Exhaust gas treatment device and organic matter treatment device

Abstract

Provided is an exhaust gas treatment device and the like that can more reliably treat exhaust gas containing dioxins in a short period of time. [Solution] The exhaust gas treatment device 1 includes a first treatment tank 10, a second treatment tank 11, and a removal unit 13, which are described below. The first treatment tank 10 produces first treated water by introducing exhaust gas containing dioxins into warm water using a UFB generator 15. The second treatment tank 11 produces second treated water by stirring and mixing the first treated water with a flocculant that adsorbs dioxins to precipitate flocs. The removal unit 13 produces third treated water by removing the flocs from the second treated water. However, the warm water is 40°C or higher, and the UFB generator 15 introduces the exhaust gas into the warm water as UFBs with a diameter of less than 1 μm. This allows the temperature of the first treated water to reach 40°C or higher, allowing a larger amount of coagulant to be added, improving reactivity and shortening the time required for coagulation precipitation.

Description

[Technical Field]

[0001] The present disclosure relates to an exhaust gas treatment device and an organic matter treatment device, in particular, an exhaust gas treatment device that can more reliably treat exhaust gas containing dioxins in a short period of time, and an organic matter treatment device equipped with this exhaust gas treatment device. [Background technology]

[0002] In recent years, dioxins contained in exhaust gases generated from incinerators and the like have become a problem. Dioxins are highly toxic, stable, and difficult to decompose, so once released into the atmosphere, they may accumulate in the natural environment for a long period of time.

[0003] Therefore, various measures have been proposed to remove dioxins from exhaust gases. For example, in Patent Document 1, a first treatment tank equipped with a dissolving device that dissolves exhaust gas generated during the thermal decomposition treatment of organic matter into water; a second treatment tank in which the water removed from the first treatment tank and an adsorbent capable of adsorbing at least dioxins are mixed by stirring; A filter that filters the water in the second treatment tank. An exhaust gas treatment system is disclosed that includes:

[0004] The document describes that with the above-mentioned configuration, the exhaust gas dissolves in water, and dioxins contained in the exhaust gas are reliably adsorbed onto the adsorbent and then removed together with the adsorbent by the filter.

[0005] However, in the configuration of Patent Document 1, since water (usually below 20°C) is used, the amount of adsorbent dissolved in the second treatment tank is small, and the reactivity of the adsorbent is also poor due to the low water temperature, so it is highly likely that it will take a long time for the adsorbent to precipitate coagulates, which may result in a long treatment process time for removing dioxins from exhaust gas.

[0006] Therefore, one possible measure to take is to use warm water (usually 40°C or higher) to increase the reactivity of the adsorbent. In the configuration of Patent Document 1, the exhaust gas is dissolved in water, so the period during which the exhaust gas exists as bubbles is considered to be short. Therefore, even if the exhaust gas exists in water when the exhaust gas and water are stirred and mixed, it is considered that the form of the exhaust gas in the water is fine bubbles (FB), which are larger than microbubbles (MB) with a diameter of 1 μm or more.

[0007] However, if the state of the exhaust gas in the water is larger than MB, the exhaust gas is more likely to be released from the water to the outside due to the influence of buoyancy. In this case, if the water is heated, the high temperature of the water increases the possibility that exhaust gas containing dioxins will be released from the heated water.

[0008] Furthermore, dioxins are thought to be poorly soluble in water and to exist as fine particles (solids) in exhaust gases, so they are unlikely to dissolve in water. In this case, when the exhaust gas containing dioxins is dissolved, the dioxins will diffuse into the water, making it difficult to aggregate them.

