JP4854270B2 - Gas purification apparatus and method - Google Patents

Description

  The present invention relates to a gas purification apparatus and method for purifying gas discharged from an internal combustion engine such as a diesel engine for power generation or a boiler that burns oil.

Exhaust gas discharged from internal combustion engines and boilers contains harmful substances such as particulate matter (PM) and sulfur oxides (sulfurous gas SO ₂ and SO ₃ ), which are efficiently used. It is necessary to clean it up well. In general, an electric dust collector, a desulfurization device or the like is provided in the exhaust gas passage to purify them.

  As a conventional gas purification device, for example, a device described in Patent Document 1 below has been proposed. In the flue gas desulfurization method described in Patent Document 1, a wet type electrostatic precipitator is disposed on the downstream side of the lime gypsum desulfurization device, and the electrostatic precipitator mainly absorbs alkali on the dust collector plate side of the corona discharge field. By forming a liquid film of the liquid, sulfur oxides in the exhaust gas are removed, and the alkali absorbing liquid film is caused to flow uniformly over the entire surface of the dust collecting electrode plate to desulfurize the flue gas.

Japanese Patent Application Laid-Open No. 08-010643

  Generally, in hazardous gas treatment such as desulfurization, in the absorption method, a large amount of absorption liquid is sprayed or a packed bed is provided in order to increase the contact efficiency between the absorption liquid and the gas. The pressure loss is large, and there is a problem that a fan is required for applications such as engines. Then, although there exists the above-mentioned patent document 1 using the wet electric dust collector with little ventilation loss, in this exhaust gas purification apparatus, the dust collection electrode plate in a wet electric dust collector is made into a flat plate shape, and opposes a discharge electrode. A liquid film of an alkaline solution is formed on the surface, and the ionic wind of the exhaust gas is guided to the liquid film of the dust collecting electrode plate to desulfurize the smoke. Since the dust collection electrode plate has a flat plate shape, fine dust in the exhaust gas is attracted by the ion wind to the vicinity of the electrode plate by the ion wind, and most of the dust is electrostatically attracted to the dust collection electrode. However, the smaller the diameter of the dust to be collected, the more the same behavior as the ion wind, and it will be rewound by the reversal of the ion wind and scattered again, reducing the dust collection efficiency. End up. In addition, since a liquid film of an alkaline solution is formed on the surface of the flat plate-shaped dust collecting electrode plate, the probability of gas-liquid contact with the increase of the ion wind increases with the increase of the ion wind. The portion other than the tip portion of the gas is reversed without coming into contact with the liquid, that is, only a part of the exhaust gas can be brought into gas-liquid contact, and high desulfurization efficiency cannot be obtained efficiently.

  The present invention solves such problems, and is capable of reliably collecting particulate matter in the gas and improving the gas purification efficiency by improving the removal performance of harmful gases such as desulfurization. It is an object of the present invention to provide a gas purification apparatus and method.

In order to achieve the above object, a gas purification apparatus according to a first aspect of the present invention includes a casing provided with an inlet and an outlet, and a predetermined voltage applied to the casing along the gas flow direction. A discharge electrode capable of generating an ion wind that induces and forms a secondary flow in a direction across the gas flow in the casing, and is disposed in the casing so as to face the discharge electrode along the gas flow direction. A dust collecting electrode having a predetermined aperture ratio that opens in a direction along the flow path crossing the gas flow by overlapping a plurality of conductive meshes and opens in the direction along the gas flow and allows the ion wind to pass through. A liquid film forming means for forming a liquid film of a harmful gas absorbing liquid that absorbs harmful components in the gas is provided on the surface of the dust collecting electrode.

  In the gas purification apparatus according to the invention of claim 2, the dust collecting electrode has a liquid path along a substantially vertical direction capable of forming a liquid film in which the harmful gas absorbing liquid continuously falls without interruption. Yes.

  In the gas purification device of the invention of claim 3, an adsorption member having a predetermined porosity and capable of adsorbing harmful components in the gas is attached to the dust collection electrode.

  In the gas purification apparatus of the invention of claim 4, the liquid film forming means is an absorbing liquid supply means for supplying a harmful gas absorbing liquid to the dust collecting electrode, and the harmful gas absorbing liquid is provided on the surface of the dust collecting electrode. A film can be formed, and the particulate matter collected by the dust collecting electrode can be washed and peeled off.

  In the gas purification device according to the fifth aspect of the present invention, an absorption liquid storage tank is provided below the casing to store an absorption liquid that has cleaned the dust collecting electrode, and can be circulated to the absorption liquid supply means. It is characterized in that it can be discharged into the process and can be replenished with a new harmful gas absorption liquid.

  The gas purification apparatus of the invention of claim 6 is characterized in that the first spraying means for spraying the harmful gas absorbing liquid is provided upstream of the discharge electrode in the gas flow direction.

  In the gas purification apparatus according to the seventh aspect of the present invention, the gas to be treated contains both sulfurous acid gas and sulfuric acid gas, and the gas treatment temperature is higher than the discharge electrode in the gas flow direction, and the gas treatment temperature is higher than the acid dew point. A second spraying means for spraying an aqueous solution containing chloride or an aqueous alkaline solution is provided.

The gas purification method of the invention of claim 8 is a dust collecting electrode that opens in a direction along the flow path cross section across the gas flow and opens in a direction along the gas flow by overlapping a plurality of conductive meshes facing the discharge electrode. By applying a predetermined voltage to the discharge electrode, an ion wind that induces a secondary flow in a direction crossing the gas flow is generated, and a harmful gas absorbing liquid film is formed on the surface of the ion wind. Further, gas dust removal treatment and harmful gas treatment are performed by passing the dust collection electrode.

According to the gas purification apparatus of the first aspect of the present invention, the ion wind that induces and forms the secondary flow in the direction crossing the gas flow when a predetermined voltage is applied in the casing provided with the inlet and the outlet. A discharge electrode that can be generated is arranged along the gas flow direction, and a plurality of conductive meshes are stacked to open in the direction along the cross section of the flow path across the gas flow and to open in the direction along the gas flow. A liquid film formation in which a dust collecting electrode having a predetermined aperture ratio that can pass through a gas is disposed opposite the discharge electrode along the gas flow direction, and a liquid film of a harmful gas absorbing liquid is formed on the surface of the dust collecting electrode Means are provided. Therefore, when the particulate matter in the gas introduced into the casing is charged by the discharge electrode, the easily charged particulate matter is originally attracted to and collected by the dust collecting electrode by a strong electrostatic force. However, the fine particulate matter that is difficult to be charged flows to the dust collecting electrode side together with the gas accelerated in the direction crossing the gas flow by the ion wind despite the fact that only the fine electrostatic force acts. While trapped while passing through the inside, the ionic wind of the gas passes through the dust collecting electrode layer and reverses, while harmful components such as sulfur oxides are contained on the surface of the dust collecting electrode. It will be absorbed by gas-liquid contact with the formed harmful gas absorbing liquid film efficiently, so that particulate matter in the gas can be reliably collected, and the detrimental gas processing efficiency such as desulfurization performance can be improved. As a result of the main gas While suppressing the air losses, it is possible to greatly improve the gas purification efficiency.

  According to the gas purification device of the second aspect of the present invention, since the liquid path along the substantially vertical direction capable of forming a liquid film in which the harmful gas absorbing liquid continuously falls without interruption on the dust collecting electrode is provided. The surface area of the harmful gas-absorbing liquid film in the dust collecting electrode that can be contacted can be greatly increased, and the desulfurization efficiency can be improved by improving the gas-liquid contact efficiency.

  According to the gas purification device of the third aspect of the present invention, since the adsorption member having a predetermined porosity and capable of adsorbing harmful components in the gas is attached to the dust collecting electrode, the ion wind of the gas is collected. While passing through the dust electrode layer and reversing, harmful components such as sulfur oxides contained in the gas are adsorbed and concentrated on the adsorbing member, and as a result, the reaction efficiency with the absorbing liquid is promoted, and the main gas The exhaust gas purification efficiency can be further improved while suppressing the pressure loss.

