CN117398834A

CN117398834A - Exhaust gas treatment device

Info

Publication number: CN117398834A
Application number: CN202310791595.6A
Authority: CN
Inventors: 中川匡; 当山广幸
Original assignee: Fuji Electric Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2022-07-15
Filing date: 2023-06-30
Publication date: 2024-01-16
Also published as: JP2024011568A; KR20240010400A

Abstract

The invention provides an exhaust gas treatment device. The exhaust gas treatment device is provided with: a tubular reaction cylinder for the introduced exhaust gas to travel while rotating; and an injection unit that injects a liquid for treating the exhaust gas into the reaction cylinder. The injection unit is provided with: a dry pipe extending on the central axis of the reaction cylinder and supplied with a liquid; a plurality of branch pipes extending from the main pipe in a radial direction of the reaction cylinder; and a spraying unit provided in each of the plurality of branch pipes and spraying liquid in a direction of rotation of the exhaust gas. The position of the peak of the spray amount distribution of the liquid in the radial direction of the spray portion corresponds to the position of the peak of the flow velocity distribution in the radial direction of the exhaust gas.

Description

Exhaust gas treatment device

Technical Field

The present disclosure relates to an exhaust gas treatment device.

Background

Conventionally, there is known an exhaust gas treatment device in which an absorbent is brought into gas-liquid contact with an exhaust gas containing a harmful substance such as sulfur oxide to absorb the harmful substance, thereby removing the harmful substance from the exhaust gas. In addition, a cyclone type device is known as such an exhaust gas treatment device. The cyclone type exhaust gas treatment device is such that: the reactor includes a reaction tower having an inlet portion and an outlet portion for the exhaust gas, and the exhaust gas is spirally advanced while being rotated from the inlet portion toward the outlet portion in the reaction tower (see, for example, patent documents 1 and 2).

Prior art literature

Patent literature

Patent document 1: japanese patent No. 5999226

Patent document 2: japanese patent No. 6747552

Disclosure of Invention

Problems to be solved by the invention

In the cyclone type exhaust gas treatment device, an absorption liquid is sprayed to exhaust gas which advances in a spiral manner in the inside of a reaction tower, and thereby, harmful substances in the exhaust gas are absorbed by droplets of the absorption liquid. However, in the conventional cyclone type exhaust gas treatment device, the amount of spray of the absorbent is insufficient with respect to the flow velocity distribution of the exhaust gas, and there is room for improvement in the treatment performance of the exhaust gas.

In view of the above, the present disclosure aims to improve processing performance.

Solution for solving the problem

In order to solve the above problems, an exhaust gas treatment device according to an aspect of the present disclosure includes: a tubular reaction cylinder for the introduced exhaust gas to travel while rotating; and an injection unit that injects a liquid for treating the exhaust gas into the reaction cylinder, the injection unit including: a dry pipe extending on a central axis of the reaction cylinder and supplied with the liquid; a plurality of branch pipes extending from the main pipe in a radial direction of the reaction cylinder; and a spray unit provided in each of the plurality of branch pipes, for spraying the liquid in a direction of rotation of the exhaust gas, wherein a position of a peak of a spray amount distribution of the liquid in the radial direction of the spray unit corresponds to a position of a peak of a flow velocity distribution of the exhaust gas in the radial direction.

Drawings

Fig. 1 is a block diagram of a ship to which an exhaust gas treatment device according to embodiment 1 is applied.

Fig. 2 is a diagram schematically showing the internal structure of the exhaust gas treatment device.

Fig. 3 is an oriented view of line III-III of fig. 2.

Fig. 4 is an explanatory diagram of a flow velocity distribution of the exhaust gas flowing in the reaction cylinder.

Fig. 5 is a graph showing the relationship among the flow velocity distribution of the exhaust gas in the radial direction, the spray amount distribution of the absorbing liquid, and the residual concentration distribution of the harmful substance.

