Exhaust gas treatment equipment

Abstract

To prevent damage of a liquid discharge pipe by a solid matter such as an inorganic salt.SOLUTION: An exhaust gas treatment apparatus includes a cylindrical absorption tower, a spray part, and a liquid discharge pipe. The absorption tower has an introduction port for introducing exhaust gas, and a discharge port for discharging the exhaust gas. The spray part sprays a liquid for treating the exhaust gas into the absorption tower. The liquid discharge pipe discharges the liquid sprayed from the spray part from the absorption tower. A liquid discharge port communicating with the liquid discharge pipe is provided in the bottom surface of the absorption tower, and a filter for capturing a solid matter toward the liquid discharge port is arranged below the introduction port in a vertical direction, in the absorption tower.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an exhaust gas treatment device.

Background Art

[0002] Exhaust gas treatment devices such as scrubbers that treat exhaust gas generated by the combustion of fossil fuels such as coal or heavy oil using a liquid such as seawater that absorbs harmful substances such as sulfur oxides that pollute the atmosphere are known. For example, the device described in Patent Document 1 includes a reactor having an exhaust gas inlet and an outlet, and an injection unit that injects seawater into the reactor. Here, the seawater injected from the injection unit is used for treating the exhaust gas in the reactor and then discharged from a drain outlet that opens to the bottom surface of the reactor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the device described in Patent Document 1, inorganic salts are likely to precipitate because high-temperature exhaust gas contacts seawater near the exhaust gas inlet of the reactor. In the device described in Patent Document 1, when such inorganic salts accumulate on the wall surface of the reactor and then become large chunks and enter the drain outlet, there is a problem of causing damage to the drain pipe communicating with the drain outlet.

Means for Solving the Problems

[0005] To solve the above problems, an exhaust gas treatment device according to one aspect of the present disclosure comprises a cylindrical absorption tower having an inlet for introducing exhaust gas and an outlet for discharging exhaust gas, a spraying unit for spraying a liquid for treating exhaust gas into the absorption tower, and a drain pipe for discharging the liquid sprayed from the spraying unit from the absorption tower, wherein a drain port communicating with the drain pipe is provided on the bottom surface of the absorption tower, and a filter for capturing solid matter heading toward the drain port is positioned vertically below the inlet within the absorption tower. [Brief explanation of the drawing]

[0006] [Figure 1] This is a schematic diagram of the exhaust gas treatment device according to the first embodiment. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a diagram illustrating the main tube and support structure. [Figure 4] This is a cross-sectional view along line BB in Figure 1. [Figure 5] This is a plan view of the structure used in the filter of the first embodiment. [Figure 6] This is a side view of the structure used in the filter of the first embodiment. [Figure 7] This is a diagram illustrating the positional relationship between the filter and support of the exhaust gas treatment device of the second embodiment. [Figure 8] This is a plan view of the filter according to the second embodiment. [Figure 9] This is a plan view of the first structure used in the filter of the second embodiment. [Figure 10] Figure 9 is a side view of the first structure. [Figure 11] This is a plan view of the second structure used in the filter of the second embodiment. [Figure 12] Figure 11 is a side view of the second structure. [Figure 13] This is a plan view of the third structure used in the filter of the second embodiment. [Figure 14] Figure 13 is a side view of the third structure. [Modes for carrying out the invention]

[0007] Preferred embodiments of the present disclosure will be described below with reference to the attached drawings. Note that the dimensions and scale of parts in the drawings may differ from actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of the present disclosure is not limited to these embodiments unless otherwise stated in the following description.

[0008] 1. First Embodiment Figure 1 is a schematic diagram of the exhaust gas treatment device 1 according to the first embodiment. The exhaust gas treatment device 1 is a cyclone-type scrubber that treats exhaust gas generated by fossil fuels such as heavy oil or coal. The exhaust gas treatment device 1 is installed, for example, on a ship that uses an internal combustion engine or an external combustion engine as a prime mover, which generates exhaust gas by burning fossil fuels. An internal combustion engine is, for example, a gasoline engine or a diesel engine. An external combustion engine is, for example, a steam engine or a steam turbine.

[0009] The exhaust gas treatment device 1 uses a liquid to treat the exhaust gas. This liquid is, for example, an absorbent that absorbs harmful substances such as sulfur oxides contained in the exhaust gas. When the exhaust gas treatment device 1 is installed on a ship that sails the ocean, a typical example of this liquid is seawater. Seawater contains HCO3 - It contains alkaline components such as sulfur dioxide, and upon contact with exhaust gas, it neutralizes sulfur oxides such as sulfur dioxide contained in the exhaust gas by converting them into sulfate ions. In the following, the liquid used to treat exhaust gas may be referred to as the absorbent.

[0010] As shown in Figure 1, the exhaust gas treatment device 1 comprises an absorption tower 10, a spray unit 20, a liquid supply pipe 30, a swirler 40, a drain pipe 50, a support 60, a filter 70, and an inlet pipe 80. The following outlines the various parts of the exhaust gas treatment device 1 based on Figure 1.

[0011] In the following, one direction along the central axis LC of the absorption tower 10 is the "Z1 direction", and the direction opposite to the Z1 direction is the "Z2 direction". Here, typically, the central axis LC is an axis parallel to the vertical line, the Z1 direction is upward in the vertical direction, and the Z2 direction is downward in the vertical direction. However, the central axis LC may be inclined within a range of 45° or less with respect to the vertical line according to the installation posture or usage situation of the exhaust gas treatment apparatus 1. Further, in the following, the term "upward" simply indicates a position in the direction along the vertical line, including both directly upward and obliquely upward in the vertical direction. Similarly, the term "downward" simply indicates a position in the direction along the vertical line, including both directly downward and obliquely downward in the vertical direction. Further, in the following, the direction around the central axis LC may be referred to as the "circumferential direction", and the direction orthogonal to the central axis LC may be referred to as the "radial direction".