  According to the gas purification device of the invention of claim 4, the liquid film forming means is an absorbing liquid supply means for supplying a harmful gas absorbing liquid to the dust collecting electrode, and a harmful gas absorbing liquid film is formed on the surface of the dust collecting electrode. In addition, the particulate matter collected by the dust collection electrode can be washed and peeled off, so this absorbing liquid supply means performs the harmful gas absorption liquid film forming process and the particulate matter peeling process. The structure can be simplified.

  According to the gas purification apparatus of the fifth aspect of the present invention, the absorption liquid storage tank for storing the absorption liquid that has cleaned the dust collecting electrode is provided below the casing, and can be circulated to the absorption liquid supply means. Since it can be discharged and a new harmful gas absorption liquid can be replenished, waste of a large amount of the harmful gas absorption liquid can be suppressed, and a predetermined treatment effect by the harmful gas absorption liquid can be secured.

  According to the gas purification device of the sixth aspect of the invention, since the first spraying means for spraying the harmful gas absorbing liquid is provided on the upstream side of the discharge electrode in the gas flow direction, the first spraying means for the gas to be processed. When the harmful gas absorption liquid is sprayed, the spray droplets of this harmful gas absorption liquid come into gas-liquid contact with harmful components in the gas, and when this gas is hot, the reaction product evaporated by its heat Or an un-evaporated reaction product is generated, and this reaction product is guided by the ionic wind as particles or mist to the dust collecting electrode as both sides, and can be reliably removed. .

According to the gas purification apparatus of the seventh aspect of the invention, the gas to be treated contains both sulfurous acid gas and sulfuric acid gas, and the gas treatment temperature is higher than the acid dew point upstream of the discharge electrode in the gas flow direction. Since the second spraying means for spraying the aqueous solution containing chloride or the alkaline aqueous solution is provided, the aqueous solution containing chloride or the alkaline aqueous solution is sprayed to the gas to be treated by the second spraying means. The spray droplets of this absorbing liquid come into gas-liquid contact with harmful components in the gas and evaporate while the droplets are scattered because the gas treatment temperature is higher than the acid dew point. A reaction product of SO ₃ is produced, and this reaction product can be reliably removed by being guided and collected as particles on the dust collection electrode by the ion wind.

According to the gas purification method of the eighth aspect of the present invention, a plurality of conductive meshes are stacked so as to face the discharge electrode, thereby opening in a direction along the flow path cross section crossing the gas flow and opening in a direction along the gas flow. By providing a dust electrode and applying a predetermined voltage to the discharge electrode, an ion wind that induces a secondary flow in a direction crossing the gas flow is generated, and a harmful gas absorption liquid film is formed on the surface of the ion wind. Gas dust removal treatment and harmful gas treatment are executed by passing the dust collection electrode, so that particulate matter is collected while the gas ion wind passes through the dust collection electrode layer. At the same time, harmful components such as sulfur oxides are efficiently absorbed by gas-liquid contact with the harmful gas absorption liquid film, and particulate matter in the gas can be reliably collected, and desulfurization performance, etc. Improve hazardous gas treatment efficiency Bets can be, as a result, while suppressing the ventilation loss of the main gas, it is possible to greatly improve the gas purification efficiency.

  Exemplary embodiments of a gas purification apparatus and method according to the present invention will be described below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.

  1 is a front view showing a gas purification apparatus according to Embodiment 1 of the present invention, FIG. 2 is a plan view showing the gas purification apparatus of Embodiment 1, and FIG. 3 is dust collection in the gas purification apparatus of Embodiment 1. FIG. 4 and FIG. 5 are schematic views showing modifications of the dust collecting electrode in the gas purification apparatus of the first embodiment, and FIG. 6 is a schematic view showing the entire configuration of the gas purification apparatus of the first embodiment. It is.

  The gas purification apparatus of this embodiment purifies exhaust gas discharged from a diesel engine or an oil fired boiler as an internal combustion engine. Specifically, by applying a high voltage to the discharge electrode, the flow of exhaust gas induced when ions generated by corona discharge move from the discharge electrode to the dust collection electrode to the counter electrode in the electric field. Is generated separately from the main flow of exhaust gas. In this case, by forming the dust collection electrode with a material having a large aperture ratio, the ion wind is introduced into the dust collection electrode without being reversed on the surface of the dust collection electrode, and particles in the exhaust gas Can be collected efficiently. Also, by forming a harmful gas absorption liquid film on the surface of the dust collection electrode, harmful components such as sulfur oxides contained in the exhaust gas can be removed from the exhaust gas while the ion wind passes through the dust collection electrode. It can be absorbed by gas-liquid contact with the membrane efficiently. As a result, it is possible to improve the exhaust purification performance by reliably removing particulate matter and harmful components in the exhaust gas without providing a layer that increases ventilation loss such as a packed layer provided orthogonal to the main gas. Can do. Hereinafter, the gas purification apparatus and method of the present embodiment will be specifically described.

In the gas purification apparatus of the first embodiment, as shown in FIG. 6, particulate matter (PM) and sulfurous acid gas (sulfur oxide, SO ₂ , SO ₂ ) are emitted from an exhaust gas emission source 11 such as a diesel engine or an oil fired boiler. ₃ ) and other harmful components are contained, and the exhaust gas is discharged. The gas treatment device 12 removes harmful components such as particulate matter and sulfurous acid gas from the exhaust gas, and the purified gas is discharged from the chimney 13 to the atmosphere. On the other hand, the processing liquid used in the gas processing apparatus 12 is processed by the liquid processing apparatus 14 and processed below the drainage standard value, and then discharged out of the system. After the reaction product (hazardous substance) is separated, for example, from solids, incineration and industrial waste treatment are performed.

  In this gas processing apparatus 12, as shown in FIGS. 1 to 3, the casing 21 has a hollow box shape, an exhaust gas passage 22 is formed inside, and exhaust gas is introduced into one end of the casing 21. An inlet portion 23 is formed, and an outlet portion 24 for discharging the purified gas is formed at the other end portion. The shape of the casing 21 is not limited to the box shape, and can be set as appropriate according to the use and location, the exhaust gas throughput, such as a cylindrical shape or an elliptical cylindrical shape.

  In the exhaust gas flow path 22 in the casing 21, a discharge electrode 25 that is located on the center side of the casing 21 and charges the particulate matter in the exhaust gas is disposed along the flow direction of the exhaust gas. Further, in the casing 21, a dust collecting electrode 26 that collects particulate matter charged by the discharge electrode 25 on the left and right inner wall faces the discharge electrode 25 and extends in the flow direction of the exhaust gas. It is arranged along.

  The discharge electrode 25 includes a plurality of main portions 25a disposed in the casing 21 along a vertical direction perpendicular to the flow direction of the exhaust gas, and a plurality of main portions 25a radially projecting at predetermined intervals. Each discharge part 25b is provided along the direction crossing the exhaust gas flow path 22. A pair of insulators 27 are fixed on the front and rear sides of the casing 21, and support frames 28 are respectively suspended and fixed from the insulators 27, and mounting frames 29 are supported by the support frames 28. The upper and lower end portions of the discharge electrode 25 (main portion 25a) are fixed to the top. In this embodiment, a pair of insulators is used. However, when supporting a plurality of discharge electrodes in a plurality of rows, a plurality of insulators are supported, and the method is the same as that of a conventional electric dust collector or the like. It can be handled by structure.

  On the other hand, the dust collection electrode 26 is made of a material having a predetermined aperture ratio through which ion wind containing charged particulate matter can pass, and at least on the exhaust gas flow path 22 side facing the discharge electrode 25 side, A conductive net, specifically, a conductive material such as a wire net is provided. In addition, as long as the aperture ratio is sufficient to allow the particulate matter entrained by the ionic wind to pass through, and a conductive material, as a wire mesh, punching metal, or expanded metal in which wires are woven into a plain weave, etc. However, it is desirable to use a material having a liquid path along a substantially vertical direction that can form a liquid film in which an alkali-absorbing liquid, which will be described later, falls continuously without interruption. In addition, when using a wire mesh, it is necessary to select the wire constituting the wire mesh so that the thickness of the wire does not become too thin so that the electric field is not concentrated locally. Further, the dust collecting electrode 26 may be made of a non-conductive material as long as the material constituting the dust collecting electrode 26 is a material having a sufficient aperture ratio other than a conductive material such as a wire mesh.