Fig. 6 is a diagram schematically showing the structure of the spraying unit according to embodiment 2.

Fig. 7 is an explanatory diagram of the configuration of the nozzle.

Description of the reference numerals

21. A reaction cylinder; 21S, inner wall surface; 30. a spraying part; 31. a dry pipe; 32. a branch pipe; 33. a spraying part; 34. a nozzle; 100. an exhaust gas treatment device; A. exhaust gas; C. a central axis; peak value of Qs and spray quantity distribution; rc, middle part; vs, peak of flow velocity distribution.

Detailed Description

The manner in which the present disclosure is practiced is described with reference to the accompanying drawings. Furthermore, there are cases where: in the drawings, the size and scale of each element are different from the actual product. In addition, the following description is an exemplary manner contemplated in the case of implementing the present disclosure. Accordingly, the scope of the present disclosure is not limited to the following exemplary manner.

1. Embodiment 1

Fig. 1 is a block diagram of a ship 200 to which an exhaust gas treatment device 100 according to embodiment 1 is applied. As shown in fig. 1, the ship 200 includes a power plant 11, a liquid feed pump 13, and an exhaust gas treatment device 100. In the following description, "upper" means upper in the vertical direction, and "lower" means lower in the vertical direction.

The power unit 11 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine or an external combustion engine including a boiler and a turbine. The power plant 11 generates propulsion of the ship 200 by burning fossil fuel such as heavy oil or coal. The power plant 11 discharges an exhaust gas a containing harmful substances such as nitrogen oxides and sulfur oxides. The hazardous material may also contain dust.

The exhaust gas treatment device 100 is a scrubber that reduces harmful substances in exhaust gas supplied from the power unit 11 through the exhaust pipe 12. The exhaust gas a treated by the exhaust gas treatment device 100 is discharged to an external space (for example, the atmosphere). In the ship 200, the power plant 11 and the exhaust gas treatment device 100 constitute an exhaust gas treatment system that purifies the exhaust gas a of the power plant 11.

The liquid feed pump 13 supplies a liquid (hereinafter referred to as "absorption liquid") that absorbs harmful substances contained in the exhaust gas a to the exhaust gas treatment device 100. Specifically, the liquid feed pump 13 supplies seawater around the ship 200 as an absorption liquid to the exhaust gas treatment device 100. For example, the alkali component (HCO) in seawater ₃ (-) absorbs the harmful substances contained in the exhaust gas a. The absorbent fed from the liquid feed pump 13 is supplied to the exhaust gas treatment device 100 via the liquid feed pipe 14.

Fig. 2 is a diagram schematically showing the internal structure of the exhaust gas treatment device 100. In fig. 2, the spray portion 33 and the nozzle 34, which will be described later, are not shown.

As shown in fig. 2, the exhaust gas treatment device 100 includes an absorption tower 20, an injection unit 30, a collection unit 40, and a waste liquid storage unit 50.

The absorption tower 20 is a cylindrical structure, and has a central axis C oriented in the vertical direction. The absorption tower 20 includes a reaction tube 21 provided below, a connection portion 22 connected to an upper end 21A of the reaction tube 21, and an exhaust tube 23 connected to an upper end 22A of the connection portion 22. The reaction tube 21, the connection portion 22, and the exhaust tube 23 are provided coaxially with the central axis C of the absorption tower 20. In the following description, the direction of the circumference of an imaginary circle having an arbitrary diameter centered on the central axis C is denoted as "circumferential direction", and the direction of the radius of the imaginary circle is denoted as "radial direction".

The reaction tube 21 is a cylindrical portion, and includes an exhaust gas introduction portion 210 connected to the exhaust pipe 12. The exhaust gas introduction portion 210 is provided in the reaction tube 21 near the lower end 21B. The connecting portion 22 is a truncated cone-shaped portion. The inner diameter of the upper end 22A of the connecting portion 22 is smaller than the inner diameter of the lower end 22B. The exhaust pipe 23 is a cylindrical portion having a diameter smaller than that of the reaction pipe 21. The exhaust port 230 from which the exhaust gas a is discharged opens at the upper end 23A of the exhaust pipe 23. The reaction cylinder 21, the connection portion 22, and the exhaust cylinder 23 may be integrally formed with each other or may be independently formed and connected to each other.

