JP2000262842A - Method and device for treatment of exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for treating exhaust gas in which harmful substance contained in exhaust gas discharged from a refuse incinerator or the like is efficiently removed by a simple method. SOLUTION: In treatment of exhaust gas in which harmful substance contained therein is removed by supplying an adsorbent to a conduit 18 for exhaust gas reaching a bag filter 10 from the outlet of an incinerator, dust contained in exhaust gas is uniformly mixed with the adsorbent by providing a gas-ascending flow vertical duct part having a throttle part 22 and a duct part having a throttle part 26 on the downstream side lower than the position for feeding the adsorbent. The adsorbent is uniformly dispersed and stuck on the surface of a filter cloth of the bag filter 10. Segregation of dust and the adsorbent is prevented by making the curved part of the duct between a vertical duct part 20 having the throttle part 22 and the inlet of the bag filter 10 into a substantially rectangularly curved duct 24. A gas-mixing part 28 for uniformly mixing exhaust gas with the adsorbent is provided on the upstream side of the throttle part 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves the efficiency of removing harmful substances by uniformly adsorbing an adsorbent on the filter cloth surface of a bag filter in an exhaust gas treatment using an adsorbent in a waste incineration facility or the like. The present invention relates to an exhaust gas treatment method and apparatus.

[0002]

2. Description of the Related Art In a waste incineration facility such as a refuse incineration facility, one of the methods for removing harmful substances in exhaust gas is as follows.
A method in which an adsorbent is blown into the exhaust gas discharged from the furnace outlet upstream of the bag filter, and the harmful substances in the exhaust gas are adsorbed (or reacted) by the adsorbent, and the harmful substances and dust in the exhaust gas are removed by the bag filter. There is. In order to remove harmful substances efficiently by this method, it is necessary to disperse the adsorbent uniformly in the exhaust gas and to uniformly adhere the adsorbent to the filter cloth surface of the bag filter.

[0003] For example, Japanese Patent Application Laid-Open No. 10-103647 discloses an adsorption reactor for supplying an adsorbent to exhaust gas from an incinerator upstream of a bag filter as means for uniformly dispersing the adsorbent in the exhaust gas. Is disclosed. Japanese Patent Application Laid-Open No. Hei 10-216440 discloses that a dispersion plate, a guide vane, a flap and the like are provided at an inlet portion of a bag filter in order to uniformly deposit dust and an adsorbent on a filter cloth surface of the bag filter. A configuration for providing a vessel is disclosed.

[0004]

However, even if an adsorber is provided upstream of the bag filter and the adsorbent is blown into the exhaust gas, the adsorbent is not uniformly mixed with the dust in the exhaust gas. Therefore, it is difficult to uniformly disperse and attach the adsorbent to the filter cloth surface of the bag filter. In addition, when the adsorbent is blown, even if the adsorbent is uniformly dispersed in the exhaust gas, the blown adsorbent is not uniformly mixed with the dust in the exhaust gas. For this reason, even if a disperser is provided at the entrance of the bag filter, it is difficult to uniformly disperse and attach the adsorbent to the filter cloth surface of the bag filter.

[0005] The present invention has been made in view of the above points,
An object of the present invention is to provide an adsorbent in an exhaust gas conduit from a furnace outlet to a bag filter in a waste incineration facility or the like to remove harmful substances in exhaust gas, and to perform a process downstream of an adsorbent supply position in exhaust gas treatment. By providing a duct section having a throttle section, or a vertical duct section of a gas rising flow having a throttle section, uniform mixing of dust in the exhaust gas and the adsorbent is achieved, and the adsorbent is evenly distributed on the filter cloth surface of the bag filter. It is an object of the present invention to provide an exhaust gas treatment method and an apparatus for improving the efficiency of removing harmful substances by dispersing and adhering to the exhaust gas. Another object of the present invention is to provide a gas duct having a narrowed portion and a bent portion of a duct between a bag filter inlet and a duct having a substantially right-angled bend, thereby reducing dust and adsorbent in exhaust gas. An object of the present invention is to provide an exhaust gas treatment method and apparatus capable of uniformly mixing and preventing segregation of dust and an adsorbent. Still another object of the present invention is to provide a gas mixing section for uniformly mixing the exhaust gas and the adsorbent on the upstream side of the throttle section, thereby efficiently adsorbing harmful substances in the exhaust gas to the adsorbent (or To provide an exhaust gas treatment method and apparatus capable of causing the reaction.

