JP4426364B2 - Exhaust gas treatment equipment - Google Patents

Description

  The present invention relates to an exhaust gas treatment device, and more particularly to an exhaust gas treatment device that removes harmful substances contained in exhaust gas.

  In general, dry exhaust gas treatment devices are widely used for the treatment of exhaust gas generated from various plants, etc., especially for treatment of combustion exhaust gas containing SOx, NOx, dust, etc. The process using is effective. Usually, in such an exhaust gas treatment apparatus, a medium such as a granular carbonaceous adsorbent that adsorbs or removes a component to be removed (hazardous substance) contained in the exhaust gas is supplied from above and is brought into contact with the medium. A cross-flow type moving bed reactor into which exhaust gas is introduced in the horizontal direction is employed. Such a reactor is provided with a plurality of reaction chambers that are divided by partition walls that allow the exhaust gas to flow and that are adjacent to each other in the flow direction of the exhaust gas and that are filled with a medium.

The lower parts of these reaction chambers are each provided with a lower hopper, and at the lower ends of the lower hoppers, granule discharging devices such as roll feeders for discharging the medium in the lower hopper are provided. This roll feeder discharges a predetermined amount of medium out of the reaction chamber from the gap between the lower hopper by a rotating rod-shaped rotating body. A common recovery hopper for temporarily storing the medium discharged from each roll feeder is installed below the reaction chamber so as to cover all the roll feeders. The medium recovered by the recovery hopper is extracted from the outlet provided at the lower end of the recovery hopper. (For example, refer to Patent Document 1).
JP 2002-282646 A

  However, in such an exhaust gas treatment apparatus, a part of the exhaust gas introduced into the reactor flows into the recovery hopper through the roll feeder installed in the upstream reaction chamber in the reactor, A bypass flow is formed that passes through a roll feeder installed in the reaction chamber on the downstream side, and this bypass flow is discharged to the subsequent stage together with the processing gas that sequentially passes through each reaction chamber, deteriorating the properties of the processing gas. .

  Also, due to this bypass flow, when a part of the exhaust gas passes through the upstream roll feeder, so-called flushing occurs in which the medium is discharged regardless of the rotation of the roll feeder rotating body. Various problems are caused. Specifically, the moving speed of the medium in the upstream reaction chamber increases, the wear of the medium is accelerated, the life of the medium is shortened, and the amount of medium used increases, and the dust in the upstream reaction chamber increases. The problem is that trapping is not performed properly and a large amount of dust flows into the downstream reaction chamber and pressure loss increases in the downstream reaction chamber. The exhaust gas flowing into the recovery hopper is cooled and drained, causing corrosion of the recovery hopper. And the drain accumulates in the recovery hopper and obstructs the extraction of the medium from the recovery hopper.

  In addition, it is possible to lengthen the lower hopper in the height direction to increase the amount of accumulated media, and to prevent exhaust gas from flowing into the recovery hopper, thereby preventing flushing. There is a problem that miniaturization cannot be achieved and a problem that the amount of medium used increases.

  The present invention has been made to solve such a problem, and suppresses deterioration of processing gas properties and prevents flushing, reduces the amount of medium used, reduces running costs, It is possible to prevent an increase in pressure loss, prevent corrosion of the recovery hopper and reduce maintenance costs, improve the extraction of the medium from the recovery hopper, stabilize the operation, and reduce the size of the reaction chamber. An object is to provide an exhaust gas treatment apparatus.

The exhaust gas treatment apparatus according to the present invention includes a reactor that removes harmful substances in the exhaust gas by bringing the exhaust gas into contact with a medium, and the reactor is adjacent to the exhaust gas flow direction by a partition wall that enables the exhaust gas to flow. In an exhaust gas treatment apparatus that is divided into a plurality of reaction chambers and includes a medium in each reaction chamber, the exhaust gas flow path is configured to go outward from the center of the exhaust gas treatment apparatus, and the plurality of reaction chambers are exhaust gas Of the reaction chambers are provided in pairs so as to sandwich the central portion therebetween, and are respectively provided at the lowermost part of the first reaction chamber which is located on the most upstream side in the flow direction of the exhaust gas and forms a pair. a first recovery hopper for collecting a medium discharged from a roll feeder that is, out of the reaction chamber, each provided at a lower portion of the second reaction chamber paired located on the most downstream side of the exhaust gas flow direction Roll feeder And a second recovery hopper for collecting the medium discharged from the these first collecting hopper and the second collecting hopper, independently of one another, a second recovery hopper the first collection hopper It is characterized by being provided to cover .