Fig. 3 is an oriented view of line III-III of fig. 2. Fig. 3 is a schematic diagram, and the sizes and scales of the respective elements may be different from those of an actual product.

As shown in fig. 3, the exhaust gas introduction portion 210 includes a through hole 212 formed in the peripheral surface of the reaction tube 21, and an introduction tube 216 extending outward from the through hole 212, and the exhaust pipe 12 is connected to the introduction tube 216. The introduction pipe 216 is joined to the reaction tube 21 so that the longitudinal direction Ea is offset from the central axis C (i.e., so as not to intersect). Therefore, the exhaust gas a flowing into the reaction tube 21 from the inlet tube 216 becomes a rotational flow as follows: along the inner wall surface 21S of the reaction tube 21, the reaction tube 21 travels in the circumferential direction and revolves around the central axis C. As a result, as shown in fig. 2, the exhaust gas a travels spirally toward the upper exhaust port 230 while rotating around the central axis C from the exhaust gas introduction portion 210 below the reaction cylinder 21. The scrubber that causes the exhaust gas a to advance in a spiral shape while rotating inside the reaction tube 21 is also commonly referred to as a cyclone scrubber.

The injection unit 30 injects the absorption liquid into the reaction cylinder 21. Specifically, as shown in fig. 2, the spray unit 30 includes a main pipe 31, a plurality of branch pipes 32, and a spray unit 33 (fig. 3) provided in each branch pipe 32.

The main pipe 31 is a tubular structure provided coaxially with the central axis C of the absorption tower 20, and extends from the lower end 21B, which is one end of the reaction tube 21, toward the upper end 21A, which is the other end. The plurality of branch pipes 32 are tubular members having a diameter smaller than that of the trunk pipe 31, and as shown in fig. 3, the plurality of branch pipes 32 extend radially from the peripheral surface of the trunk pipe 31 perpendicularly to the peripheral surface. In the present embodiment, the distal ends 32A of the branch pipes 32 are joined to the inner wall surface 21S of the reaction cylinder 21 by welding or the like. The distal end 32A of the branch pipe 32 may be a free end which is not joined to the inner wall surface 21S but forms a gap with the inner wall surface 21S.

As shown in fig. 3, the spraying portion 33 is provided in each of the plurality of branch pipes 32, and sprays (i.e., sprays) the absorption liquid in a mist form. The spraying section 33 includes a plurality of nozzles 34 for spraying the absorbing liquid.

In the exhaust gas treatment device 100, the absorbent fed from the liquid feed pump 13 (fig. 1) is supplied to the main pipe 31 via the liquid feed pipe 14 (fig. 1), and is supplied from the main pipe 31 to the plurality of branch pipes 32, respectively, and is sprayed from the nozzles 34 of the spraying unit 33. By spraying the absorbing liquid, the exhaust gas a and the absorbing liquid are in gas-liquid contact, and the harmful substances contained in the exhaust gas a are absorbed by the droplets of the absorbing liquid. In each of the branch pipes 32, the spraying portion 33 sprays the absorbent toward the direction of the flow of the revolving flow of the exhaust gas a. As a result, the mist of the absorbent is prevented from blocking the rotational flow of the exhaust gas a.