[0006]

In order to achieve the above object, an exhaust gas treatment method of the present invention supplies an adsorbent to exhaust gas discharged from an exhaust gas generation source such as an incinerator and contains the adsorbent in the exhaust gas. Adsorbing some of the harmful substances to be adsorbed or reacting with the adsorbent, introducing them to the bag filter, and adsorbing or reacting the remaining harmful substances in the exhaust gas with the adsorbent attached to the filter cloth surface of the bag filter In the exhaust gas treatment method for removing dust and adsorbed or reacted harmful substances in the exhaust gas by the filter cloth of the bag filter and adsorbing the exhaust gas conduit (duct) from the outlet of the exhaust gas source to the inlet of the bag filter, A duct having a throttle section is provided downstream of the agent supply position, dust in the exhaust gas and the adsorbent are uniformly mixed in the exhaust gas conduit, and the adsorbent is evenly distributed on the filter cloth surface of the bag filter. Dispersing or adhere, and is configured to contact an adsorbent attached to toxic substances and the filter cloth surface in the exhaust gas uniformly (see FIGS. 1-9).

In the above-mentioned method of the present invention, a constricted portion is formed in a vertical (vertical) duct portion in which exhaust gas on the downstream side of the adsorbent supply position in the exhaust gas conduit from the outlet of the exhaust gas generation source to the inlet of the bag filter flows upward. The dust in the exhaust gas and the adsorbent are uniformly mixed in the exhaust gas conduit, and the adsorbent is evenly dispersed and adhered to the filter cloth surface of the bag filter, so that the harmful substances in the exhaust gas and the filter cloth surface The attached adsorbent can be uniformly contacted (see FIGS. 2 to 4). Further, in the method of the present invention, the bent portion of the duct between the vertical duct portion having the constricted portion and the exhaust gas conduit on the bag filter inlet side is made into a substantially bent duct so that dust in the exhaust gas and the adsorbent Is preferably mixed to avoid segregation of dust and adsorbent (see FIGS. 2 to 4).
Further, in these methods of the present invention, a gas mixing section is provided on the upstream side of the throttle section in the exhaust gas conduit from the outlet of the exhaust gas generation source to the inlet of the bag filter to uniformly mix the exhaust gas and the adsorbent, It is preferable to efficiently adsorb or react the harmful substances to the adsorbent (FIGS. 4 and 10).
reference).

The exhaust gas treatment apparatus of the present invention supplies an adsorbent to exhaust gas from an incinerator flowing through an exhaust gas conduit (duct) by an adsorbent supply means, and removes a part of harmful substances contained in the exhaust gas in the exhaust gas conduit. The adsorbent is caused to adsorb or react with the adsorbent, these are introduced into the bag filter from the exhaust gas conduit, and the adsorbent attached to the filter cloth surface of the bag filter removes the remaining harmful substances in the exhaust gas by adsorption or reaction. In an exhaust gas treatment apparatus in which dust and adsorbed or reacted harmful substances in exhaust gas are removed by a filter cloth of a bag filter, the dust and the adsorbent in the exhaust gas conduit are located downstream of the adsorbent supply means in the exhaust gas conduit. And a duct portion having a throttle portion for uniformly dispersing and adsorbing the adsorbent on the filter cloth surface of the bag filter (FIG. 1). 9 reference).

