Deodorizer

Abstract

To provide a deodorizer capable of deodorizing exhaust gas without requiring an apparatus for making exhaust gas rise, such as an air blower.SOLUTION: A deodorizer includes: a dilution flue through which exhaust gas discharged from an industrial furnace and containing odor gas passes while being diluted by dilution gas; a gas treatment flue that includes a burner for heating inside and through which exhaust gas passes while being heated by the burner; and an exhaust flue through which the exhaust gas heated by the burner in the gas treatment flue passes through to be discharged to outside. The dilution flue, the gas treatment flue, and the exhaust flue are coupled so that exhaust gas discharged from the industrial furnace sequentially passes upwardly through the dilution flue, the gas treatment flue, and the exhaust flue.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a deodorizing device. [Background technology]

[0002] Conventionally, various types of deodorizing furnaces or deodorizing devices have been devised for deodorizing exhaust gases emitted from industrial furnaces and the like, depending on the components to be deodorized. For example, Patent Document 1 discloses a deodorizing device for an asphalt plant that includes a deodorizing furnace, a chimney erected at the top end of the deodorizing furnace, an air preheater, and a blower. This deodorizing device is provided with an external fan to draw the exhaust gases emitted from the industrial furnaces and the like into the interior and ventilate it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-302029 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the deodorizing device described in Patent Document 1 has limitations on the heat resistance temperature of the equipment that ventilates the exhaust gas, such as fans and exhaust fans, and it may be difficult to treat high-temperature exhaust gas. In fact, fans and exhaust fans cannot be used for exhaust gases that are, for example, 600°C or higher, and such high-temperature exhaust gases must be cooled to a treatable temperature using a gas cooler or the like. In addition, fans and exhaust fans require energy to operate, and because exhaust gas often contains corrosive gases, there are problems with the fans and exhaust fans being prone to corrosion. Furthermore, as mentioned above, the deodorizing device described in Patent Document 1 requires an external fan, and therefore requires a site for installing the fan in addition to the area occupied by the deodorizing device.

[0005] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a deodorizing device that can deodorize exhaust gas without requiring any equipment for ventilating exhaust gas, such as a blower or exhaust fan. [Means for solving the problem]

[0006] A deodorizing device according to a first aspect of the present invention comprises a dilution flue through which exhaust gas containing odorous gases discharged from an industrial furnace passes while being diluted with dilution gas; a gas treatment flue equipped with a burner for heating the interior thereof and through which the exhaust gas passes while being heated by the burner; and an exhaust flue through which the exhaust gas heated by the burner passes within the gas treatment flue and is exhausted to the outside; the dilution flue, gas treatment flue, and exhaust flue are connected so that the exhaust gas discharged from the industrial furnace passes upward through the dilution flue, gas treatment flue, and exhaust flue in that order.

[0007] A deodorizing device according to a second aspect of the present invention comprises a plurality of dilution ducts corresponding to a plurality of industrial furnaces, through which exhaust gas containing odorous gases discharged from the plurality of industrial furnaces passes while being diluted with dilution gas, a burner for heating the interior, and a junction section for merging the exhaust gases flowing out from the plurality of dilution ducts, a gas treatment duct through which the exhaust gas merged at the junction section passes while being heated by the burner, and an exhaust duct through which the exhaust gas heated by the burner in the gas treatment duct passes and is discharged to the outside, and the dilution ducts, gas treatment duct, and exhaust duct are connected so that the exhaust gas discharged from the plurality of industrial furnaces passes sequentially upward through the dilution duct, gas treatment duct, and exhaust duct. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a deodorizing device that can deodorize exhaust gas without requiring any equipment for ventilating exhaust gas, such as a blower. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view schematically showing an example of a deodorizing device according to a first embodiment. [Figure 2] FIG. 2 is a side view schematically showing a modified example of the deodorizing device shown in FIG. [Figure 3] 2 is a graph showing temperature changes and flow rate changes with height during operation of the deodorizing device shown in FIG. 1. [Figure 4] 3 is a graph showing temperature changes and flow rate changes with height during operation of the deodorizing device shown in FIG. 2. [Figure 5] FIG. 2 is a side view schematically showing a configuration in which a heat exchanger is provided in an exhaust flue in the deodorization device of the first embodiment. [Figure 6] FIG. 6 is a side view schematically showing a modified example of the deodorizing device shown in FIG. [Figure 7] 6 is a graph showing temperature changes and flow rate changes with height during operation of the deodorizing device shown in FIG. 5. [Figure 8] 7 is a graph showing temperature and flow rate changes with height during operation of the deodorizing device shown in FIG. 6. [Figure 9] FIG. 6 is a side view schematically showing an example of a deodorizing device according to a second embodiment. [Figure 10] FIG. 10 is a side view schematically showing a modified example of the deodorizing device of the second embodiment. [Figure 11] FIG. 10 is a side view schematically showing a modified example of the deodorizing device of the second embodiment. [Figure 12] FIG. 10 is a side view schematically showing a modified example of the deodorizing device of the second embodiment. [Figure 13] FIG. 10 is a side view schematically showing a modified example of the deodorizing device of the second embodiment. [Figure 14] FIG. 10 is a side view schematically showing a modified example of the deodorizing device of the second embodiment. [Figure 15] FIG. 1 is a perspective view of a deodorizing device that can be connected to four industrial furnaces. DETAILED DESCRIPTION OF THE INVENTION