[0012] The absorption tower 10 is a structure having a space S for bringing the exhaust gas into contact with the absorption liquid as an internal space. The absorption tower 10 has a bottom surface FB and a side wall WS, and has a bottomed cylindrical shape around the central axis LC. Here, the space S is a space surrounded by the bottom surface FB and the side wall WS.

[0013] Each of the bottom surface FB and the side wall WS is made of a material having durability against both the exhaust gas and the treatment liquid before and after treatment. Specifically, examples of the material constituting the bottom surface FB and the side wall WS include copper alloys such as naval brass, aluminum alloys such as aluminum brass, nickel alloys such as cupronickel, Hastelloy (registered trademark), stainless steels such as SUS316L, SUS329J4L or SUS312. Note that each of the bottom surface FB and the side wall WS is not limited to the above-mentioned materials, and may be made of a ferrous material such as a rolled steel sheet for welded structures such as SS400, SM400A or SM490A defined in JIS G 3106. In this case, coating or painting is appropriately applied so that each of the bottom surface FB and the side wall WS has durability against both the exhaust gas and the treatment liquid before and after treatment.

[0014] The absorption tower 10 has an inlet 11, an outlet 12, and a drain port 13, and a spray section 20 and a swirler 40 are arranged in the space S.

[0015] The inlet 11 opens in the side wall WS of the absorption tower 10 at a position below the center of the absorption tower 10 and introduces exhaust gas into the space S. An introduction pipe 80 is connected to the inlet 11. The introduction pipe 80 is connected to an exhaust pipe of an internal combustion engine or an external combustion engine (not shown) and introduces the exhaust gas from the exhaust pipe into the space S through the inlet 11. The exhaust gas introduced into the space S through the inlet 11 flows in the Z1 direction while swirling around the central axis LC. Details of the introduction pipe 80 will be described later based on FIG. 2.

[0016] The spray section 20 sprays an absorption liquid into the absorption tower 10. Thereby, the exhaust gas and the absorption liquid come into contact with each other in the absorption tower 10.

[0017] In the example shown in FIG. 1, the spray section 20 has spray sections 20a, 20b, and 20c, and each of the spray sections 20a, 20b, and 20c sprays an absorption liquid into the absorption tower 10. The spray sections 20a, 20b, and 20c are arranged side by side in the Z1 direction in this order. Each of the spray sections 20a, 20b, and 20c has a main pipe 21, a plurality of branch pipes 22, and a plurality of nozzles 23.

[0018] The main pipe 21 extends along the central axis LC in the absorption tower 10 and supplies the absorption liquid from the liquid supply pipe 30 to the plurality of branch pipes 22. Each of the plurality of branch pipes 22 extends radially from the main pipe 21 toward the side wall WS in the absorption tower 10 and supplies the absorption liquid from the main pipe 21 to at least one nozzle 23. Each of the plurality of nozzles 23 is provided on the branch pipe 22 and sprays the absorption liquid from the branch pipe 22 into the absorption tower 10 in a predetermined direction and range.

[0019] Each of the spray sections 20a, 20b, and 20c described above is supported by the absorption tower 10 by an appropriate configuration. Here, the main pipe 21 of spray section 20a is supported on the bottom surface FB of the absorption tower 10 via a support 60. A filter 70 for capturing solid matter is attached to the support 60. This solid matter is, for example, an inorganic salt produced by the reaction of acidic components in the exhaust gas with alkaline components in the absorbent liquid. Details of the support 60 and the filter 70 will be described later with reference to Figures 2 to 6.

[0020] The configuration of the spray unit 20 is not limited to the example shown in Figure 1. For example, it may be configured by omitting at least one of the spray units 20b and 20c, or by adding one or more other spray units in addition to the spray units 20a, 20b, and 20c. Furthermore, the length, number, and arrangement of the main pipe 21 and branch pipes 22 are not limited to the example shown in Figure 1 and are arbitrary. For example, the branch pipes 22 may be joined to the side wall WS. In addition, the number, arrangement, spray direction, and spray range of the nozzles 23 are not particularly limited and are arbitrary.

[0021] The liquid supply pipe 30 is a pipe for supplying absorbent liquid to the spray section 20, and a pump (not shown) for transferring absorbent liquid into the liquid supply pipe 30 is connected to one end of the liquid supply pipe 30. For example, if the exhaust gas treatment device 1 is installed on a ship sailing in the ocean, the pump will draw in seawater from around the ship, thereby transferring seawater as absorbent liquid into the liquid supply pipe 30.

[0022] In the example shown in Figure 1, the liquid supply pipe 30 has three branched liquid supply pipes 30a, 30b, and 30c, each of which penetrates the side wall WS of the absorption tower 10. Liquid supply pipe 30a is a pipe for supplying absorbent liquid to the spray section 20a, and the main pipe 21 of the spray section 20a is connected to liquid supply pipe 30a. Liquid supply pipe 30b is a pipe for supplying absorbent liquid to the spray section 20b, and the main pipe 21 of the spray section 20b is connected to liquid supply pipe 30b. Liquid supply pipe 30c is a pipe for supplying absorbent liquid to the spray section 20c, and the main pipe 21 of the spray section 20c is connected to liquid supply pipe 30c.