[0009] As a result, in the configuration of Patent Document 1, exhaust gas containing dioxins is released in the first treatment tank, and in the second treatment tank, the amount of dioxins adsorbed to the adsorbent decreases as the dioxins diffuse, which may result in a low yield of dioxins in the coagulate. Therefore, the configuration of Patent Document 1 may result in insufficient recovery of dioxins. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 7669074 Summary of the Invention [Problem to be solved by the invention]

[0011] The present disclosure has been made to solve the above problems, and its object is to provide an exhaust gas treatment device that can more reliably treat exhaust gas containing dioxins in a short period of time. Another object of the present disclosure is to provide an organic matter treatment device including this exhaust gas treatment device. [Means for solving the problem]

[0012] According to the present disclosure, the exhaust gas treatment device includes a first treatment tank, a second treatment tank, and a removal unit, which will be described below. In the first treatment tank, first treated water is produced by introducing exhaust gas containing dioxins into hot water using an ultra-fine bubble (UFB) generator. In the second treatment tank, the first treated water and a flocculant that adsorbs dioxins are stirred and mixed to precipitate flocculants, thereby producing second treated water. The removal unit produces third treated water by removing the coagulates from the second treated water. However, the hot water must be 40°C or higher. The UFB generator converts exhaust gas into UFB particles with a diameter of less than 1 μm and introduces them into hot water.

[0013] This allows the temperature of the first treated water to reach 40°C or higher, allowing a larger amount of coagulant to be added, improving reactivity and shortening the time required for coagulation precipitation. The UFB contained in the first treated water dissolves in the warm water due to mechanical disturbances during the stirring and mixing process, reacting with the coagulant to precipitate coagulants.

[0014] Furthermore, even if the hot water is 40°C or higher, the exhaust gas can be introduced into the hot water as UFB, allowing the exhaust gas to remain in the hot water for a long time. Generally, UFBs have a small diameter, making them less susceptible to buoyancy and less likely to dissolve.

[0015] Furthermore, because UFBs are generally negatively charged and repel each other, they are less likely to coalesce even when there are a large number of UFBs, which reduces the likelihood of them coalescing into MBs, which are then released into the hot water, or dissolved in the hot water. For this reason, UFB is said to have a lifespan of several weeks to several months.

[0016] In other words, even if the first treated water is at a high temperature of 40°C or higher, it contains a high amount of exhaust gas containing dioxins. Furthermore, since dioxins are thought to remain in the exhaust gas, they do not disperse unnecessarily into the hot water. Therefore, a larger amount of dioxins can be precipitated as agglomerates in the second treatment tank. As a result, exhaust gas containing dioxins can be treated more reliably.

[0017] Furthermore, since UFB is negatively charged, the use of a positively charged flocculant allows for the formation of basal flocs more quickly, further shortening the time required for the precipitation of flocs. As a result, exhaust gas containing dioxins can be treated in a shorter time.

[0018] The organic matter treatment device includes an exhaust gas treatment device according to the present disclosure. Therefore, the organic matter treatment device can more reliably treat dioxins, which are inevitably generated during the thermal decomposition of organic matter, in a shorter time. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is an explanatory diagram of an organic matter treatment apparatus (Example 1). [Figure 2] FIG. 1 is an explanatory diagram of a UFB generating device (Example 1). [Figure 3] FIG. 1 is an explanatory diagram of a UFB generating device (Example 2). DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, modes for carrying out the present disclosure will be described based on examples. It should be noted that the following examples disclose specific examples, and it goes without saying that the present disclosure is not limited to the following examples. [Example]

[0021] [Configuration of Example 1] The configuration of an organic matter treatment device 2 including an exhaust gas treatment device 1 according to a first embodiment will be described with reference to FIGS. The organic matter treatment device 2 includes a thermal decomposition device 3 and an exhaust gas treatment device 1, which will be described below.

[0022] [1. Organic matter treatment equipment] [1.1. Pyrolysis equipment] The thermal decomposition device 3 generates exhaust gas containing dioxins by thermally decomposing organic matter. Here, examples of organic matter that can be thermally decomposed in the thermal decomposition device 3 include petroleum-derived products, food waste, fishery waste, livestock waste, and medical waste. During the thermal decomposition process in the thermal decomposition device 3, so-called dioxins are produced from carbon, oxygen, chlorine, hydrogen, and the like contained in these organic substances.

[0023] The pyrolysis device 3 pyrolyzes organic matter under low-oxygen conditions. The pyrolysis device 3 can be blocked from outside air by an inner lid 5, and has an inlet 6 that introduces magnetized air into the space partitioned by the inner lid 5. Organic matter to be treated by the pyrolysis device 3 is introduced through an inlet 7 and led into a space partitioned by an inner lid 5 .

