Deodorizing apparatus

Abstract

This deodorizing apparatus (10A, 10B) comprises: a dilution flue (12) through which an exhaust gas containing an odor gas and discharged from an industrial furnace is passed while being diluted with a dilution gas; a gas treatment flue (16) which is provided with a burner (18) for heating the interior and through which the exhaust gas is passed while being heated by the burner; and an exhaust flue (20) through which the exhaust gas heated by the burner in the gas treatment flue is passed and exhausted to the outside, wherein the dilution flue, the gas treatment flue, and the exhaust flue are connected so that the exhaust gas discharged from the industrial furnace passes through the dilution flue, the gas treatment flue, and the exhaust flue sequentially while proceeding upward.

Description

Deodorizing equipment

[0001] The present disclosure relates to a deodorizing device.

[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 and ventilate the exhaust gases emitted from the industrial furnaces and the like.

[0003] Japanese Patent Application Laid-Open No. 2003-302029

[0004] However, the deodorizing device described in Patent Document 1 has a limited heat resistance temperature for devices that ventilate 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 above 600°C, for example, 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 since exhaust gas often contains corrosive gases, there are problems with the fans and exhaust fans being prone to corrosion. Furthermore, as described 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 disclosure has been made in consideration of the problems inherent in the conventional technology, and an object of the present disclosure is to provide a deodorizing device that can deodorize exhaust gas without requiring a device for ventilating exhaust gas, such as a blower or an exhaust fan.

[0006] A deodorizing device according to a first aspect of the present disclosure 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, and 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 disclosure 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 exhausted 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.

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

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

[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> A deodorization apparatus according to a first embodiment includes a dilution flue through which odorous exhaust gas discharged from an industrial furnace passes while being diluted with a dilution gas. The deodorization apparatus also includes a gas treatment flue that includes a burner for heating the interior thereof and through which the exhaust gas passes while being heated by the burner. The deodorization apparatus 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 is a schematic side view of a deodorizing apparatus 10A, which is an example of the 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 thereof, 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 exhausted from the outlet of the exhaust flue 20. The dilution flue, the gas treatment flue, and the exhaust flue will be 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 the exhaust gas 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 the exhaust gas are organic gases, it is desirable to dilute the exhaust gas to a concentration 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 a concentration below the lower explosion limit, and more preferably to a concentration below 1 / 4 of the lower explosion limit. By diluting the exhaust gas in this way, safety in the operation of the deodorizing device can be ensured.

[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 is also equipped with a burner 18 that heats the interior. 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, it is necessary to retain the exhaust gas passing through the gas treatment flue 16 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, thereby ensuring a longer residence time for the exhaust gas than if the exhaust gas were simply discharged 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 caused by applying the inclination angle α at the confluence point can be reduced, and further space can be saved. Furthermore, 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, the boundary between the gas treatment flue 16 and the exhaust flue 20 is the position of point P. The position of 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 temperature measurement position.

[0020] As shown in Fig. 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 Fig. 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 Fig. 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 discharges 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 Fig. 1) to check the state of the high-temperature combustion gas discharged 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 castables, refractory bricks, etc. can be used as the refractory material. The combustion chamber in which the burner 18 is installed can also have a multi-layer structure consisting of "refractory castables or refractory bricks, etc. (high-temperature gas contact side)" and "insulating castables or insulating bricks, etc. (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 in which 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 from the time exhaust gas generation is stopped to the time operation is performed can be tolerated by each flue.

[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 exhausted to the outside. That is, the exhaust flue 20 serves to guide and exhaust the exhaust gas that has been deodorized in the gas treatment flue 16 to the outside. In Figure 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, assuming the total height to be 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 flue temperature or 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 inlet of the gas treatment flue 16 to a maximum temperature (100%), and its temperature decreases as it travels through the gas treatment flue 16, before flowing into the exhaust flue 20. Thereafter, its temperature decreases slightly in the exhaust flue 20 and it is discharged to the outside. Meanwhile, with regard to the flow rate of the exhaust gas, 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 inlet due to the combustion exhaust gas from the burner 18, and then it 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 longer, more preferably 0.3 to 1.0 seconds.