Most of the absorption liquid sprayed from the spraying portion 33 is spirally moved in the reaction cylinder 21 along with the exhaust gas a, and is adhered to the inner wall surface 21S of the reaction cylinder 21 to form a liquid film, thereby being recovered. On the other hand, a part of the absorbent reaches the exhaust pipe 23 together with the exhaust gas a. As shown in fig. 2, the trap unit 40 is disposed in the exhaust pipe 23, and includes a trap device that traps the absorption liquid that has reached the exhaust pipe 23. The trapping device may be, for example, a demister or a cyclone. The trap portion 40 traps the absorption liquid, and thus can prevent the absorption liquid from being discharged to the outside from the discharge port 230. In addition, such a situation can be prevented: the absorption liquid discharged to the outside is poured onto the ground (in this description, the deck of the ship 200).

The waste liquid storage unit 50 stores the absorption liquid collected by the collected unit 40 and the inner wall surface 21S of the reaction tube 21. Specifically, as shown in fig. 2, the waste liquid storage unit 50 includes a storage tank 500, and the storage tank 500 stores the collected absorbent. The storage tank 500 is disposed at a position lower than the reaction cylinder 21 in the vertical direction, and a drain pipe 502 extending from the bottom of the reaction cylinder 21 is connected thereto. The absorbent collected by the reaction tube 21 and the collecting unit 40 is guided to the storage tank 500 through the drain 502, and stored in the storage tank 500. The storage tank 500 is, for example, a gas-tight chamber. A drain pipe 503 is connected to the storage tank 500, and the absorption liquid stored in the storage tank 500 is drained to the outside (for example, sea in sea navigation) through the drain pipe 503.

The structure of the ejection portion 30 is further detailed.

Hereinafter, as shown in fig. 2, the length of the reaction tube 21 in the vertical direction from the lower end 21B to the upper end 21A is defined as a height H. The central axis of the reaction tube 21 in the present embodiment coincides with the central axis C of the absorption tower 20, and the same reference numerals as those of the central axis C of the absorption tower 20 are given to the central axis of the reaction tube 21. In the reaction tube 21 of the present embodiment, the direction of the height H is parallel to the central axis C.

In the direction of the height H of the reaction tube 21, a plurality of branch pipes 32 are provided at predetermined intervals α in the main pipe 31. As shown in fig. 3, the plurality of branch pipes 32 provided at the same height H are provided at equal intervals (at equal angles) around the central axis C of the reaction cylinder 21. Hereinafter, the plurality of branch pipes 32 provided at the same height H are collectively referred to as "branch pipe group 32U" (fig. 2). As shown in fig. 2, the branch pipe groups 32U are respectively provided in the following states: the reaction tube 21 is rotated by a predetermined angle (0 degrees < predetermined angle < 360 degrees) in the circumferential direction around the central axis C of the reaction tube 21 from below to above in the direction of the height H of the reaction tube 21. That is, in a plan view seen from the direction of the height H, the branch tube groups 32U are each configured to: the branch pipes 32 do not overlap each other between the other branch pipe groups 32U adjacent to each other up and down. By the arrangement of the branch pipe group 32U, the spiral flow of the exhaust gas a in the reaction tube 21 is suppressed from being unevenly disturbed by the branch pipes 32 of the injection unit 30. In addition, the number of the branch pipes 32 included in the branch pipe group 32U may be one. In the direction of the height H, the predetermined interval α may be constant or different. For example, the predetermined interval α may be smaller in the portion closer to the exhaust gas introduction portion 210 than in the portion closer to the upper end 21A, and the branch pipes 32 may be densely arranged in the portion closer to the exhaust gas introduction portion 210.

Fig. 4 is an explanatory diagram of a flow velocity distribution of the exhaust gas a flowing through the reaction cylinder 21.

Hereinafter, a plane perpendicular to the central axis C at a predetermined height position of the reaction cylinder 21 is defined as an observation plane P. In the present embodiment, the direction of the height H is parallel to the vertical direction, and therefore the observation plane P is a horizontal plane orthogonal to the vertical direction. In the radial direction of the reaction tube 21, the circumferential surface of the stem tube 31 located at the central axis C and the vicinity thereof are defined as the 1 st end Ra, the inner wall surface 21S of the reaction tube 21 and the vicinity thereof are defined as the 2 nd end Rb, and the intermediate portion Rc is defined between the 1 st end Ra and the 2 nd end Rb.

