JP7323076B2 - Exhaust gas purifier - Google Patents

Description

The present disclosure relates to an exhaust gas purifier that reduces sulfur oxides contained in exhaust gas generated by burning fossil fuels such as coal or heavy oil.

An example of an exhaust gas purifying device that reduces sulfur oxides contained in exhaust gas generated by combustion of fossil fuels is a device that uses an absorbent containing an alkaline component. Exhaust gas purifiers using absorbents are broadly classified into open-loop types and closed-loop types. In an open-loop type exhaust gas purifier, the used absorbent for absorbing sulfur oxides is stored in a tank or the like and then discarded. In the closed-loop type exhaust gas purifier, the used absorbent is stored in a tank or the like and reused as the absorbent.

Patent Literature 1 discloses a closed-loop type exhaust gas purifier. The exhaust gas purifier disclosed in Patent Document 1 has an absorption tower integrated with a chimney. Inside the absorber, a spray nozzle is arranged for spraying the absorbent onto the flue gas flowing into the absorber. A guide vane is arranged on the upper inner surface of the absorption tower to give a centrifugal force to the flue gas rising toward the chimney. The flue gas given centrifugal force by the guide vanes rises along the inner surface of the chimney. Liquid droplets may be entrained in the flue gas rising along the inside surface of the chimney. A scraper is arranged on the inner surface of the upper part of the chimney for collecting droplets entrained in the exhaust gas. A drain pipe for returning droplets to the absorption tower is connected to the scraping portion, and the droplets returned to the absorption tower via the drain pipe are reused as the absorbing liquid.

JP-A-11-151426

If the droplets collected by the scraping portion do not smoothly flow into the drain pipe, collection of the droplets by the scraping portion is impeded, and the exhaust gas accompanied by the droplets is discharged from the chimney. If the exhaust gas is accompanied by droplets, sulfur oxides remaining in the exhaust gas will dissolve in the moisture of the droplets to produce acid, which may corrode metal products around the chimney. This problem also occurs in an open-loop type exhaust gas purifier.

The present disclosure has been made in view of the above-described problems, and provides an exhaust gas purifying device configured to collect droplets accompanying exhaust gas rising toward an exhaust stack so that collection of droplets is not hindered. The purpose is to provide technology to

In order to solve the above problems, the exhaust gas purification apparatus of the present disclosure includes an absorption tower that communicates with an exhaust stack and into which exhaust gas generated by combustion of fossil fuel flows, and an absorption liquid for absorbing sulfur oxides. a spraying part for spraying inside, a drain pipe for draining the absorbent sprayed by the spraying part from the absorption tower, a tank for storing the absorbent drained from the drain pipe, and from the absorption tower to the A collecting part provided in the exhaust pipe for collecting droplets accompanying the exhaust gas rising toward the exhaust pipe, and a drain pipe communicating with the collecting part to drain the droplets collected by the collecting part. a drain pipe that drains as water.

In order to solve the above problems, another aspect of the exhaust gas purifying apparatus of the present disclosure includes an absorption tower communicating with an exhaust pipe and into which exhaust gas generated by combustion of fossil fuel flows; A spraying section for spraying the absorbent into the absorption tower, a drain pipe for discharging the absorbent sprayed by the spraying section from the absorption tower, and a tank for storing the absorbent discharged from the drainage pipe. a collection unit provided in the exhaust stack for collecting droplets entrained in the exhaust gas rising from the absorption tower toward the exhaust stack; and a drain pipe that drains water to the tank as a drain pipe, and a degassing mechanism that connects the tank to an external space.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structural example of 1 A of exhaust gas purification apparatuses which concern on 1st Embodiment of this indication. 4 is a diagram showing a configuration example of an exhaust gas purifier 1E having a configuration in which a drain pipe 60 is communicated with a tank 40. FIG. It is a figure which shows the structural example of the exhaust gas purification apparatus 1B which concerns on 2nd Embodiment of this indication. It is a figure showing an example of composition of exhaust gas purification equipment 1C concerning a 3rd embodiment of this indication. FIG. 10 is a diagram showing a configuration example of an exhaust gas purifier 1D of Modification 1; It is a figure which shows the other structural example of the exhaust gas purification apparatus 1F of the modification 1. FIG.

