JP3731440B2 - Discharge type exhaust gas treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a discharge exhaust gas treatment apparatus. More specifically, the present invention is made incinerator, boiler, internal combustion engine, etc., combustion equipment such as incinerators, exhaust gas, exhaust gas etc. discharged from the heat engine to thermally decompose and detoxify harmful substances such as dioxins. The present invention relates to an exhaust gas treatment apparatus.
[0002]
[Prior art]
Smoke and exhaust gas from incineration facilities for garbage and industrial waste, and heat engines such as boilers and internal combustion engines contain various harmful substances such as dioxins, carbon monoxide, nitrogen oxides, and sulfur oxides. It causes pollution and environmental destruction.
[0003]
In order to remove such harmful substances, various combustion furnaces are used, for example, supplying a mixture of petroleum fuel such as kerosene or heavy oil and air and combusting it with waste at a temperature of about 800 ° C. or less. Are known. In such a combustion furnace, the combustion temperature is still low, and polyhalogenated organic compounds such as dioxins in various chemical reactions with halogen-containing substances such as various chlorine-containing compounds including vinyl chloride resin contained in waste Hazardous substances such as these are likely to occur, and since such harmful substances are inherently present in flue gas and exhaust gas, they are decomposed at a high temperature of 1400 ° C or higher, for example. Dioxins that are produced cannot be rendered harmless.
[0004]
On the other hand, an arc furnace is known as one that enables combustion at high temperatures. However, the arc furnace is inefficient in terms of energy efficiency and is inevitably costly.
[0005]
[Problems to be solved by the invention]
Under such circumstances, the present invention has been made for the purpose of providing an exhaust gas treatment apparatus capable of efficiently performing high-temperature thermal decomposition of harmful substances in exhaust gas at a reduced cost. It is.
[0006]
[Means for Solving the Problems]
Based on this knowledge, the present inventors have found that the purpose can be achieved by adopting a discharge unit having a specific shape as a result of various studies to develop the above-described preferable exhaust gas treatment apparatus. The present invention has been completed.
[0007]
That is, the present invention relates to a means for introducing exhaust gas, a rectangular cylinder comprising an external electrode or a dielectric and an external electrode disposed on the outer surface thereof, and a central portion of the internal space of the rectangular cylinder A discharge unit comprising a plate-like internal electrode disposed on the substrate and a support for fixing and holding the internal electrode in the rectangular cylindrical body, wherein a space portion between the rectangular cylindrical body and the internal electrode An exhaust gas discharge processing means using an exhaust gas passage, a power source for discharging by energizing each electrode, and a means for discharging the discharged exhaust gas, and in a space between the rectangular cylindrical body and the internal electrode The conductive heating element made of carbonaceous particles is filled , and the support is an end plate disposed in close contact with the inner surface at each end edge on the both opening sides of the rectangular cylindrical body. And that there are enough pores to pass the exhaust gas. Moni, a discharge type exhaust gas treatment apparatus being characterized in that it is assumed that suitable holes are provided so that each end of the plate constituting the internal electrode may be fitted or fitted into the central portion It is to provide.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The apparatus of the present invention is mainly composed of exhaust gas discharge treatment means, to which means for introducing exhaust gas and means for discharging the discharge-treated exhaust gas are connected. As this exhaust gas introduction means, for example, there is a type in which the exhaust gas introduction port is connected to the exhaust side of an exhaust duct connected to an incinerator, a combustion apparatus or the like, and the exhaust gas is sucked by a suction fan. As this exhaust gas discharging means, for example, there is a type in which the inflow port is connected to the downstream side or the outflow side of the exhaust gas discharge processing means and the exhaust gas discharged by the suction fan is sucked. The exhaust gas discharge treatment means includes a rectangular cylindrical body, a plate-like internal electrode disposed and fixed to a central portion of the internal space by a support body provided inside the cylindrical body, the support body, In this discharge unit, the space between the rectangular cylindrical body and the internal electrode serves as an exhaust gas passage. As the rectangular cylinder in this discharge element, a horizontally long rectangular square cylinder is preferable, and among them, the aspect ratio of the inner surface is 0.7 or less, particularly 0.6 or less, the contact area of the internal electrode with the exhaust gas Is preferable. In addition, a rectangular cylindrical body is preferable because it can extend the contact time with the exhaust gas. In addition, the rectangular cylindrical body may be composed of a rectangular bowl-shaped member with an open top surface and a lid-shaped member, or may be composed of a divided material that is equally divided up and down. In such a case, after the inner electrode is accommodated in the hook-shaped member, the lid-shaped member is covered on the hook-shaped member, or the lower member of the divided material equally divided into the upper and lower parts is internally After accommodating the electrode, the upper member of the divided material is covered on the lower member, and then the rectangular cylinder is formed by a simple operation such as integration by a suitable means such as welding. Can be easily created. Further, it is preferable to provide steps that can be fitted to each other on the flange-like member and the lid-like member, or on each of the upper and lower divided members, because the covering operation is simple and easy. Further, it is preferable that at least the inner surfaces of the four corners of the rectangular cylindrical body are rounded and formed into R. The rectangular cylinder is composed of only an external electrode, or is composed of a dielectric and an external electrode provided in contact with the outer surface. As the material of the external electrode, a metal or a carbonaceous material is used. As the metal, stainless steel or aluminum is preferable, and as the carbonaceous material, graphite or amorphous carbon is preferable.