  Further, as described above, the dust collection electrode 26 effectively causes the secondary flow to act on the cross section intersecting with the flow direction of the exhaust gas, but it is preferable in the direction along the cross section of the flow path crossing the gas flow. In the case of an aperture ratio, for example, a metal mesh material, a plurality of materials having an aperture ratio of about 70% are used in layers, and the aperture ratio is also provided in the direction along the gas flow. In order to ensure a two-dimensional flow circulation in a direction perpendicular to the gas flow, it is also necessary that the exhaust gas guided to the dust collecting electrode 16 can move in the gas flow direction again.

  Further, the thickness of the dust collection electrode 26 should be determined from the pressure loss of the dust collection electrode 26 and the required dust collection performance. Although it is related to the porosity of the material used, it is preferable to reduce the pressure loss as much as possible so that the exhaust gas can pass through. Accordingly, a material that is relatively thin and has a large aperture ratio is used. However, in order to make the secondary flow pattern in the cross section orthogonal to the flow direction of the exhaust gas effective, the convection between the portion where the dust collecting electrode 26 is installed and the flow path through which the exhaust gas flows is effective. Therefore, it is necessary to set the distance from the discharge electrode 25 appropriately.

  One side of the high-voltage power supply 30 is connected to the main portion 25 a of the discharge electrode 25, and the other side is connected to the dust collection electrode 26. A high voltage can be applied between the discharge electrode 25 and the dust collection electrode 26. it can. In this case, the discharge electrode 25 side is applied to the negative electrode, and the dust collecting electrode 26 is grounded. Corona discharge generated at the tip of the discharge portion 25b in the discharge electrode 25 by applying the discharge electrode 25 to the negative electrode. Particulate matter contained in the exhaust gas is ionized in the vicinity of the starting point. As the ionized particulate matter moves due to the electric field, the surrounding exhaust gas is also drawn from the tip of the discharge portion 15b of the discharge electrode 25 toward the dust collection electrode 26 to generate an ion wind. In the present embodiment, the discharge electrode 25 side is a negative pole, but even if it is a positive pole, an ion wind can be generated and is not particularly limited.

  Therefore, when a high voltage is applied to the discharge electrode 25 by the high-voltage power supply 30, ions generated by corona discharge move from the discharge electrode 25 toward the dust collecting electrode 26 in the electric field. An ion wind, which is the next flow, is generated in a direction crossing the flow of the main exhaust gas, and an ion wind containing charged particulate matter is introduced into the dust collecting electrode 26. As a result, the ion wind in the exhaust gas Particulate matter can be electrostatically collected on the dust collecting electrode 26.

  The casing 21 is provided with an absorbing liquid supply device 31 for supplying an alkaline absorbing liquid to the dust collecting electrode 26 as a liquid film forming means for forming a liquid film of a harmful gas absorbing liquid on the surface of the dust collecting electrode 26. ing. The absorption liquid supply device 31 includes a plurality of liquid supply nozzles 32 that supply an alkaline absorption liquid to the dust collection electrode 26 at the upper part of the casing 21. Therefore, an alkali absorbing liquid film can be formed on the surface of the dust collecting electrode 26 by supplying the alkali absorbing liquid to the dust collecting electrode 26 from the plurality of liquid supply nozzles 32. Here, the absorbing liquid supply device 31 having the liquid supply nozzle 32 is provided as the liquid film forming means. However, the present invention is not limited to this configuration, and a liquid film can be uniformly formed on the surface of the dust collection electrode 26. Any overflow method may be used.

  And the absorption liquid storage tank 33 which stores an alkaline absorption liquid is provided in the lower part of the casing 21. An absorption liquid circulation passage 34 that can circulate the alkali absorption liquid from the absorption liquid storage tank 33 to each liquid supply nozzle 32 of the absorption liquid supply apparatus 31 is provided, and a circulation pump 35 is attached to the absorption liquid circulation path 34. Has been. The absorption liquid circulation path 34 is connected to a discharge path 36 for discharging the waste liquid to the liquid processing apparatus 14 (see FIG. 6) and a replenishment path 37 for replenishing a new alkaline absorption liquid.

Therefore, by driving the circulation pump 35, the alkali absorbent stored in the absorbent storage tank 33 can be circulated to the absorbent supply device 31 through the absorbent circulation path 34 and supplied from the liquid supply nozzle 32. . In this case, an alkali absorbing liquid film can be formed on the surface of the dust collecting electrode 26 by intermittently supplying the alkali absorbing liquid from each liquid supply nozzle 32 to the dust collecting electrode 26 every predetermined time. While the ionic wind passes through the dust collecting electrode 26 and reverses, harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas efficiently come into gas-liquid contact with the alkali absorbing liquid film and are absorbed. can do. Further, by continuously supplying the alkali absorbing liquid from each liquid supply nozzle 32 to the dust collecting electrode 26 every predetermined time, the particles collected on the surface of the dust collecting electrode 26 using the alkali absorbing liquid as a cleaning liquid. It is possible to clean and peel off the substance and the like, and the alkaline absorbing liquid used for cleaning is stored in the absorbing liquid storage tank 33.

  In addition, as an alkali absorption liquid, the aqueous solution containing caustic soda, magnesium hydroxide, calcium hydroxide, etc., or seawater can be applied.

  From the viewpoint as described above, in this embodiment, the dust collection electrode 26 is formed by laminating a plurality of expanded metals 38 in multiple layers as shown in detail in FIG. In this case, the expanded metal 38 is formed with a plurality of rhombus-shaped openings 38a, and the expanded metal 38 has a plurality of openings 38a that are overlapped to allow particulate matter accompanied by the ionic wind to pass therethrough. A sufficient aperture ratio can be ensured. Then, a liquid film of the alkali absorbing liquid can be formed on the surface of the expanded metal 38 by the alkali absorbing liquid supplied from the liquid supply nozzle 32 of the absorbing liquid supply apparatus 31.

The configuration of the dust collection electrode 26 is not limited to this structure. For example, as shown in FIG. 4, a porous board-shaped dust collecting electrode 26 is formed by using a conductive adsorbing member 39 having an adsorbing property such as activated carbon fiber as a raw material and integrally forming the adsorbing member 39. Then, by providing the adsorbing member 39 with an oxidation function (for example, adding an oxidation catalyst), harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas are adsorbed and oxidized, so that the alkaline absorbing liquid is obtained. It can be easily absorbed.

Further, as shown in FIG. 5, the dust collecting electrode 26 is configured by sandwiching a non-conductive adsorbing member 40 having a high porosity with adsorbability between a pair of conductive meshes (expanded metal) 38. To do. Further, by providing an oxidation catalyst inside the adsorbing member 40, harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas can be adsorbed and oxidized to be easily absorbed by the alkali absorbent. it can.

  In the gas purification apparatus of the present embodiment configured as described above, as shown in FIGS. 1 and 2, the exhaust gas introduced into the casing 21 from the inlet 23 passes through the exhaust gas passage 22 and is discharged to the discharge electrode. The particulate matter in the exhaust gas is ionized in the vicinity of the starting point of the corona discharge generated at the tip of the discharge portion 25b of the discharge electrode 25, and the ionized particulate matter is collected from the tip of the discharge electrode 25 to the dust collecting electrode. An ionic wind is generated by entraining the surrounding exhaust gas 26. As a result, with respect to the exhaust gas introduced into the casing 21 and flowing through the exhaust gas passage 22, a secondary flow of the exhaust gas is formed by the ion wind in a cross section intersecting with the flow of the exhaust gas, and is ionized. Exhaust gas containing particulate matter is blown onto the dust collection electrode 26. Therefore, the exhaust gas flowing in the casing 21 is accelerated toward the dust collection electrode 26 by the ion wind, and charged particulate matter is collected when passing through the dust collection electrode 26.