[0010] The deodorizing device according to this embodiment will be described in detail below with reference to the drawings. This embodiment is not limited to the following description. In addition, some or all of the components in this embodiment can be combined as appropriate. Note that the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0011] First Embodiment The deodorizing device of the first embodiment includes a dilution flue through which odorous exhaust gas discharged from an industrial furnace passes while being diluted with dilution gas. It also includes a gas treatment flue that has a burner for heating the interior and through which the exhaust gas passes while being heated by the burner. It also includes an exhaust flue through which the exhaust gas heated by the burner passes within the gas treatment flue and is then discharged to the outside. The dilution flue, gas treatment flue, and exhaust flue are connected so that the exhaust gas discharged from the industrial furnace passes upward through the dilution flue, gas treatment flue, and exhaust flue in that order.

[0012] In the deodorizing apparatus of this embodiment, as described above, the dilution flue, gas treatment flue, and exhaust flue are connected so that the exhaust passes through them sequentially upward. Because flue gas discharged from an industrial furnace is hotter than the ambient temperature and flows into the chimney, a chimney effect is generated. The flue gas flowing into the deodorizing apparatus ascends sequentially through the dilution flue, gas treatment flue, and exhaust flue. More specifically, the higher the temperature of the flue, the lower the density of the flue. Because the temperature inside the flue is higher than the outside, the flue's density is lower than that outside, creating buoyancy. This buoyancy draws cold air from the outside into the chimney through an air intake at the bottom of the chimney, while warm air rises. This phenomenon is commonly known as the chimney effect. In this embodiment, flue gas is attracted through the inlet at the bottom of the dilution flue. At the same time, the hot flue gas rises through the flue, passing through the gas treatment flue and the exhaust flue, and is exhausted from the top of the exhaust flue. In other words, the deodorizing device of this embodiment does not require any equipment for ventilating exhaust gas, such as a fan or exhaust fan, because exhaust gas is exhausted to the outside by the chimney effect. Consequently, it is possible to deodorize high-temperature exhaust gas that exceeds the heat resistance temperature of the fan or exhaust fan. Furthermore, it is possible to achieve space-saving and energy-saving effects in the deodorizing device.

[0013] The deodorizing apparatus of this embodiment will be described below with reference to the drawings. FIG. 1 schematically shows a side view of a deodorizing apparatus 10A, which is an example of a deodorizing apparatus of this embodiment. The deodorizing apparatus 10A shown in FIG. 1 includes a dilution flue 12, a gas treatment flue 16, and an exhaust flue 20. An industrial furnace (not shown) is located below the dilution flue 12, and exhaust gas discharged from the industrial furnace is drawn into the dilution flue 12. The dilution flue 12 is a flue through which exhaust gas passes while being diluted with dilution gas. The gas treatment flue 16 is equipped with a burner 18 that heats the interior, and is a flue through which the exhaust gas passes while being heated by the burner 18. The exhaust flue 20 is a flue through which the exhaust gas heated by the burner 18 in the gas treatment flue 16 passes and is exhausted to the outside. The dilution flue 12, the gas treatment flue 16, and the exhaust flue 20 are connected so that the exhaust gas discharged from the industrial furnace passes upward (in the X direction in FIG. 1 ) through the dilution flue 12, the gas treatment flue 16, and the exhaust flue 20 in that order. Therefore, the exhaust gas that flows into the dilution flue 12 rises due to the stack effect, and is finally discharged from the outlet of the exhaust flue 20. The dilution flue, gas treatment flue, and exhaust flue are each described in detail below.