[0009]
Further, when the dielectric is used together with the external electrode, it is preferable that at least one of the dielectric and the external electrode, in particular, at least the dielectric is formed in a horizontally long rectangular square tube. When formed in such a rectangular tube, the external electrode is applied by applying a metal paste to the outer periphery of the rectangular tube-shaped dielectric and firing it, or by winding a metal coil, If the external electrode is formed in such a rectangular tube, it is arranged by being fitted with a rectangular rectangular tube made of a horizontally long metal or carbonaceous material having a slightly larger size. Apply ceramic paste on the inner surface of the external electrode and bak it to deposit it, or insert it into the external electrode as a rectangular square tube made of horizontally long metal or carbonaceous material with a slightly smaller size. Make It is arranged by the. The dielectric material is preferably ceramics, particularly heat-resistant ceramics, particularly alumina.
[0010]
Further, as the material of the internal electrode, a heat resistant metal or a carbonaceous material is used, the heat resistant metal is preferably a heat resistant steel such as stainless steel, and the carbonaceous material is preferably graphite or amorphous carbon. The form of the internal electrode is not particularly limited as long as it is a plate shape, but a structure having a large surface area, for example, a structure in which concave and convex portions are continuously formed is preferable. Examples of the concavo-convex portion include a triangular shape, a trapezoidal shape, a wavefront shape, and an embossed shape. Further, in the internal electrode, it is preferable that both end portions corresponding to the four corners of the rectangular cylindrical body are rounded and formed into R. In this case, the internal electrodes are also formed on the inner surfaces of the four corners of the rectangular cylindrical body. It is preferable to form a rounded surface corresponding to the rounded shape. Such rounded R formation can prevent the inconvenience of plasma concentrating at the corners, which occurs when rounding is not performed.
[0011]
The support for fixing and holding the internal electrode in the rectangular cylindrical body is not particularly limited as long as the internal electrode is disposed in the center of the internal space of the rectangular cylindrical body, and preferably the rectangular cylindrical body. The surface of the internal electrode is arranged in the internal space so that the surface of the internal electrode is substantially equidistant from the inner surface. In this way, the plasma can be generated substantially evenly by setting the interval between the rectangular cylindrical body and the internal electrodes at equal intervals. As this support, for example, it can be inserted so as to maintain a constant gap between the central portion where the internal electrode can be sandwiched between both ends of the rectangular tube and the upper and lower sides of the internal electrode and the rectangular tube. An insertion tool having an end, an interposition tool that can be inserted so as to maintain a constant spacing between the internal electrode and the upper and lower sides of the rectangular cylindrical body, and a lower inner surface of the rectangular cylindrical body A supported leg or support is used. It is preferable to arrange the intervening tools, support legs, and support columns at least at both end portions and the central portion when the rectangular cylindrical body is of a cylinder length, and more than that, it is disposed at almost equal intervals. Also good. Particularly preferred as the support is an end plate disposed in close contact with the inner surface of each end edge of the rectangular tube on both open ports, and having sufficient pores to allow exhaust gas to pass through. together provided, in which each end of the plate constituting the internal electrode is suitable holes so as to be able to enter fitted or fitted is provided at the center thereof. The pores are preferably provided so as to be distributed substantially uniformly. When such a support is used, the internal electrode can be easily and easily disposed at the center of the internal space of the rectangular structure. Such a support preferably has a thickness and pore size adjusted to such an extent that the influence of high heat on the outside due to plasma treatment can be sufficiently prevented. Further, when the carbonaceous material is present in the internal space, for example, when the carbonaceous material is filled, the carbonaceous material is added to the support so that the support can also have a sealing function capable of stopping the carbonaceous material there. The pore size should be suitably smaller than that of the carbonaceous material so as not to pass through the support.