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. Note that the dimensions and scale of each part in the drawings are appropriately different from the actual ones. Also, the embodiments described below are preferred specific examples of the present disclosure. Therefore, various technically preferable limitations are attached to the following embodiments. However, the scope of the present disclosure is not limited to these forms unless there is a description to the effect that the present disclosure is particularly limited in the following description.

1. First Embodiment FIG. 1 is a diagram showing a configuration example of an exhaust gas purification device 1A according to a first embodiment of the present disclosure. 1 A of exhaust gas purification apparatuses are mounted in the ship 2 which burns fossil fuels, such as heavy oil or coal, and generates propulsion. The engine that generates propulsion in the ship 2 includes an internal combustion engine such as a gasoline engine or a diesel engine, or an external combustion engine that includes a turbine and a boiler that supplies steam to the turbine. An exhaust gas purifier 1A shown in FIG. 1 is a device for reducing sulfur oxides such as sulfur dioxide contained in exhaust gas generated by combustion of fossil fuels. The exhaust gas whose sulfur oxides have been reduced by the exhaust gas purifying device 1A is discharged from an exhaust pipe 3 provided in a funnel to an external space, specifically, into the atmosphere.

As shown in FIG. 1, the exhaust gas purification apparatus 1A includes an absorption tower 10, a spray section 20, a supply pipe 30, a water pipe 32, a drain pipe 34 and a drain pipe 36, a tank 40, and a collection unit 50. , a drain pipe 60 , a pump 70 and a swirler 80 . Exhaust gas generated by burning fossil fuel in the engine of the ship 2 flows into the absorption tower 10 through the exhaust pipe 5 . The exhaust pipe 5 is an example of an exhaust pipe that allows communication between the engine of the ship 2 , that is, the source of exhaust gas, and the absorption tower 10 . The absorption tower 10 communicates with the exhaust stack 3 . The absorption tower 10 may be integrated with the exhaust stack 3 .

The spray section 20 includes, for example, a plurality of spray nozzles. The spraying section 20 sprays into the absorption tower 10 an absorption liquid for absorbing sulfur oxides contained in the exhaust gas flowing into the absorption tower 10 . In this embodiment, the ship 2 is a ship that navigates the ocean, and seawater SW is used as an absorbent for absorbing sulfur oxides.

The pump 70 sucks seawater SW around the ship 2 and sends out the sucked seawater SW to the spray section 20 . A suction port of the pump 70 is connected to a supply pipe 30 that opens to the bottom of the ship 2 . The pump 70 sucks seawater SW around the ship 2 through the supply pipe 30 . One end of the water pipe 32 is connected to the discharge port of the pump 70 . The other end of the water pipe 32 branches into a plurality of branches, each of which is connected to the spray section 20 . The pump 70 sends out the seawater SW sucked through the supply pipe 30 to the spray section 20 through the water pipe 32 .

In the exhaust gas purifier 1A of the present embodiment, the spray units 20 are provided in three stages in the vertical direction of the absorption tower 10 . In ships, there is a limit to the area that can be allocated to the equipment to be mounted, and the inner diameter of the absorber 10 cannot be made sufficiently large, and there are cases where a sufficient number of spray units 20 cannot be provided in the radial direction of the absorber 10. . The reason why the spraying units 20 are provided in three stages in the vertical direction of the absorption tower 10 is to provide a sufficient number of spraying units 20 for the entire absorption tower 10 even if the inner diameter of the absorption tower 10 cannot be sufficiently secured. is. Therefore, if the inside diameter of the absorption tower 10 can be sufficiently large, the number of stages in the vertical direction of the spray section 20 may be one or two. Moreover, when the inner diameter of the absorption tower 10 needs to be further reduced, the number of stages in the vertical direction of the spray section 20 may be set to four or more.