In the above-described apparatus of the present invention, dust and adsorbent in the exhaust gas are uniformly mixed in a vertical (vertical) duct portion in which the exhaust gas downstream of the adsorbent supply means in the exhaust gas conduit flows upward. In addition, a throttle portion for uniformly dispersing and adsorbing the adsorbent can be provided on the filter cloth surface of the bag filter (see FIGS. 2 to 4). Further, in the above-described apparatus of the present invention, the bent portion of the duct between the vertical duct portion having the constricted portion and the exhaust gas conduit on the bag filter inlet side uniformly mixes dust and adsorbent in the exhaust gas with dust. Preferably, the duct is formed by a substantially right-angle bent duct for preventing segregation of the adsorbent (see FIGS. 2 to 4). Further, in these apparatuses of the present invention, a duct diameter for uniformly mixing the exhaust gas and the adsorbent and efficiently adsorbing or reacting the harmful substances in the exhaust gas to the adsorbent is provided on the upstream side of the throttle portion in the exhaust gas conduit. It is preferable to provide a gas mixing section in which is enlarged (see FIGS. 4 and 10).

Further, in these apparatuses of the present invention, the diameter of the duct at the outlet of the throttle on the downstream side in the gas flow direction can be made different from the diameter of the duct at the inlet of the throttle on the upstream side (see FIGS. 6 and 6). 7). Further, in these apparatuses of the present invention, the inner diameter of the large diameter portion (convex portion) of the throttle portion on the downstream side in the gas flow direction is different from the inner diameter of the large diameter portion (convex portion) of the upstream throttle portion. (See FIGS. 6 and 7).
In these devices of the present invention, the length of the large-diameter portion (convex portion) of the throttle portion on the downstream side in the gas flow direction is different from the length of the large-diameter portion (convex portion) of the throttle portion on the upstream side. (See FIGS. 6 and 7).

Further, in these apparatuses according to the present invention, a gas blow-through preventing member can be provided at a large diameter portion (convex portion) of the throttle portion inside the duct portion having the throttle portion (see FIG. 8). Further, in these apparatuses of the present invention, the small-diameter portion (concave portion) of the throttle portion can be decentered on the upstream side and the downstream side in the gas flow direction (see FIG. 9). Further, in these apparatuses of the present invention, the gas inlet and the gas outlet of the gas mixing section can be decentered on the upstream side and the downstream side in the gas flow direction (see FIG. 10). Further, in the above-described apparatus of the present invention, instead of forming the bent portion of the duct between the vertical duct portion having the constricted portion and the exhaust gas conduit on the bag filter inlet side by a substantially right-angled duct, the outer side of the duct inner surface is formed. It can be formed to have a substantially right-angled step shape (see FIG. 11).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described for treating exhaust gas from an incinerator such as a refuse incinerator, but the present invention is not limited to the following embodiment. Instead, the present invention can be implemented with appropriate changes. 1 to 4 show an exhaust gas treatment apparatus according to a first embodiment of the present invention. As shown in FIG.
Exhaust gas from the incinerator is blown in from an adsorbent supply pipe 14 in an exhaust gas conduit (duct) 12 on the upstream side of the bag filter 10, and a part of harmful substances in the exhaust gas is adsorbed by the adsorbent. Or reacts with adsorbents. As the adsorbent to be blown, for example, activated carbon, slaked lime, quicklime, limestone, zeolite, dolomite, etc. are used depending on the type of harmful substances contained in the exhaust gas. Exhaust gas into which the adsorbent has been blown is uniformly mixed with dust (fly ash) in the exhaust gas and the adsorbent in a duct portion having a throttle portion 16 provided in the exhaust gas conduit 12 leading to the inlet of the bag filter 10. Is done. Thereby, the bag filter 10
The adsorbent is uniformly dispersed and adhered to the surface of the filter cloth to form an adsorbent layer, and the harmful substances in the exhaust gas not adsorbed (or reacted) to the adsorbent by the inlet of the bag filter 10 and the bag filter. The adsorbent adhering to the filter cloth surface of No. 10 comes into uniform contact, and the remaining harmful substances in the exhaust gas are efficiently removed by adsorption or reaction. The exhaust gas from which dust and harmful substances have been removed by the filter cloth of the bag filter 10 and the adsorbent adhering to the filter cloth surface is discharged out of the system through an exhaust gas conduit 17.

