KR20170120684A - Demister unit and egr system - Google Patents

Abstract

A demister unit and an EGR system are provided with a casing 51 having a hollow shape and having an inlet portion 61 and an outlet portion 62 of the exhaust gas and a casing 51 disposed in the casing 51 so as to be opposed to the inlet portion 61 Side flow path 63 formed in the casing 51 so as to form a curved upstream-side flow path 63 and a downstream-side flow path 63 in the casing 51, which is disposed downstream of the upstream-side flow path 63 in the flow direction of the exhaust gas, The demister main body 55 and the housing member 56 accommodating the droplets generated by the collision of the exhaust gas with the obstruction plate 52 are formed so that the mist removed from the fluid can be prevented from flowing back into the fluid, Thereby improving the efficiency.

Description

Demister Unit and EGR System {DEMISTER UNIT AND EGR SYSTEM}

The present invention relates to an EGR system in which mist is removed from exhaust gas, and an EGR system to which this demister unit is applied.

Since the exhaust gas discharged from the boiler through the wet-type exhaust gas treatment device contains mist, it is necessary to remove the mist contained in the exhaust gas. There is a demister or a mist eliminator for removing mist contained in the exhaust gas and is described in, for example, Patent Document 1 below. In the wet exhaust gas treatment device described in Patent Document 1, exhaust gas from a boiler is introduced into a dust-eliminating column by an inlet flue (a flue), and then the solids in the exhaust gas are removed. Thereafter, The mist is removed from the exhaust gas.

There is exhaust gas recirculation (EGR) to reduce NOx in the exhaust gas. In this EGR, a part of the exhaust gas discharged from the combustion chamber of the internal combustion engine is returned to the combustion chamber as a combustion gas. Therefore, the combustion gas is lowered in oxygen concentration, and the burning temperature is lowered by slowing the rate of combustion, which is the reaction between fuel and oxygen, and the amount of NOx generated can be reduced.

Japanese Patent Application Laid-Open No. 08-131764

In the above-described demister, the mist contained in the exhaust gas is removed by causing the exhaust gas introduced from the inlet to collide with the obstruction plate. At this time, the exhaust gas collides with the obstruction plate to remove the mist, and then passes under the obstruction plate. On the other hand, the mist contained in the exhaust gas becomes a droplet by collision with the obstruction plate, and drops downward through the obstruction plate. Therefore, when the exhaust gas from which the mist is removed passes under the obstruction plate, the exhaust gas draws the droplet falling through the obstruction plate, and the exhaust gas flows again into the mist to increase the amount of mist contained there is a problem.

It is an object of the present invention to provide a mist unit and an EGR system which are capable of suppressing the mist introduced into the fluid from flowing back into the fluid to improve the mist removing efficiency.

In order to achieve the above object, the present invention provides a demister unit comprising: a casing having a hollow shape and having an inlet and an outlet of a fluid; an obstruction plate disposed in the casing so as to face the inlet to form a curved passage; And a housing member which is disposed on the downstream side in the flow direction of the fluid in the casing with respect to the flow direction of the fluid so as to remove mist from the fluid and receives the droplet generated by the fluid colliding with the disturbance plate .

Therefore, the fluid introduced into the casing from the inlet portion collides with the obstruction plate, so that the mist contained therein becomes a droplet and attached to the obstruction plate. The droplet adhered to the obstruction plate flows down on the flat portion of the obstruction plate by its own weight and is accommodated in the accommodating member. On the other hand, the fluid from which a part of the mist is removed flows through the bending passage, the mist is further removed by the centrifugal force, and the mist remaining finally is removed by the demister main body. Here, since the droplet generated by colliding the fluid with the obstruction plate flows down through the plane portion of the obstruction plate by its own weight and is housed in the receiving member, there is no case that the fluid flowing through the bending channel again flows the droplet as mist, It is possible to prevent the removed mist from flowing back into the fluid, thereby improving the mist removing efficiency.

In the demister unit of the present invention, the receiving member is a receiving channel along the lateral direction of the obstruction plate.

Therefore, the droplet adhered to the obstruction plate flows through the plane portion of the obstruction plate by its own weight and is accommodated in the accommodating flow passage, and the accommodated droplet can be collected by the accommodating flow passage at a predetermined position.

In the demister unit of the present invention, the containing passage has a bottom portion and a side portion formed along the flow direction of the liquid droplet.

Therefore, by constructing the receiving channel with the bottom portion and the side portion, a large amount of droplets can be appropriately accommodated without flowing over from the receiving channel.