[0012]
In the apparatus of the present invention, a power source is disposed to discharge by energizing each electrode of the exhaust gas discharge processing means.
[0013]
The apparatus of the present invention preferably includes a magnetic field generating means for confining the plasma generated by the discharge in the exhaust gas discharge processing means. As a result, the plasma, and thus the high-temperature portion thereof, can be pushed into the inside of the rectangular cylindrical body of the discharge unit with the lines of magnetic force generated by the magnetic field.
[0014]
In the apparatus of the present invention, means for introducing exhaust gas, or means for bringing the exhaust gas into an oxygen-free state, for example, an oxygen scavenger, an oxygen adsorbent, or a reducing agent is disposed between the means and the exhaust gas discharge treatment means. It is preferable to provide an established zone, and further, means for discharging the exhaust gas subjected to the discharge treatment, or means between the means and the exhaust gas discharge treatment means, for example, oxygen absorber or oxygen It is preferable to provide a zone in which an adsorbent and a reducing agent are disposed. In this way, the inflow of oxygen into the exhaust gas discharge treatment means can be prevented including the backflow from the exhaust gas discharge side, and the inside of the exhaust gas discharge treatment means can be brought into an oxygen-free state. Even a material that is reactive with oxygen, such as a carbonaceous material, can be used. As a means for making the oxygen-free state in this way, for example, silver, copper or the like is used as a raw material, and it is used as a granular material, a wire material, a foil material, a plating material, etc. It can be used in the form of a structure or the like. When silver is used as a material, oxygen can be taken in by heating by electric heating or the like. In order to reduce the burden on the means for making oxygen-free, an inert gas such as nitrogen or carbon dioxide can be mixed with the exhaust gas. If it does in this way, the density | concentration of oxygen in waste gas can be diluted, for example, the usage-amount of an oxygen scavenger can be saved.
[0015]
In the device of the present invention, filling the space between the rectangular cylinder and the internal electrode with a conductive heating element made of carbonaceous particles can increase the discharge and increase the temperature. preferable. Examples of the carbonaceous particles include those having an irregular shape, for example, a coke-like one, which increases the surface area by mixing rounded ones with sharp ones such as spines and needles. Is preferable because the discharge region is widened.
[0016]
Further, in the present invention apparatus is a space bisecting vertically between the conductive heating body and the rectangular pipe-shaped body and the internal electrodes, to attaching a diaphragm or partition plate, the space of the heat generating member This is preferable because it can be distributed with good dispersibility.
[0017]
【Example】
The apparatus of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory view of a facility in which an example of the present invention device is incorporated between an exhaust duct provided in an incinerator and an exhaust cooling device in a conventional incineration processing facility for waste and industrial waste. Specifically, in a conventional incineration processing facility in which exhaust gas from an incinerator is cooled through a cooling device through an exhaust duct and then cooled from a chimney, an example of the device in which the present invention device is incorporated between an exhaust duct and a cooling device. It is explanatory drawing.
[0018]
In FIG. 1, X and Y indicate the exhaust duct and the cooling device in the conventional incineration processing facility, respectively, and one example of the exhaust gas processing device of the present invention is connected to the exhaust side of the exhaust duct X. In this exhaust gas treatment device, an exhaust gas is provided on the outflow side or downstream side of the exhaust gas introduction device A that is provided with a deoxygenation zone that removes oxygen from the exhaust gas and makes the exhaust gas oxygen-free, and sucks the exhaust gas by a suction fan. The exhaust gas that has been connected to the discharge treatment device B and has been detoxified by the exhaust gas discharge treatment device B is sucked and discharged by the suction fan of the exhaust gas discharge device C connected to the outflow side or the downstream side of the exhaust gas discharge treatment device B. Is done. The exhaust gas discharge device C is connected to the cooling device Y. In the exhaust gas discharge treatment apparatus B, a power source D that discharges when energized is provided between an external electrode and an internal electrode described later. The exhaust gas discharge treatment apparatus B is preferably enclosed with a refractory brick or heat-resistant ceramics such as alumina because the safety in terms of heat and electricity is improved.