When the flow velocity distribution of the rotational flow of the exhaust gas a in the radial direction of the reaction tube 21 is observed, the flow velocity distribution becomes different in the observation plane P (that is, the flow velocity V is not necessarily the same) as shown in fig. 4. Specifically, the flow velocity distribution has a curve shape in which the maximum peak Vs is located at the intermediate portion Rc. That is, the flow velocity V of the exhaust gas becomes greater at the intermediate portion Rc than at the 1 st end portion Ra and the 2 nd end portion Rb. The tendency of the flow velocity distribution of the exhaust gas a is the same in any observation plane P at any height H of the reaction cylinder 21.

Therefore, if the spraying portion 33 sprays the absorbing liquid in a certain amount in the radial direction, the amount of the absorbing liquid required for absorbing the harmful substances becomes excessive or insufficient. Specifically, the absorbent is excessive at the 1 st end Ra and the 2 nd end Rb of the reaction tube 21, and insufficient at the intermediate portion Rc. Therefore, in order to suppress the excess and deficiency of the absorbing liquid in the radial direction, the spray portion 33 of each branch pipe 32 has a distribution of the amount of the absorbing liquid sprayed in the radial direction corresponding to the flow velocity distribution of the exhaust gas a in the radial direction. Specifically, the position of the peak Qs (fig. 5) of the spray amount distribution in the radial direction corresponds to the position of the peak Vs of the flow velocity distribution in the radial direction of the exhaust gas a.

Fig. 5 is a graph showing the relationship among the flow velocity distribution, spray amount distribution, and residual concentration distribution of the harmful substance in the radial exhaust gas a. In fig. 5, the pattern U1 shows a case where the spray amount distribution corresponds to the flow velocity distribution of the exhaust gas a. Specifically, in the spray amount distribution of the form U1, the peak Qs of the spray amount is located at the intermediate portion Rc in the radial direction corresponding to the position of the peak Vs of the flow velocity distribution of the exhaust gas a. The form U2 is a comparative example with respect to the form U1, and shows a case where the spray amount distribution is constant at all of the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc in the radial direction.

When the distribution of the residual concentrations of the harmful substances in the form U1 and the form U2 is compared, the residual concentration of the form U1 is reduced with respect to the residual concentration of the form U2 at the intermediate portion Rc in the radial direction. That is, as in the form U1, the position of the peak Qs of the spray amount distribution in the radial direction is arranged at a position (i.e., the intermediate portion Rc) corresponding to the peak Vs of the flow velocity distribution of the exhaust gas a. With this arrangement, the amount of absorption of the harmful substance at the peak Vs of the flow velocity distribution is increased, and the shortage of the absorbent is suppressed at the position of the peak Vs of the flow velocity distribution.

The 1 st spray amount Q1 in the form U2 is set based on the total flow rate of the exhaust gas a flowing in the range from the 1 st end Ra to the 2 nd end Rb. Specifically, the 1 st spray amount Q1 is set to a spray amount corresponding to the following value or a spray amount corresponding to the value: this value is obtained by averaging the total amount of the absorbent required to obtain a predetermined treatment capacity (purification capacity in the present embodiment) for the total content of the harmful substances contained in the total flow rate of the exhaust gas a, with the length from the 1 st end Ra to the 2 nd end Rb.

On the other hand, in the form U1, the 2 nd spray amount Q2 at the 1 st end Ra and the 3 rd spray amount Q3 at the 2 nd end Rb are set to be smaller than the 1 st spray amount Q1 of the form U2. By this setting, excessive spraying of the absorbent liquid is suppressed at the 1 st end Ra and the 2 nd end Rb.