  In this case, the distance of the discharge electrode 15 in the cross section intersecting with the flow of the exhaust gas is appropriately selected. For example, if the distance between the adjacent discharge electrodes 15 in the longitudinal cross section along the flow direction of the exhaust gas is reduced, the current can flow evenly and generate corona discharge to generate ion wind. If they are short, they interfere with each other, so a certain distance is necessary. On the other hand, if it is opened too much, the area where the ion wind does not act effectively increases when viewed from the flow direction of the exhaust gas, and sufficient efficiency cannot be obtained.

The absorbing liquid supply device 31 forms an alkali absorbing liquid film on the surface of the dust collecting electrode 26 by supplying the alkali absorbing liquid to the dust collecting electrode 26 from a plurality of liquid supplying nozzles 32. While the exhaust gas ion wind passes through the dust collection electrode 26 and reverses, harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas are efficiently gas-liquid to the alkali absorbing liquid film. Absorbed and removed by contact. The purified gas from which particulate matter and harmful components have been removed is discharged from the outlet portion 24 to the outside of the casing 21.

  The absorbing liquid supply device 31 continuously supplies the alkali absorbing liquid from each liquid supplying nozzle 32 to the dust collecting electrode 26 at predetermined time intervals, so that the particulate matter collected on the surface of the dust collecting electrode 26 is collected. The alkaline absorbing liquid used for cleaning is stored in the absorbing liquid storage tank 33. A part of the alkali absorbing liquid stored in the absorbing liquid storage tank 33 is discharged from the discharge passage 36 to the liquid processing apparatus 14 (see FIG. 6), where SS (solid matter such as dust) processing and COD processing are performed. After the waste liquid treatment is performed, harmful components are incinerated, for example, while the purified alkali absorbent is returned to the absorbent reservoir tank 33 from the replenishment passage 37.

  As described above, in the gas purification apparatus according to the first embodiment, an ion wind that induces and forms a secondary flow in a direction across the flow of the exhaust gas when a predetermined voltage is applied to the exhaust gas passage 22 of the casing 21. Is disposed on the inner wall surface of the casing 21, and a dust collection electrode 26 having a predetermined aperture ratio capable of passing ion wind is disposed on the inner wall surface of the casing 21. An absorbing liquid supply device 31 including a plurality of liquid supply nozzles 32 for supplying an alkali absorbing liquid to be absorbed and forming a liquid film on the surface thereof is provided.

  Therefore, when the particulate matter contained in the exhaust gas introduced into the casing 21 is charged by the discharge electrode 25, an ion wind is generated from the discharge electrode 25 toward the dust collecting electrode 26, and the exhaust gas is exhausted by the ion wind. Particulate matter is collected while the gas passes through the dust collection electrode 26, and harmful components such as sulfur oxides are efficiently gas-liquid on the alkali absorbing liquid film formed on the surface of the dust collection electrode 26. It will be absorbed and removed by contact, so that particulate matter in the exhaust gas can be reliably collected, and the harmful gas treatment efficiency such as desulfurization performance can be improved. Gas purification efficiency can be greatly improved while suppressing loss.

  Moreover, in the gas purification apparatus of the present embodiment, the discharge electrode 25 can generate an ion wind that induces and forms a secondary flow in the casing 21 in a direction across the flow of the exhaust gas when a voltage is applied. The dust collection electrode 26 has a predetermined aperture ratio that can pass the secondary flow. Although the particulate matter that is easily charged is originally attracted to and collected by the dust collecting electrode 26 by a strong electrostatic force, the fine particulate matter that is difficult to be charged is not limited to the fact that only a minute electrostatic force acts. It flows to the dust collecting electrode 26 side together with the exhaust gas accelerated in the direction crossing the gas flow by the ion wind, and is collected while passing through the dust collecting electrode 26, so that only a fine electrostatic force acts. Fine particulate matter that is difficult to be charged can be efficiently collected by convection of the gas flowing through the flow path so as to pass through the dust collection electrode 26. In this case, since the alkali absorbing liquid film is formed on the surface of the dust collecting electrode 26, that is, the opening having a predetermined opening ratio, the exhaust gas passes through the opening of the dust collecting electrode 26 and reverses. In addition, the exhaust gas makes efficient gas-liquid contact with the liquid film, so that the exhaust gas can be efficiently desulfurized.

  Furthermore, in the gas purification apparatus of the present embodiment, the dust collection electrode 26 is formed by laminating a plurality of expanded metals 38 in multiple layers, and the surface area of the alkali absorbing liquid film in the dust collection electrode 26 that can contact the exhaust gas is increased. The desulfurization efficiency can be improved by increasing the gas-liquid contact efficiency.

  Further, the liquid film forming means of the present invention is an absorption liquid supply device 31 that supplies an alkali absorption liquid to the dust collection electrode 26, and the alkali absorption liquid is supplied to the dust collection electrode 26 by a plurality of liquid supply nozzles 32. An alkali-absorbing liquid film can be formed on the surface, and the structure can be simplified. Then, the particulate matter collected on the dust collecting electrode 26 can be peeled off and washed by continuously injecting the alkali absorbing liquid onto the dust collecting electrode 26 by the liquid supply nozzles 32 of the absorbing liquid supply device 31. By using the alkali absorbing liquid as the cleaning liquid, the alkali absorbing liquid film forming process and the particulate matter peeling process can be performed with one apparatus. That is, it is possible to efficiently perform dust removal and gas absorption processing simultaneously.

  Further, an absorption liquid storage tank 33 for storing the alkaline absorption liquid that has cleaned the dust collecting electrode 26 is provided below the casing 21, and can be circulated to the absorption liquid supply apparatus 31 through the absorption liquid circulation passage 34. In addition to being able to be discharged, a new alkali absorbing solution can be replenished, and waste of a large amount of the alkali absorbing solution can be suppressed, and a predetermined treatment effect by the alkali absorbing solution can be ensured.

  FIG. 7 is a front view showing a gas purification apparatus according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

  In the gas purification apparatus according to the second embodiment, as shown in FIG. 7, a casing 21 having a hollow box shape has an exhaust gas passage 22 formed therein, and an inlet 23 for introducing exhaust gas into one end. Is formed at the other end portion of the other end portion. In the casing 21, a discharge electrode 25 for charging particulate matter in the exhaust gas is disposed along the flow direction of the exhaust gas, and the particulate form charged by the discharge electrode 25 opposite to both sides thereof. A dust collecting electrode 26 for collecting the substance is disposed along the flow direction of the exhaust gas.

  One of the high-voltage power supplies 30 is connected to the discharge electrode 25 and the other is connected to the dust collection electrode 26, and a high voltage can be applied between the discharge electrode 25 and the dust collection electrode 26. In this case, the discharge electrode 25 side is applied to the negative electrode, and the dust collecting electrode 26 is grounded. In the vicinity of the starting point of the corona discharge generated at the tip of the discharge electrode 25 when the discharge electrode 25 is applied to the negative electrode. Particulate matter contained in the exhaust gas is ionized. As the ionized particulate matter moves by the electric field, the surrounding exhaust gas is also drawn from the tip of the discharge electrode 25 toward the dust collection electrode 26 to generate an ion wind.

  Therefore, when a high voltage is applied to the discharge electrode 25 by the high-voltage power supply 30, ions generated by corona discharge move from the discharge electrode 25 toward the dust collecting electrode 26 in the electric field. An ion wind, which is the next flow, is generated in a direction crossing the flow of the main exhaust gas, and an ion wind containing charged particulate matter is introduced into the dust collecting electrode 26. As a result, the ion wind in the exhaust gas Particulate matter can be electrostatically collected on the dust collecting electrode 26.

  The casing 21 is provided with an absorption liquid supply device 31 for supplying an alkali absorption liquid to the dust collecting electrode 26 to form an alkali absorption liquid film on the surface thereof. The absorption liquid supply device 31 includes a plurality of liquid supply nozzles 32 that supply an alkaline absorption liquid to the dust collection electrode 26 at the upper part of the casing 21. Therefore, an alkali absorbing liquid film can be formed on the surface of the dust collecting electrode 26 by supplying the alkali absorbing liquid to the dust collecting electrode 26 from the plurality of liquid supply nozzles 32.

