Patent Grant
8966881
The present invention relates to a device and a combustion method for combusting particulate matters in which particulate matters discharged from an internal combustion engine can be effectively combusted.
A variety of techniques have been studied to remove particulate matters (PM) in exhaust gas discharged from an internal combustion engine. In Patent Document 1, a technique is proposed in which particulate matters are captured by a ceramic honeycomb filter, and when the amount of the captured particulate matters exceeds the predetermined acceptable value, the captured particulate matters are heated to be combusted away. In Patent Document 2, in order to overcome the drawback that the ceramic honeycomb filter used in Patent Document 1 is expensive, fragile and hard to handle, and in order to decrease the power consumption required for burning away particulate matters, a technique is proposed in which a combustion heater is placed between a permeable filter made of ceramic fiber and a heat insulator, and heating is performed by using the heater to burn particulate matters with a timing controlling the inflow of particulate matter-containing gas.
Since the techniques in the above Patent Documents 1 and 2 are a technique in which particulate matters are captured by a heat resistant filter and the captured particulate matters are heated to be combusted away in an arbitrary timing, there is concern about a reduced filter life due to a rapid temperature change, a local heating or the like. To address such issues, in Patent Document 3, a technique is proposed in which cracking means for cracking without causing a rapid temperature change or a local heating on a filter which captures particulate matters, and oxidizing means for oxidizing the residual combustion particulate matters by ozone gas are combined.
In Patent Document 4, a technique is proposed in which manganese oxide-supported substrate in a gas flow channel is placed and adsorbed particulate matters are oxidatively decomposed, as well as the oxidation decomposition of particulate matters is accelerated by further containing active species such as an OH radical, an oxide atom, oxygen ion and ozone gas. In this technique, particulate matters are charged by electrons generated at the time of discharge in a plasma discharge device so that the adhesion to manganese oxide-supported substrate is accelerated, and the oxidative decomposition of the particulate matters by the catalysis of manganese oxide can be effectively performed, and further, since an OH radical and ozone generated in the plasma discharge device per se oxidatively decompose the particulate matters, the particulate matters can be removed by oxidation.
However, the technique in the above Patent Document 3 includes a filter which captures and cracks particulate matters and generating means for generating an oxidizing and decomposing gas such as ozone gas, and the technique in the above Patent Document 4 includes a catalytic substrate on which particulate matters are adsorbed and heated to be oxidatively decomposed and generating means for generating an oxidizing and decomposing gas such as ozone gas. Both of the techniques require a heating device such as a heater and an oxidizing and decomposing gas generation device. For this reason, the device configuration is complex, large and heavy, and the complex, large and heavy device has a problem when vehicles or the like mounts it from the viewpoint of energy saving. Also, the filter has a problem such as clogging or heat-deterioration, and the oxidation catalyst has a problem such as catalyst life or heat-deterioration, too.
Although the related arts individually include a technique of cracking by a heater or the like, a high combustion efficiency cannot be obtained by heating using a heater, and therefore, timing of the combustion is controlled, inflow of a gas is controlled or the combustion is complemented by an ozone generating device or the like.
The present invention is devised to solve the above problems, and an object thereof is to provide a device and a method for combusting particulate matters in which particulate matters discharged from an internal combustion engine can be effectively combusted, and the device configuration is simple and does not become large and heavy.
The present inventor discovered a device configuration in which an effective combustion is realized and the device configuration is simple and not large and heavy by developing means for lengthening the time when particulate matters receive discharge energy, in order to effectively perform combustion of the particulate matter by silent discharge. Therefore, the present inventor completed the present invention.
Specifically, a combustion device for combusting particulate matters of the present invention for solving the above-described problems comprises:
an introduction portion which connects to an exhaust port of an internal combustion engine, and is used to introduce a particulate matter-containing gas discharged from the exhaust port; a charging unit which is provided on the downstream side of the introduction portion, and in which all or part of the particulate matters are negatively charged by bringing the particulate matter-containing gas into contact with; an electric discharge unit which is provided in an insulation pipe which is connected to the downstream side of the charging unit, and in which the particulate matters, all or part of which are negatively charged, are introduced into a silent discharge area and are combusted with an increased retention time, the silent discharge area being generated between an anode and a cathode; a discharge portion which is connected to the insulation pipe at the downstream side of the electric discharge unit and which discharges the combusted gas; and a power source unit which applies an electric field to the charging unit and the electric discharge unit.