The absorbent sprayed into the absorber 10 by the spray unit 20 and used to absorb the sulfur dioxide contained in the exhaust gas is drained from the absorber 10 to the tank 40 via the drain pipe 34 . Hereinafter, the liquid discharged from the absorption tower 10 via the drain pipe 34 may be referred to as waste liquid.

In the exhaust gas purifying apparatus 1A of the present embodiment, sulfur oxides in the exhaust gas are absorbed using the alkali component (HCO ₃ ⁻ ) contained in the seawater SW. More specifically, when the absorbent sprayed by the spraying section 20 contacts the exhaust gas, sulfur oxides contained in the exhaust gas are absorbed in the absorbent. Sulfite ions (HSO ₃ ⁻ ) are generated in the absorbent during the process of absorbing sulfur oxides. The absorbent used to absorb sulfur oxides is oxidized by contact with a large amount of air in the tank 40, and the sulfite ions in the used absorbent are rendered harmless as sulfate ions (SO ₄ ²⁻ ). . The used absorbent that has undergone the oxidation treatment is neutralized and aerated in the tank 40 to adjust the pH and recover the dissolved oxygen before being discharged into the ocean. The chemical reactions of absorption, oxidation, and neutralization in the exhaust gas purifier 1A are as follows.
Absorption: SO ₂ +H ₂ O→H ⁺ +HSO ₃ ⁻
Oxidation: HSO ₃ ⁻ +(1/2)O ₂ →H ⁺ +SO ₄ ²⁻
Neutralization: HCO ₃ ⁻ +H ⁺ →H ₂ O+CO ₂ ↑

The exhaust gas that has flowed into the absorption tower 10 comes into contact with the absorbent sprayed by the spraying section 20 , absorbs and removes at least part of the contained sulfur oxides, and then rises toward the exhaust stack 3 . Hereinafter, exhaust gas in which at least part of sulfur oxides has been absorbed is referred to as treated exhaust gas. The swirler 80 is a guide blade that applies centrifugal force to the treated exhaust gas rising from the absorber 10 toward the exhaust stack 3 . A swirler 80 is provided at the boundary between the absorber 10 and the exhaust stack 3 . That is, in this embodiment, the portion below the swirler 80 is the absorption tower 10 , and the portion above the swirler 80 is the exhaust stack 3 . The treated exhaust gas rises along the swirler 80 , is given a centrifugal force, and rises along the inner surface of the exhaust stack 3 .

When the flow velocity of the exhaust gas flowing into the absorption tower 10 is high, the treated exhaust gas rising along the inner surface of the exhaust stack 3 may be accompanied by droplets of unused absorbent or used absorbent. . The collection unit 50 is for separating the droplets from the treated exhaust gas entrained with the droplets. The collecting portion 50 corresponds to the scraping portion in Patent Document 1. As shown in FIG. 1 , the collecting part 50 is provided at the upper end of the exhaust pipe 3 in this embodiment, but may be provided at a position below the upper end of the exhaust pipe 3 and above the swirler 80 . The collection unit 50 has an opening that opens to the inner surface of the exhaust pipe 3, and collects liquid droplets rising along the inner surface of the exhaust pipe 3 together with the treated exhaust gas through the opening.

As shown in FIG. 1 , the collection part 50 and the drain pipe 34 communicate with each other through the drain pipe 60 . The drain pipe 60 drains the liquid droplets collected by the collection unit 50 to the drain pipe 34 as drain water. Drain water discharged from the drain pipe 60 flows into the tank 40 through the drain pipe 34 together with the waste liquid, and is stored in the tank 40 .