According to the thus configured exhaust gas treatment apparatus, a first recovery hopper for collecting the medium discharged from each provided with roll feeder at the bottom of the first reaction chamber pairs upstream of the exhaust gas flow direction , there is a collection hopper which they are independent of each other with the second recovery hopper for collecting the medium discharged from each provided with roll feeder at the bottom of the second reaction chamber paired with the downstream side is provided Therefore, the bypass flow flowing from the first reaction chamber to the second reaction chamber is eliminated, and the flow of exhaust gas from the first reaction chamber to the first recovery hopper is reduced by eliminating this bypass flow. Furthermore, space saving is achieved by providing the second collection hopper so as to cover the first collection hopper.

Here, at least three or more pairs of reaction chambers may be provided, and at least one of the first recovery hopper and the second recovery hopper may recover the medium discharged from the other pair of reaction chambers.

  Thus, according to the exhaust gas treatment apparatus of the present invention, the bypass flow flowing from the first reaction chamber to the second reaction chamber is eliminated, and the inflow of exhaust gas from the first reaction chamber to the first recovery hopper is reduced. , Prevent deterioration of processing gas properties and prevent flushing, reduce the amount of media used and reduce running costs, prevent pressure loss in the reaction chamber from increasing, prevent corrosion of the recovery hopper and maintain maintenance costs It is possible to provide an exhaust gas treatment apparatus capable of suppressing the above-described problem, improving the extraction of the medium from the recovery hopper, stabilizing the operation, and reducing the size of the reaction chamber.

Hereinafter, preferred reference embodiments of an exhaust gas treatment apparatus according to the present invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is a longitudinal sectional view of a reaction tower of an exhaust gas treatment apparatus according to a reference embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a main part of the reactor in FIG.

The exhaust gas treatment apparatus of the reference form is installed in, for example, an ironworks and is made of sulfur oxide (SO _X ), nitrogen oxide (NO _X ), hydrogen chloride, mercury, etc. contained in combustion exhaust gas discharged from a sintering furnace. It removes toxic components such as heavy metals, organic chlorine compounds such as dioxins, and dust.

  As shown schematically in FIG. 1, this exhaust gas treatment apparatus is supplied with a carbonaceous adsorbent (medium) P that adsorbs harmful components and a reaction tower 2 into which treated exhaust gas W is introduced, and adsorbs harmful components. A regeneration tower (not shown) for regenerating the carbonaceous adsorbent P is provided. The carbonaceous adsorbent P used here is in the form of pellets, and is composed of, for example, activated carbon, activated coke, activated char, etc., and has the ability to adsorb and decompose harmful components contained in the exhaust gas. .

  The reaction tower 2 includes therein a reactor 5 extending in the vertical direction, an exhaust gas supply chamber 14 for supplying the reactor 5 with the exhaust gas W, and a gas for discharging the gas treated in the reactor 5 to a subsequent chimney. A discharge chamber 15 is provided.

  Hereinafter, the reactor 5 will be described in detail. This reactor 5 has an exhaust gas supply port on the front wall 9 that forms the partition wall between the reactor 5 and the exhaust gas supply chamber 14, and a gas exhaust port on the rear wall 10 that forms the partition wall between the reactor 5 and the gas discharge chamber 15. I have. These exhaust gas supply ports and gas discharge ports enable the passage of gas.