By the present invention, all or part of particulate matters included in a particulate matter-containing gas discharged from an internal combustion engine are negatively charged by a charging unit. Further, the negatively charged particulate matters are introduced into a silent discharge area on the downstream side of the charging unit, and electrically attracted or repelled by constituting electrodes in order to reduce the speed of the negatively charged particulate matters. Therefore, time for the particulate matters to be retained in the silent discharge area can be increased, as well as the combustion efficiency of the particulate matters in the silent discharge area can be improved. As a result, efficient combustion can be realized, and further, miniaturization and weight reduction of the combustion device can be realized by a simple device configuration.
The combustion device for combusting particulate matters of the present invention has following three embodiments having the above technical features.
In the first embodiment of the combustion device for combusting particulate matters, the introduction portion has a gas flow conversion member which changes the flow of the particulate matter-containing gas to a spiral flow, the charging unit has a ring anode provided along the internal circumference of the pipe where the spiral flow flows, and the electric discharge unit has a cylindrical cathode provided on inner wall of the insulation pipe, a cylindrical dielectric provided inside the cathode and a cylindrical mesh anode is spaced from the cylindrical dielectric at predetermined gap on the inside of the cylindrical dielectric.
In the first embodiment of the present invention, the particulate matters in the gas flow changed to the spiral flow by the gas flow conversion member have negative space charge (negative charge) gathered around the ring anode. The particulate matters having the negative space charge are attracted by the electrostatic force of the cylindrical mesh anode and enter the silent discharge area while flowing on the spiral gas flow at the vicinity of the inner wall of the pipe. The speed of the flow of the particulate matters which enter the silent discharge area is reduced by Coulomb force at the silent discharge area extending in the longitudinal direction of the pipe. As a result, the particulate matters obtain much discharge energy and can be efficiently combusted.
In the second embodiment of the combustion device for combusting particulate matters, the charging unit has a planar mesh anode provided orthogonal to a flow channel of the particulate matter-containing gas, the electric discharge unit has: a cylindrical cathode spaced from the inner wall of the insulation pipe at predetermined gap; a cylindrical dielectric provided inside the cathode; a cylindrical mesh anode spaced from the cylindrical dielectric on the inside of the cylindrical dielectric; and a gas flow conversion member which introduces particulate matters charged by the planar mesh anode into the silent discharge area between the cylindrical dielectric and the cylindrical mesh anode.
In the second embodiment of the present invention, the particulate matters in the gas flow have negative space charge gathered around the planar mesh anode. The particulate matters have negative space charge are guided by the gas flow conversion member to the silent discharge area extending in the longitudinal direction of the pipe, and the speed of the flow of the particulate matters is reduced by Coulomb force at the silent discharge area. As a result, the particulate matters obtain much discharge energy and can be efficiently combusted.
In the third embodiment of the combustion device for combusting particulate matters, the charging unit has a planar mesh anode provided orthogonal to a flow channel of the particulate matter-containing gas; and the electric discharge unit has: a planar mesh cathode provided orthogonal to the flow channel; and an anode spaced from the planar mesh cathode at predetermined gap on the upstream side of the planar mesh cathode, and the predetermined gap forms a silent discharge area.
In the third embodiment of the present invention, the particulate matters in the gas flow have negative space charge gathered around the planar mesh anode. The particulate matters have negative space charge are introduced into the silent discharge area through the anode, and the particulate matters are electrically repelled by the planar mesh cathode and the speed of the particulate matters is reduced. As a result, the particulate matters obtain much discharge energy and can be efficiently combusted.