[0023] The discharge port 12 opens at the end of the absorption tower 10 opposite the bottom surface FB, and discharges the treated exhaust gas from the space S. An exhaust pipe (not shown) that communicates with the outside space is connected to the discharge port 12, and the treated exhaust gas from space S is released into the outside space through the exhaust pipe from the discharge port 12. For example, if the exhaust gas treatment device 1 is installed on a ship, the exhaust pipe is provided on the ship's funnel.

[0024] In the example shown in Figure 1, the treated exhaust gas is discharged from the outlet 12 via a swirler 40. The swirler 40 is located inside the absorption tower 10 near the outlet 12 and generates a swirling flow in the same direction as the swirling flow described later in the exhaust gas after treatment with the absorbent liquid. The exhaust gas after passing through the swirler 40 is discharged from the outlet 12. The swirler 40 may be provided as needed or omitted. In addition, a demister may be placed inside the absorption tower 10 between the spray section 20 and the outlet 12 to separate droplets of the absorbent liquid from the exhaust gas, either in place of the swirler 40 or in addition to the swirler 40.

[0025] The drain port 13 is an opening provided in the bottom surface FB of the absorption tower 10, and discharges the treated absorbent liquid from the space S. A water treatment system including a tank such as a gas seal chamber (not shown) is connected to the drain port 13 via a drain pipe 50. The treated absorbent liquid is stored in the tank. The water treatment system discharges the absorbent liquid in the tank into the ocean or the like when the pH and dissolved oxygen level of the absorbent liquid in the tank meet predetermined standards. Alternatively, the water treatment system may return the absorbent liquid in the tank to the feed pipe 30 for reuse instead of discharging it into the ocean or the like. In other words, the exhaust gas treatment device 1 may be an open-loop type that discards the treated absorbent liquid, or a closed-loop type that reuses the treated absorbent liquid. Furthermore, the exhaust gas treatment device 1 may be a hybrid type that switches between open-loop and closed-loop.

[0026] The drain pipe 50 is a pipe that communicates with the drain port 13. In the example shown in Figure 1, the drain pipe 50 is bent or curved in the middle. The drain pipe 50 is made of a material that is durable against the treated liquid after processing. Specifically, the material that makes up the drain pipe 50 is not particularly limited, but the same material as that which makes up the absorption tower 10 can be used. Here, from the viewpoint of reducing the cost of the drain pipe 50, for example, a pipe made of iron material such as SS400, SM400A or SM490A for welded structures as specified in JIS G 3106, etc., with a resin coating such as polyethylene on the inner surface is suitably used as the drain pipe 50. Note that the shape of the drain pipe 50 is not limited to the example shown in Figure 1, but is arbitrary.

[0027] Figure 2 is a cross-sectional view taken along line AA in Figure 1. Figure 2 shows a cross-section of the absorption tower 10 taken by a plane perpendicular to the central axis LC and passing through the inlet 11. For clarity, the filter 70 is simplified in Figure 2 by a dashed line.

[0028] As shown in Figure 2, the inlet pipe 80 is connected to the absorption tower 10 in such a way that its extension does not coincide with the central axis LC when viewed along the central axis LC of the absorption tower 10. Therefore, the exhaust gas introduced into the absorption tower 10 from the inlet pipe 80 through the inlet 11 flows towards the outlet 12 while swirling around the central axis LC along the side wall WS of the absorption tower 10. In the example shown in Figure 2, when viewed in the Z2 direction, the inlet pipe 80 generates a clockwise swirling flow of exhaust gas.

[0029] Figure 3 is a diagram illustrating the main pipe 21 and the support 60. In Figure 3, the main pipe 21 and the support 60 are shown in a direction perpendicular to the central axis LC. In Figure 2, for ease of viewing, the filter 70 is simply shown with a dashed line.

[0030] As shown in Figure 3, a drain port 13 is opened in the bottom surface FB of the absorption tower 10. A main pipe 21 is positioned in the Z1 direction relative to the drain port 13. The main pipe 21 is supported by the bottom surface FB via a support 60. Here, the support 60 is fixed to the main pipe 21 and the bottom surface FB by welding or the like.

[0031] In the example shown in Figure 3, the width of the drain port 13 is greater than the width of the main pipe 21. However, the width of the drain port 13 may be less than or equal to the width of the main pipe 21. Furthermore, the shape of the drain port 13 and the cross-sectional shape of the main pipe 21 are not limited to the example shown in Figure 3 and are arbitrary.

[0032] Figure 4 is a cross-sectional view along line BB in Figure 1. In Figure 4, the support 60 and filter 70 are shown in the Z2 direction. For ease of explanation, in Figure 4, a portion of the filter 70 is shown with a solid line, and the rest of the filter 70 is simply shown with a dashed line.

[0033] As shown in Figure 4, the support body 60 comprises four support members 61.

[0034] Each of the four support members 61 is plate-shaped, extending radially from the central axis LC and spreading in a direction intersecting the bottom surface FB. The four support members 61 are arranged at equal angular intervals around the central axis LC. That is, the angle between two adjacent support members 61 in the circumferential direction is 90°. Each of the four support members 61 is joined to the bottom surface FB and the main pipe 21 by welding or the like.

[0035] The configuration of the support 60 is not limited to the example shown in Figure 4. For example, the number of support members 61 constituting the support 60 may be three or fewer, or five or more. Also, the shape of the support members 61 is not limited to a plate shape, but may be, for example, a rod shape. Furthermore, the support 60 may be fixed to the side wall WS instead of being fixed to the bottom surface FB. In addition, the multiple support members 61 do not have to be arranged at equal angular intervals around the central axis LC.