Tank 40 is, for example, a gas seal chamber. As shown in FIG. 1, the tank 40 stores the waste liquid discharged from the drain pipe 34 and the drain water discharged from the drain pipe 60 together with air. A drain pipe 36 that opens to the bottom of the ship 2 protrudes into the internal space of the tank 40 . The liquid stored in the tank 40, ie, a mixture of waste liquid and drain water, is inspected for pH and dissolved oxygen content by the water treatment system 4 and discharged to the ocean through the drain pipe 36. That is, the exhaust gas purifier 1A of the present embodiment is an open-loop type exhaust gas purifier that discards the used absorbent for absorbing sulfur oxides contained in the exhaust gas without reusing it. The sea on which the ship 2 carrying the exhaust gas purifier 1A navigates serves as an external water source for the absorbent.

Although detailed illustration is omitted in FIG. 1 , a valve that opens and closes under the control of the water treatment system 4 is provided at the upper end of the drain pipe 36 . The water treatment system 4 opens the valve at the upper end of the drain pipe 36 when the pH and dissolved oxygen content of the liquid stored in the tank 40 meet predetermined reference values. When the valve at the upper end of the drain pipe 36 is open, liquid exceeding the height of the drain pipe 36 projecting into the internal space of the tank 40 is discharged to the ocean outside the vessel 2 through the drain pipe 36. . Note that the predetermined reference values for the pH and the dissolved oxygen content are determined according to the sea area where the ship 2 navigates.
The above is the configuration of the exhaust gas purification device 1A.

FIG. 2 is a diagram showing a configuration example of an open-loop type exhaust gas purifier 1E having a configuration in which a drain pipe 60 is communicated with a tank 40. As shown in FIG. Although the exhaust gas purifier 1E is of the open loop type, it has the same configuration as the exhaust gas purifier disclosed in Patent Document 1 in that a drain pipe 60 is connected to a tank 40 where the used absorbent is stored. be. Hereinafter, the effect of this embodiment will be described by comparing the exhaust gas purification device 1E and the exhaust gas purification device 1A.

In the exhaust gas purifier 1A and the exhaust gas purifier 1E, every time the waste liquid flows down to the tank 40 through the drain pipe 34, the liquid surface of the liquid stored in the tank 40 oscillates, and the tank 40 The pressure of the air in 40, that is, the internal pressure of tank 40 fluctuates.

The drain pipe 60 communicates with the tank 40 in the exhaust gas purifier 1E. Therefore, in the exhaust gas purifier 1E, fluctuations in the internal pressure of the tank 40 are directly transmitted to the inside of the drain pipe 60, and this pressure fluctuation may make it difficult for the drain water to flow. When it becomes difficult for the drain water to flow through the drain pipe 60, the function of the collecting portion 50 is deteriorated. In other words, collection of droplets by the collection unit 50 is hindered. As a result, the treated exhaust gas accompanied by the droplets is discharged from the exhaust stack 3, and the acid generated by the reaction between the sulfur oxides remaining in the treated exhaust gas and the water content of the droplets causes Problems such as corroding certain metal products occur.

In the exhaust gas purifier 1A of this embodiment, the drain pipe 60 communicates with the drain pipe 34 . Since the drain pipe 34 communicates with the tank 40 , fluctuations in the internal pressure of the tank 40 propagate to the drain pipe 34 . However, since the drain pipe 34 also communicates with the external space via the absorption tower 10 and the exhaust stack 3, the pressure fluctuation in the drain pipe 34 becomes gentle, and the pressure fluctuation propagated in the drain pipe 60 is also used for exhaust gas purification. It is less severe than in device 1E. Therefore, in the exhaust gas purifying device 1A, the occurrence of a phenomenon in which drain water becomes difficult to flow is suppressed compared to the exhaust gas purifying device 1E, and collection of liquid droplets by the collecting section 50 is less likely to be hindered.

As described above, according to the exhaust gas purifier 1A of the present embodiment, collection of droplets accompanying the exhaust gas rising toward the exhaust stack 3 is less likely to be hindered.