The combustion method for combusting particulate matters of the present invention for solving the above-described problems comprises: negatively charging all or part of particulate matters included in a particulate matter-containing gas discharged from an internal combustion engine; electrically attracting or repelling the negatively charged particulate matters in order to reducing the speed of the negatively charged particulate matters; and increasing retention time for the particulate matters to be retained in a silent discharge area in order to extend time for applying discharge energy at the silent discharge area.
By the present invention, since the particulate matters are combusted in a state that the retention time in the silent discharge area is increased, the combustion efficiency in the silent discharge area can be increased. As a result, an efficient combustion can be realized.
In the first embodiment of the combustion method for combusting particulate matters, the retention time is increased at the silent discharge area by electrostatically attracting the negatively charged particulate matters to a mesh anode which is provided on the downstream side of a flow channel of the particulate matter-containing gas.
In the second embodiment of the combustion method for combusting particulate matters, the retention time is increased at the silent discharge area by electrostatically attracting the negatively charged particulate matters to a mesh anode which is provided on the downstream side of a flow channel of the particulate matter-containing gas.
In the third embodiment of the combustion method for combusting particulate matters, the retention time is increased at the silent discharge area by attracting the negatively charged particulate matters to a mesh anode and depositing the negatively charged particulate matters on the mesh node, the mesh anode being provided on the downstream side of a flow channel of the particulate matter-containing gas.
By the combustion devise and the method combustion for combusting particulate matters of the present invention, all or part of particulate matters included in a particulate matter-containing gas discharged from an internal combustion engine are negatively charged by a charging unit. Further, the negatively charged particulate matters are introduced into a silent discharge area on the downstream side of the charging unit, and electrically attracted or repelled by constituting electrodes in order to reduce the speed of the negatively charged particulate matters. Therefore, time for the particulate matters to be retained in the silent discharge area can be increased, as well as the combustion efficiency of the particulate matters in the silent discharge area can be improved. As a result, efficient combustion can be realized, and further, miniaturization and weight reduction of the combustion device can be realized by a simple device configuration.
Next, embodiments of the present invention will be described. The present invention includes the scope including the technical idea thereof, and is not limited to the following description, drawings or the like.
A combustion device and a combustion method for combusting particulate matters of the present invention have means for lengthening the time for receiving discharge energy in order to perform combustion efficiently in silent discharge. The term, “silent discharge” refers to discharge which occurs when one or both of electrode plates with a fixed distance in between is(are) covered with an insulator (dielectric) and an alternating voltage is applied to the electrode plates. Also, the silent discharge is referred to as dielectric barrier discharge. Since the electrode(s) is(are) covered with an insulator(s), an electric charge cannot flow into the electrode(s), and therefore, a large current does not flow. For this reason, in silent discharge, a sound is not heard unlike the case of spark discharge or corona discharge, and thus such discharge is referred to as “silent discharge.”
The basic configuration has means for negatively charging all or part of particulate matters included in a particulate matter-containing gas discharged from an internal combustion engine, and means for lengthening time for the particulate matters to be retained in a silent discharge area by reducing the speed of the particulate matters by electrically attracting or repelling the particulate matters in the silent discharge area. By such means, time for applying discharge energy at the silent discharge area can be increased and the particulate matters can be combusted in a state that the retention time in the silent discharge area is increased. As a result, the combustion efficiency in the silent discharge area can be increased, and efficient combustion can be realized.
As shown in
As shown in
There are three embodiments, the first to the third embodiments, of the present invention in which negatively charged particulate matters 6′ are electrically attracted or repelled to reduce the speed of negatively charged particulate matters 6′.
As shown in
As shown in
As shown in
By such a combustion device and a combustion method for combusting particulate matters of the present invention, all or part of particulate matters 6 included in particulate matter-containing gas 5 discharged from internal combustion engine 1 are negatively charged by charging unit (11, 21, 31); negatively charged particulate matters 6′ are introduced into silent discharge area (A1, A2, A3) and electrically attracted or repelled by constituting electrodes (13, 23, 33 or 14, 24, 34), in order to reduce the speed of negatively charged particulate matters 6′. As a result, and retain time for particulate matters 6′ to be retained in silent discharge area (A1, A2, A3) is increased, and the particulate matters can be combusted in such a state. By such an invention, the combustion efficiency in silent discharge area (A1, A2, A3) can be improved and efficient combustion can be realized, and further, miniaturization and weight reduction of the device can be realized by a simple device configuration.