  Inside the reactor 5, partition walls 19 and 20 having openings that allow passage of exhaust gas are provided upright, and a front chamber (first reaction chamber) 5 a sandwiched between the front wall 9 and the partition wall 19, a partition wall 19 is divided into a front main chamber (other reaction chamber) 5b sandwiched between the partition wall 20 and a rear main chamber (second reaction chamber) 5c sandwiched between the partition wall 20 and the rear wall 10. An adsorbent supply port 6 through which the carbonaceous adsorbent P is supplied to the front chamber 5a, the front main chamber 5b, and the rear main chamber 5c is provided at the upper portion of the reactor 5.

  The lower part of the reactor 5 is provided with a plurality of lower hoppers 12a to 12c each having a single throttle shape that is squeezed as one side goes downward. The lower hopper 12c is connected to the lower part of the rear main chamber 5c. Roll feeders 21a to 21c are provided at the lower ends of the lower hoppers 12a to 12c to discharge the carbonaceous adsorbent P to the lower part of the reaction tower 2, respectively.

  Each of the roll feeders 21a to 21c includes a rod-like rotating body 30 that is connected to a driving unit (not shown) and rotates. As shown in FIG. 2, the lower hoppers 12a to 12c are configured to be spaced apart above the rotating body 30. A carbonaceous adsorbent discharge gate H for discharging the carbonaceous adsorbent P is formed in a gap with the interval maintaining plate 29 that is vertically suspended. The roll feeders 21 a to 21 c can adjust the discharge amount of the carbonaceous adsorbent P by changing the rotation speed of the rotating body 30 and the interval between the carbonaceous adsorbent discharge gates H.

Here, in the particularly this preferred embodiment, the bottom of the reaction column 2, as shown in FIG. 1, a first collection of recovering carbonaceous adsorbent P discharged from the front chamber 5a and the front main chamber 5b A hopper 25 and a second recovery hopper 26 that recovers the carbonaceous adsorbent P discharged from the rear main chamber 5c, and a carbonaceous adsorbent recovery region X formed inside the first recovery hopper 25; The carbonaceous adsorbent collection area Y formed inside the second collection hopper 26 is an area independent from each other.

  Specifically, the first collection hopper 25 is installed so as to cover the roll feeders 21a and 21b, and the second collection hopper 26 is installed so as to cover the roll feeder 21c. The lower part of these collection | recovery hoppers 25 and 26 comprises reverse square pyramid shape, and the adsorbent extraction nozzles 32 and 33 for extracting the carbonaceous adsorbent P in this collection | recovery hoppers 25 and 26 are formed in the center lower end. Each. The adsorbent extraction nozzles 32 and 33 are provided with opening and closing valves V1 and V2, respectively.

Next, the operation of the exhaust gas processing apparatus configured as described above will be described. The exhaust gas W supplied from the outside of the system together with ammonia passes through the exhaust gas supply chamber 14 and the front wall 9 and is introduced into the reactor 5, sequentially passes through the reaction chambers 5 a to 5 c, and is supplied from the upper portion to each reaction chamber. in contact with the carbonaceous adsorbent P moving bed of moving to gradually downward by being discharged from the roll feeder 21a~21c with respectively deposited in the bodies 5a to 5c, during this contact, SO _X or the like in the exhaust gas The sulfur content is adsorbed on the carbonaceous adsorbent P in the form of sulfuric acid produced by reacting with moisture in the exhaust gas or the ammonium sulfate salt produced by reacting this sulfuric acid with ammonia, and NO in the exhaust gas. _X reacts with ammonia by the catalytic action of the carbonaceous adsorbent P and is reduced to N ₂ , dioxins in the exhaust gas are adsorbed on the carbonaceous adsorbent P, and dust such as soot dust in the exhaust gas is carbon For adsorbent P Ri filtered dust collection, such processing is made gas passes through the rear wall 10, is led into the gas discharge chamber 15 is discharged from the later stage of the chimney to the atmosphere.