2. Second Embodiment FIG. 3 is a diagram showing a configuration example of an exhaust gas purification device 1B according to a second embodiment of the present disclosure. The exhaust gas purifier 1B of this embodiment is an open loop type exhaust gas purifier, like the exhaust gas purifier 1A. In FIG. 3, the same components as in FIG. 1 are given the same reference numerals as in FIG. As is clear from a comparison between FIG. 3 and FIG. 1, there are two points of difference in configuration between the exhaust gas purifier 1B and the exhaust gas purifier 1A. The first difference is that the drain pipe 60 is provided with a drain trap 90 . A drain trap is a structure in which a portion of a drain pipe is bent to hold water in order to prevent the inflow of gas or the like from the drain destination. Specific examples of the drain trap include a U-shaped trap formed by bending a drain pipe into a U-shape, and an S-shaped trap formed by bending a drain pipe into an S-shape. Although the drain trap 90 in this embodiment is a U-type trap, it may be an S-type trap. The second difference is that a degassing mechanism 100 for communicating the drain pipe 60 with the external space, specifically the atmosphere, is provided near the upper end of the drain pipe 60, that is, near the connection portion to the collecting section 50. This is the point.

In the exhaust gas purifier 1B of the present embodiment, the drain pipe 60 communicates with the drain pipe 34, so that collection of droplets by the collector 50 is less likely to be hindered, as in the exhaust gas purifier 1A of the first embodiment. In addition, in the exhaust gas purifier 1B of the present embodiment, the drain pipe 60 is provided with the drain trap 90, and the drain water flowing through the drain pipe 60 is collected in the drain trap 90 to form the drain pool W. Since the exhaust gas purifier 1B has the wastewater reservoir W, it is possible to prevent the exhaust gas that has flowed into the absorber 10 from being discharged into the atmosphere through the drain pipe 34 and the drain pipe 60. FIG. If the depth of the drain pool W in the drain trap 90, that is, the amount of water in the drain pool W is not sufficient compared to the pressure of the exhaust gas in the drain pipe 34, the drain pool W cannot completely seal the exhaust gas flowing from the drain pipe 34. , the exhaust gas is discharged into the atmosphere via the drain pipe 60 . The depth of the drain pool W may be determined according to the pressure of the exhaust gas within the drain pipe 34, and may be determined according to the maximum value of the pressure when the pressure of the exhaust gas within the drain pipe 34 fluctuates. . For example, if the maximum value of the exhaust gas pressure in the drain pipe 34 is about 200 mmAq, the depth of the drain pool W should be at least 500 mm.

Further, in the exhaust gas purifying apparatus 1B of the present embodiment, a degassing mechanism 100 is provided in the vicinity of the connecting portion between the drain pipe 60 and the collecting portion 50 to allow the drain pipe 60 to communicate with the external space. Therefore, a flow of exhaust gas is generated from the inlet portion of the drain pipe 60 toward the degassing mechanism 100 , and collection of droplets by the collecting portion 50 can be promoted. That is, according to the exhaust gas purifying device 1B of the present embodiment, droplets can be efficiently collected in the collecting section 50 compared to the exhaust gas purifying device 1A of the first embodiment.

The exhaust gas purifier 1B of the present embodiment has a drain trap 90 and a gas venting mechanism 100, but either one may be omitted. Even if the drain trap 90 is omitted from the exhaust gas purifier 1B, it is possible to efficiently collect droplets in the collector 50 compared to the exhaust gas purifier 1A. Further, even if the gas venting mechanism 100 is omitted from the exhaust gas purifier 1B, the exhaust gas that has flowed into the absorption tower 10 can be prevented from being released into the atmosphere through the drain pipe 34 and the drain pipe 60. FIG.

3. Third Embodiment FIG. 4 is a diagram showing a configuration example of an exhaust gas purification device 1C according to a third embodiment of the present disclosure. The exhaust gas purifier 1C of the present embodiment is also an open loop type exhaust gas purifier like the exhaust gas purifier 1A. In FIG. 4, the same components as in FIG. 1 are given the same reference numerals as in FIG. As is clear from a comparison between FIG. 4 and FIG. 1, there are two points of difference in configuration between the exhaust gas purifier 1C and the exhaust gas purifier 1A. The first difference is that the collection section 50 and the tank 40 are communicated with each other via the drain pipe 60 . A second difference is that a degassing mechanism 102 is provided to connect the tank 40 to the external space.