Further, the casing 21 is provided with a first spraying device 51 for spraying the alkali absorbing liquid, which is located upstream of the discharge electrode 25 in the exhaust gas flow direction. The first spraying device 51 is configured by a plurality of injection nozzles 52 that inject an alkali absorbing liquid to the exhaust gas flowing from the exhaust gas passage 22 to the discharge electrode 25. Therefore, by spraying an alkali absorbing liquid on the exhaust gas from the plurality of injection nozzles 52, the spray droplets react with harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas and are evaporated by exhaust heat. Reaction product (dust) or unvaporized reaction product (mist) can be formed.

  An absorption liquid storage tank 33 for storing an alkaline absorption liquid is provided at the lower portion of the casing 11, and an absorption liquid circulation passage 34 having a circulation pump 35 is connected to the absorption liquid supply device 31 from the absorption liquid storage tank 33. In addition to being connected to each liquid supply nozzle 32, a first absorption liquid supply passage 53 branched from the absorption liquid circulation passage 34 is connected to a plurality of injection nozzles 52.

Therefore, by driving the circulation pump 35, the alkali absorption liquid stored in the absorption liquid storage tank 33 is circulated to the absorption liquid supply device 31 through the absorption liquid circulation passage 34 and supplied from the liquid supply nozzle 32. A liquid film of an alkali absorbing liquid can be formed on the surface of the dust electrode 26. Further, the alkali absorbing liquid stored in the absorbing liquid storage tank 33 is supplied from the absorbing liquid circulation passage 34 to the first spraying device 51 through the first absorbing liquid supply passage 53 and is injected from the injection nozzle 52 into the high-temperature exhaust gas. be able to. Then, while the ionic wind of the exhaust gas passes through the dust collecting electrode 26 and reverses, harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas are efficiently gas-liquid to the alkali absorbing liquid film. While being able to contact and absorb, the reaction product produced by the reaction with the alkali absorbing liquid jetted from the jet nozzle 52 can be electrostatically collected on the dust collecting electrode 26.

In the gas purification apparatus of the present embodiment configured as described above, the exhaust gas introduced into the casing 21 from the inlet portion 23 flows through the exhaust gas flow path 22, and the first spraying device 51 receives the exhaust gas from the exhaust gas passage 22. By spraying the alkali absorbing liquid from each spray nozzle 52, the spray droplets react with harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas, and reaction products (dust) evaporated by exhaust heat. Or an unevaporated reaction product (mist) is formed. The exhaust gas containing the reaction product reaches the discharge electrode 25, and the particulate matter in the exhaust gas is ionized in the vicinity of the starting point of the corona discharge generated at the tip of the discharge electrode 25, and the ionized particulate matter is obtained. However, the surrounding exhaust gas is entrained from the tip of the discharge electrode 25 toward the dust collection electrode 26 to generate ion wind. As a result, with respect to the exhaust gas introduced into the casing 21 and flowing through the exhaust gas passage 22, a secondary flow of the exhaust gas is formed by the ion wind in a cross section intersecting with the flow of the exhaust gas, and is ionized. Exhaust gas containing particulate matter is blown onto the dust collection electrode 26.

On the other hand, in the dust collection electrode 26, the alkali absorption liquid is intermittently supplied from the liquid supply nozzles 32 of the absorption liquid supply device 31 to the dust collection electrode 26, so that the surface of the dust collection electrode 26 absorbs alkali. A liquid film of liquid is formed. Therefore, a reaction product (dust, sulfur oxide, etc.) that reacts with the charged particulate matter or spray droplets of the alkali absorbing liquid while the ionic wind of the exhaust gas passes through the dust collecting electrode 26 and reverses. Mist) is collected. Further, harmful components such as sulfur oxide (SO ₂ ) remaining in the exhaust gas are efficiently absorbed and removed by gas-liquid contact with the alkali absorbing liquid film. In this case, the high-temperature exhaust gas introduced into the casing 21 is cooled by the alkali absorbing liquid injected from each injection nozzle 52 of the first spraying device 51 and becomes a low temperature, but the contained sulfur oxide is almost removed. Therefore, operation is possible even at a temperature below the water dew point. However, in consideration of corrosion of the casing 21 and peripheral equipment, it is desirable to maintain the gas temperature above the water dew point temperature or to take countermeasures against corrosion. The purified gas from which particulate matter and harmful components have been removed is discharged from the outlet portion 24 to the outside of the casing 21.

  As described above, in the gas purification apparatus according to the second embodiment, an ion wind that induces and forms a secondary flow in a direction across the flow of the exhaust gas when a predetermined voltage is applied to the exhaust gas passage 22 of the casing 21. Is disposed on the inner wall surface of the casing 21, and a dust collection electrode 26 having an aperture ratio that allows the passage of ion wind is disposed on the inner wall surface of the casing 21, and an alkali absorbing liquid is supplied to the dust collection electrode 26. An absorption liquid supply device 31 comprising a plurality of liquid supply nozzles 32 that form a liquid film on the surface is provided, and an alkali absorption liquid is sprayed on the exhaust gas upstream of the discharge electrode 25 in the flow direction of the exhaust gas. A first spraying device 51 comprising a spray nozzle 52 is provided.

Therefore, the exhaust gas introduced into the casing 21 reacts with the sprayed droplets of the alkali absorbing liquid ejected from the first spraying device 51 due to harmful components such as sulfur oxide (SO ₂ ) contained therein, and is exhausted. Evaporated reaction product (dust) and non-evaporated reaction product (mist) are charged by the discharge electrode 25 together with the contained particulate matter, and ion wind is generated from the discharge electrode 25 toward the dust collecting electrode 26, The exhaust gas is collected while passing through the dust collection electrode 26 by the ion wind, and harmful components such as residual sulfur oxide are efficiently applied to the alkali absorbing liquid film formed on the surface of the dust collection electrode 26. It will be absorbed and removed by gas-liquid contact well, so that particulate matter in the exhaust gas can be reliably collected and the desulfurization performance can be improved. As a result, the exhaust purification efficiency is greatly improved. Rukoto can.

  FIG. 8 is a front view illustrating a gas purification apparatus according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

The gas purification apparatus of Example 3 processes exhaust gas containing both sulfurous acid gas SO ₂ and sulfuric acid gas SO ₃ , and as shown in FIG. 8, a casing 21 having a hollow box shape is provided inside. An exhaust gas passage 22 is formed. An inlet portion 23 for introducing exhaust gas is formed at one end portion, and an outlet portion 24 for discharging purified gas is formed at the other end portion. In the casing 21, a discharge electrode 25 for charging particulate matter in the exhaust gas is disposed along the flow direction of the exhaust gas, and the particulate form charged by the discharge electrode 25 opposite to both sides thereof. A dust collecting electrode 26 for collecting the substance is disposed along the flow direction of the exhaust gas.

  One of the high-voltage power supplies 30 is connected to the discharge electrode 25 and the other is connected to the dust collection electrode 26, and a high voltage can be applied between the discharge electrode 25 and the dust collection electrode 26. In this case, the discharge electrode 25 side is applied to the negative electrode, and the dust collecting electrode 26 is grounded. In the vicinity of the starting point of the corona discharge generated at the tip of the discharge electrode 25 when the discharge electrode 25 is applied to the negative electrode. Particulate matter contained in the exhaust gas is ionized. As the ionized particulate matter moves by the electric field, the surrounding exhaust gas is also drawn from the tip of the discharge electrode 25 toward the dust collection electrode 26 to generate an ion wind.

  Therefore, when a high voltage is applied to the discharge electrode 25 by the high-voltage power supply 30, ions generated by corona discharge move from the discharge electrode 25 toward the dust collecting electrode 26 in the electric field. An ion wind, which is the next flow, is generated in a direction crossing the flow of the main exhaust gas, and an ion wind containing charged particulate matter is introduced into the dust collecting electrode 26. As a result, the ion wind in the exhaust gas Particulate matter can be electrostatically collected on the dust collecting electrode 26.