As shown in FIG. 2, between the exhaust gas outlet of the incinerator (not shown) and the bag filter 10, a constriction section 22 is formed in a vertical duct section 20 where exhaust gas flows upward in an exhaust gas conduit (duct) 18. Is provided, the dust in the exhaust gas and the adsorbent are mixed more uniformly. Other configurations and operations are the same as those in FIG. Usually, equipment such as an air preheater is installed between the exhaust gas outlet of the incinerator and the bag filter, and the height (level) of these equipment and the installation position of the bag filter are different. ,
A vertical duct section will be provided. Further, as shown in FIG. 2, the bent portion of the duct between the vertical duct portion 20 having the throttle portion 22 and the exhaust gas conduit 18 on the inlet side of the bag filter 10 is a substantially right-angled bent duct 24 bent at a substantially right angle. You. By making the duct 24 a substantially right angle bend, the exhaust gas collides with the inner wall of the duct and changes its direction rapidly,
The dust and the adsorbent in the exhaust gas can be uniformly mixed to avoid segregation of the dust and the adsorbent.

Further, as shown in FIG.
In the vertical duct 20 where the exhaust gas flows upward in the
And a duct portion having a second throttle portion 26 can be provided in the substantially horizontal exhaust gas conduit 18 on the inlet side of the bag filter 10. In this case, the dust in the exhaust gas and the adsorbent are more uniformly mixed by the throttle units 22 and 26. Other configurations and operations are the same as those in FIGS. Further, as shown in FIG. 4, by providing a gas mixing section 28 having an enlarged duct diameter on the upstream side of the first throttle section 22 in the exhaust gas pipe 18, the exhaust gas and the adsorbent are uniformly mixed. In addition, harmful substances in exhaust gas can be efficiently adsorbed or reacted with the adsorbent. The gas mixing section 28 is connected to the adsorbent supply pipe 14.
Although provided on the downstream side, it is also possible to adopt a configuration in which the adsorbent is supplied into the gas mixing section 28. Other configurations and operations are the same as those in FIG. Further, it is of course possible to provide the gas mixing section 28 upstream of the throttle section in FIGS.

FIG. 5 shows a throttle section in an exhaust gas treatment apparatus according to a second embodiment of the present invention. The throttle unit 30 shown in FIG. 5 has a configuration in which a large-diameter part 32 and a small-diameter part 34 are arranged in an abacus bead shape, and the inside is hollow, and the throttle unit 30 separates dust in exhaust gas and an adsorbent. Evenly mixed. Other configurations and operations are the same as those in the first embodiment.

FIGS. 6 and 7 show a throttle section in an exhaust gas treatment apparatus according to a third embodiment of the present invention. FIG.
The throttle section 36 shown in FIG. 3 has a duct diameter d1 at the outlet of the throttle section on the downstream side in the gas flow direction larger than a duct diameter d2 at the inlet of the throttle section on the upstream side to prevent blow-through of the gas. Is intended to achieve more uniform mixing. In the throttle section 36, the inner diameter of the large-diameter section 38 on the downstream side in the gas flow direction can be made larger than the inner diameter of the large-diameter section 40 on the upstream side. Further, the length of the large diameter portion 38 on the downstream side in the gas flow direction can be made longer than the length of the large diameter portion 40 on the upstream side. These also make it possible to prevent gas from flowing through. The throttle section 42 shown in FIG. 7 has a duct diameter d3 at the outlet of the throttle section on the downstream side in the gas flow direction smaller than a duct diameter d4 at the inlet of the throttle section on the upstream side to prevent gas blow-through and adsorb the exhaust gas. It is intended to achieve more uniform mixing with the agent. In the throttle section 42, the inside diameter of the large diameter section 44 on the downstream side in the gas flow direction can be made smaller than the inside diameter of the large diameter section 46 on the upstream side. Further, the length of the large diameter portion 44 on the downstream side in the gas flow direction can be made shorter than the length of the large diameter portion 46 on the upstream side. With these,
It is possible to prevent gas from flowing through. Other configurations and operations are the same as those in the first embodiment.