[0019]
FIG. 2 is a schematic diagram of an example of a discharge unit in the exhaust gas discharge treatment apparatus B. The discharge unit 1 includes an external electrode 111 made of a metal such as stainless steel or aluminum or a graphite 112 and a dielectric 112. It is formed into a horizontally long rectangular tube with openings at both ends, and is fitted and integrated with the external electrode 111 on the outside and the dielectric 112 on the inside. The supports 13 and 13 are end plates made of a heat-resistant insulating material disposed in close contact with the inner surface of each end edge of the rectangular cylindrical body on the both ends opening side, and allow exhaust gas to pass therethrough. A sufficient hole is provided at the center, and an appropriate hole is provided at the center so that each end of the plate-like body constituting the internal electrode can be fitted. A graphite plate-like internal electrode 12 is inserted into this hole, and the support 13 is arranged so that the distance between the surface of the internal electrode and the inner surface of the rectangular cylindrical body, that is, the inner surface of the dielectric is equal throughout. Configured. Here, the four corners of the inner surface of the dielectric and both end portions of the corresponding plate-like internal electrode are rounded and formed in an R shape.
[0020]
【The invention's effect】
The exhaust gas treatment apparatus of the present invention enables high-temperature thermal decomposition of harmful substances such as dioxin in exhaust gas efficiently and at a reduced cost, for example, using a combustion apparatus such as an existing incinerator, By incorporating the device of the present invention between the exhaust gas sending part after the combustion treatment and the cooling device, there is a remarkable effect that the exhaust gas treatment can be performed economically.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a facility in which an example of the device of the present invention is incorporated between an exhaust duct and a cooling device in a conventional exhaust gas treatment facility.
FIG. 2 is a schematic view of an example of a discharge unit of the device of the present invention.
[Explanation of symbols]
A Exhaust gas introduction device B Exhaust gas discharge treatment device C Exhaust gas discharge device D Power source X Exhaust duct in conventional incineration processing equipment Y Cooling device in conventional incineration processing equipment 1 Discharge unit 11 Rectangular cylinder 111 External electrode 112 Dielectric 12 Internal electrode 13 Support

Claims (6)

Means for introducing exhaust gas, a rectangular cylinder made of an external electrode or made of a dielectric and an external electrode arranged on the outer surface thereof, and a plate arranged at the center of the internal space of the rectangular cylinder A discharge unit comprising a cylindrical internal electrode and a support that fixes and holds the internal electrode in the rectangular cylindrical body, and an exhaust gas having a space portion between the rectangular cylindrical body and the internal electrode as an exhaust gas passage A discharge treatment means, a power source that discharges by energizing each electrode, and a means for discharging the discharged exhaust gas, and a conductive portion made of carbonaceous particles in the space between the rectangular cylinder and the internal electrode. In addition to filling the heat generating element, the support member is an end plate disposed in close contact with the inner surface of each end of the rectangular cylindrical body on both open ports, and allows exhaust gas to pass therethrough. There is enough space in the center and at the center Discharge type exhaust gas treatment apparatus being characterized in that it is assumed that suitable holes are provided so that each end of the plate-like body constituting a part electrodes can fitted or inserted.   2. The discharge type exhaust gas treatment apparatus according to claim 1, wherein the rectangular cylinder is made of a rectangular bowl-shaped member having an open top surface and a lid-shaped member, or made of a divided material that is equally divided up and down. 3. The discharge type exhaust gas treatment apparatus according to claim 1, further comprising magnetic field generation means for confining the plasma generated by the discharge in the exhaust gas discharge treatment means. 4. The discharge type exhaust gas treatment apparatus according to claim 1 , wherein means for introducing exhaust gas or means for making the exhaust gas oxygen-free is provided between the means and the exhaust gas discharge treatment means. The discharge type exhaust gas treatment apparatus according to any one of claims 1 to 4 , wherein the carbonaceous particles have an indefinite shape. The discharge type exhaust gas treatment apparatus according to any one of claims 1 to 5 , further comprising a partition plate that bisects the conductive heating element in the vertical direction in a space portion between the rectangular cylindrical body and each internal electrode.

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