In the exhaust gas purifying apparatus 1C of the present embodiment, the tank 40 communicates with the external space via the gas venting mechanism 102, so that the internal pressure of the tank 40 fluctuates more slowly than in the case where the gas venting mechanism 102 is not provided. Become. Therefore, in the exhaust gas purifying device 1C, compared with the exhaust gas purifying device 1E described above, the occurrence of a phenomenon in which drain water becomes difficult to flow into the drain pipe 60 is suppressed, and collection of liquid droplets by the collection unit 50 is less likely to be hindered. Become.

4. Modifications Each of the above embodiments can be modified in various ways. Specific modification modes are exemplified below. Two or more aspects arbitrarily selected from the following examples may be combined as appropriate unless contradictory.

4-1. Modification 1
The exhaust gas purifying apparatus 1A in the first embodiment is an open-loop type exhaust gas purifying apparatus that takes in seawater SW serving as an absorbing liquid from around the ship 2 and discharges the used absorbing liquid and drain water to the outside of the ship 2. Met. However, the technical features of the first embodiment may be employed in a closed-loop type exhaust gas purifying apparatus having a collecting portion and a drain pipe. Similarly, the technical features of the second embodiment or the third embodiment may be applied to a closed-loop exhaust gas purifier having a collection section and a drain pipe. Even in a closed-loop type exhaust gas purifier having a collecting portion and a drain pipe, if droplets collected by the collecting portion do not flow smoothly into the drain pipe, collection of droplets by the collecting portion is hindered. , because the exhaust gas with droplets is discharged from the exhaust stack.

FIG. 5 is a diagram showing an application example of the technical feature of the first embodiment to a closed-loop type exhaust gas purifier having a collecting portion and a drain pipe. In the exhaust gas purifier 1D, a certain amount of absorbent is stored in the tank 40 in advance. The supply pipe 30 is connected to the tank 40 in the exhaust gas purifier 1D shown in FIG. The pump 70 sucks the absorbent stored in the tank 40 through the supply pipe 30 and sends it out to the spray section 20 through the water pipe 32 . The exhaust gas purification apparatus 1D shown in FIG. 5 is not provided with a drain pipe 36, and the used absorbent and drain water returned to the tank 40 are neutralized and aerated and reused as the absorbent. . In the exhaust gas purifier 1D shown in FIG. 5, the collector 50 and the drain pipe 34 communicate with each other through the drain pipe 60, so that the liquid is Drop collection is less likely to be obstructed.

FIG. 6 is a diagram showing an example of adopting the technical features of the first embodiment to an exhaust gas purifier of a hybrid system. An exhaust gas purifier 1F shown in FIG. 6 includes a supply pipe 30a and a supply pipe 30b connected to a suction port of a pump 70 via a switching valve (not shown). The supply pipe 30 a opens to the bottom of the ship 2 . The supply pipe 30 b is connected to the tank 40 . In the exhaust gas purifier 1F, one of the supply pipe 30a and the supply pipe 30b communicates with the suction port of the pump 70 by switching a switching valve (not shown). In a state where the suction port of the pump 70 is communicated with the supply pipe 30a, the exhaust gas purifier 1F functions as an open loop type exhaust gas purifier. In a state where the suction port of the pump 70 is communicated with the supply pipe 30b, the exhaust gas purification device 1F functions as a closed loop type exhaust gas purification device.

According to the exhaust gas purifier 1F, exhaust gas can be purified in an open-loop type in sea areas where regulations on wastewater to the ocean are loose, while exhaust gas can be purified in a closed-loop type in sea areas where wastewater regulations are strict. An example of a sea area where wastewater regulations are loose is the open ocean. Coastal seas are one example of seas where wastewater regulations are strict. The exhaust gas purifier 1F shown in FIG. 6 may be modified to have a configuration in which the supply pipe 30b is connected to the supply pipe 30a via a switching valve. This configuration may be modified to a configuration in which a second pump separate from the pump 70 is further provided, and seawater sucked by the second pump is injected into the tank 40 via the supply pipe 30b. A configuration in which the supply pipe 30b is connected to the water pipe 32 is also conceivable. is required.