FIG. 8 shows a throttle section in an exhaust gas treatment apparatus according to a fourth embodiment of the present invention. The throttle portion 48 shown in FIG. 8 has a gas blow-through prevention member 52 such as metal or heat-resistant plastic installed at a substantially central portion inside a large-diameter portion 50 in order to prevent gas blow-through. Other configurations and operations are the same as those in the first embodiment.

FIG. 9 shows a throttle section in an exhaust gas treatment apparatus according to a fifth embodiment of the present invention. In the throttle portion 54 shown in FIG. 9, a small-diameter portion 56 of the throttle portion is eccentrically provided on the upstream side and the downstream side in the gas flow direction in order to prevent gas from flowing through. Other configurations and operations are the same as those in the first embodiment. In addition, it is also possible to appropriately combine and use the configurations of the aperture portions in the first to fifth embodiments.

FIG. 10 shows a gas mixing section in an exhaust gas treatment apparatus according to a sixth embodiment of the present invention. FIG.
The gas mixing section 58 having an enlarged duct diameter shown in FIG. 0 is provided such that the gas inlet 60 and the gas outlet 62 are eccentric on the upstream side and the downstream side in the gas flow direction. This allows
In the gas mixing section 58, gas blow-through is prevented,
More uniform mixing of the exhaust gas and the adsorbent can be achieved. Other configurations and operations are the same as those in the first embodiment.

FIG. 11 shows a bent portion of a duct in an exhaust gas treatment apparatus according to a seventh embodiment of the present invention.
As shown in FIG. 11, the curved portion of the duct between the vertical duct portion 64 and the exhaust gas conduit 66 on the inlet side of the bag filter (not shown) is formed by a step such that the outside on the inner surface of the duct has a substantially right-angled step shape. By forming the curved duct 68, segregation of dust and the adsorbent can be avoided, and abrasion at the bent portion of the duct can be prevented. Other configurations and operations are the same as those in the first embodiment. It is needless to say that the configurations of the first to seventh embodiments described above can be appropriately combined and implemented.

[0021]

As described above, the present invention has the following effects. (1) In exhaust gas treatment to remove harmful substances in exhaust gas by supplying an adsorbent into the exhaust gas conduit from the furnace outlet to the bag filter in a waste incineration facility, etc., a throttle is provided downstream of the adsorbent supply position. By providing a duct part having, the dust in the exhaust gas and the adsorbent are mixed uniformly in the exhaust gas conduit, and the adsorbent is evenly dispersed and adhered to the filter cloth surface of the bag filter, thereby eliminating harmful substances in the exhaust gas. The adsorbent adhering to the filter cloth surface can be uniformly contacted to improve the harmful substance removal efficiency. (2) In order to mix the dust in the exhaust gas and the adsorbent more uniformly, if a throttle is provided in the vertical duct where the exhaust gas flows upward, the adsorbent is evenly dispersed on the filter cloth surface of the bag filter. The harmful substances contained in the exhaust gas and the adsorbent adhered to the surface of the filter cloth are uniformly contacted with each other, so that the harmful substance removal efficiency can be further improved. In this case, the dust in the exhaust gas and the adsorbent are further uniformly mixed by providing the throttle on the downstream side of the bent portion of the duct between the vertical duct having the throttle and the bag filter. (3) When the bent portion of the duct between the vertical duct portion having the constricted portion and the bag filter inlet is a substantially right-angled duct, the dust and the adsorbent in the exhaust gas are uniformly mixed, and the dust and the adsorbent are mixed. Segregation can be avoided. (4) When a gas mixing section for uniformly mixing the exhaust gas and the adsorbent is provided upstream of the throttle section, harmful substances in the exhaust gas can be efficiently adsorbed (or reacted) to the adsorbent. Further, since the contact efficiency between the exhaust gas and the adsorbent can be increased by the gas mixing section, the utilization efficiency of the adsorbent in the gas mixing section can be increased. (5) The duct diameter at the outlet of the throttle portion on the downstream side in the gas flow direction is made larger (or smaller) than the duct diameter at the inlet of the throttle portion on the upstream side, or the inner diameter and length of the large diameter portion of the throttle portion are changed.
In the case of installing a gas blow-through prevention member such as hardware, heat-resistant plastic, etc. inside the duct portion having the throttle portion, or when the throttle portion or the gas mixing portion is eccentric, prevent gas blow-through and reduce exhaust gas More uniform mixing with the adsorbent can be achieved. (6) When forming the bent portion of the duct between the vertical duct portion having the constricted portion and the bag filter inlet so that the outside on the inner surface of the duct has a substantially right-angled step shape, segregation of dust and the adsorbent is avoided. At the same time, it is possible to prevent abrasion at the bent portion of the duct.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an exhaust gas treatment device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing another example of the exhaust gas treatment apparatus according to the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing another example of the exhaust gas treatment apparatus according to the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing still another example of the exhaust gas treatment apparatus according to the first embodiment of the present invention.