[0036] In the configuration in which the support 60 described above is placed on the bottom surface FB, the drain port 13 is exposed through the gaps in the support 60 so as to be divided into four openings when viewed in the Z2 direction.

[0037] The filter 70 is positioned vertically below the inlet 11 and is a structure that captures solids of a predetermined diameter or larger that are heading toward the drain outlet 13. The filter 70 has a plurality of holes 72 that block the passage of solids of a predetermined diameter or larger while allowing the passage of liquid and solids of a diameter smaller than the predetermined diameter.

[0038] The filter 70 has four structures 71_1 to 71_4 corresponding to the four openings of the drain port 13. Each of the four structures 71_1 to 71_4 has multiple holes 72. The four structures 71_1 to 71_4 are identical in configuration except for their arrangement. In Figure 4, of the four structures 71_1 to 71_4 that make up the filter 70, structure 71_1 is shown by a solid line, and structures 71_2 to 71_4 are each shown simply by dashed lines. Hereafter, each of structures 71_1 to 71_4 may be referred to as structure 71. The configuration of structure 71 will be described in detail later based on Figures 5 and 6.

[0039] The four structures 71_1 to 71_4 are arranged in this order, counterclockwise around the central axis LC of the absorption tower 10. Here, the four structures 71_1 to 71_4 are separated from each other via the support 60. More specifically, each structure 71 is positioned between two adjacent support members 61 in the circumferential direction. That is, the four support members 61 and the four structures 71 are arranged such that the support members 61 and structures 71 alternate in the circumferential direction.

[0040] The structure 71 is fixed to each of two circumferentially adjacent support members 61 by welding or the like. Here, gaps are provided between the structure 71 and each of the two support members 61, between the structure 71 and the bottom surface FB, and between the structure 71 and the main pipe 21, which prevent the passage of solids larger than a predetermined diameter while allowing the passage of liquid and solids smaller than a predetermined diameter. In this way, the four structures 71_1 to 71_4 work together with the bottom surface FB, the main pipe 21 of the spray section 20a, and the four support members 61 to prevent solids larger than a predetermined diameter from entering the drain port 13.

[0041] Figure 5 is a plan view of the structure 71 used in the filter 70 of the first embodiment. Figure 6 is a side view of the structure 71 used in the filter 70 of the first embodiment. In Figures 5 and 6, the structure 71 is shown by a solid line, and the plate surface and bottom surface FB of the support member 61 are shown by a dashed line.

[0042] The structure 71 is roughly plate-shaped and, as shown in Figure 5, is trapezoidal when viewed in the thickness direction. The structure 71 has a plurality of holes 72. In the example shown in Figure 5, the holes 72 are elongated holes, and the width W of the holes 72 is such that it prevents the passage of solids larger than a predetermined diameter while allowing the passage of liquids and solids smaller than a predetermined diameter.

[0043] More specifically, the structure 71 comprises a pair of first members 71a, a plurality of second members 71b, and four mounting members 71c. These, like the absorption tower 10, are made of materials that are durable against both exhaust gas and the treatment liquid before and after treatment. Specifically, examples of materials that make up the structure 71 include copper alloys such as Neval brass, aluminum alloys such as aluminum brass, nickel alloys such as Cupronickel, stainless steels such as Hastelloy®, SUS316L, SUS329J4L, or SUS312.

[0044] Each of the pair of first members 71a is rod-shaped. The cross-section of each of the pair of first members 71a is L-shaped. The pair of first members 71a are arranged along opposite sides of the trapezoid, excluding the top and bottom bases. Multiple second members 71b are spanned between the pair of first members 71a, extending in a direction parallel to the top and bottom bases of the trapezoid, and both ends of each of the multiple second members 71b are joined to the pair of first members 71a by welding or the like. The cross-section of each of the multiple second members 71b is circular. In addition, two mounting members 71c are joined to each of the pair of first members 71a by welding or the like. Each mounting member 71c protrudes from the first member 71a, as shown in Figure 6.

[0045] The cross-sectional shapes of the first member 71a and the second member 71b are not limited to the illustrated examples and are arbitrary. The number of second members 71b is also not limited to the illustrated examples and is arbitrary. Furthermore, the position, shape, number, and other characteristics of the mounting members 71c are not limited to the illustrated examples and are arbitrary. Also, at least two of the first member 71a, the second member 71b, and the mounting members 71c may be integrally formed by bending a metal plate or the like.

[0046] In such a structure 71, as shown in Figure 5, the space enclosed by a pair of first members 71a and two adjacent second members 71b constitutes a hole 72. In the example shown in Figure 5, multiple second members 71b are arranged parallel to each other at equal intervals, and the width W of the multiple holes 72 is equal to each other. Note that the multiple second members 71b do not have to be arranged at equal intervals, nor do the multiple second members 71b have to be parallel to each other.

[0047] It is preferable that the total cross-sectional area (sum of opening areas) of the multiple holes 72 in the filter 70 is larger than the cross-sectional area (opening area) of the drain port 13. In this case, drainage performance comparable to that of a configuration without a filter 70 can be achieved. Note that the total cross-sectional area may also be the sum of the cross-sectional area of ​​the multiple holes 72 and the gaps d1, d2, and d3.

[0048] More specifically, when the total cross-sectional area of ​​the multiple holes 72 is S1 and the cross-sectional area of ​​the drain port 13 is S2, it is preferable that the relationship S1 / S2 ≥ 2 is satisfied. When this relationship is satisfied, it is easy to achieve drainage performance comparable to that of a configuration without a filter 70. On the other hand, if S1 / S2 is too small, depending on the width of the holes 72 of the filter 70, it may lead to a decrease in drainage performance compared to a configuration without a filter 70. Conversely, if S1 / S2 is too large, depending on the shape of the filter 70, it may be difficult to secure the necessary mechanical strength for the filter 70.