In the form U1, the 4 th spray amount Q4 of the form U1 is set to be larger than the 1 st spray amount Q1 of the form U2 with the total value of the reduction amount of the absorbent at the 1 st end Ra and the reduction amount of the absorbent at the 2 nd end Rb as the upper limit. The amount of the absorption liquid at the 1 st end Ra is equivalent to the "1 st spray amount Q1-2 nd spray amount Q2", and the amount of the absorption liquid at the 2 nd end Rb is equivalent to the "1 st spray amount Q1-3 rd spray amount Q3". By this setting, the total spray amount of form U1 in the range from 1 st end Ra to 2 nd end Rb is at least equal to or less than the total spray amount of form U2. Therefore, the utilization efficiency of the absorbent in the form U1 is improved as compared with the form U2.

Next, a specific configuration for obtaining the spray amount distribution shown in the form U1 of fig. 5 will be described.

As described above, the injection unit 30 has the plurality of branch pipes 32 extending in the radial direction from the main pipe 31, the spray unit 33 is provided in each branch pipe 32, and the spray unit 33 has the plurality of nozzles 34 for spraying the absorbent toward the direction of the flow of the revolving flow of the exhaust gas a. As shown in fig. 3, each of the branch pipes 32 is provided with 1 nozzle 34 at each of the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc. Further, by balancing the spray amounts of the absorbent in the respective nozzles 34, a spray amount distribution corresponding to the flow velocity distribution of the exhaust gas a is realized. Specifically, in the spraying section 33, the nozzle 34 of the intermediate section Rc among the nozzles 34 sprays the absorption liquid mainly toward the position of the peak Qs of the spray amount distribution, and the nozzle 34 of the 1 st end Ra and the nozzle 34 of the 2 nd end Rb spray the absorption liquid mainly toward the positions other than the position of the peak Qs. The spray amount of the nozzle 34 at the intermediate portion Rc is larger than the spray amounts of the 1 st end Ra and the 2 nd end Rb. The spraying amounts of the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc are equal to the 2 nd spraying amount Q2, the 3 rd spraying amount Q3, and the 4 th spraying amount Q4 described in the above-described form U1. Accordingly, in each branch pipe 32, as shown in the form U1 of fig. 5, a spray amount distribution having a peak Qs of the spray amount at the intermediate portion Rc in the radial direction corresponding to the peak Vs of the flow velocity distribution of the exhaust gas a is obtained.

The number of nozzles 34 at each of the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc is not limited to 1, but may be two or more, as long as the spray amounts at each of the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc are maintained at the 2 nd spray amount Q2, the 3 rd spray amount Q3, and the 4 th spray amount Q4. The number of nozzles 34 may be different between the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc. Further, nozzles 34 having different amounts of spray may be combined at the 1 st end Ra, the 2 nd end Rb, and the intermediate portion Rc.

As described above, the exhaust gas treatment device 100 includes: a tubular reaction cylinder 21 in which the introduced exhaust gas a travels while rotating; and an injection unit 30 that injects an absorption liquid for treating the exhaust gas a into the reaction cylinder 21. The injection unit 30 includes: a dry pipe 31 extending on the central axis C of the reaction tube 21 and supplied with the absorption liquid; a plurality of branch pipes 32 extending from the main pipe 31 in the radial direction of the reaction cylinder 21; and a spraying unit 33 provided in each of the plurality of branch pipes 32 and spraying the absorbent toward the direction of rotation of the exhaust gas a. The position of the peak Qs of the spray amount distribution of the absorbent in the radial direction of the spray portion 33 corresponds to the position of the peak Vs of the flow velocity distribution in the radial direction of the exhaust gas a. The position of the peak Qs of the spray amount distribution of the absorbent corresponds to the position of the peak Vs of the flow velocity distribution in the radial direction of the exhaust gas a, whereby the amount of absorption of the harmful substances at the peak Vs of the flow velocity distribution increases, and the shortage of the absorbent is suppressed at the position of the peak Vs of the flow velocity distribution of the exhaust gas a. As a result, the treatment performance of the exhaust gas a can be improved.