  The casing 21 is provided with an absorption liquid supply device 31 for supplying an alkali absorption liquid to the dust collecting electrode 26 to form an alkali absorption liquid film on the surface thereof. The absorption liquid supply device 31 includes a plurality of liquid supply nozzles 32 that supply an alkaline absorption liquid to the dust collection electrode 26 at the upper part of the casing 21. Therefore, an alkali absorbing liquid film can be formed on the surface of the dust collecting electrode 26 by supplying the alkali absorbing liquid to the dust collecting electrode 26 from the plurality of liquid supply nozzles 32.

In addition, the inlet portion 23 of the casing 21 is located upstream of the discharge electrode 25 in the exhaust gas flow direction, and is sprayed with an aqueous solution containing chloride under conditions where the exhaust gas treatment temperature is equal to or higher than the acid dew point. A two spraying device 61 is provided. The second spraying device 61 is constituted by a plurality of injection nozzles 62 for injecting an aqueous solution containing chloride with respect to the exhaust gas introduced into the casing 21, that is, in this embodiment, an alkali absorbing solution. Therefore, by spraying the alkali absorbing liquid to the exhaust gas from the plurality of injection nozzles 62, the spray droplets react with harmful components such as sulfur oxide (SO ₃ ) contained in the exhaust gas and are evaporated by exhaust heat. Reaction product (dust) can be formed. The aqueous solution containing chloride is an aqueous solution containing a sulfate or carbonate dissolved salt of any one of Na, K, Mg and Ca, and an aqueous solution containing caustic soda, magnesium hydroxide, calcium hydroxide, Alternatively, seawater can be applied. In this case, by maintaining the temperature condition of spraying at or above the acid dew point, SO ₃ that tends to be mist can be reacted preferentially over SO ₂ in a gaseous state, and SO ₃ can be efficiently removed.

  An absorption liquid storage tank 33 for storing an alkaline absorption liquid is provided at the lower portion of the casing 11, and an absorption liquid circulation passage 34 having a circulation pump 35 is connected to the absorption liquid supply device 31 from the absorption liquid storage tank 33. In addition to being connected to each liquid supply nozzle 32, a second absorption liquid supply passage 63 branched from the absorption liquid circulation passage 34 is connected to a plurality of injection nozzles 62.

Therefore, by driving the circulation pump 35, the alkali absorbing liquid stored in the absorbing liquid storage tank 33 is circulated to the absorbing liquid supply device 31 through the absorbing liquid circulation passage 34 and supplied from the liquid supply nozzle 32. A liquid film of an alkali absorbing liquid can be formed on the surface of the dust collecting electrode 26. Further, the alkali absorbing liquid stored in the absorbing liquid storage tank 33 is supplied from the absorbing liquid circulation passage 34 to the first spraying device 61 through the second absorbing liquid supply passage 63 and is injected from the injection nozzle 62 into the high-temperature exhaust gas. be able to. Then, while the ionic wind of the exhaust gas passes through the dust collecting electrode 26 and reverses, harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas are efficiently gas-liquid to the alkali absorbing liquid film. While being able to contact and absorb, the reaction product of the sulfur oxide (SO ₃ ) generated by the reaction by the alkali absorbing liquid ejected from the ejection nozzle 62 can be electrostatically collected on the dust collecting electrode 26. it can.

In the gas purification apparatus of the present embodiment configured as described above, the exhaust gas introduced into the casing 21 from the inlet 23 flows through the exhaust gas flow path 22, and the second spraying device 61 performs the exhaust gas on the exhaust gas. By spraying the alkali absorbing liquid from each injection nozzle 62, the spray droplets react with harmful components such as sulfur oxide (SO ₃ ) contained in the exhaust gas, and reaction products (dust) evaporated by exhaust heat. Is formed. In this case, it is necessary to react sulfur oxide (SO ₃ ) in the exhaust gas with the alkali absorbing liquid and then evaporate it by exhaust heat to obtain a solid reaction product (dust). The temperature must be equal to or higher than the acid dew point temperature, and the injection amount of the alkali absorbing liquid injected from the injection nozzle 62 is adjusted according to the temperature of the exhaust gas introduced into the casing 21. When the acid dew point temperature or lower, sulfur oxide (SO ₃ ) becomes very fine mist at a stretch and is collected later by the electrostatic dust collecting effect. Compared with the case of absorbing with liquid, ultrafine mist is physically collected, and sufficient collection efficiency cannot be expected.

  The exhaust gas containing the reaction product reaches the discharge electrode 25, and the particulate matter in the exhaust gas is ionized in the vicinity of the starting point of the corona discharge generated at the tip of the discharge electrode 25, and the ionized particulate matter is obtained. However, the surrounding exhaust gas is entrained from the tip of the discharge electrode 25 toward the dust collection electrode 26 to generate ion wind. As a result, with respect to the exhaust gas introduced into the casing 21 and flowing through the exhaust gas passage 22, a secondary flow of the exhaust gas is formed by the ion wind in a cross section intersecting with the flow of the exhaust gas, and is ionized. Exhaust gas containing particulate matter is blown onto the dust collection electrode 26.

On the other hand, in the dust collection electrode 26, the alkali absorption liquid is intermittently supplied from the liquid supply nozzles 32 of the absorption liquid supply device 31 to the dust collection electrode 26, so that the surface of the dust collection electrode 26 absorbs alkali. A liquid film of liquid is formed. For this reason, the charged particulate matter and the reaction products (dust) such as sulfur oxide (SO ₃ ) are collected while the ionic wind of the exhaust gas passes through the dust collection electrode 26 and reverses. Further, harmful components such as sulfur oxide (SO ₂ ) remaining in the exhaust gas are efficiently absorbed and removed by gas-liquid contact with the alkali absorbing liquid film. The purified gas from which particulate matter and harmful components have been removed is discharged from the outlet portion 24 to the outside of the casing 21.

  As described above, in the gas purification apparatus according to the third embodiment, an ion wind that induces and forms a secondary flow in a direction across the flow of the exhaust gas when a predetermined voltage is applied to the exhaust gas passage 22 of the casing 21. Is disposed on the inner wall surface of the casing 21, and a dust collection electrode 26 having an aperture ratio that allows the passage of ion wind is disposed on the inner wall surface of the casing 21, and an alkali absorbing liquid is supplied to the dust collection electrode 26. An absorption liquid supply device 31 comprising a plurality of liquid supply nozzles 32 for forming a liquid film on the surface is provided, and an alkaline absorption liquid is provided under the condition that the processing temperature of the exhaust gas is higher than the acid dew point with respect to the exhaust gas at the inlet 23 The 2nd spraying device 61 which consists of the injection nozzle 62 which sprays is provided.

Therefore, the exhaust gas introduced into the casing 21 reacts with the sprayed droplets of the alkali absorbing liquid ejected from the second spraying device 61 due to the harmful components such as sulfur oxide (SO ₃ ) contained therein, and is exhausted. The evaporated reaction product (dust) is charged by the discharge electrode 25 together with the particulate matter contained therein, and an ion wind is generated from the discharge electrode 25 toward the dust collection electrode 26, and the exhaust gas is converted into the dust collection electrode by the ion wind. In addition to being collected while passing through 26, harmful components such as residual sulfur oxide (SO ₂ ) are efficiently brought into gas-liquid contact with the alkali absorbing liquid film formed on the surface of the dust collecting electrode 26. As a result, the particulate matter in the exhaust gas can be reliably collected and the desulfurization performance can be improved. As a result, the exhaust purification efficiency can be greatly improved.

  FIG. 9 is a front view illustrating a gas purification device according to a fourth embodiment of the present invention, and FIG. 10 is a side view illustrating the gas purification device according to the fourth embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

  In the gas purification apparatus according to the fourth embodiment, as shown in FIGS. 9 and 10, the casing 71 has a hollow box shape, an exhaust gas passage 72 is formed inside, and exhaust gas is introduced into the lower end portion. While the inlet 73 is formed, an outlet 74 for discharging the purified gas is formed at the upper end. In the casing 71, the discharge electrode 25 for charging the particulate matter in the exhaust gas is disposed along the flow direction of the exhaust gas, and the particulate form charged by the discharge electrode 25 facing both sides thereof. A dust collecting electrode 26 for collecting the substance is disposed along the flow direction of the exhaust gas.