[0049] The width W of each of the multiple holes 72 is preferably 40 mm or less, more preferably 10 mm to 40 mm, and even more preferably 10 mm to 30 mm. By keeping the width W within this range, the entry of solid objects large enough to damage the drain pipe 50 into the drain port 13 is effectively prevented. On the other hand, if the width W is too small, it becomes difficult to achieve both the mechanical strength of the filter 70 and proper drainage. Conversely, if the width W is too large, depending on the configuration of the drain pipe 50, damage to the drain pipe 50 by solid objects tends to occur more easily.

[0050] Furthermore, in the structure 71, the mounting member 71c is joined to the support member 61 by welding or the like. This fixes the structure 71 to the support 60. Here, as shown in Figure 5, the first member 71a is arranged along the plate surface of the support member 61, and a gap d1 is provided between the first member 71a and the support member 61. The gap d1 preferably prevents the passage of solids of a predetermined diameter or larger, while allowing the passage of liquids and solids of a diameter smaller than the predetermined diameter. That is, the size of the gap d1 is preferably in the same range as the width W. Note that the gap d1 may be provided as needed or omitted.

[0051] Furthermore, the second member 71b closest to the bottom surface FB among the multiple second members 71b is positioned along the bottom surface FB, and a gap d2 is provided between the second member 71b closest to the bottom surface FB and the bottom surface FB. The gap d2 preferably prevents the passage of solids of a predetermined diameter or larger while allowing the passage of liquids and solids of a diameter smaller than the predetermined diameter. That is, the size of the gap d2 is preferably in the same range as the width W. Note that the gap d2 may be provided as needed or omitted.

[0052] Furthermore, the second member 71b closest to the main pipe 21 is positioned along the end face of the main pipe 21, and a gap d3 is provided between the second member 71b closest to the main pipe 21 and the main pipe 21. The gap d3 preferably prevents the passage of solids of a predetermined diameter or larger while allowing the passage of liquids and solids of a diameter smaller than the predetermined diameter. That is, the size of the gap d3 is preferably in the same range as the width W. The gap d3 may be provided as needed or omitted.

[0053] As described above, the exhaust gas treatment device 1 comprises a cylindrical absorption tower 10, a spray unit 20, and a drain pipe 50. The absorption tower 10 has an inlet 11 for introducing exhaust gas and an outlet 12 for discharging exhaust gas. The spray unit 20 sprays a liquid for treating the exhaust gas into the absorption tower 10. The drain pipe 50 discharges the liquid sprayed from the spray unit 20 from the absorption tower 10.

[0054] Here, a drain port 13 is provided on the bottom surface FB of the absorption tower 10, which communicates with the drain pipe 50. Inside the absorption tower 10, a filter 70 for capturing solid matter heading towards the drain port 13 is positioned vertically below the inlet 11.

[0055] In the exhaust gas treatment device 1 described above, the filter 70 that captures solid matter heading towards the drain port 13 is positioned vertically below the inlet 11 in the absorption tower 10. Therefore, the filter 70 reduces the amount of solid matter such as inorganic salts generated in the absorption tower 10 that enters the drain pipe 50 through the drain port 13. As a result, even if the drain pipe 50 is constructed from inexpensive materials, damage to the drain pipe 50 caused by such solid matter can be reduced.

[0056] In this embodiment, as described above, the filter 70 has a plurality of holes 72. Here, if the total cross-sectional area of ​​the plurality of holes 72 is larger than the cross-sectional area of ​​the drain port 13, drainage performance comparable to that of a configuration without a filter 70 can be achieved. The holes 72 can also be described as gaps formed between two adjacent second members 71b.

[0057] Furthermore, as mentioned above, when the total cross-sectional area of ​​the multiple holes 72 is S1 and the cross-sectional area of ​​the drain port 13 is S2, if the relationship S1 / S2 ≥ 2 is satisfied, it is easy to achieve drainage performance comparable to that of a configuration without a filter 70. On the other hand, if S1 / S2 is too small, depending on the width of the holes 72 in the filter 70, it may lead to a decrease in drainage performance compared to a configuration without a filter 70. Conversely, if S1 / S2 is too large, depending on the shape of the filter 70, it may be difficult to secure the necessary mechanical strength of the filter 70, and solid particles such as inorganic salts of an unacceptable size may pass through the filter 70. In addition, if S1 / S2 is too large, it becomes necessary to enlarge the filter 70 and increase the number of holes 72, which leads to the problem of increased costs for the filter 70.

[0058] Furthermore, as mentioned above, the width W of each of the multiple holes 72 is preferably 40 mm or less, more preferably 10 mm to 40 mm, and even more preferably 10 mm to 30 mm. By setting the width W within this range, the entry of solid objects large enough to damage the drain pipe 50 into the drain port 13 is effectively prevented.

[0059] Furthermore, as mentioned above, a gap d2 is provided between the filter 70 and the bottom surface FB of the absorption tower 10. This allows the liquid to be efficiently guided along the bottom surface FB of the absorption tower 10 to the drain port 13. In addition, by not joining the filter 70 to the bottom surface FB of the absorption tower 10 by welding or the like, the work of fixing the filter 70 to the absorption tower 10 by welding or the like does not require work such as removing welding burns from the outside of the absorption tower 10, thus limiting the scope of such work and improving the efficiency of such work.

[0060] Furthermore, as mentioned above, the exhaust gas introduced into the absorption tower 10 from the inlet 11 flows toward the outlet 12 while swirling around the central axis LC of the absorption tower 10. This reduces the localized generation of inorganic salts. As a result, the solid particles can be reduced in size.