In the demister unit of the present invention, the receiving passage is formed to be inclined downward toward the inner wall surface of the casing.

Accordingly, the receiving flow path is inclined downward toward the inner wall surface of the casing, whereby the received liquid droplets can be appropriately flowed to the inner wall surface side of the casing by the receiving flow path and discharged.

In the demister unit of the present invention, the housing member is formed on a flat surface portion facing the inlet portion of the obstruction plate.

Therefore, the housing member is formed on the flat portion opposite to the inlet portion of the obstruction plate, so that the droplet generated by collision with the flat portion of the obstruction plate can be appropriately accommodated by the housing member.

In the demister unit of the present invention, the housing member is formed in a lower portion of the baffle plate in the vertical direction.

Therefore, the housing member is formed in the lower portion in the vertical direction of the obstruction plate, so that the droplet produced by colliding with the flat portion of the obstruction plate can be effectively accommodated by the receiving member in the lower portion of the obstruction plate.

In the demister unit of the present invention, a plurality of the accommodating members are formed in parallel in the vertical direction.

Therefore, by forming a plurality of the accommodating members in parallel in the vertical direction, it is possible to surely accommodate the droplets generated by colliding with the planar portion of the obstruction plate.

The demister unit of the present invention is characterized in that a drain member is formed to flow a droplet accommodated in the accommodating member to a lower portion of the casing.

Therefore, the droplet adhered to the obstruction plate flows down through the plane portion of the obstruction plate by its own weight and is accommodated in the accommodating member. The droplet accommodated by the accommodating member flows to the storage portion by the drain member, It is possible to prevent contact with the fluid flowing in the bending member.

In the demister unit of the present invention, the drainage passage is formed between the end of the housing member and the inner wall surface of the casing.

Therefore, by forming the drainage flow path in the vicinity of the inner wall surface of the casing, it is possible to prevent the generated droplets from contacting with the fluid flowing through the bending flow path, and to simplify the structure.

In the demister unit of the present invention, the drainage passage is a pipe portion communicating with the storage portion from the collection portion of the storage member.

Therefore, by making the drainage flow path from the collection part of the housing member to the piping part communicating with the storage part, the generated droplet is caused to flow to the storage part by the piping part, and the generated droplet and the fluid flowing in the bending flow path can be prevented from coming into contact with each other.

The EGR system of the present invention includes an exhaust gas recirculation line for recirculating a part of the exhaust gas discharged from the engine to the engine as a part of the combustion gas and an exhaust gas recirculation line for injecting water into the exhaust gas flowing through the exhaust gas recirculation line A scrubber for removing harmful substances, and a demister unit for introducing the exhaust gas discharged from the scrubber.

Therefore, when a part of the exhaust gas discharged from the engine passes through the exhaust gas recirculation line, water is sprayed on the exhaust gas flowing through the exhaust gas recirculation line by the scrubber to remove harmful substances, After the mist contained therein is removed, it is supplied to the engine. At this time, in the demister unit, the exhaust gas collides with the obstruction plate, and the mist contained therein becomes a droplet and is adhered to the obstruction plate, and the droplet flows down through the flat portion of the obstruction plate by its own weight and is accommodated in the accommodating member. Therefore, there is no case where the fluid flowing through the bending flow path again flows the liquid droplet as a mist, and the mist removed from the fluid can be restrained from flowing back into the fluid, thereby improving the mist removing efficiency.

According to the demister unit and the EGR system of the present invention, the mist removed from the fluid can be prevented from flowing back into the fluid, and the mist removal efficiency can be improved.

1 is a schematic view showing a diesel engine equipped with an EGR system to which a demister unit according to the first embodiment is applied.
2 is a schematic configuration diagram showing the EGR system of the first embodiment.
3 is a longitudinal sectional view showing the demister unit of the first embodiment.
4 is a cross-sectional view taken along the line IV-IV in Fig. 3 showing a horizontal section of the demister unit.
5 is a cross-sectional view taken along the line V-V of Fig. 3 showing the inlet of the demister unit;
6 is a cross-sectional view showing a receiving channel.
7A is a cross-sectional view showing a modified example of the receiving passage.
Fig. 7B is a cross-sectional view showing a modified example of the receiving passage.
7C is a cross-sectional view showing a modified example of the accommodation passage.
Fig. 7D is a cross-sectional view showing a modified example of the receiving passage. Fig.
8 is a longitudinal sectional view showing a modified example of the demister unit of the first embodiment.
9 is a longitudinal sectional view showing a modified example of the demister unit of the first embodiment.
10 is a longitudinal sectional view showing an inlet portion of the demister unit according to the second embodiment.
11 is a cross-sectional view showing a receiving channel.
12 is a longitudinal sectional view showing a modified example of the demister unit according to the second embodiment.
13 is a longitudinal sectional view showing an inlet portion of the demister unit according to the third embodiment.
14 is a longitudinal sectional view showing the demister unit of the fourth embodiment.
Fig. 15 is a longitudinal sectional view showing an inlet portion of the demister unit. Fig.