  One side of the high-voltage power supply 30 is connected to the main portion 25 a of the discharge electrode 25, and the other side is connected to the dust collection electrode 26. A high voltage can be applied between the discharge electrode 25 and the dust collection electrode 26. it can. In this case, the discharge electrode 25 side is applied to the negative electrode, and the dust collecting electrode 26 is grounded. In the vicinity of the starting point of the corona discharge generated at the tip of the discharge electrode 25 when the discharge electrode 25 is applied to the negative electrode. Particulate matter contained in the exhaust gas is ionized. As the ionized particulate matter moves by the electric field, the surrounding exhaust gas is also drawn from the tip of the discharge electrode 25 toward the dust collection electrode 26 to generate an ion wind.

  Therefore, when a high voltage is applied to the discharge electrode 25 by the high-voltage power supply 30, ions generated by corona discharge move from the discharge electrode 25 toward the dust collecting electrode 26 in the electric field. An ion wind, which is the next flow, is generated in a direction crossing the flow of the main exhaust gas, and an ion wind containing charged particulate matter is introduced into the dust collecting electrode 26. As a result, the ion wind in the exhaust gas Particulate matter can be electrostatically collected on the dust collecting electrode 26.

  The casing 71 is provided with an absorbing liquid supply device 31 that supplies an alkali absorbing liquid to the dust collecting electrode 26 to form an alkali absorbing liquid film on the surface thereof. The absorbing liquid supply device 31 includes a plurality of liquid supplying nozzles 32 that supply an alkali absorbing liquid to the dust collecting electrode 26 at the upper part of the casing 71. Therefore, an alkali absorbing liquid film can be formed on the surface of the dust collecting electrode 26 by supplying the alkali absorbing liquid to the dust collecting electrode 26 from the plurality of liquid supply nozzles 32.

Further, the casing 71 is provided with a first spraying device 51 for spraying the alkali absorbing liquid, located upstream of the discharge electrode 25 in the exhaust gas flow direction (downward in FIG. 9). The first spraying device 51 is configured by a plurality of injection nozzles 52 that inject an alkali absorbing liquid to the exhaust gas flowing from the exhaust gas passage 22 to the discharge electrode 25. Therefore, by spraying an alkali absorbing liquid on the exhaust gas from the plurality of injection nozzles 52, the spray droplets react with harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas and are evaporated by exhaust heat. Reaction product (dust) or unvaporized reaction product (mist) can be formed.

Furthermore, an aqueous solution containing chloride is sprayed on the inlet portion 73 of the casing 71 on the upstream side of the discharge electrode 25 in the flow direction of the exhaust gas and the exhaust gas treatment temperature is equal to or higher than the acid dew point. A two spraying device 61 is provided. The second spraying device 61 is constituted by a plurality of injection nozzles 62 for injecting an aqueous solution containing chloride with respect to the exhaust gas introduced into the casing 21, that is, in this embodiment, an alkali absorbing solution. Therefore, by spraying the alkali absorbing liquid to the exhaust gas from the plurality of injection nozzles 62, the spray droplets react with harmful components such as sulfur oxide (SO ₃ ) contained in the exhaust gas and are evaporated by exhaust heat. Reaction product (dust) can be formed. The aqueous solution containing chloride is an aqueous solution containing a sulfate or carbonate dissolved salt of any one of Na, K, Mg and Ca, and an aqueous solution containing caustic soda, magnesium hydroxide, calcium hydroxide, Alternatively, seawater can be applied.

  A cover 75 for preventing the alkali absorbing liquid sprayed from the liquid supply nozzle 32 from splashing around is attached above each dust collecting electrode 26, while below each dust collecting electrode 26, An inclined gutter 76 for receiving the alkali absorbing liquid flowing down from the dust collecting electrode 26 is attached, and the gutter 76 is connected to the absorbing liquid storage tank 33 by a connecting passage 77. An absorption liquid circulation passage 34 having a circulation pump 35 is connected from the absorption liquid storage tank 33 to each liquid supply nozzle 32 of the absorption liquid supply device 31 and the second absorption liquid branched from the absorption liquid circulation path 34. A supply passage 63 is connected to the plurality of injection nozzles 62.

Therefore, by driving the circulation pump 35, the alkali absorbing liquid stored in the absorbing liquid storage tank 33 is circulated to the absorbing liquid supply device 31 through the absorbing liquid circulation passage 34 and supplied from the liquid supply nozzle 32. A liquid film of an alkali absorbing liquid can be formed on the surface of the dust collecting electrode 26. Further, the alkali absorbing liquid stored in the absorbing liquid storage tank 33 is supplied from the absorbing liquid circulation passage 34 to the first spraying device 61 through the second absorbing liquid supply passage 63 and is injected from the injection nozzle 62 into the high-temperature exhaust gas. be able to. Then, while the ionic wind of the exhaust gas passes through the dust collecting electrode 26 and reverses, harmful components such as sulfur oxide (SO ₂ ) contained in the exhaust gas are efficiently gas-liquid to the alkali absorbing liquid film. It can be absorbed by contact, and a reaction product of sulfur oxide (SO ₂ ) produced by reaction with the alkali absorbing liquid injected from the injection nozzle 52 and reaction with the alkali absorbing liquid injected from the injection nozzle 62. The reaction product of the generated sulfur oxide (SO ₃ ) can be electrostatically collected on the dust collection electrode 26.

In the gas purification apparatus of the present embodiment configured as described above, the exhaust gas introduced into the casing 71 from the inlet 73 flows through the exhaust gas passage 22. First, the second spray device is applied to the exhaust gas. 61. By spraying the alkali absorbing liquid from each of the spray nozzles 61, the spray droplets react with harmful components such as sulfur oxide (SO ₃ ) contained in the exhaust gas, and reaction products evaporated by exhaust heat ( Dust) is formed. In this case, it is necessary to react sulfur oxide (SO ₃ ) in the exhaust gas with the alkali absorbing liquid and then evaporate it by exhaust heat to obtain a solid reaction product (dust). The temperature must be equal to or higher than the acid dew point temperature, and the injection amount of the alkali absorbing liquid injected from the injection nozzle 62 is adjusted according to the temperature of the exhaust gas introduced into the casing 21.

Next, the alkali absorbing liquid is jetted from the jet nozzles 52 of the first spray device 51 to the exhaust gas flowing through the exhaust gas flow path 72, whereby the sulfur oxide ( It reacts with harmful components such as SO ₂ ) to form a reaction product (dust) evaporated by exhaust heat or a non-evaporated reaction product (mist). Then, the exhaust gas containing each reaction product reaches the discharge electrode 25, and the particulate matter in the exhaust gas is ionized in the vicinity of the starting point of the corona discharge generated at the tip of the discharge electrode 25. The substance entrains the surrounding exhaust gas from the tip of the discharge electrode 25 toward the dust collection electrode 26 to generate ion wind. As a result, with respect to the exhaust gas introduced into the casing 71 and flowing through the exhaust gas passage 72, a secondary flow of the exhaust gas is formed by the ion wind in the cross section intersecting with the flow of the exhaust gas, and is ionized. Exhaust gas containing particulate matter is blown onto the dust collection electrode 26.

On the other hand, in the dust collection electrode 26, alkali absorption liquid is intermittently ejected from each liquid supply nozzle 32 of the absorption liquid supply device 31 to the dust collection electrode 26, so that alkali absorption is performed on the surface of the dust collection electrode 26. A liquid film of liquid is formed. Therefore, the charged particulate matter and reaction products (mist, dust) such as sulfur oxide (SO ₂ , SO ₃ ) are charged while the ionic wind of the exhaust gas passes through the dust collection electrode 26 and reverses. It is collected. Further, harmful components such as sulfur oxide (SO ₂ ) remaining in the exhaust gas are efficiently absorbed and removed by gas-liquid contact with the alkali absorbing liquid film. The purified gas from which particulate matter and harmful components have been removed is discharged from the outlet portion 74 to the outside of the casing 71.