[0061] Furthermore, as mentioned above, the exhaust gas treatment device 1 further comprises a liquid supply pipe 30. The liquid supply pipe 30 penetrates the side wall WS of the absorption tower 10 and supplies liquid to the spray section 20. The spray section 20 has a main pipe 21, a plurality of branch pipes 22, and a plurality of nozzles 23. The main pipe 21 extends from the liquid supply pipe 30 within the absorption tower 10 along the central axis LC of the absorption tower 10. Each of the plurality of branch pipes 22 extends from the main pipe 21 within the absorption tower 10 toward the side wall WS of the absorption tower 10. At least one nozzle 23 is provided in each of the plurality of branch pipes 22 within the absorption tower 10.

[0062] In the spray section 20 with the above configuration, the liquid can be efficiently brought into contact with the exhaust gas swirling inside the absorption tower 10. As a result, the exhaust gas treatment efficiency can be improved. Furthermore, since the main pipe 21 is positioned vertically above the drain port 13, the filter 70 can be fixed to the support 60 that supports the main pipe 21. Therefore, there is no need to join the filter 70 to the bottom surface FB of the absorption tower 10 by welding or the like. This eliminates the need to remove welding burns from the outside of the absorption tower 10 when fixing the filter 70 to the absorption tower 10 by welding or the like, thus limiting the scope of the work and improving the efficiency of the work.

[0063] Furthermore, as mentioned above, the filter 70 has multiple structures 71_1 to 71_4 arranged in a line around the central axis LC of the absorption tower 10. Therefore, even after the main pipe 21 has been installed in the absorption tower 10, the filter 70 can be installed in the absorption tower 10 more easily than when the filter is constructed using cylindrical structures around the central axis LC.

[0064] Furthermore, as mentioned above, the exhaust gas treatment device 1 further includes a support 60. The support 60 is joined to the bottom surface FB of the absorption tower 10 and to the main pipe 21, respectively. This allows the main pipe 21 to be stably installed in the absorption tower 10. Also, by fixing the filter 70 to the support 60, there is no need to join the filter 70 to the bottom surface FB of the absorption tower 10 by welding or the like. Therefore, in the process of fixing the filter 70 to the absorption tower 10 by welding or the like, work such as removing welding burns from the outside of the absorption tower 10 is unnecessary, thus limiting the scope of the work and improving the efficiency of the work.

[0065] Furthermore, as mentioned above, the multiple structures 71_1 to 71_4 are separated and arranged via the support 60. Therefore, the filter 70 can be installed more easily compared to a filter that covers the support 60.

[0066] 2. Second Embodiment A second embodiment of this disclosure will be described below. For elements whose operation and function are the same as those in the above-described embodiment, the reference numerals used in the above-described embodiment will be reused, and detailed descriptions of each will be omitted as appropriate.

[0067] Figure 7 is a diagram illustrating the positional relationship between the filter 70A and the support 60 of the exhaust gas treatment device 1A of the second embodiment. Figure 8 is a plan view of the filter 70A of the second embodiment. The exhaust gas treatment device 1A is configured in the same way as the exhaust gas treatment device 1 of the first embodiment described above, except that it is equipped with a filter 70A instead of a filter 70. In Figure 7, for the sake of explanation, the filter 70A is simply shown by a dashed line.

[0068] As shown in Figures 7 and 8, the filter 70A covers the support 60. In the example shown in Figures 7 and 8, the filter 70A is substantially box-shaped and open in the Z2 direction. As shown in Figure 8, the filter 70A has a plurality of holes 72A that block the passage of solids larger than a predetermined diameter while allowing the passage of liquid and solids smaller than a predetermined diameter.

[0069] The filter 70A has four first structures 73_1 to 73_4, four second structures 74_1 to 74_4, and four third structures 75_1 to 75_4.

[0070] The four first structures 73_1 to 73_4 are arranged in this order, counterclockwise around the central axis LC of the absorption tower 10. Here, each of the four first structures 73_1 to 73_4 is positioned to straddle two adjacent support members 61 in the circumferential direction. The four first structures 73_1 to 73_4 are identical in configuration except for their arrangement. In the following, each of the first structures 73_1 to 73_4 may be referred to as the first structure 73. The configuration of the first structure 73 will be described in detail later with reference to Figures 9 and 10.

[0071] The four second structures 74_1 to 74_4 are arranged in this order, counterclockwise around the central axis LC of the absorption tower 10. Here, each of the four second structures 74_1 to 74_4 is positioned to fill a portion of the gap between two adjacent first structures 73 in the circumferential direction. The four second structures 74_1 to 74_4 are identical in configuration except for their arrangement. In the following, each of the second structures 74_1 to 74_4 may be referred to as the second structure 74. The configuration of the second structure 74 will be described in detail later with reference to Figures 11 and 12.

[0072] The four third structures 75_1 to 75_4 are arranged in this order, counterclockwise around the central axis LC of the absorption tower 10. Here, each of the four third structures 75_1 to 75_4 is positioned in a different region from the four second structures 74_1 to 74_4, filling a portion of the gap between two adjacent first structures 73 in the circumferential direction. The four third structures 75_1 to 75_4 are identical in configuration except for their different arrangements. In the following, each of the third structures 75_1 to 75_4 may be referred to as the third structure 75. The configuration of the third structure 75 will be described in detail later with reference to Figures 13 and 14.