Representative three embodiments of a combustion device for combusting particulate matters of the present invention will be described in detail with reference to the drawings.
As shown in
As shown in
(Introduction Portion)
As shown in
As illustrated in
In the example of
(Charging Unit)
Charging unit 11 is a unit which is provided on the downstream side of introduction portion 8, and in which negative space charge 122 (also simply referred to as “negative charge”) is charged on all or part of particulate matter 6 included in particulate matter-containing gas 5 by bringing particulate matter-containing gas 5 into contact with. In the first embodiment, as shown in
Since negative charge 122 gathers around ring anode 121, particulate matter-containing gas 5 which flows along the inner wall of the pipe as spiral flow 107 is in contact with anode 121. As a result, particulate matter 6 included in particulate matter-containing gas 5 has negative charge 122, and negatively charged particulate matter 6′ flows in the pipe as spiral flow 107. Since spiral flow 107 provide particulate matter 6′ with a centrifugal force, a force in the inner wall direction of the pipe is applied to particulate matter 6′, and therefore, spiral flow 107 proceeds along the inner wall of the pipe.
(Discharge Device)
As shown in
Electric discharge unit 15 is preferably provided in ceramic insulation pipe 100 having heat resistance, heat insulating properties and electrical insulating properties. Not only in electric discharge unit 15, but also in the above-mentioned charging unit 11, it is preferable that electric discharge unit 15 and charging unit 11 be provided in integrated insulation pipe 100 as shown in
On the inner surface of insulation pipe 100, cylindrical cathode 131 is provided, and cathode 131 may be a stainless metal body having a thickness of, for example, about 0.1 mm. Insulation pipes 134, 134 are provided on the both ends (the upstream end and the downstream end) of cylindrical cathode 131 in the longitudinal direction. Cathode 131 may be in close contact with insulation pipe 100, and spaced from insulation pipe 100 at a little gap as shown in
Cylindrical dielectric 132 is provided inside (on the center side of the pipe, same as below) the above-mentioned cylindrical cathode 131. Preferably, dielectric 132 is ceramic dielectric having, for example, a thickness of 1 mm, and specifically, formed by alumina or the like. Generally, the dielectric 132 is provided in close contact with cathode 131.
Preferably, cylindrical mesh anode 133 is formed on the inside of cylindrical dielectric 132, and spaced from dielectric 132 at gap G, which is about 1 mm, for example. Anode 133 has mesh structure which has openings allowing particulate matter 6′ to pass through. The size of the opening is such that, for example, particulate matter 6 of 2 μm can freely pass through the opening, but not limited. The material of anode 133 is not limited, but tungsten mesh having high heat resistance is preferably used. For example, a tungsten mesh having a wire diameter of 0.4 mm and 20 mesh/inch can be exemplified.
A high voltage with a high frequency is applied between cathode 131 and anode 133 from power source unit 4 in order to generate silent discharge. Since particulate matter 6′ flows on spiral flow 107 near the inner wall of the pipe, duration time of discharging in silent discharge area A1 becomes longer than the duration time when the particulate matter 6′ flows straightly in the pipe. Further, since particulate matter 6′ which flows on the inner wall side of the pipe passes through the mesh opening of anode 133 by the centrifugal force based on spiral flow 107, it is easy that particulate matter 6′ flows in silent discharge area A1, and receives silent discharge. Further, since particulate matter 6′ is negatively charging and then, attracted to anode 133 by Coulomb force, and particulate matter 6′ tends to retain in silent discharge area A1 for a long time. As a result of this retention of particulate matter 6′ in silent discharge area A1, particulate matter 6′ receives the discharge energy of the silent discharge for a long time, more efficient combustion is performed due to Joule heat by a large discharge energy or the residual heat of combustion of particulate matter 6′.