[0025] By using the deodorizing device shown in Figure 1, the odorous gas in the exhaust gas to be treated was decomposed with a deodorizing efficiency of over 92%, achieving an improvement of 85% or less compared to the allowable odor index, the regulated value under the Offensive Odor Control Act. The odor index is calculated by multiplying the common logarithm of the dilution ratio (odor concentration) obtained by diluting a sample with odorless air until subjects (hereinafter referred to as "panels") who have previously passed a test to confirm that they have a normal sense of smell can no longer detect the odor, in accordance with Environment Agency Notification No. 63 of 1995, "Method for Calculating Odor Index and Odor Emission Intensity." The odor index is calculated by multiplying the common logarithm of the dilution ratio by 10. That is, 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" in the Ministry of the Environment Notification. Olfactory Measurement: A method of measuring odors using the human nose (sense of smell) is called an olfactory measurement method, and is managed and supervised by a nationally certified "odor evaluator" as the operator. In the above measurement, three panelists sniffed two prepared bags (one odorized bag and one odorless bag) and then picked up one of the bags containing the odor, which was gradually diluted with odorless air. The odor intensity was expressed as the dilution factor when the odor-containing bag could no longer be identified. The deodorizing efficiency is given by the following formula: Deodorizing efficiency = (inlet odor concentration - outlet odor concentration) ÷ inlet odor concentration x 100% Here, the inlet odor concentration is the odor concentration of the flue gas at the bottom end of the dilution flue 12, and the outlet odor concentration is the odor concentration of the flue gas at the top 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 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 allows the exhaust 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 device 10B shown in Figure 2 are shown in the graphs of Figure 4. Specific examples of the height at each position in the deodorizing device 10B are the same as those for the deodorizing device 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. Also, 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 is provided as a heat exhaust unit 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., thereby making effective use of 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 show 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 connection 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, it can be seen that the heat exchanger 22 removes heat from the exhaust gas at the upper part of the exhaust flue 20, lowering its temperature. When the exhaust gas is discharged from the exhaust flue 20 to the outside, its temperature has dropped 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 to lower the temperature of the exhaust gas, thereby enabling low-temperature exhaust gas to be discharged to the outside with less 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 provided 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 A deodorizing apparatus according to a 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 a dilution gas. The deodorizing apparatus also includes a burner for heating the interior of the deodorizing apparatus, a confluence section for confluence of the exhaust gases flowing out of 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 together 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 simultaneously treated 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 simultaneously treat exhaust gases from industrial furnaces A and B. 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 equipped with dampers 50A and 50B that introduce only dilution gas for diluting the exhaust gas. Both the dilution flue 42A and the dilution flue 42B communicate with 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 emitted high-temperature combustion gas 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. 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 the exhaust gas to pass through and a closed state that prevents the exhaust gas from passing through. Furthermore, as shown in FIG. 9 , the gas treatment flue 46 is partially crank-shaped, and a communication passage with an inclination angle α is provided between the flue on the dilution flue 42A / 42B side and the flue on the exhaust flue 48 side. By inclining the communication passage at an angle α with respect to the horizontal, the component of buoyancy acting on the flue gas in the vertical direction 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. As a result, the residence time of the flue gas in the gas treatment flue 16 is longer. Each flue is supported by a support member (not shown).

[0035] As described above, with the deodorization device 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, industrial furnace A and 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, while 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 descriptions 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 given the same reference numerals and their description will be omitted.

[0039] 12 differs from the deodorization apparatus shown in FIG. 9 in that a heat exchanger 22 is provided in the exhaust flue 48 of the gas treatment flue 46. Since the other components are substantially the same as those of the deodorization apparatus shown in FIG. 9, the same components are denoted by the same reference numerals and description thereof will be omitted. Similar to the deodorization apparatuses shown in FIGS. 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., thereby enabling effective utilization 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 substantially 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 second embodiment of a deodorizing apparatus 40 capable of simultaneously treating exhaust gases flowing from four industrial furnaces. The deodorizing apparatus 40 shown in FIG. 15 includes four dilution ducts 43A-43D, each connected at its lower end to 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 through, and a closed state, which prevents the exhaust gas from passing through. Similar to the deodorizing apparatus shown in FIG. 9 , the deodorizing apparatus shown in FIG. 15 also includes a burner 44 that heats the interior of a gas treatment duct 46 and a confluence section that combines the exhaust gases flowing from the four dilution ducts 43A-43D. The combined exhaust gases are heated by the burner 44 and pass through the gas treatment duct 46. 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 exhausted to the outside. Furthermore, 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 sequence. 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. Furthermore, 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.

[0044] The entire contents of Japanese Patent Application No. 2024-046219 (filing date: March 22, 2024) are incorporated herein by reference.

[0045] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment.

[0046] 10A 10B 30A 30B 40 Deodorization 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 deodorizing device comprising: a dilution flue through which odorous exhaust gas 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, wherein 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.

2. A deodorizing device as described in 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. The deodorizing device 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. A deodorizing apparatus according to any one of claims 1 to 3, wherein the inner wall of the gas treatment flue is lined with a fire-resistant material.

5. A deodorizing device as described in claim 2 or 3, 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. A deodorizing device according to claim 2 or 3, wherein the connecting portion between the gas treatment flue and the exhaust flue is located below the upper end of the gas treatment flue.

7. A deodorizing device according to any one of claims 1 to 6, wherein the exhaust flue is provided with a heat dissipation section for lowering the temperature of the exhaust gas.

8. A deodorizing device according to any one of claims 1 to 7, further comprising a damper at the lower portion of the dilution flue for introducing dilution gas from the outside.

9. A deodorizing device comprising: 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 inside, and a confluence section for confluence of exhaust gases flowing out from the plurality of dilution ducts, the gas treatment duct through which the exhaust gases combined at the confluence section pass while being heated by the burner; and an exhaust duct through which the exhaust gas heated by the burner passes within the gas treatment duct and is exhausted to the outside, wherein the plurality of dilution ducts, the gas treatment duct, and the exhaust duct are connected so that the exhaust gases discharged from the plurality of industrial furnaces pass upward through the dilution duct, the gas treatment duct, and the exhaust duct in that order.

10. A deodorizing device as described in claim 9, wherein the gas treatment flue is connected to the plurality of dilution flue ducts 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. A deodorizing apparatus according to claim 9 or 10, wherein a portion of the gas treatment flue is inclined relative to the horizontal direction.

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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