  On the other hand, the carbonaceous adsorbent P that adsorbs harmful components such as sulfur and dust is discharged by a certain amount by the roll feeders 21a to 21c, and the carbonaceous adsorbent P discharged from the roll feeders 21a and 21b is the first recovery. The carbonaceous adsorbent P discharged from the roll feeder 21c to the hopper 25 is collected by each of the second recovery hoppers 26 and extracted through the adsorbent extraction nozzles 32 and 33. The carbonaceous adsorbent P supplied to the regeneration tower by the transfer machine is removed from the harmful components adsorbed on the carbonaceous adsorbent P, and the processing performance such as desulfurization performance is recovered and regenerated. The regenerated carbonaceous adsorbent P is supplied to the reactor 5 again.

  Here, as the exhaust gas W introduced into the reactor 5 passes through the moving bed of the carbonaceous adsorbent P, its gas pressure decreases, and a pressure difference is generated between the front chamber 5a and the rear main chamber 5c. ing. However, since the first recovery hopper 25 and the second recovery hopper 26 are installed independently of each other, the exhaust gas flowing into the first recovery hopper 25 does not flow to the second recovery hopper 26, The occurrence of conventional bypass flow is prevented.

As described above, in the exhaust gas treatment apparatus of the reference form, the first recovery hopper 25 that recovers the carbonaceous adsorbent P discharged from the upstream front chamber 5a in the exhaust gas flow direction and the downstream rear main chamber 5c are discharged. And a second recovery hopper 26 that recovers the carbonaceous adsorbent P to be collected and these are independent recovery hoppers, so that the bypass flow flowing from the front chamber 5a to the rear main chamber 5c is eliminated. By eliminating this bypass flow, the flow of exhaust gas from the front chamber 5a to the first recovery hopper 25 is reduced. As a result, deterioration of processing gas properties is suppressed and flushing is prevented. Further, since the flushing is prevented, the following problems are solved. Specifically, the moving speed of the carbonaceous adsorbent P in the front chamber 5a can be controlled, so that the wear of the carbonaceous adsorbent P is prevented, the amount of use of the carbonaceous adsorbent P is reduced, and the running cost can be reduced. It becomes possible. Further, the amount of carbonaceous adsorbent P deposited in the front chamber 5a can be controlled, dust is properly collected in the front chamber 5a, and excessive dust inflow into the rear main chamber 5c is prevented. An increase in pressure loss in the rear main chamber 5c is prevented. Further, the flow of exhaust gas into the first recovery hopper 25 is reduced, corrosion of the first recovery hopper 25 is prevented, and maintenance costs are reduced. Further, since the inflow of exhaust gas into the first recovery hopper 25 is reduced, the generation of drain is suppressed, the extraction of the carbonaceous adsorbent P from the first recovery hopper 25 is improved, and the operation is stabilized. Can do. Further, it is not necessary to lengthen the lower hopper 12a in the height direction for the purpose of preventing flushing, and the reactor 5 can be downsized.

Figure 3 is a longitudinal sectional view of the reactor of the exhaust gas treatment apparatus according to implementation embodiments of the present invention, FIG. 4 is a partial cross-sectional perspective view of a main part of the reaction column shown in FIG. That the exhaust gas treatment apparatus of the implementation form of this is different from the exhaust gas treatment apparatus of reference embodiment is that the reaction column 42 is provided with a plurality of reactor 5.

  That is, as shown in FIG. 3, the reaction tower 42 includes the reactors 5 facing each other, and a common exhaust gas supply chamber 34 between these reactors 5, 5, and a gas outside each reactor 5, 5. Discharge chambers 35 and 35 are respectively disposed.

  As shown in FIGS. 3 and 4, a first recovery hopper 45 covering the roll feeders 21 a and 21 b provided in the front chamber 5 a and the front main chamber 5 b of both reactors 5 is installed at the lower part of the reaction tower 42. On the outside, a first recovery hopper 45 and a second recovery hopper 46 that covers the roll feeder 21c provided in the rear main chamber 5c of both reactors 5 are installed. The adsorbent extraction nozzle 32 extending from the first recovery hopper 45 passes through the conical surface of the second recovery hopper 45 and is led out to the outside, and the adsorbent recovery area X of the first recovery hopper 45 and the second The adsorbent recovery area Y of the recovery hopper 46 is an area independent of each other.