The peak value Qs of the spray amount distribution of the absorbent in the radial direction of the spray portion 33 is located at the intermediate portion Rc between the 1 st end Ra in the vicinity of the dry pipe 31 and the 2 nd end Rb in the vicinity of the inner wall surface 21S of the reaction tube 21. When the peak Vs of the flow velocity distribution of the exhaust gas a is located at the intermediate portion Rc, the shortage of the absorbent at the intermediate portion Rc is appropriately suppressed.

In addition, in the spray amount distribution of the absorbent in the radial direction of the spray portion 33, the 2 nd spray amount Q2 at the 1 st end Ra and the 3 rd spray amount Q3 at the 2 nd end Rb are smaller than the amount obtained by averaging the total amount of the absorbent required for the treatment of the exhaust gas a flowing between the dry pipe 31 and the inner wall surface 21S of the reaction cylinder 21 with the length from the dry pipe 31 to the inner wall surface 21S of the reaction cylinder 21. As a result, excessive spraying of the absorbent is suppressed at the 1 st end Ra and the 2 nd end Rb, and the utilization efficiency of the absorbent is improved.

The spraying section 33 includes a plurality of nozzles 34 for spraying the absorbing liquid. Among the plurality of nozzles 34, the spray amount of the nozzle 34 spraying the absorption liquid mainly toward the position of the peak Qs of the spray amount distribution of the absorption liquid is larger than the spray amount of the other nozzles 34 spraying the absorption liquid mainly toward the position other than the peak Qs of the spray amount distribution of the absorption liquid. By balancing the spray amounts of the plurality of nozzles 34, a spray amount distribution corresponding to the flow velocity distribution of the exhaust gas a can be easily achieved.

2. Embodiment 2

Fig. 6 is a diagram schematically showing the structure of spray unit 33 according to embodiment 2.

In embodiment 1, the following structure is described: in order to obtain the spray amount distribution of the absorbent shown in the form U1 of fig. 5, the spray portion 33 includes the nozzles 34 at the 1 st end Ra, the intermediate portion Rc, and the 2 nd end Rb, respectively, and the spray amount of the nozzles 34 at the intermediate portion Rc is larger than the spray amount of the 1 st end Ra and the 2 nd end Rb, respectively.

As shown in fig. 6, the spray unit 33 of the present embodiment is the same as the spray unit 33 of embodiment 1 in that a plurality of nozzles 34 are provided, but differs in the following points: in the longitudinal direction of the branch pipe 32, the nozzles 34 are densely arranged at the intermediate portion Rc, compared with the 1 st end portion Ra and the 2 nd end portion Rb. Specifically, as shown in fig. 7, the nozzles 34 located at the 1 st end Ra are disposed at a distance β from the intermediate portion Rc, and thus the nozzles 34 are densely disposed at the intermediate portion Rc. With this arrangement, the spray amount at the intermediate portion Rc increases, and the spray amount distribution having the peak Qs of the spray amount at the intermediate portion Rc is obtained.

According to the spray unit 33 of the present embodiment, the spray amount distribution corresponding to the flow velocity distribution of the exhaust gas a can be easily realized by adjusting the arrangement of the nozzles 34 in the longitudinal direction of the branch pipe 32.

In addition, in the spraying portion 33 of embodiment 2, the amount of the spray from each nozzle 34 may be the same or different. When the injection amounts of the respective nozzles 34 are different, the arrangement of the respective nozzles 34 is adjusted so as to be a spray amount distribution corresponding to the flow velocity distribution of the exhaust gas a.

3. Modification examples

The following exemplifies a mode of adding specific modifications to the modes already exemplified above. Two or more modes arbitrarily selected from the following examples may be appropriately combined within a range not contradictory to each other.