4-2. Modification 2
Although the vessel 2 in each of the above embodiments is a vessel that navigates the ocean, it may be a vessel that navigates freshwater areas. In this case, sodium hydroxide, magnesium hydroxide, or the like may be added to the water sucked from around the ship 2 to replenish the alkali component. That is, the absorbing liquid in the present disclosure is not limited to seawater, and may be an alkaline aqueous solution containing an alkaline component. Also, the alkali component is not limited to HCO ₃ ^- .

4-3. Modification 3
In each of the above embodiments, an example of application of the present disclosure to an exhaust gas purifying device mounted on a ship that burns fossil fuel to generate propulsion has been described. However, the exhaust gas purifying apparatus of the present disclosure can be used in land fixed facilities such as thermal power plants or ironworks, generators using internal combustion engines, or vehicles that generate propulsion with internal or external combustion engines. The present disclosure may be applied to purification of exhaust gas generated by Also, the swirler 80 in each of the above embodiments is not an essential component of the present disclosure and may be omitted.

5. Aspects grasped from at least one of the embodiment and each modification One aspect of the exhaust gas purification apparatus of the present disclosure includes an absorption tower, a spray section, a drain pipe, a tank, a collection section, a drain pipe, Prepare. Exhaust gas generated by combustion of fossil fuel flows into the absorption tower. The absorber tower communicates with a stack that releases sulfur oxides-reduced flue gas to the exterior space. The spray section sprays an absorption liquid for absorbing sulfur oxides into the absorption tower. A drain pipe is provided for draining the absorbent sprayed by the spraying part from the absorption tower. The tank stores the absorbent drained from the drain pipe. The collection part is provided in the exhaust stack to collect droplets entrained in the exhaust gas rising from the absorption tower toward the exhaust stack. The drain pipe communicates with the drain pipe, and drains the droplets collected by the collector as drain water. In the exhaust gas purifier of this aspect, the drain pipe communicates with the drain pipe. Since the drain pipe communicates with the external space via the absorption tower and the exhaust stack, pressure fluctuations in the drain pipe are gentler than fluctuations in the internal pressure of the tank. Therefore, in the exhaust gas purifier of this aspect, compared with the aspect in which the drain pipe communicates with the tank, the occurrence of the phenomenon that the drain water becomes difficult to flow due to the pressure fluctuation of the communication destination of the drain pipe can be suppressed. Collection of liquid droplets by the collector is less likely to be hindered.

In a more preferred embodiment of the exhaust gas purifier, the drain pipe may be provided with a drain trap. According to the exhaust gas purifier of this aspect, in addition to the effect that collection of liquid droplets by the collecting portion is less likely to be hindered, the following effects are achieved. That is, according to the exhaust gas purifying apparatus of this aspect, it is possible to prevent the exhaust gas that has flowed into the absorption tower from being discharged to the external space through the drain pipe and the drain pipe by the waste water pool of the waste water trap. The depth of the wastewater pool in the wastewater trap may be determined according to the pressure of the exhaust gas flowing into the absorption tower.

An exhaust gas purifier of still another preferred embodiment may include a gas venting mechanism communicating with the external space above the drain pipe. According to this aspect, it becomes possible to collect droplets in the collecting portion more efficiently than in the case where the gas venting mechanism is not provided.

In still another preferred embodiment of the exhaust gas purifier, water sucked from an external water source by a pump is used as the absorbent sent to the spray section, and the absorbent stored in the tank is discharged to the external water source. may be According to this aspect, in the open-loop type exhaust gas purifying apparatus provided with the collecting section and the drain pipe, collection of droplets by the collecting section is less likely to be hindered.