[0014] [Dilution Flue] The dilution flue 12 serves to pass exhaust gas containing odorous gases emitted from an industrial furnace while diluting it with dilution gas. In the dilution flue 12, the dilution gas for diluting the exhaust gas may be taken in from the industrial furnace side, or a damper may be provided and the dilution gas may be taken in through the damper. In the deodorizing device 10A shown in FIG. 1, a damper 14 is provided below the dilution flue 12, and the dilution gas for diluting the exhaust gas is taken in through the damper 14. A valve or the like can be used instead of the damper as long as it has an adjustable mechanism. Examples of dilution gases include air and inert gases (nitrogen, argon, carbon dioxide, etc.).

[0015] Examples of odorous gases include ammonia, methyl mercaptan, hydrogen sulfide, methyl sulfide, methyl disulfide, trimethylamine, acetaldehyde, propionaldehyde, normal butyraldehyde, isobutyraldehyde, normal valeraldehyde, isovaleraldehyde, isobutanol, ethyl acetate, methyl isobutyl ketone, toluene, styrene, xylene, propionic acid, normal butyric acid, normal valeric acid, and isovaleric acid.

[0016] Since most of the odorous gases in exhaust gas are organic gases, it is desirable to dilute the exhaust gas to below the lower explosion limit before introducing it into the flue. Therefore, in the dilution flue, it is preferable to dilute the odorous gas concentration in the exhaust gas to below the lower explosion limit, and more preferably to below 1 / 4 of the lower explosion limit. By diluting the exhaust gas in this way, safety can be ensured during operation of the deodorizing device.

[0017] Furthermore, as mentioned above, since many odorous gases are explosive gases, it is dangerous to handle them at concentrations above the explosion limit. Therefore, it is preferable to install a damper at the entrance of the dilution flue 12, i.e., as close as possible to the entrance of the dilution flue 12, to dilute the exhaust gas.

[0018] [Gas treatment flue] The gas treatment flue 16 serves to heat the exhaust gas while allowing it to pass through. The gas treatment flue 16 also has a burner 18 that heats the inside of it. That is, the gas treatment flue 16 serves to heat odorous gases in the exhaust gas with the burner 18 and perform high-temperature oxidation treatment to deodorize them.

[0019] In order to sufficiently oxidize odorous gases in the exhaust gas, the exhaust gas passing through the gas treatment flue 16 must be retained for a certain period of time. For example, the temperature of the high-temperature oxidation treatment of the exhaust gas in the gas treatment flue 16 is preferably approximately 650 to 800°C, and the residence time of the exhaust gas is preferably 0.3 to 1.0 seconds. Therefore, the gas treatment flue 16 preferably has a certain length or more to ensure the above temperature and residence time. For example, a portion of the gas treatment flue 16, i.e., from the connection with the dilution flue 12 to the connection with the exhaust flue 20, can be positioned at the same horizontal position. Alternatively, at least a portion of the section from the connection with the dilution flue 12 to the connection with the exhaust flue 20 can be inclined so that the connection with the exhaust flue 20 is located higher than the connection with the dilution flue 12. This ensures a longer residence time for the exhaust gas than simply discharging it upward. Furthermore, because the exhaust gas and the high-temperature combustion gas discharged from the burner 18 join at the gas treatment flue 16 and flow into the exhaust flue 20, mixing of the exhaust gas and the high-temperature combustion gas discharged from the burner 18 is promoted in the gas treatment flue 16, thereby improving deodorization efficiency. FIG. 1 shows a configuration in which the connecting portion with the exhaust flue 20 is inclined higher than the connecting portion with the dilution flue 12. That is, the deodorization device 10A shown in FIG. 1 shows a configuration in which a portion of the gas treatment flue 16 is inclined at an inclination angle α with respect to the horizontal. The gas treatment flue 16 of the deodorization device 10A starts at the connecting portion between the dilution flue 12 and the gas treatment flue 16, and ends at point P in FIG. 1. By inclining a portion of the gas treatment flue 16 at an inclination angle α with respect to the horizontal, the vertically upward component of the buoyancy force acting on the exhaust gas due to the stack effect is reduced, and the upward rising speed of the exhaust gas is slower than that of the exhaust gas rising vertically upward. This increases the residence time of the flue gas in the gas treatment flue 16. The inclination angle α of the inclined portion is preferably 0 to 90° with respect to the horizontal direction, and more preferably 0 to 80°. The smaller the inclination angle α of the inclined portion of the gas treatment flue 16 and the longer its length, the longer the residence time of the flue gas in the gas treatment flue 16 can be.Conversely, the larger the inclination angle α of the inclined portion of the gas treatment flue 16, the more advantageous it is that the stack effect can be further increased by changing the stack height in the vertical direction, the pressure loss can be reduced by adding the inclination angle α to the confluence, and further space can be saved.In addition, the larger the inclination angle α, the more advantageous it is that an ejector effect can be obtained by the high-temperature combustion gas released from the burner 18 located below. As mentioned above, point P in Fig. 1 is the end point of the gas treatment flue 16. In other words, point P is located at the boundary between the gas treatment flue 16 and the exhaust flue 20. Point P is determined as the position where all odorous gases in the exhaust gas are oxidized. Point P can also be used as a position for measuring temperature.