Toxic components (NOx, SOx) included in particulate matter-containing gas 5 can be reformed and removed by a high electric field in silent discharge area A1.
(Power Source Unit)
Power source unit 4 is a unit which applies an electric field to charging unit 11 and electric discharge unit 15. As shown in
The positive voltage terminal of high voltage and high frequency generator 141 is connected to ring anode 121 of charging unit 11 and cylindrical mesh anode 133 of electric discharge unit 15. On the other hand, the negative voltage terminal is connected to cylindrical cathode 131. Silent discharge is generated between cylindrical mesh anode 133 to which the positive voltage terminal is connected and cylindrical cathode 131 to which the negative voltage terminal is connected. Ring anode 12 to which a positive voltage terminal is connected attracts negative space charge 122.
(Discharge Portion)
Discharge portion 9 is connected to insulation pipe 100 on the downstream side of electric discharge unit 15, and discharges combusted gas 151. Herein, the term “connected to insulation pipe 100” means that an discharge portion is formed by a discharge pipe which is a separate member, and the discharge portion is connected to insulation pipe 100 (see
As described above, in the first embodiment of combustion device 10A, particulate matter 6 in the gas flow converted to spiral flow 107 by gas flow conversion member 101 has negative space charge 122 gathered around ring anode 121. While particulate matter 6′ having negative space charge 122 flows on spiral flow 107 near the inner wall of a pipe, particulate matter 6′ is attracted also by cylindrical mesh anode 133 and flows in silent discharge area A1. The speed of the flow of particulate matter 6′ which flows in silent discharge area A1 is reduced by Coulomb force at silent discharge area A1 extending in the longitudinal direction of the pipe. As a result, the particulate matters obtain much discharge energy and can be efficiently combusted.
By such combustion device 10A, the combustion of particulate matter is performed under a more power saving condition, by being connected near exhaust port 2 of engine 1, preventing heat loss by covering the combustion portion by insulation pipe 100, increasing the retention time at silent discharge area A1 by Coulomb force by providing particulate matter 6 with negative charge 122, and using a high frequency or high pulse discharge. Further, other toxic components (NOx, SOx) included in particulate matter-containing gas 5 can be decomposed and removed. Since combustion device 10 of the present invention which can realize such an effective combusting is simple and small and has light weight, combustion device 10 is suitable for vehicle or the like.
As shown in
In the same manner as in the first embodiment, introduction portion 8 is connected to exhaust port 2 of internal combustion engine 1, and particulate matter-containing gas 5 discharged from exhaust port 2 is introduced into introduction portion 8. In the example in
The term “upstream side” herein refers to the side of internal combustion engine 1 as shown in
The configurations of introduction portion 8 and discharge portion 9 are not limited to the examples of connecting pipes illustrated in the figures. Namely, it is only necessary for pipe 201 which constitutes introduction portion 8 to be connected to insulation pipe 100 which constitutes charging unit 21 and electric discharge unit 25. Also, it is only necessary for pipe 241 which constitutes introduction portion 9 to be connected to insulation pipe 100 which constitutes charging unit 21 and electric discharge unit 25. Although, in the illustrated example, silent discharge area A2 and inner wall flow channel 243 is secured by configuring pipe 241 to have a smaller diameter, it is unnecessary to use pipe 241 having a smaller diameter. Silent discharge area A2 and inner wall flow channel 243 are formed by using another member.
In introduction portion 8, a gas flow conversion member which converts particulate matter-containing gas 5 into spiral flow 107 as shown in
Plate-like flow channel control member 237 is supported by pillar 238 extending from the center portion of the below-mentioned planar mesh anode 221. On the other hand, the periphery of plate-like flow channel control member 237 supports the upstream side of cylindrical mesh anode 233. The downstream side of cylindrical mesh anode 233 is supported by insulation pipe 241 which constitutes discharge portion 9. Insulation pipe 241 is fixed to insulation pipe 100 via coaxial ring 242 which is inserted into the periphery thereof.
