas, wherein the plasma generating means and the catalyst means are alternately positioned along a direction in which the gas passes.

  Thereby, the purification by the plasma region and the purification by the catalyst can be performed alternately along the direction in which the gas passes, so that the purification efficiency can be increased.

  In the gas purification apparatus according to the present invention, the plasma generating means includes the first electrode and the second electrode positioned at a predetermined angle with respect to a direction in which the gas passes through the annular member.

  As a result, plasma is generated by discharge on a surface wider than the cross section of the annular member. Therefore, more stable plasma generation is possible.

  In the gas purification apparatus according to the present invention, the first electrode and the second electrode have a passage hole through which the gas passes.

  Thereby, passage of gas is not prevented in the 1st electrode and the 2nd electrode. Therefore, the purification efficiency can be increased without losing the gas passage efficiency.

  In the gas purification apparatus according to the present invention, the catalyst means includes a photocatalyst. Thereby, the photocatalyst can be excited by ultraviolet rays generated from the plasma region. Therefore, since purification by plasma and purification by a photocatalyst can be performed, purification efficiency can be increased.

  In the gas purification apparatus according to the present invention, the catalyst means is located within a range where the ultraviolet rays generated by the plasma generating means reach.

  Thereby, a photocatalyst can be excited reliably. Therefore, high purification efficiency can be obtained with certainty.

  In the gas purification apparatus according to the present invention, the gas is an exhaust gas. Thereby, exhaust gas can be purified.

  The exhaust gas purification method according to the present invention includes a plasma region passage step for passing the exhaust gas through a plasma region in a plasma state, and a catalyst region passage step for passing the catalyst region where a catalyst for purifying the exhaust gas is disposed. In the exhaust gas purification method, the plasma region passage step and the catalyst region passage step are alternately performed along the direction in which the exhaust gas passes.

Thereby, the purification by the plasma region and the purification by the catalyst can be performed alternately along the direction in which the exhaust gas passes, so that the purification efficiency of the exhaust gas can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view including a partial cross section of an exhaust gas purification apparatus 1 showing a first embodiment relating to a gas purification apparatus according to the present invention. 1 is a schematic cross-sectional view of an exhaust gas purification device 1. FIG. It is a figure which shows the exhaust gas processing apparatus 100 which is the conventional gas purification apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. Configuration of Exhaust Gas Purification Device An automobile exhaust gas purification device which is one embodiment of the gas purification device according to the present invention will be described with reference to FIG. FIG. 1 is a perspective view including a partial cross section of the exhaust gas purification device 1. The exhaust gas purification device 1 is used to purify exhaust gas discharged from a gasoline engine of an automobile.

  The exhaust gas purification device 1 is disposed in a ventilation path through which exhaust gas discharged from a gasoline engine is blown. Specifically, it is arranged in the exhaust pipe EP. The exhaust gas purification device 1 has a plasma purification unit P1 and a catalyst purification unit C1. The plasma purification part P1 and the catalyst purification part C1 are alternately arranged.

  The plasma purification part P1 has the 1st electrode 11, the 2nd electrode 13, and the power supply circuit 15 (not shown). The first electrode 11 and the second electrode 13 have a disk shape in which a honeycomb structure is formed. The first electrode 11 and the second electrode 13 are made of a heat-resistant metal such as stainless steel. Thus, since the first electrode 11 and the second electrode 13 have a honeycomb structure, they do not become an obstacle when exhaust gas passes through the exhaust pipe EP. The first electrode 11 and the second electrode 13 are positioned so that the diameter direction thereof is perpendicular to the direction in which the exhaust gas flows in the exhaust pipe EP, that is, the direction of the arrow a1 that is the axial direction of the exhaust pipe EP. ing. Therefore, for the exhaust gas flowing through the exhaust pipe EP, the first electrode 11 and the second electrode 13 do not become an obstacle that prevents the flow.

  The catalyst purification unit C1 includes a honeycomb carrier 21 and a photocatalyst 23 (not shown). The honeycomb carrier 21 has a cylindrical shape in which a honeycomb structure is formed. The honeycomb carrier 21 is made of stainless steel, ceramic, or the like. Thus, since the honeycomb carrier 21 has a honeycomb structure, it does not become an obstacle when exhaust gas passes through the exhaust pipe EP. The honeycomb carrier 21 is positioned so that the diameter direction thereof is perpendicular to the direction in which the exhaust gas flows in the exhaust pipe EP, that is, the direction of the arrow a1 that is the axial direction of the exhaust pipe EP. Therefore, for the exhaust gas flowing in the exhaust pipe EP, the honeycomb carrier 21 does not become an obstacle that prevents the flow.

  A photocatalyst 23 such as titanium dioxide is supported on the inner surface of the honeycomb structure of the honeycomb support 21.

  A schematic diagram of a cross section of the exhaust gas purification apparatus 1 is shown in FIG. The first electrode 11 and the second electrode 13 are connected to the power supply circuit 15. The first electrode 11 and the second electrode 13 are raised to a predetermined voltage by the power supply circuit 15. When the voltage is increased to a predetermined voltage, the first electrode 11 and the second electrode 13 are discharged on the surfaces facing each other, and a plasma region R1 is generated between the first electrode 11 and the second electrode 13.