[0073] Each of the first structure 73, the second structure 74, and the third structure 75 is made of a material that is durable against both exhaust gas and the treatment liquid before and after treatment. Specifically, examples of materials that make up the first structure 73 include copper alloys such as Neval brass, aluminum alloys such as aluminum brass, nickel alloys such as Cupronickel, stainless steel such as Hastelloy®, SUS316L, SUS329J4L, or SUS312. Furthermore, each of the first structure 73, the second structure 74, and the third structure 75 can be obtained, for example, by appropriately combining metal plate bending and welding.

[0074] Figure 9 is a plan view of the first structure 73 used in the filter 70A of the second embodiment. Figure 10 is a side view of the first structure 73 shown in Figure 9. In Figure 9, the first structure 73 is shown in the Z2 direction, and the plate surface of the support member 61 is shown by a dashed line. In Figure 10, the first structure 73 is shown in the direction of arrow C in Figure 9. The direction of arrow C is perpendicular to the central axis LC.

[0075] As shown in Figure 9, the first structure 73 has a top plate 73a, a side plate 73b, a protrusion 73c, and a pair of protrusions 73d.

[0076] The top plate 73a is plate-shaped, extending in a direction intersecting the central axis LC. The top plate 73a has a plurality of holes 72A. The top plate 73a has a pair of edges 73a2 that run along two circumferentially adjacent support members 61 when viewed in the Z1 or Z2 direction. The pair of edges 73a2 are joined to the two support members 61 by welding or the like. The side plate 73b extends in the Z2 direction from the radially outer end of the top plate 73a and is plate-shaped, extending in a direction intersecting the radial direction. The side plate 73b has a plurality of holes 72A. The projection 73c extends in the Z1 direction from the radially inward end of the top plate 73a and has a curved shape that runs along the outer circumferential surface of the main pipe 21. As shown in Figure 9, the pair of protrusions 73d are plate-shaped and extend in a direction perpendicular to the side plate 73b, at a position adjacent to the side plate 73b when viewed in the Z1 or Z2 direction. Also, as shown in Figure 10, the pair of protrusions 73d protrude from the top plate 73a in the Z1 direction.

[0077] Here, the end of the side plate 73b in the Z2 direction is positioned along the bottom surface FB, and a gap d2 is provided between this end and the bottom surface FB. The gap d2 preferably prevents the passage of solids larger than a predetermined diameter while allowing the passage of liquids and solids smaller than a predetermined diameter. The gap d2 may be provided as needed or omitted.

[0078] Figure 11 is a plan view of the second structure 74 used in the filter 70A of the second embodiment. Figure 12 is a side view of the second structure 74 shown in Figure 11. In Figure 11, the second structure 74 is shown in the Z2 direction, and the support member 61 and side plate 73b are indicated by dashed lines. In Figure 12, the second structure 74 is shown in the direction of arrow D in Figure 11. The direction of arrow D is perpendicular to the central axis LC.

[0079] As shown in Figure 11, the second structure 74 has a side plate 74a and protrusions 74b and 74c.

[0080] The side plate 74a is a plate-like shape that is bent at a right angle in the Z1 or Z2 direction so as to close an opening provided between the side plates 73b of two circumferentially adjacent first structures 73. The side plate 74a has a plurality of holes 72A. Edge portions 74a1 are provided at each of the radial ends of the side plate 74a. The edge portions 74a1 are joined to the side plate 73b of the first structure 73 by welding or the like. The protruding portion 74b protrudes in the Z1 direction from the bent portion of the side plate 74a. The protruding portion 74c protrudes radially inward from the bent portion of the side plate 74a. An edge portion 74c1 is provided at the radially inward end of the protruding portion 74c. The edge portion 74c1 is joined to the radially outward edge of the support member 61 by welding or the like.

[0081] Here, the end of the side plate 74a in the Z2 direction is positioned along the bottom surface FB, and a gap d2 is provided between this end and the bottom surface FB. The gap d2 preferably prevents the passage of solids larger than a predetermined diameter while allowing the passage of liquids and solids smaller than a predetermined diameter. The gap d2 may be provided as needed or omitted.

[0082] Figure 13 is a plan view of the third structure 75 used in the filter 70A of the second embodiment. Figure 13 is a side view of the third structure 75 shown in Figure 13. In Figure 13, the third structure 75 is shown in the Z2 direction, and the protrusions 73d and 74b are indicated by dashed lines. In Figure 14, the third structure 75 is shown in the direction of arrow E in Figure 13. The direction of arrow E is perpendicular to the central axis LC.

[0083] As shown in Figure 13, the third structure 75 has a top plate 75a and a pair of protrusions 75b and 75c.

[0084] The top plate 75a is plate-shaped, extending in a direction perpendicular to the Z1 or Z2 direction so as to close the opening provided between the top plates 73a of two circumferentially adjacent first structures 73. A projection 75b is connected to the radially outer end of the top plate 75a. The projection 75b protrudes from the top plate 75a in the Z1 direction and is joined to the projection 74b of the aforementioned second structure 74 by welding or the like. Projections 75c are connected to each of the circumferential ends of the top plate 75a. The projection 75c protrudes from the top plate 75a in the Z1 direction and is joined to the projection 73d of the aforementioned first structure 73 by welding or the like.

[0085] It is preferable that the total cross-sectional area (sum of opening areas) of the multiple holes 72A in the filter 70A is larger than the cross-sectional area (opening area) of the drain port 13. In this case, drainage performance comparable to that of a configuration without the filter 70A can be achieved. Note that the total cross-sectional area may also be the sum of the cross-sectional area of ​​the multiple holes 72A and the gaps d1, d2, and d3.