[0024] In the pyrolysis device 3, the space partitioned by the inner lid 5 is always kept at a limit oxygen level of 8% or less, and magnetized air is supplied in a controlled manner from the inlet 6. As a result, the organic matter put in is pyrolyzed in a steaming state at around 400°C without coming into contact with the outside air. More specifically, the water in the organic matter generates hydrogen ions and hydroxide ions through weak electrolysis caused by magnetic force, and these ions collide to generate heat, causing the organic matter to be thermally decomposed under oxygen-limiting conditions. The organic matter is then further chemically decomposed by the magnetic fluid, ultimately being decomposed into ash that is 1 / 400 to 1 / 200 of its volume.

[0025] [1.2. Exhaust gas treatment equipment] [1.2.1. First treatment tank] The exhaust gas treatment device 1 includes a first treatment tank 10, a second treatment tank 11, and a removal section 13, which will be described below. In the first treatment tank 10, the dioxin-containing exhaust gas produced by the thermal decomposition device 3 is introduced into hot water of 40° C. or higher by an ultra-fine bubble (UFB) generator 15 to produce first treated water. Although there are four UFB generators 15 in FIG. 1, the present invention is not limited to this configuration. The first treatment layer 10 is filled with hot water in advance.

[0026] Here, the internal space of each UFB generator 15 and the space partitioned by the inner lid 5 of the thermal decomposition device 3 are communicated with each other by a branch pipe 16 . Each UFB generator 15 is also provided with a pump 18 that supplies the hot water in the first treatment tank 10 to the respective UFB generator 15 .

[0027] [1.2.1.1. UFB Generator] The specific configuration of the UFB generator 15 will be described with reference to FIG. The UFB generator 15 includes a water ejector unit 20 that uses hot water to suck in the exhaust gas from the thermal decomposition device 3 and forms a mixed fluid of the hot water and the exhaust gas. More specifically, the exhaust gas is sucked by the flow of hot water pumped at high pressure by the pump 18. Then, in the water ejector section 20, a mixed fluid is formed in which the hot water and the exhaust gas are mixed.

[0028] The UFB generator 15 further includes a cylindrical container 21, an introduction section 22, and an outlet pipe 23, which will be described below. The cylindrical container 21 is partitioned by one end 25 and the other end 26, and an internal space S is formed. The shapes of the one end 25 and the other end 26 are not particularly limited, and an optimum shape can be selected depending on the purpose, such as a flat plate shape or an outwardly convex hemisphere.

[0029] The introduction section 22 introduces the mixed fluid of hot water and exhaust gas formed by the water ejector section 20 into the internal space S so as to form a vortex flow with the axis A of the cylindrical container 21 as the rotation axis. The position where the introduction part 22 is formed is not particularly limited as long as it can generate a vortex flow in the internal space S, but it is preferable to form the introduction part 22 at a position where the flow direction of the mixed fluid in the introduction part 22 does not overlap with the axis A.

[0030] The outlet pipe 23 is arranged with its axis coincident with the axis A of the cylindrical container 21 and is disposed in the internal space S with a gap between itself and one end 25, and connects the internal space S with the inside of the first treatment tank 10. Then, the mixed fluid is introduced into the first treatment tank 10. More specifically, the mixed fluid pumped at high pressure is discharged into the lower pressure interior of the first treatment tank 10 through the outlet pipe 23. At this time, the mixed fluid is hot water into which the exhaust gas has been introduced as UFB.

[0031] That is, the UFB generator 15 is a so-called high-speed liquid flow swirling type UFB generator. As a result, the first treated water in the first treatment tank 10 contains exhaust gas containing dioxins introduced as UFB.

[0032] [1.2.2. Second Treatment Tank] In the second treatment tank 11, the first treated water and a flocculant that adsorbs dioxins are stirred and mixed to precipitate flocculants, thereby producing second treated water. More specifically, the first treated water in the first treatment tank 10 is pumped to the second treatment tank 11 by a pump 28, and in the second treatment tank, the first treated water and a coagulant that adsorbs dioxins are stirred and mixed using a stirring device 30 to produce second treated water in which coagulants have precipitated. The temperature of the first treated water is higher than the initial hot water temperature due to the endothermic effect of the exhaust gas temperature and the absorption of energy due to mechanical disturbances.