The material of plate-like flow channel control member 237 is not limited. When cylindrical mesh anode 233 and planar mesh anode 221 placed on the upstream side are electrically connected as shown in
On the upstream side of plate-like flow channel control member 237 and on the downstream side of introduction portion 8, planar mesh anode 221 as charging unit 21 is provided orthogonal to the flow channel of particulate matter-containing gas 5. Planar mesh anode 221 is supported by cylindrical dielectric 234 so that the periphery of cylindrical dielectric 234 is inserted in the upstream end of cylindrical dielectric 234. On the center portion of planar mesh anode 221, pillar 238 for supporting the above-mentioned plate-like flow channel control member 237 which is placed on the downstream side of planar mesh anode 221 is provided.
In the same manner as in the first embodiment, planar mesh anode 221 is a member used to bring particulate matter-containing gas 5 into contact with, and to negatively-charge all or part of particulate matter 6 included in particulate matter-containing gas 5 by negative charge 22. For this reason, a positive voltage is preferably applied to planar mesh anode 221 from power source unit 4. Since negative space charge (negative charge) 222 gathers to planar mesh anode 221 on which a positive voltage is applied, particulate matter 6 included in particulate matter-containing gas 5 which passes through planar mesh anode 221 has negative charge 222. Namely, particulate matter 6 is negatively-charged by passing through planar mesh anode 221, and flows to the downstream side. The flow of particulate matter 6′ which flowed to the downstream side is controlled by plate-like flow channel control member 237 and flows into silent discharge area A2 by electrically attracting to cylindrical mesh anode 233.
Planar mesh anode 221 may have a mesh structure which has, for example, an opening through which particulate matter 6 of 2 μm can freely pass. The material of planar mesh anode 221 is not limited, and preferably a heat resistant metal mesh. For example, a tungsten mesh or a tungsten alloy mesh is preferably used, but not limited thereto. For example, a tungsten mesh having a wire diameter of 0.4 mm and 20 mesh/inch can be used.
As shown in
Cylindrical cathode 235 is spaced from the inner wall side of insulation pipe 100 at a predetermined gap (not limited, but, for example, in a range of 1 mm to 10 mm), and may be formed, for example, by a metal body of stainless steel having a thickness of about 0.5 mm. In the example of
Cylindrical dielectric 234 is provided inside the above-mentioned cylindrical cathode 235. Dielectric 234 is fixed on insulation pipe 100 by a plurality of supporting bolts 236. Dielectric 234 is a ceramic dielectric having a thickness of about 1 mm. Specifically, dielectric is preferably formed by a material such as alumina. Dielectric 234 fixed in the insulation pipe by supporting bolts 236 has a space which is able to form inner wall flow channel 243 between dielectric 234 and insulation pipe 100.
Cylindrical mesh anode 233 is preferably formed by a heat resistant metal fiber mesh (for example, wire diameter (20 μm), porosity: 80%, thickness: 1.3 mm) For example, stainless metal fiber mesh is preferably used, but not limited thereto. The openings of the mesh may have such a size that, for example, particulate matter 6′ of 0.1 μm does not easily pass the mesh and the mesh can capture.
Since this cylindrical mesh anode 233 can capture particulate matter 6′, particulate matter 6′ is provided with sufficient discharge energy while particulate matter 6′ introduced into silent discharge area A2 by circular plate-like flow channel control member 237 is captured by the mesh structure. As a result, efficient combustion can be realized. After the combustion, particulate matter 6′ becomes combustion gas 250 and passes through the mesh and is discharged from discharge portion 9 as exhaust gas 151.
As shown in
Since particulate matter 6 in particulate matter-containing gas 5 which has flowed into silent discharge area A2 cannot pass through the metal fiber mesh structure of cylindrical mesh anode 233 and is captured by the structure, particulate matter 6 receives discharge energy and is combusted while being captured.
Because the second embodiment of combustion device 10B has a double pipe structure having two routes of flow channels, combustion device 10B has a flow channel which introduces particulate matters from both the upstream side and the downstream side of cylindrical metal fiber mesh anode 233. Therefore, the particulate matters can be deposited with economy on metal fiber mesh 233 along the longitudinal direction of cylindrical mesh anode 233, and provided with discharge energy and combusted.