[0086] More specifically, it is preferable that the relationship S1 / S2 ≥ 2 is satisfied when S1 is the total cross-sectional area of ​​the multiple holes 72A and S2 is the cross-sectional area of ​​the drain port 13. When this relationship is satisfied, it is easy to achieve drainage performance comparable to that of a configuration without a filter 70A.

[0087] The width W of each of the multiple holes 72A is preferably 40 mm or less, more preferably 10 mm to 40 mm, and even more preferably 10 mm to 30 mm. By keeping the width W within this range, the entry of solid objects large enough to damage the drain pipe 50 into the drain port 13 is effectively prevented. On the other hand, if the width W is too small, it becomes difficult to achieve both the mechanical strength of the filter 70A and proper drainage. Conversely, if the width W is too large, depending on the configuration of the drain pipe 50, damage to the drain pipe 50 by solid objects tends to occur more easily.

[0088] Even with the second embodiment described above, damage to the drain pipe 50 caused by solid matter can be reduced, even if the drain pipe 50 is made of inexpensive material. In this embodiment, as mentioned above, the filter 70A covers the support 60. Therefore, solid matter that should pass through the filter 70A is prevented from becoming trapped by the support 60.

[0089] 3. Variant Each of the above embodiments can be modified in various ways. Specific examples of modifications are given below. Two or more embodiments arbitrarily selected from the following examples can be combined as appropriate, provided they are not contradictory.

[0090] 3-1. Variation 1 Vessels equipped with exhaust gas treatment systems are not limited to those operating in the ocean, but may also be those operating in freshwater areas. In this case, a liquid obtained by adding a hydroxide such as sodium hydroxide or magnesium hydroxide to water drawn in from around the vessel may be used as an absorbent solution containing alkaline components. Furthermore, the liquid used for exhaust gas treatment is not limited to alkaline aqueous solutions, as long as it is capable of performing the desired treatment on the exhaust gas.

[0091] 3-2. Variation 2 The exhaust gas treatment system is not limited to being installed on a ship, but may also be installed in a factory or other facility, for example.

[0092] 3-3. Modified Example 3 The exhaust gas treatment device is not limited to a cyclone-type scrubber; for example, it may be a scrubber of a different type. For example, the extension of the inlet pipe 80 may intersect the central axis LC. [Explanation of Symbols]

[0093] 1... Exhaust gas treatment device, 1A... Exhaust gas treatment device, 10... Absorption tower, 11... Inlet, 12... Outlet, 13... Drain port, 20... Spray section, 20a... Spray section, 20b... Spray section, 20c... Spray section, 21... Main pipe, 22... Branch pipe, 23... Nozzle, 30... Liquid supply pipe, 30a... Liquid supply pipe, 30b... Liquid supply pipe, 30c... Liquid supply pipe, 40... Swirl, 50... Drain pipe, 60... Support, 61... Support member, 70... Filter, 70A... Filter, 71... Structure, 71_1... Structure, 71_2... Structure, 71a... First member, 71b... Second member, 71c... Mounting member, 72... Hole 72A...hole, 73...first structure, 73_1...first structure, 73a...top plate, 73a2...edge, 73b...side plate, 73c...protrusion, 73d...protrusion, 74...second structure, 74_1...second structure, 74a...side plate, 74a1...edge, 74b...protrusion, 74c...protrusion, 74c1...edge, 75...third structure, 75_1...third structure, 75a...top plate, 75b...protrusion, 75c...protrusion, 80...inlet pipe, C...arrow, D...arrow, E...arrow, FB...bottom, LC...central axis, S...space, W...width, WS...side wall, d1...gap, d2...gap, d3...gap.

Claims

1. A cylindrical absorption tower having an inlet for introducing exhaust gas and an outlet for discharging exhaust gas, A spray unit that sprays a liquid for treating exhaust gas into the absorption tower, A drain pipe for discharging the liquid sprayed from the spray section from the absorption tower, The absorption tower is equipped with a liquid supply pipe that penetrates the side wall and supplies liquid to the spray section, The spraying unit is Within the absorption tower, a main pipe extends from the liquid supply pipe along the central axis of the absorption tower, Within the absorption tower, there are a number of branch pipes extending from the main pipe toward the side wall of the absorption tower, The absorption tower has a plurality of nozzles, each of which is provided with at least one nozzle in each of the plurality of branch tubes, The exhaust gas introduced into the absorption tower from the aforementioned inlet flows toward the outlet while swirling around the central axis of the absorption tower. The bottom surface of the absorption tower is provided with a drain port that communicates with the drain pipe. Inside the absorption tower, a filter for capturing solid matter heading toward the drain port is positioned vertically below the inlet. The filter is joined to a support that is joined to the bottom surface of the absorption tower and to the main tube, and has multiple plate-like structures having multiple holes or gaps. Exhaust gas treatment device.

2. The total cross-sectional area of ​​the plurality of holes or the plurality of gaps is greater than the cross-sectional area of ​​the drain port. The exhaust gas treatment apparatus according to claim 1.

3. When the total cross-sectional area of ​​the plurality of holes or gaps is S1, and the cross-sectional area of ​​the drain port is S2, The relationship S1 / S2 ≥ 2 is satisfied. The exhaust gas treatment apparatus according to claim 2.

4. The width of each of the aforementioned multiple holes or gaps is 40 mm or less. The exhaust gas treatment apparatus according to claim 2 or 3.

5. A gap is provided between the filter and the bottom surface of the absorption tower. The exhaust gas treatment apparatus according to claim 1.

6. The plurality of structures are arranged in a divided manner via the support. The exhaust gas treatment apparatus according to claim 1.

7. The filter covers the support, The exhaust gas treatment apparatus according to claim 1.

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