[0020] As shown in Figure 1, the connection portion of the gas processing flue 16 with the dilution flue 12 is located between the end of the gas processing flue 16 (the left end in Figure 1) and the connection portion of the gas processing flue 16 and the exhaust flue 20. The end of the gas processing flue 16 (the left end in Figure 1) is exposed to the outside, and a burner 18 is provided at this end. The burner 18 is provided so that the high-temperature combustion gas it releases faces the other end of the gas processing flue 16 in the longitudinal direction. A sight glass can be attached to the end of the gas processing flue 16 (the right end in Figure 1) to check the state of the high-temperature combustion gas released by the burner 18.

[0021] Since the high-temperature combustion gas from the burner 18 comes into direct contact with the inner wall of the gas treatment flue 16, it is preferable to lay a refractory material on the inner wall. Refractory materials that can be used include refractory castables and refractory bricks. The combustion chamber in which the burner 18 is installed can also have a multi-layer structure made up of "refractory castables or refractory bricks (high-temperature gas contact side)" and "insulating castables or insulating bricks (steel shell side)."

[0022] The connection between the gas treatment flue 16 and the exhaust flue 20 is preferably located between the end of the gas treatment flue 16 (the right end in FIG. 1 ) and the connection between the gas treatment flue 16 and the dilution flue 12. That is, rather than the exhaust flue 20 being connected to the end of the gas treatment flue 16 (the right end in FIG. 1 ), it is preferable that there is play near the end of the exhaust flue 20 (the right end in FIG. 1 ), as shown in FIG. 1 . With such a configuration, compared to a case where the gas treatment flue 16 and the exhaust flue 20 are directly connected end to end, it is possible to achieve a structure in which the vertical and horizontal components of thermal expansion of the gas treatment flue 16 and the exhaust flue 20 can be tolerated by each flue, from the time when exhaust gas generation is stopped to the time when operation is underway.

[0023] [Exhaust flue] The exhaust flue 20 is a flue through which the exhaust gas heated by the burner 18 in the gas treatment flue 16 passes and is discharged to the outside. In other words, the exhaust flue 20 serves to guide and discharge to the outside the exhaust gas that has been deodorized in the gas treatment flue 16. In Fig. 1, the exhaust flue 20 is shown in a state in which it is installed vertically upward.

[0024] Next, the graph in Figure 3 shows the temperature change (◆ plot) and flow rate change (● plot) versus height of the deodorization device 10A shown in Figure 1. In the deodorization device 10A, if the total height is 100%, the height of the connection between the dilution flue 12 and the gas treatment flue 16 is approximately 26%, the height of the boundary (point P) between the gas treatment flue 16 and the exhaust flue 20 is approximately 61%, and the height of the upper end of the dilution flue 12 is 100%. The vertical axis indicates the temperature inside the flue or the flue flow rate. The flue temperature is shown relative to the maximum temperature, which is set to 100%. Similarly, the flue flow rate is shown relative to the maximum flow rate, which is set to 100%. As shown in Figure 3, the flue gas passes through the dilution flue 12 at a temperature that is 10% of the maximum temperature (above atmospheric temperature and above the dew point of the flue gas). The exhaust gas is then heated by the burner 18 near the entrance of the gas treatment flue 16 to a maximum temperature (100%), and as it travels down the gas treatment flue 16 its temperature drops and it flows into the exhaust flue 20. It then drops slightly in temperature in the exhaust flue 20 before being discharged to the outside. Meanwhile, the flow rate of the exhaust gas passes through the dilution flue 12 at a constant flow rate, but in the gas treatment flue 16 the flow rate increases near the entrance due to the combustion exhaust gas from the burner 18, and it then passes through the exhaust flue 20 at a constant flow rate and is discharged to the outside. As described above, in order to sufficiently treat odorous gases, the temperature of the high-temperature oxidation treatment in the gas treatment flue 16 is preferably about 650°C or higher, more preferably 650°C to 800°C, and the residence time of the exhaust gas is preferably 0.3 seconds or more, more preferably 0.3 seconds to 1.0 seconds.