In still another preferable aspect of the exhaust gas purifier, the pump may suck the absorbent stored in the tank and send it to the spray section. According to this aspect, in the closed-loop type exhaust gas purifier provided with the collecting section and the drain pipe, collection of droplets by the collecting section is less likely to be hindered.

Further, an exhaust gas purifying apparatus of another aspect of the present disclosure includes an absorption tower, a spray section, a drain pipe, a tank, a degassing mechanism that communicates the tank with an external space, a collection section, a drain pipe, Prepare. Exhaust gas generated by combustion of fossil fuel flows into the absorption tower. The absorber tower communicates with a stack that releases sulfur oxides-reduced flue gas to the exterior space. The spray section sprays an absorption liquid for absorbing sulfur oxides into the absorption tower. A drain pipe is provided to drain the absorbent sprayed by the spraying part from the absorption tower. The tank stores the absorbent drained from the drain pipe. The collecting part is provided in the exhaust stack. The collection part collects droplets accompanying the exhaust gas rising from the absorption tower toward the exhaust stack. The drain pipe discharges the liquid droplets collected by the collection unit to the tank as drain water. In the exhaust gas purifier of this aspect, since the tank communicates with the external space via the gas venting mechanism, fluctuations in the internal pressure of the tank are gentler than in an aspect without the gas venting mechanism. Therefore, it is possible to suppress the occurrence of a phenomenon in which drain water becomes difficult to flow due to fluctuations in the internal pressure of the tank, and the collection of liquid droplets by the collecting section is less likely to be hindered. This aspect is also applicable to both closed-loop and open-loop exhaust gas purifiers.

DESCRIPTION OF SYMBOLS 1A, 1B, 1C, 1D, 1E... Exhaust gas purification apparatus, 2... Ship, 3... Exhaust pipe, 4... Water treatment system, 5... Exhaust pipe, 10... Absorber tower, 20... Spray section, 30... Supply pipe, 32 Water supply pipe 34, 36 Drainage pipe 40 Tank 50 Collection unit 60 Drain 70 Pump 80 Swirler 90 Drainage trap 100, 102 Degassing mechanism.

Claims (7)

an absorption tower that communicates with the exhaust stack and into which exhaust gas generated by combustion of fossil fuel flows;
a spraying part for spraying an absorption liquid for absorbing sulfur oxides into the absorption tower;
a drain pipe for draining the absorbent sprayed by the spraying part from the absorption tower;
a tank for storing the absorbent discharged from the drain pipe;
a collection unit provided in the exhaust stack for collecting droplets accompanying the exhaust gas rising from the absorption tower toward the exhaust stack;
a drain pipe that communicates with the drain pipe and drains droplets collected by the collecting unit as drain water;
Exhaust gas purification device. 2. The exhaust gas purifier according to claim 1, wherein the drain pipe is provided with a drain trap. 3. The exhaust gas purifying apparatus according to claim 2, wherein the depth of the wastewater pool in said wastewater trap is determined according to the pressure of the exhaust gas flowing into said absorption tower. 4. The exhaust gas purifier according to any one of claims 1 to 3, further comprising a degassing mechanism communicating with an external space above said drain pipe. Water sucked from an external water source by a pump is used as the absorbent sent to the spraying part,
5. The exhaust gas purifier according to claim 1, wherein the absorbent stored in said tank is discharged to said external water source. 6. The exhaust gas purifier according to claim 5, wherein the pump sucks the absorbent stored in the tank and sends it to the spray section. an absorption tower that communicates with the exhaust stack and into which exhaust gas generated by combustion of fossil fuel flows;
a spraying part for spraying an absorption liquid for absorbing sulfur oxides into the absorption tower;
a drain pipe for draining the absorbent sprayed by the spraying part from the absorption tower;
a tank for storing the absorbent discharged from the drain pipe;
a collection unit provided in the exhaust stack for collecting droplets accompanying the exhaust gas rising from the absorption tower toward the exhaust stack;
a drain pipe for discharging liquid droplets collected by the collection unit to the tank as drain water;
a degassing mechanism that communicates the tank with an external space;
Exhaust gas purification device.

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