  By generating the plasma region R1, ultraviolet rays are emitted from the plasma region R1. Part of the ultraviolet rays is emitted in the directions of arrows a1 and a3 along the axial direction of the exhaust pipe EP, and reaches a predetermined region.

  The photocatalyst 21 (not shown) carried on the honeycomb carrier 21 is excited by ultraviolet rays emitted from the plasma region R1. The excited photocatalyst 21 purifies the exhaust gas that passes through the honeycomb carrier 21.

Here, the honeycomb carrier 21 is disposed in a region where the ultraviolet rays emitted from the plasma region R1 reach. Thus, by disposing the honeycomb carrier 21 in the region where the ultraviolet rays reach, the photocatalyst 21 carried by the honeycomb carrier 21 can be excited reliably.

  [Other Examples]

  (1) Arrangement of the first electrode 11 and the second electrode 13: In the first embodiment, the diameter direction of the first electrode 11 and the second electrode 13 is the direction in which the exhaust gas flows in the exhaust pipe EP, that is, The exhaust pipe EP is positioned so as to be perpendicular to the central axis direction of the exhaust pipe EP. That is, the discharge is performed along the central axis direction of the exhaust pipe EP. However, as long as the plasma region R1 can be generated between the first electrode 11 and the second electrode 13, the invention is not limited to the example. For example, the first electrode 11 and the second electrode 13 may be formed along the inner peripheral surface of the exhaust pipe EP, and discharge may be performed perpendicular to the central axis direction of the exhaust pipe EP.

  In the first embodiment, the first electrode 11 and the second electrode 13 are positioned so as to be perpendicular to the central axis direction of the exhaust pipe EP. However, the first electrode 11 and the second electrode 13 may not interfere with the passage of exhaust gas. For example, it is not limited to the example. You may make it arrange | position the 1st electrode 11 and the 2nd electrode 13 so that it may become a predetermined angle with respect to the center axis direction of the exhaust pipe EP.

  (2) Positional relationship between the first electrode 11 and the second electrode 13 and the honeycomb carrier 21: In Example 1 described above, the ultraviolet rays emitted from the plasma region R1 generated by a certain first electrode 11 and second electrode 13 are emitted. It is supposed that the honeycomb carrier 21 is included in the reaching region, but it is generated in each plasma region R1 formed by the first electrode 11 and the second electrode 13 arranged before and after a certain honeycomb carrier 21. The honeycomb carrier 21 may be included in the combined region where the ultraviolet rays reach. Thus, by disposing the honeycomb carrier 21 in the reach region of the ultraviolet rays generated in the front and rear plasma regions R1, the distance between the first electrode 11 and the second electrode 13 and the honeycomb carrier 21 is increased. Can take.

  (3) Exhaust gas: In Example 1 described above, exhaust gas from a gasoline engine is purified. However, as long as it is exhaust gas, exhaust gas from a diesel engine, for example, may be used.

  (4) Structure of the first electrode 11 and the second electrode 13: In the first embodiment, the first electrode 11 and the second electrode 13 have a honeycomb structure, but the exhaust gas passes through the exhaust pipe EP. The present invention is not limited to the example as long as it does not become an obstacle. For example, a porous structure other than the honeycomb structure may be used. Moreover, the annular structure which follows the inner surface of the exhaust pipe EP may be sufficient.

(5) Plasma region R1: In Example 1 described above, the plasma region R1 is generated by the discharge of the first electrode 11 and the second electrode 13, but the plasma region R1 can be generated before the catalyst purification unit C1. If there is, it is not limited to the example.

The gas purification apparatus according to the present invention can be used for purification of automobile exhaust gas, for example.

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification apparatus 11 ... 1st electrode 13 ... 2nd electrode 15 ... Power supply circuit 21 ... Honeycomb carrier 23 ...・ Photocatalyst EP: Exhaust pipe

Claims (7)

An annular member through which gas passes,
Plasma generating means located on the annular member, the plasma generating means having a first electrode and a second electrode,
Catalyst means located on the annular member for purifying the gas;
A gas purification device having
The plasma generating means and the catalyst means are alternately positioned along the direction in which the gas passes;
A gas purification device characterized by the above. In the gas purification apparatus according to claim 1,
The plasma generating means includes
Having the first electrode and the second electrode positioned at a predetermined angle with respect to the direction in which the gas passes through the annular member;
A gas purification device characterized by the above. In the gas purification apparatus according to claim 2,
The first electrode and the second electrode are:
Having a passage hole through which the gas passes,
A gas purification device characterized by the above. In the gas purification apparatus which concerns on Claims 1-3,
The catalyst means includes
Having a photocatalyst,
A gas purification device characterized by the above. In the gas purification apparatus which concerns on Claims 1-4,
The catalyst means includes
Being located within the reach of the ultraviolet rays generated by the plasma generating means;
A gas purification device characterized by the above. In the gas purification apparatus which concerns on Claims 1-5,
The gas is
Exhaust gas,
A gas purification device characterized by the above. A plasma region passing step of passing the exhaust gas through a plasma region in a plasma state;
A catalyst region passing step for passing through a catalyst region in which a catalyst for purifying the exhaust gas is disposed;
An exhaust gas purification method comprising:
Alternately performing the plasma region passing step and the catalyst region passing step along the direction in which the exhaust gas passes;
An exhaust gas purification method characterized by the above.

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