[0025] By using the deodorizing equipment shown in Figure 1, the odorous gases in the exhaust gas that were the target for treatment were decomposed to a deodorizing efficiency of over 92%, and the allowable odor index, which is the regulated value under the Offensive Odor Control Act, was reduced to 85% or less. The odor index is calculated in accordance with Environment Agency Notification No. 63 of 1995, "Method for Calculating Odor Index and Odor Emission Intensity," by diluting a sample with odorless air until subjects (hereinafter referred to as "panels") who have passed a test to prove that they have a normal sense of smell can no longer detect the odor, and then multiplying the dilution factor (odor concentration) by 10. In other words, it is given by the following formula: Odor index = 10 x Log (odor concentration) In this embodiment, the odor concentration was measured based on the "Simple Olfactory Measurement Method" of the Ministry of the Environment Notification below. <Olfaction measurement> The method of measuring odors using the human nose (sense of smell) is called olfactory measurement, and is managed and supervised by a nationally certified "odor evaluator." In this measurement, a panel of three people smells two prepared bags (one with an odor and one without), and then identifies the bag containing the odor, which is gradually diluted with odorless air. The strength of the odor is expressed as the dilution factor when the bag containing the odor can no longer be identified. The deodorizing efficiency is given by the following formula: Deodorizing efficiency = (inlet odor concentration - outlet odor concentration) ÷ inlet odor concentration × 100% Here, the inlet odor concentration is the odor concentration of the exhaust gas at the lower end of the dilution flue 12, and the outlet odor concentration is the odor concentration of the exhaust gas at the upper end of the exhaust flue 20, and both odor concentrations are values ​​obtained by calculating as described above.

[0026] The configuration shown in FIG. 1 described above is a configuration in which the connection portion with the exhaust flue 20 is inclined so that it is located higher than the connection portion with the dilution flue 12. In contrast to this configuration, FIG. 2 shows a configuration in which the connection portion with the dilution flue 12 and the connection portion with the exhaust flue 20 are located at the same horizontal position as the gas treatment flue 16. The deodorization device 10B shown in FIG. 2 shows a configuration in which the connection portion with the dilution flue 12 and the connection portion with the exhaust flue 20 are located at the same horizontal position as the gas treatment flue 16. Therefore, only the gas treatment flue 16, which is different from the configuration shown in FIG. 1, will be described below. In the configuration shown in FIG. 2, the inclination angle α of the gas treatment flue 16 with respect to the horizontal direction is 0°. By setting the inclination angle to 0°, the vertically upward component of the buoyancy force acting on the flue gas due to the stack effect is reduced, and the upward velocity of the flue gas is slower than that of flue gas rising vertically upward. This allows the flue gas to remain in the gas treatment flow path for a longer period of time.

[0027] On the other hand, the temperature change (◆ plot) and flow rate change (● plot) versus height for the deodorizing apparatus 10B shown in Figure 2 are shown in the graph of Figure 4. Specific examples of the height at each position in the deodorizing apparatus 10B are the same as those for the deodorizing apparatus 10A, but the behavior of the temperature change is different because part of the gas treatment flue 16 is horizontal. That is, because the horizontal part of the gas treatment flue 16 has a constant height, the slope of the graph for that part is a right angle, as shown in Figure 4.

[0028] Next, modified examples of the deodorizing apparatus of this embodiment will be described. A deodorizing apparatus 30A shown in Fig. 5 differs from the deodorizing apparatus 10A shown in Fig. 1 in that a heat exchanger 22 is provided in the exhaust flue 20, but other components are the same as the deodorizing apparatus 10A shown in Fig. 1. Furthermore, a deodorizing apparatus 30B shown in Fig. 6 differs from the deodorizing apparatus 10B shown in Fig. 2 in that a heat exchanger 22 is provided in the exhaust flue 20, but other components are the same as the deodorizing apparatus 10B shown in Fig. 2. Therefore, in Figs. 5 and 6, components that are substantially the same as the components shown in Figs. 1 and 2 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0029] A heat exchanger 22 serving as a heat exhaust section is provided near the upper end of the exhaust flue 20 of the deodorizing devices 30A and 30B shown in Figures 5 and 6. The heat exchanger 22 recovers heat from the exhaust gas and prevents high-temperature gas from being discharged into the outside air. The heat recovered by the heat exchanger 22 can be used in a recuperator, regenerative burner, etc., making it possible to effectively utilize the exhaust heat from the exhaust gas.