FIG. 5 is a schematic configuration diagram illustrating a throttle unit in an exhaust gas treatment device according to a second embodiment of the present invention.

FIG. 6 is a schematic configuration diagram illustrating an example of a throttle unit in an exhaust gas treatment device according to a third embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing another example of a throttle unit in an exhaust gas treatment device according to a third embodiment of the present invention.

FIG. 8 is a schematic configuration diagram showing a throttle unit in an exhaust gas treatment device according to a fourth embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing a throttle unit in an exhaust gas treatment device according to a fifth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram illustrating a gas mixing unit in an exhaust gas treatment device according to a sixth embodiment of the present invention.

FIG. 11 is a schematic configuration diagram showing a bent portion of a duct in an exhaust gas treatment device according to a seventh embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Bag filter 12, 17, 18, 66 Exhaust gas pipe (duct) 14 Adsorbent supply pipe 16, 22, 26, 30, 36, 42, 48, 54 Throttle part 20, 64 Vertical duct part 24 Substantially right-angled duct 28, 58 Gas mixing section 32, 38, 40, 44, 46, 50 Large diameter section 34, 56 Small diameter section 52 Gas blow-through prevention member 60 Gas inlet 62 Gas outlet 68 Stepped bent duct d1, d2, d3, d4 Duct diameter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23J 15/00 ZAB (72) Inventor Takahito Tanigawa 1-1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries Akashi Co., Ltd. Inside the factory (72) Inventor Kenjiro Shindo 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd.Akashi factory Co., Ltd. F-term (reference) BA14 CA11 CA20 DA05 DA11 DA12 DA41 DA45 EA01 HA10 4D012 CA12 CC13 CE01 CF10 CG01 CH01 CK09 4D058 JA04 QA01 QA13 TA02

Claims (15)