Since power source unit 4 is the same as in the first embodiment, the description thereof is omitted.
As described above, in the second embodiment of combustion device for combusting particulate matters 10B, particulate matter 6 in the gas flow has negative space charge 222 gathered around planar mesh anode 221. Particulate matter 6′ having negative space charge 222 is introduced into silent discharge area A2 extending in the longitudinal direction of pipe 100 by plate-like flow channel control member 237, attracted by Coulomb force of silent discharge area A2 and captured by cylindrical mesh anode 233 which constitutes silent discharge area A2, whereby the retention time at silent discharge area A2 is increased. As a result, the particulate matter obtains much discharge energy and can be efficiently combusted.
As shown in
In the same manner as in the first embodiment, introduction portion 8 is connected to exhaust port 2 of internal combustion engine 1, and particulate matter-containing gas 5 discharged from exhaust port 2 is introduced into introduction portion 8. Introduction portion 8 is formed by pipe 301 which has a smaller diameter than that of insulation pipe 100, and is connected to the upstream side of insulation pipe 100. On the other hand, in the same manner as in the first embodiment, discharge portion 9 is also connected to insulation pipe 100 and discharges combusted gas 151. Discharge portion 9 is formed by pipe 341 having a diameter smaller than that of insulation pipe 100, and is connected to the downstream side of electrically insulating quadrangular prism pipe 100. The connection configurations of pipes 301, 341 to electrically insulating quadrangular prism pipe 100 are not limited.
The term “upstream side” herein refers to the side of engine 1 as shown in
On the downstream side of introduction portion 8, planar mesh anode 321 as charging unit 31 is provided orthogonal to the flow channel of particulate matter-containing gas 5. Planar mesh anode 321 is attached to the inner surface of pipe 301 by an attachment which is not illustrated in the figure.
In the same manner as in the first and the second embodiment, planar mesh anode 321 is a member which negatively-charge all or part of particulate matter 6 included in particulate matter-containing gas 5 by bringing particulate matter-containing gas 5 into contact with. For this reason, a positive voltage is preferably applied to planar mesh anode 321 from power source unit 4. Since negative space charge (negative charge) 322 gathers to planar mesh anode 321 on which a positive voltage is applied, part of particulate matter 6 included in particulate matter-containing gas 5 which passes through planar mesh anode 221 has negative charge 322. Namely, particulate matter 6 is negatively-charged by passing through planar mesh anode 221, and flows to the downstream side.
Planar mesh anode 321 may have a mesh structure which has, for example, openings through which particulate matter 6 of 2 μm can freely pass. The material of planar mesh anode 321 is not limited, and preferably a heat resistant metal mesh. For example, a tungsten mesh or a stainless mesh having a wire diameter of 0.4 mm and 20 mesh/inch can be exemplified, but not limited thereto. The distance between this anode 321 and cathode 331 provided on the downstream side of anode 321 is not limited, and usually, may be in a range of 10 mm to 100 mm.
As shown in
As shown in
Rod anode 332 which constitutes dielectric covered anodes 330 is preferably a heat resistant metal. For example, a tungsten rod or a stainless rod is preferably used, but not limited thereto. Rod anode 332 having a diameter of about 1 mm can be exemplified. A dielectric covered mesh anode having a ceramic covered wire diameter of 2 mm and a metal wire diameter of 0.4 mm, and having about 10 mesh/inch can be exemplified.
Examples of dielectric 333 which covers rod anode 332 include ceramics. Covering on rod anode 332 can be performed by, for example, sputtering. Here, although rod anode 332 is described to be covered, rod anode 332 may be configured to be inserted into a ceramic pipe by using the ceramic pipe as dielectric 333.