(1) In embodiment 1 and embodiment 2, the case where the peak value Vs of the flow velocity distribution in the radial direction of the exhaust gas a is located at the intermediate portion Rc is described. However, when the peak Vs is located at the 1 st end Ra or the 2 nd end Rb due to some main reasons such as the structure of the spraying portion 30 and the installation posture of the reaction tube 21, the position of the peak Qs of the distribution of the amount of the absorption liquid sprayed in the radial direction of the spraying portion 33 is also located at the 1 st end Ra or the 2 nd end Rb. In the case where the position of the peak Vs of the flow velocity distribution in the direction of the height H of the reaction tube 21 is different depending on the height H, the position of the peak Qs of the spray amount distribution is also different depending on the height H. In addition, when the flow velocity distribution in the radial direction of the exhaust gas a has a plurality of peaks Vs, the spray amount distribution also has peaks Qs at positions corresponding to the positions of the plurality of peaks Vs.

(2) In embodiment 1 and embodiment 2, an exhaust gas treatment device 100 in which seawater is used for the absorption liquid is illustrated. However, in the exhaust gas treatment device 100, the liquid used for the treatment of the exhaust gas a is not limited to seawater. Specifically, any of sea water, an amine solution, an aqueous alkali solution, and an aqueous acidic solution may be used for the liquid according to the treatment object contained in the exhaust gas a. For example, in the case where the treatment target is carbon dioxide, an amine solution may be used as the liquid. In addition, for example, when the object to be treated is hydrogen chloride, an aqueous alkali solution or an aqueous acidic solution may be used as the liquid.

(3) In embodiment 1 and embodiment 2, a case where the exhaust gas treatment device 100 is provided in the ship 200 is illustrated. However, the installation site is not limited to the ship 200. The installation site may be, for example, a factory.

Claims

1. An exhaust gas treatment device, wherein,

the exhaust gas treatment device is provided with:

a tubular reaction cylinder for the introduced exhaust gas to travel while rotating; and

an injection unit that injects a liquid for treating the exhaust gas into the reaction cylinder,

the injection unit includes:

a dry pipe extending on a central axis of the reaction cylinder and supplied with the liquid;

a plurality of branch pipes extending from the main pipe in a radial direction of the reaction cylinder; and

a spraying portion provided in each of the plurality of branch pipes, for spraying the liquid in a direction of rotation of the exhaust gas,

the position of the peak of the spray amount distribution of the liquid in the radial direction of the spray portion corresponds to the position of the peak of the flow velocity distribution in the radial direction of the exhaust gas.

2. The exhaust gas treatment device according to claim 1, wherein,

the peak of the spray amount distribution in the radial direction of the spray portion is located in an intermediate portion between the dry pipe and the inner wall surface of the reaction cylinder.

3. The exhaust gas treatment device according to claim 2, wherein,

in the distribution of the amount of the spray,

the amount of spray in the vicinity of the dry pipe and the amount of spray in the vicinity of the inner wall surface of the reaction cylinder are smaller than the amount obtained by averaging the total amount of liquid required for the treatment of the exhaust gas flowing between the dry pipe and the inner wall surface of the reaction cylinder with the length from the dry pipe to the inner wall surface of the reaction cylinder.

4. The exhaust gas treatment device according to claim 1, wherein,

the spraying part is provided with a plurality of nozzles for spraying the liquid,

among the plurality of nozzles, the spray amount of the nozzle that sprays the liquid mainly toward the position of the peak of the spray amount distribution is larger than the spray amount of the other nozzles that spray the liquid mainly toward the position other than the peak of the spray amount distribution.

5. The exhaust gas treatment device according to claim 1, wherein,

the nozzles are densely arranged in the longitudinal direction of each of the plurality of branch pipes at positions corresponding to the positions of the peaks of the spray distribution, compared to other positions.

6. The exhaust gas treatment device according to claim 1, wherein,

the liquid may be any of seawater, an amine solution, an aqueous alkali solution, and an aqueous acidic solution, depending on the object to be treated contained in the exhaust gas.