[Claims] 1. An adsorbent is supplied to exhaust gas discharged from an exhaust gas generation source to cause a part of harmful substances contained in the exhaust gas to be adsorbed by the adsorbent or to react with the adsorbent, and these are introduced into a bag filter. The adsorbent attached to the filter cloth surface of the bag filter removes the remaining harmful substances in the exhaust gas by adsorption or reaction, and the bag filter cloth removes dust and the adsorbed or reacted harmful substances in the exhaust gas. In a method of treating exhaust gas, a duct having a throttle portion is provided downstream of an adsorbent supply position of an exhaust gas conduit from an outlet of an exhaust gas generation source to an inlet of a bag filter, and dust and adsorbent in the exhaust gas are exhausted. Mix uniformly in the pipe, uniformly disperse and adhere the adsorbent on the filter cloth surface of the bag filter, and uniformly contact the harmful substances in the exhaust gas and the adsorbent adhering to the filter cloth surface. Exhaust gas treatment method comprising. 2. A throttle section is provided in a vertical duct portion where exhaust gas flows upward from an adsorbent supply position in an exhaust gas conduit from an exhaust gas source outlet to an inlet of a bag filter from an exhaust gas generation source to reduce dust in the exhaust gas. The adsorbent is evenly mixed in the exhaust gas conduit, and the adsorbent is evenly dispersed and adhered to the filter cloth surface of the bag filter, so that the harmful substances in the exhaust gas and the adsorbent adhering to the filter cloth surface are evenly contacted. The exhaust gas treatment method according to claim 1, wherein 3. The dust in the exhaust gas and the adsorbent are uniformly mixed by making the bent portion of the duct between the vertical duct portion having the throttle portion and the exhaust gas conduit on the bag filter inlet side a substantially right angled duct. The exhaust gas treatment method according to claim 2, wherein the segregation of dust and adsorbent is avoided. 4. A gas mixing section is provided upstream of a throttle section in an exhaust gas conduit from an exhaust gas source outlet to an inlet of a bag filter to uniformly mix exhaust gas and an adsorbent to adsorb harmful substances in the exhaust gas. 4. The exhaust gas treatment method according to claim 1, wherein the agent is efficiently adsorbed or reacted with the agent. 5. An adsorbent is supplied to exhaust gas from an incinerator flowing through an exhaust gas conduit by an adsorbent supply means, and a part of harmful substances contained in the exhaust gas is adsorbed by the adsorbent or reacted with the adsorbent in the exhaust gas conduit. These are introduced into the bag filter from the exhaust gas conduit, and the remaining harmful substances in the exhaust gas are removed by adsorption or reaction with the adsorbent attached to the filter cloth surface of the bag filter. In an exhaust gas treatment apparatus configured to remove dust and adsorbed or reacted harmful substances, the dust in the exhaust gas and the adsorbent are uniformly mixed downstream of the adsorbent supply means of the exhaust gas conduit, and a bag filter is provided. An exhaust gas treatment apparatus, characterized in that a duct portion having a throttle portion for uniformly dispersing and adsorbing the adsorbent is provided on the surface of the filter cloth. 6. The dust in the exhaust gas and the adsorbent are uniformly mixed in a vertical duct where the exhaust gas on the downstream side of the adsorbent supply means in the exhaust gas conduit flows upward, and is adsorbed on the filter cloth surface of the bag filter. The exhaust gas treatment apparatus according to claim 5, further comprising a throttle section for uniformly dispersing and attaching the agent. 7. A bent portion of a duct between a vertical duct portion having a constricted portion and an exhaust gas conduit on the bag filter inlet side uniformly mixes dust and adsorbent in exhaust gas to reduce segregation of dust and adsorbent. 7. The exhaust gas treatment device according to claim 6, wherein the exhaust gas treatment device is formed by a substantially right-angle bent duct for prevention. 8. A gas having an enlarged duct diameter for uniformly mixing the exhaust gas and the adsorbent on the upstream side of the throttle portion in the exhaust gas conduit and for efficiently adsorbing or reacting harmful substances in the exhaust gas to the adsorbent. The mixing unit is provided with a mixing unit.
An exhaust gas treatment device as described in the above. 9. The exhaust gas treatment apparatus according to claim 5, wherein a duct diameter at the outlet of the throttle portion on the downstream side in the gas flow direction is different from a duct diameter at the inlet of the throttle portion on the upstream side. 10. The exhaust gas according to claim 5, wherein the inner diameter of the large-diameter portion of the throttle portion on the downstream side in the gas flow direction is different from the inner diameter of the large-diameter portion of the throttle portion on the upstream side. Processing equipment. 11. The exhaust gas according to claim 5, wherein the length of the large-diameter portion of the downstream throttle portion in the gas flow direction is different from the length of the large-diameter portion of the upstream throttle portion. Processing equipment. 12. The exhaust gas treatment apparatus according to claim 5, wherein a gas blow-through prevention member is provided at a large diameter portion of the throttle inside the duct having the throttle. 13. The exhaust gas treatment apparatus according to claim 5, wherein the small-diameter portion of the throttle portion is eccentric on the upstream side and the downstream side in the gas flow direction. 14. The exhaust gas treatment apparatus according to claim 8, wherein the gas inlet and the gas outlet of the gas mixing section are eccentric on the upstream side and the downstream side in the gas flow direction. 15. A bent portion of a duct between a vertical duct portion having a constricted portion and an exhaust gas conduit on the bag filter inlet side,
8. The exhaust gas treatment device according to claim 7, wherein instead of being formed by a substantially right-angled duct, the outside on the inner surface of the duct is formed in a substantially right-angled stepped shape.