[0030] Next, the graphs in FIG. 7 show the temperature change (◆ plot) and flow rate change (● plot) versus height of the deodorizing device 30A shown in FIG. 5 . Similar to the graphs in FIG. 3 , the graphs in FIG. 7 plot the temperature change and flow rate change versus height of the deodorizing device 30A. The overall height of the deodorizing device and the height of each connecting section are also the same as those of the deodorizing device 10A shown in FIG. 3 . As shown in FIG. 7 , the temperature change from the dilution flue 12 to the gas treatment flue 16 is similar to that shown in FIG. 3 . However, because the deodorizing device 30A has a heat exchanger 22 installed in the exhaust flue 20, the exhaust gas temperature is lowered by the heat exchanger 22 at the upper part of the exhaust flue 20. By the time the exhaust gas is discharged from the exhaust flue 20 to the outside, it has already cooled to above atmospheric temperature and above the exhaust gas dew point temperature. In this way, by installing the heat exchanger 22 in the exhaust flue 20, the recovered heat can be effectively utilized while lowering the temperature of the exhaust gas, allowing low-temperature exhaust gas to be discharged to the outside with minimal environmental impact.

[0031] On the other hand, the temperature change (◆ plot) and flow rate change (● plot) versus height of the deodorizing device 30B shown in Figure 6 are shown in the graph of Figure 8. Specific examples of the height of each position in the deodorizing device 10B are the same as those of the deodorizing device 30A, but the behavior of the temperature change is different because part of the gas treatment flue 16 is horizontal. That is, because the horizontal part of the gas treatment flue 16 has a constant height, the slope of the graph for that part is a right angle, as shown in Figure 8.

[0032] In Figure 5, a heat exchanger 22 is shown as a heat dissipation section to be installed in the exhaust flue 20, but if effective use of the exhaust heat is not taken into consideration, the heat dissipation section only needs to be able to cool the exhaust gas, and may simply be an exhaust gas cooling device such as a gas cooler.

[0033] Second Embodiment The deodorizing apparatus of the second embodiment includes a plurality of dilution ducts corresponding to the plurality of industrial furnaces, through which odorous exhaust gas discharged from the plurality of industrial furnaces passes while being diluted with dilution gas. The deodorizing apparatus also includes a burner for heating the interior and a confluence section for confluence of the exhaust gases flowing out from the plurality of dilution ducts, and a gas treatment duct through which the combined exhaust gas at the confluence section passes while being heated by the burner. The deodorizing apparatus further includes an exhaust duct through which the exhaust gas heated by the burner passes within the gas treatment duct and is then discharged to the outside. The dilution ducts, gas treatment duct, and exhaust duct are connected so that the exhaust gas discharged from the plurality of industrial furnaces passes upward through the dilution duct, gas treatment duct, and exhaust duct in that order.

[0034] In the second embodiment, exhaust gases from multiple industrial furnaces can be treated simultaneously and collectively by a single deodorizing device. The deodorizing device of the second embodiment will be described with reference to FIG. 9. The deodorizing device 40 shown in FIG. 9 can treat exhaust gases from industrial furnaces A and B simultaneously. The deodorizing device 40 includes a dilution flue 42A into which exhaust gas from industrial furnace A flows and a dilution flue 42B into which exhaust gas from industrial furnace B flows. The ends of the dilution flue 42A and the dilution flue 42B on the industrial furnace A and B sides, respectively, are provided with dampers 50A and 50B that introduce only dilution gas for diluting the exhaust gas. The dilution flue 42A and the dilution flue 42B are both connected to a gas treatment flue 46. The gas treatment flue 46 is vertically installed so that the connection between the gas treatment flue 46 and the exhaust flue 48 is located higher than the connection between the dilution flue 42A and the dilution flue 42B and the gas treatment flue 46. A burner 44 is provided below the gas treatment flue 46, where the dilution flue 42A and the dilution flue 42B join. The burner 44 is provided so that the high-temperature combustion gas emitted from the burner 44 faces the other longitudinal (upward) end of the gas treatment flue 46. An exhaust flue 48 is connected to the upper end of the gas treatment flue 46, and the upper end of the exhaust flue 48 is exposed to the outside. In addition, the dilution flue 42A and the dilution flue 42B are provided with knife gate valves 52A and 52B, respectively, which can be switched between an open state that allows exhaust gas to pass through and a closed state that prevents exhaust gas from passing through. Furthermore, as shown in Figure 9, the gas treatment flue 46 is partially crank-shaped and has a communication passage with an inclination angle α between the flue on the dilution flue 42A and 42B side and the flue on the exhaust flue 48 side. By inclining the communication passage at the inclination angle α with respect to the horizontal, the upward vertical component of the buoyancy force acting on the flue gas due to the stack effect is reduced, and the upward velocity of the flue gas is slower than that of flue gas rising vertically upward. This increases the residence time of the flue gas in the gas treatment flue 16. Each flue is supported by a support member (not shown).