  As described above, in the gas purification apparatus according to the fourth embodiment, the discharge electrode 25 and the dust collection electrode 26 are arranged in the exhaust gas passage 22 of the casing 21 so as to face each other in the exhaust gas flow direction. An absorption liquid supply device 31 including a plurality of liquid supply nozzles 32 for supplying an alkali absorption liquid to the dust collecting electrode 26 to form a liquid film on the surface thereof is provided, and the exhaust gas is supplied to the exhaust gas at the inlet 23. A second spraying device 61 comprising a spray nozzle 62 for spraying an alkali absorbing liquid under a condition where the treatment temperature is at or above the acid dew point; and upstream of the discharge electrode 25 and downstream of the second spraying device 61 in the exhaust gas flow direction. The 1st spraying device 51 which consists of the injection nozzle 52 which sprays alkali absorption liquid with respect to exhaust gas is provided in the side.

Therefore, the exhaust gas introduced into the casing 21 reacts with the sprayed droplets of the alkali absorbing liquid ejected from the second spraying device 61 due to the harmful components such as sulfur oxide (SO ₃ ) contained therein, and is exhausted. Evaporated reaction products (dust) and harmful components such as sulfur oxide (SO ₂ ) contained react with the spray droplets of the alkali absorbing liquid ejected from the first spray device 51 and evaporate by exhaust heat. The reaction product (dust) and the non-evaporated reaction product (mist) are charged by the discharge electrode 25 together with the particulate matter, and an ion wind is generated from the discharge electrode 25 toward the dust collection electrode 26. The exhaust gas is trapped while passing through the dust collecting electrode 26, and harmful components such as residual sulfur oxide (SO ₂ ) are deposited on the alkali absorbing liquid film formed on the surface of the dust collecting electrode 26. efficiency It will be absorbed and removed by contact with gas and liquid, and particulate matter in the exhaust gas can be reliably collected and desulfurization performance can be improved. As a result, exhaust purification efficiency is greatly improved. be able to.

  In each of the above-described embodiments, the gas purification apparatus and method of the present invention have been described as purifying exhaust gas discharged from a diesel engine, an oil fired boiler, or the like, but the present invention is limited to this field. It is not something. For example, in addition to removing harmful substances such as sulfur oxides, it can be used for purifying nitrogen oxides (NOx) in exhaust gas contained in the air. In this case, nitrogen monoxide is collected. It can be removed by converting it to nitrogen dioxide, which is easily absorbed by the oxidation catalyst attached in the dust electrode layer, and washing away with harmful gas absorption liquid.For example, as an air purification device in tunnels and underground parking lots, NOx can be removed simultaneously.

  Further, in the gas purification apparatus of the present invention, by utilizing the function of efficiently collecting fine particles on the dust collecting electrode and the ability to uniformly form a liquid film and absorb harmful gas components, a large amount of air can be subjected to low pressure loss. And collected very fine particulate organisms such as bacteria and viruses contained in the air efficiently, and collected the cleaning solution by using a disinfectant having a sterilizing function. It can also be used as an air cleaning device having a sterilizing function for killing fungi and improving safety. In this case, it goes without saying that the cleaning liquid can be circulated and used in the same manner as in a normal gas processing apparatus.

  As described above, the gas purification device of the present invention can efficiently perform dust removal and gas treatment without increasing the pressure loss of a large amount of gas. It is possible to achieve a certain effect.

  The gas purification apparatus according to the present invention is for purifying gas by removing harmful components such as particulate matter and sulfur oxide in the gas. Can also be applied.

It is a front view showing the gas purification apparatus which concerns on Example 1 of this invention. It is a top view showing the gas purification apparatus of Example 1. FIG. FIG. 3 is a schematic diagram illustrating a dust collection electrode in the gas purification apparatus according to the first embodiment. FIG. 6 is a schematic diagram illustrating a modification example of the dust collection electrode in the gas purification apparatus according to the first embodiment. FIG. 6 is a schematic diagram illustrating a modification example of the dust collection electrode in the gas purification apparatus according to the first embodiment. It is the schematic showing the whole structure of the gas purification apparatus of Example 1. FIG. It is a front view showing the gas purification apparatus which concerns on Example 2 of this invention. It is a front view showing the gas purification apparatus which concerns on Example 3 of this invention. It is a front view showing the gas purification apparatus which concerns on Example 4 of this invention. It is a side view showing the gas purification apparatus of Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Exhaust gas discharge source 12 Gas processing apparatus 13 Chimney 14 Liquid processing apparatus 21,71 Casing 22,72 Exhaust gas flow path 23,73 Inlet part 24,74 Outlet part 25 Discharge electrode 26 Dust collection electrode 30 High voltage power supply 31 Absorption liquid supply Apparatus (Liquid film forming means, Absorbing liquid supply means)
32 Liquid supply nozzle 33 Absorption liquid storage tank 34 Absorption liquid circulation passage 35 Circulation pump 36 Discharge passage 37 Replenishment passage 51 First spraying device (first spraying means)
52 spray nozzle 61 second spraying device (second spraying means)
62 Injection nozzle

Claims (8)

A casing provided with an inlet portion and an outlet portion, and a secondary flow is induced in the casing in a direction transverse to the gas flow by being arranged in the casing along the gas flow direction and applying a predetermined voltage. A discharge electrode capable of generating ionic wind, and a direction along a cross-section of the flow path that crosses the gas flow by overlapping a plurality of conductive meshes disposed in the casing facing the discharge electrode along the gas flow direction And a dust collecting electrode having a predetermined opening ratio that allows the ion wind to pass through in a direction along the gas flow, and a harmful gas absorbing liquid that absorbs harmful components in the gas on the surface of the dust collecting electrode A gas purification apparatus comprising a liquid film forming means for forming a liquid film.   2. The gas purification device according to claim 1, wherein the dust collecting electrode has a liquid path along a substantially vertical direction capable of forming a liquid film in which the harmful gas absorption liquid continuously falls without interruption. Gas purification device to do.   2. The gas purification apparatus according to claim 1, wherein an adsorption member having a predetermined porosity and capable of adsorbing harmful components in the gas is attached to the dust collection electrode. .   2. The gas purification apparatus according to claim 1, wherein the liquid film forming means is an absorbing liquid supply means for supplying a harmful gas absorbing liquid to the dust collecting electrode, and a harmful gas absorbing liquid is provided on a surface of the dust collecting electrode. A gas purification apparatus characterized in that a film can be formed and particulate matter collected by the dust collecting electrode can be washed and peeled off.   5. The gas purification device according to claim 4, wherein an absorption liquid storage tank is provided below the casing to store an absorption liquid that has cleaned the dust collecting electrode, and can be circulated to the absorption liquid supply means. A gas purification apparatus characterized in that it can be discharged into a process and can be replenished with a new harmful gas absorbing liquid. 6. The gas purification apparatus according to claim 1, wherein a first spraying means for spraying a harmful gas absorbing liquid is provided upstream of the discharge electrode in the gas flow direction. Gas purification device to do.   6. The gas purification apparatus according to claim 1, wherein the gas to be treated contains both sulfurous acid gas and sulfuric acid gas, and the gas treatment is performed upstream of the discharge electrode in the gas flow direction. A gas purifier comprising a second spraying means for spraying an aqueous solution containing chloride or an alkaline aqueous solution under a condition where the temperature is equal to or higher than the acid dew point. A plurality of conductive meshes are opposed to the discharge electrode, and a dust collecting electrode that opens in a direction along the cross section of the flow path crossing the gas flow and opens in a direction along the gas flow is disposed, and a predetermined voltage is applied to the discharge electrode. Is applied to generate an ion wind that induces and forms a secondary flow in a direction crossing the gas flow, and the ion wind is passed through the dust collecting electrode on which a harmful gas absorbing liquid film is formed. A gas purification method comprising performing gas dust removal treatment and harmful gas treatment.

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