Even in this configuration, similarly to the reference embodiment, from the first recovery hopper 45 for recovering the carbonaceous adsorbent P discharged from the upstream front chamber 5a in the exhaust gas flow direction and the downstream rear main chamber 5c. Since the second recovery hopper 46 for recovering the discharged carbonaceous adsorbent P is provided and these are independent recovery hoppers, the bypass flow flowing from the front chamber 5a to the rear main chamber 5c is eliminated. The same operations and effects as the reference form are achieved. Further, a common first recovery hopper 45 and a common second recovery hopper 46 are installed for the plurality of reactors 5 to save space.

As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. For example, in the above embodiment has a configuration comprising a reaction chamber 5a~5c three pairs with respect to one reactor 5, the number of the reaction chamber, two pairs but may even four or more pairs, a main is discharged from the first and the collecting hopper 4 5, a reaction chamber located on the most downstream side for recovering the carbonaceous adsorbent P discharged from the reaction chamber located on the most upstream side in the flow direction of the exhaust gas W a second recovery hopper 4 6 for collecting the carbonaceous adsorbent P is only to be mutually independent recovery hopper.

Also, the reactor 4 2 of the above embodiment has a configuration to recover the carbonaceous adsorbent material P discharged from the front main chamber 5b in the first recovery hopper 4 5, the second collection hopper 4 6 It is good also as a structure collect | recovered by (1), and it is good also as a structure which installs and collects another independent collection | recovery hopper.

  In the above embodiment, the exhaust gas treatment apparatus is applied to the treatment of combustion exhaust gas discharged from a sintering furnace such as a steel mill. However, other boilers such as a power generation boiler, cement sintering furnace, various chemical plants, and incineration You may apply to the process of the waste gas discharged | emitted from a furnace etc.

It is a longitudinal cross-sectional view of the reaction tower of the exhaust gas processing apparatus which concerns on the reference form of this invention. It is a longitudinal cross-sectional view which shows the principal part of the reactor in FIG. It is a longitudinal sectional view of the reactor of the exhaust gas treatment apparatus according to implementation embodiments of the present invention. It is a fragmentary sectional perspective view of the principal part of the reaction tower shown in FIG.

Explanation of symbols

  5 ... reactor, 5a ... front chamber (first reaction chamber), 5b ... front main chamber (other reaction chamber), 5c ... rear main chamber (second reaction chamber), 19, 20 ... partition walls, 25, 45 ... First recovery hopper, 26, 46, second recovery hopper, P, carbonaceous adsorbent (medium), W, exhaust gas.

Claims (2)

A reactor that removes harmful substances in the exhaust gas by bringing the exhaust gas into contact with a medium; and the reactor is provided in a plurality of reaction chambers adjacent to the exhaust gas flow direction by partition walls that allow the exhaust gas to flow. In the exhaust gas treatment apparatus that is divided and includes the medium in each reaction chamber,
The exhaust gas flow path is configured to go outward from the center of the exhaust gas treatment device,
The plurality of reaction chambers are installed in pairs so as to sandwich the central portion in the exhaust gas flow path,
A first recovery hopper for collecting the medium discharged from the out of the reaction chamber, each roll feeder provided at a lower portion of the first reaction chamber forming was versus position on the most upstream side in the flow direction of the exhaust gas ,
Of said reaction chamber, and a second recovery hopper for collecting the medium discharged from each roll feeder provided at a lower portion of the second reaction chamber forming was versus position on the most downstream side in the flow direction of the exhaust gas With
These first recovery hopper and second recovery hopper are independent of each other,
The exhaust gas processing apparatus, wherein the second recovery hopper is provided so as to cover the first recovery hopper . 2. The reaction chamber is provided with at least three pairs, and at least one of the first recovery hopper and the second recovery hopper recovers a medium discharged from another pair of reaction chambers. Exhaust gas treatment equipment.

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