[0035] As described above, according to the deodorization apparatus 40, by opening both the knife gate valves 52A and 52B, the exhaust gas from the industrial furnace A and the exhaust gas from the industrial furnace B can be simultaneously treated. Furthermore, by opening one of the knife gate valves 52A and 52B and closing the other, the exhaust gas from the industrial furnace A and the exhaust gas from the industrial furnace B can be selectively treated. Note that FIG. 9 shows a case where the knife gate valve 52A is closed and the knife gate valve 52B is open, and only the exhaust gas that has flowed into the dilution flue 42B is treated. Furthermore, although FIG. 9 shows a configuration in which exhaust gas from two industrial furnaces, the industrial furnace A and the industrial furnace B, is treated, exhaust gas from three or more industrial furnaces may also be treated.

[0036] Next, five modified examples of the second embodiment are shown (Figs. 10 to 14). In all of these examples, as shown in the first embodiment, a portion of the gas treatment flue is inclined at an inclination angle of 0 to 90°. Figs. 10 to 11 show examples of a deodorization device in which a heat exchanger is not provided in the exhaust flue, and Figs. 12 to 14 show examples of a deodorization device in which a heat exchanger is provided in the exhaust flue.

[0037] Figure 10 differs from the deodorizing device shown in Figure 9 in that the inclination angle of the connecting passage between the flue on the dilution flue 42A and 42B side and the flue on the exhaust flue 48 side in the gas treatment flue 46 is 0°.Other than that, the components are substantially the same as those of the deodorizing device shown in Figure 9, and therefore the same components are given the same symbols and their explanations are omitted.

[0038] Figure 11 differs from the deodorizing device shown in Figure 9 in that the inclination angle of the connecting passage between the flue on the dilution flue 42A and 42B side and the flue on the exhaust flue 48 side in the gas treatment flue 46 is 90°.Other than that, the components are substantially the same as those of the deodorizing device shown in Figure 9, and therefore the same components are designated by the same reference numerals and their description will be omitted.

[0039] Figure 12 differs from the deodorization apparatus shown in Figure 9 in that a heat exchanger 22 is provided in the exhaust flue 48 of the gas treatment flue 46, but other components are substantially the same as those of the deodorization apparatus shown in Figure 9, and therefore the same components are given the same reference numerals and their description will be omitted. Similar to the deodorization apparatuses shown in Figures 5 and 6, the heat exchanger 22 recovers heat from the exhaust gas and serves to prevent high-temperature gas from being discharged into the outside air. The heat recovered by the heat exchanger 22 can be used in a recuperator, regenerative burner, etc., allowing for effective use of the exhaust heat from the exhaust gas.

[0040] Figure 13 differs from the deodorizing device shown in Figure 10 in that a heat exchanger 22 is provided in the exhaust flue 48 of the gas treatment flue 46, but the other components are essentially the same as those of the deodorizing device shown in Figure 10, so the same components are given the same symbols and their descriptions are omitted.

[0041] Figure 14 differs from the deodorizing device shown in Figure 11 in that a heat exchanger 22 is provided in the exhaust flue 48 of the gas treatment flue 46, but the other components are essentially the same as those of the deodorizing device shown in Figure 11, so the same components are given the same symbols and their descriptions are omitted.

[0042] In the second embodiment, if the total height is 100%, the height of the dilution flue 42A and the dilution flue 42B is 38%, the height of the gas treatment flue 46 is 79%, and the height of the exhaust flue 48 is 100%.