[0033] [1.2.3. Removal part] The removal unit 13 produces third treated water by removing the coagulates from the second treated water. More specifically, the removal unit 13 is a filter such as an open-cell foam. The third treated water, which has passed through the removal section 13 and from which the coagulates that have adsorbed dioxins have been removed, is temporarily stored in the third treatment tank 31 and then discharged.

[0034] [Effects of Example 1] The exhaust gas treatment device 1 of the first embodiment includes a first treatment tank 10, a second treatment tank 11, and a removal section 13, which will be described below. In the first treatment tank 10, a dioxin-containing exhaust gas is introduced into hot water by a UFB generator 15 to produce first treated water. In the second treatment tank 11, the first treated water and a flocculant that adsorbs dioxins are stirred and mixed to precipitate flocculants, thereby producing second treated water. The removal unit 13 produces third treated water by removing the coagulates from the second treated water. However, the hot water is 40°C or higher, and the UFB generator introduces the exhaust gas into the hot water as UFBs with a diameter of less than 1 μm.

[0035] This allows the temperature of the first treated water to reach 40°C or higher, allowing a larger amount of coagulant to be added, improving reactivity and shortening the time required for coagulation precipitation. The UFB contained in the first treated water dissolves in the warm water due to mechanical disturbance caused by the agitator 30 during the agitation and mixing process, and reacts with the flocculant to precipitate a floc.

[0036] Furthermore, even if the hot water is 40°C or higher, the exhaust gas can be introduced into the hot water as UFB, allowing the exhaust gas to remain in the hot water for a long time. Generally, UFBs have a small diameter, making them less susceptible to buoyancy and less likely to dissolve.

[0037] Furthermore, because UFBs are generally negatively charged and repel each other, they are less likely to coalesce into bubbles even when there are a large number of UFBs in the hot water. This reduces the likelihood of UFBs coalescing to form MBs, which are then released into the water or dissolved in the water.

[0038] In other words, even if the first treated water is at a high temperature of 40°C or higher, it contains a high amount of exhaust gas containing dioxins. Furthermore, since dioxins are thought to remain in the exhaust gas, they do not disperse unnecessarily into the hot water. Therefore, a larger amount of dioxins can be precipitated in the second treatment tank 11 as agglomerates. As a result, exhaust gas containing dioxins can be treated more reliably.

[0039] Here, since UFB is negatively charged, the use of a positively charged flocculant allows for the formation of basal flocs more quickly, further shortening the time required for the precipitation of flocs. As a result, exhaust gas containing dioxins can be treated in a short time. It is also believed that a flocculant that generates positive ions when dissolved in warm water will have a similar effect.

[0040] In the exhaust gas treatment device 1 of the first embodiment, the UFB generator 15 is provided with a water ejector unit 20 that uses hot water to suck in exhaust gas and form a mixed fluid of hot water and exhaust gas. This makes it possible to introduce the exhaust gas into the UFB generator 15 with a simple configuration. Furthermore, by using a simple configuration that does not have a drive unit, the number of mechanical parts can be reduced, and the possibility of malfunctions and the effort required for maintenance can be reduced. Furthermore, since the number of mechanical parts can be reduced, the exhaust gas processing device 1 can be provided at low cost.

[0041] In the exhaust gas treatment device 1 of the first embodiment, the UFB generator 15 further includes a cylindrical container 21, an introduction section 22, and an outlet pipe 23, which will be described below. The cylindrical container 21 has an internal space S defined by one end 25 and the other end 26 . The introduction section 22 introduces the mixed fluid into the internal space S so as to form a vortex flow with the axis A of the cylindrical container 21 as the rotation axis. The outlet pipe 23 is arranged with its axis coincident with the axis A of the cylindrical container 21 and is disposed in the internal space S with a gap between itself and one end 25, and connects the internal space S with the inside of the first treatment tank 10.