Planar metal fiber mesh cathode 331 is preferably heat resistant metal mesh (for example, wire diameter: 20 μm, porosity: 83%, thickness: 1.3 mm). For example, a tungsten mesh or a tungsten alloy mesh is preferably used, but not limited thereto. The openings of the mesh may have such a size that, for example, particulate matter 6′ of 0.1 μm does not easily pass the mesh and the mesh can capture. As illustrated, planar metal fiber mesh cathode 331 is held by retention member 336 of electrically insulating quadrangular prism pipe 100.
Since this planar metal fiber mesh cathode 331 can capture particulate matter 6′, particulate matter 6′ is provided with sufficient discharge energy while particulate matter 6′ introduced into silent discharge area A3 is captured by the mesh structure. As a result, efficient combustion can be realized. After the combustion, particulate matter 6′ becomes combustion gas 350 and passes through the mesh and is discharged from discharge portion 9 as exhaust gas 151.
Namely, negatively charged particulate matter 6′ in the particulates which pass through dielectric covered anode 330 is electrostatically attracted to dielectric covered anode 330, and passes there at a reduced speed to introduce into silent discharge area A3. Since particulate matter 6′ which has introduced into silent discharge area A3 is electrostatically repelled by planar metal fiber mesh cathode 331, the speed of particulate matter 6′ is further reduced and the deposition effect to the mesh is increased. Further, since planar metal fiber mesh cathode 331 is formed by a mesh which does not allow particulate matter 6′ to pass through irrelative of electrification, particulate matter 6′ is deposited on the mesh. As a result, charged particulate matters and non-charged particulate matters are deposited on the surface of the mesh, receive much discharge energy and can be efficiently combusted.
Since power source unit 4 is the same as in the first and the second embodiment, the description thereof is omitted.
As described above, in the third embodiment of combustion device 10C for combusting particulate matters, the particulate is deposited on the mesh by trapping effect of planar metal fiber mesh, and further, part of particulate matter 6′ in the gas flow has negative space charge 322 gathered around planar mesh anode 321. Particulate matter 6′ having negative space charge 322 proceeds with maintaining the negatively-charged state, passes through dielectric covered anode 330 to be introduced into silent discharge area A3, and repelled by the electrostatic force of silent discharge area A3. Particulate matter 6′ is deposited on planar metal fiber mesh cathode 331 which constitutes silent discharge area A3 by these two effects. As a result, particulate matter 6′ obtains much discharge energy and can be efficiently combusted.
| Number | Date | Country | Kind |
|---|---|---|---|
| P2009-120554 | May 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/057967 | 5/11/2010 | WO | 00 | 1/31/2012 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2010/134448 | 11/25/2010 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5698012 | Yoshikawa | Dec 1997 | A |
| 5787704 | Cravero | Aug 1998 | A |
| 5956946 | Yamada | Sep 1999 | A |
| 6994830 | Raybone et al. | Feb 2006 | B1 |
| 20050194583 | Taylor et al. | Sep 2005 | A1 |
| 20060021503 | Thaler | Feb 2006 | A1 |
| 20060113181 | Hirata et al. | Jun 2006 | A1 |
| 20060156791 | Tikkanen et al. | Jul 2006 | A1 |
| 20060187609 | Dunn | Aug 2006 | A1 |
| 20080056934 | Tsui | Mar 2008 | A1 |
| 20100072055 | Tanaka et al. | Mar 2010 | A1 |
| Number | Date | Country |
|---|---|---|
| 1 662 104 | May 2006 | EP |
| H05-096129 | Apr 1993 | JP |
| H08-112549 | May 1996 | JP |
| 2002-263523 | Sep 2002 | JP |
| 2003-172123 | Jun 2003 | JP |
| 2004-514820 | May 2004 | JP |
| 2005-106022 | Apr 2005 | JP |
| 2005-337153 | Dec 2005 | JP |
| 2007-021380 | Feb 2007 | JP |
| 2007-187136 | Jul 2007 | JP |
| 2008-64015 | Mar 2008 | JP |
| 2009-50840 | Mar 2009 | JP |
| WO-0242615 | May 2002 | WO |
| WO 2008006981 | Jan 2008 | WO |
| WO 2008062554 | May 2008 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20120124969 A1 | May 2012 | US |