[0043] FIG. 15 shows a deodorization apparatus 40 according to a second embodiment, which is capable of simultaneously treating exhaust gases flowing out from four industrial furnaces. The deodorization apparatus 40 shown in FIG. 15 includes four dilution ducts 43A-43D, each connected at its lower end to one of four industrial furnaces (not shown). Each of the dilution ducts 43A-43D is provided with a knife gate valve 53A-53D that can be switched between an open state, which allows the exhaust gas to pass, and a closed state, which prevents the exhaust gas from passing through. Similarly to the deodorization apparatus shown in FIG. 9, the deodorization apparatus shown in FIG. 15 also includes a burner 44 that heats the interior of a gas treatment duct 46 and a junction that joins the exhaust gases flowing out from the four dilution ducts 43A-43D. The gas treatment duct 46 allows the joined exhaust gases to pass through while being heated by the burner 44. The deodorizing device 40 also includes an exhaust flue 48 through which exhaust gas heated by the burner 44 in the gas treatment flue 46 passes and is discharged to the outside. The dilution flue, gas treatment flue, and exhaust flue are connected so that exhaust gas discharged from the multiple industrial furnaces passes upward through the dilution flue, gas treatment flue, and exhaust flue in that order. In the deodorizing device 40, by opening all of the knife gate valves 53A to 53D, exhaust gas from the four industrial furnaces can be treated simultaneously and collectively. By opening any of the knife gate valves 53A to 53D and closing the others, exhaust gas from the four industrial furnaces can be selectively treated. [Explanation of symbols]

[0044] 10A 10B 30A 30B 40 Deodorizing device 12 42A 42B Dilution flue 14 50A 50B Damper 16 46 Gas treatment flue 18 44 Burner 20 48 Exhaust flue 42A 42B Knife Gate Valve

Claims

1. a dilution flue through which exhaust gas containing odorous gas discharged from an industrial furnace passes while being diluted with a dilution gas; a gas treatment flue having a burner for heating the inside thereof, through which the exhaust gas passes while being heated by the burner; an exhaust flue through which the exhaust gas heated by the burner in the gas treatment flue passes and is discharged to the outside; A deodorizing device in which a dilution flue, a gas treatment flue, and an exhaust flue are connected so that the exhaust gas discharged from the industrial furnace passes upward through the dilution flue, the gas treatment flue, and the exhaust flue in that order.

2. 2. The deodorizing device according to claim 1, wherein the gas treatment flue has a connection portion with the dilution flue and a connection portion with the exhaust flue that are at the same horizontal position, or at least a portion of the gas treatment flue is inclined so that the connection portion with the exhaust flue is located higher than the connection portion with the dilution flue.

3. 3. The deodorizing apparatus according to claim 2, wherein the inclination angle of the inclined portion of the gas treatment flue is 0 to 90 degrees with respect to the horizontal direction.

4. 3. The deodorizing apparatus according to claim 1, wherein the inner wall of the gas treatment flue is covered with a fireproof material.

5. 4. The deodorizing device according to claim 2, wherein the connection portion of the gas treatment flue with the dilution flue is located between the lower end of the gas treatment flue and the connection portion of the gas treatment flue and the exhaust flue, and the burner is provided at the lower end of the gas treatment flue.

6. 4. The deodorizing apparatus according to claim 2, wherein a connecting portion between the gas treatment flue and the exhaust flue is located below an upper end of the gas treatment flue.

7. 3. The deodorizing device according to claim 1, further comprising a heat exhaust section provided in the exhaust flue for lowering the temperature of the exhaust gas.

8. 3. The deodorizing apparatus according to claim 1, further comprising a damper for introducing dilution gas from the outside, disposed in a lower portion of said dilution flue.

9. a plurality of dilution ducts corresponding to the plurality of industrial furnaces, through which exhaust gas containing odorous gas discharged from the plurality of industrial furnaces passes while being diluted with a dilution gas; a gas treatment flue including a burner for heating the inside thereof and a confluence portion for confluence of exhaust gases flowing out from the plurality of dilution flue gases, wherein the confluenced exhaust gases at the confluence portion pass through the gas treatment flue while being heated by the burner; an exhaust flue through which the exhaust gas heated by the burner in the gas treatment flue passes and is discharged to the outside; A deodorization device in which the dilution flue, the gas treatment flue, and the exhaust flue are connected so that the exhaust gas discharged from the multiple industrial furnaces passes upward through the dilution flue, the gas treatment flue, and the exhaust flue in that order.

10. 10. The deodorizing device according to claim 9, wherein the gas treatment flue is connected to the plurality of dilution flues at the confluence, and is installed vertically so that the connection between the gas treatment flue and the exhaust flue is located higher than the connection between the dilution flue and the gas treatment flue.

11. 11. The deodorizing apparatus according to claim 9, wherein a portion of the gas treatment flue is inclined relative to the horizontal direction.

12. 12. The deodorizing apparatus according to claim 11, wherein the inclination angle of the inclined portion of the gas treatment flue is 0 to 90 degrees with respect to the horizontal direction.

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