[0042] As a result, the UFB generator 15 is a so-called high-speed liquid flow swirling type UFB generator, and is therefore relatively easy to obtain. Furthermore, since it does not have a drive unit, it is easy to maintain. Therefore, the exhaust gas processing device 1 can be provided at a lower cost.

[0043] The organic matter treatment device 2 of the first embodiment includes a thermal decomposition device 3 that generates exhaust gas containing dioxins by thermally decomposing organic matter, and an exhaust gas treatment device 1. This allows the organic matter treatment device 2 to more reliably treat exhaust gas containing dioxins in a short period of time.

[0044] [Configuration of Example 2] The configuration of an organic matter treatment apparatus 2 of Example 2 will be described with reference to Fig. 3, focusing on the parts that differ from Example 1. In the figure, components with the same functions as those of Example 1 are given the same reference numerals.

[0045] In the second embodiment, as shown in FIG. 3, the UFB generator 15 includes an agitator 40 that moves in the internal space S along with the vortex flow. The shape, size, etc. of the stirring body 40 are not particularly limited, and the optimum shape, size, etc. can be selected depending on the purpose.

[0046] [Effects of Example 2] The agitator 40 rotates together with the vortex flow and repeats rotation and revolution, thereby generating a larger amount of UFB. This allows more exhaust gas to be introduced into the hot water as UFB.

[0047] [Variations] The present invention can be modified in various ways without departing from the spirit of the invention. In the embodiment, the agitator 30 is used to agitate and mix the first treated water and the flocculant in the second treatment tank 11, but the present invention is not limited to this embodiment. For example, the set flow rate of the pump 28 may be increased to generate a vortex flow, thereby stirring and mixing the first treated water and the flocculant. This makes it possible to eliminate the need for the agitator 30, and therefore the exhaust gas processing device 1 can be provided at lower cost.

[0048] In the embodiment, the first treated water was pressure-fed to the second treatment tank 11 using a pump 28, but the configuration may also be such that the first treated water is sent from the first treatment tank 10 to the second treatment tank 11, which is located at a lower position, by utilizing the difference in elevation. This makes it possible to suppress dissolution of UFB into the hot water due to mechanical disturbance caused by the pump 28, and therefore makes it possible to more reliably precipitate dioxins as agglomerates in the second treatment tank 11.

[0049] In the embodiment, the UFB generator 15 is of the so-called high-speed liquid flow swirling type, but the invention is not limited to this type. For example, a batch-type UFB generator that mechanically crushes bubbles may be used. This allows for more options for the UFB generator 15. [Explanation of symbols]

[0050] 1 exhaust gas treatment device 10 first treatment tank 11 second treatment tank 13 removal section 15 Ultra Fine Bubble (UFB) Generator

Claims

1. a first treatment tank for generating first treated water by introducing dioxin-containing exhaust gas into hot water using an ultra-fine bubble (UFB) generator; a second treatment tank for generating second treated water by stirring and mixing the first treated water and a flocculant capable of adsorbing dioxins to precipitate flocculants; a removal unit that produces third treated water by removing the coagulates from the second treated water. However, the hot water is 40°C or higher, The UFB generator introduces the exhaust gas into the hot water as UFB having a diameter of less than 1 μm.

2. The exhaust gas treatment device according to claim 1 , wherein the UFB generator includes a water ejector unit that uses the hot water to suck in the exhaust gas and forms a mixed fluid of the hot water and the exhaust gas.

3. The UFB generator is a cylindrical container having an internal space partitioned by one end and the other end; an introducing section that introduces the mixed fluid into the internal space so as to form a vortex flow with the axis of the cylindrical container as a rotation axis; 3. The exhaust gas treatment device according to claim 2, further comprising an outlet pipe that is arranged in the internal space with a gap between the one end and the axis of the cylindrical container, and that connects the internal space with the inside of the first treatment tank.

4. The UFB generator is The exhaust gas treatment device according to claim 3 , further comprising an agitator that moves in association with the vortex flow within the internal space.

5. a thermal decomposition device that generates exhaust gas containing dioxins by thermally decomposing organic matter; An organic matter treatment device comprising the exhaust gas treatment device according to any one of claims 1 to 4.

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