Hereinafter, preferred embodiments of a demister unit and an EGR system according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments, and when a plurality of embodiments are provided, the embodiments may be combined.

[First Embodiment]

Fig. 1 is a schematic view showing a diesel engine provided with an EGR system to which a demister unit according to the first embodiment is applied, and Fig. 2 is a schematic structural view showing an EGR system according to the first embodiment.

1, the marine diesel engine 10 is provided with an engine main body 11, a turbocharger 12, and an EGR system 13. The engine main body 11,

As shown in Fig. 2, the engine main body 11 is a propulsion engine (main engine), not shown, for propelling propelling propellers through a propeller shaft. The engine main body 11 is a diesel engine of a uniprojection type and is a two stroke diesel engine and has a structure in which the flow of the intake and exhaust in the cylinder is made one direction from the lower side to the upper side, . The engine main body 11 includes a plurality of cylinders (combustion chambers) 21 in which the pistons move up and down, a small trunk 22 communicating with the cylinders 21, and an exhaust manifold 23). A scavenging port 24 is formed between each cylinder 21 and the scavenging trunk 22 and an exhaust passage 25 is formed between each cylinder 21 and the exhaust manifold 23. [ The engine main body 11 is connected to a supply line G1 to the scavenging trunk 22 and to an exhaust line G2 to the exhaust port 23. [

The turbocharger 12 is configured such that the compressor 31 and the turbine 32 are integrally rotated by the rotary shaft 33. [ The turbocharger 32 is rotated by the exhaust gas discharged from the exhaust line G2 of the engine main body 11 and the rotation of the turbine 32 is transmitted by the rotary shaft 33 to the compressor 31 are rotated and the compressor 31 compresses the air and / or the recirculating gas and supplies the air and / or the recirculating gas to the engine body 11 from the air supply line G1. The compressor 31 is connected to a suction line G6 for sucking air from the outside (atmosphere).

The turbocharger 12 is connected to an exhaust line G3 for exhausting the exhaust gas that has rotated the turbine 32. The exhaust line G3 is connected to a chimney (funnel) not shown. An EGR system 13 is formed between the exhaust line G3 and the air supply line G1.

The EGR system 13 includes exhaust gas recirculation lines G4, G5 and G7, a scrubber 42, a demister unit 14 and an EGR blower (blower) 47. The EGR system 13 mixes a part of the exhaust gas discharged from the marine diesel engine 10 with air, compresses it by a supercharger, and recirculates it as a combustion gas to the marine diesel engine 10, Thereby suppressing the generation of NOx. Although a part of the exhaust gas is extracted from the downstream side of the turbine 32 in this example, a part of the exhaust gas may be added from the upstream side of the turbine 32.

The exhaust gas recirculation line G4 is connected at one end to the middle portion of the exhaust line G3. In the exhaust gas recirculation line G4, an EGR inlet valve (open / close valve) 41A is formed and the other end is connected to the scrubber 42. [ The EGR inlet valve 41A turns on and off the exhaust gas that is divided (branched) from the exhaust line G3 to the exhaust gas recirculation line G4 by opening and closing the exhaust gas recirculation line G4. The flow rate of the exhaust gas passing through the exhaust gas recirculation line G4 may be adjusted by using the EGR inlet valve as the flow rate regulating valve.

The scrubber 42 is a venturi type scrubber and has a hollow throat portion 43, a venturi portion 44 into which exhaust gas is introduced, and an enlarged portion 45 that is stepwise returned to the original flow rate . The scrubber 42 is provided with a water jetting section 46 for jetting water against the exhaust gas introduced into the venturi section 44. The scrubber 42 is connected to an exhaust gas recirculation line G5 for discharging exhaust gas from which harmful substances such as SOx and particulate matter PM are removed, and the waste water containing harmful substances. In the present embodiment, the venturi type is adopted as the scrubber, but the present invention is not limited to this configuration.

In the exhaust gas recirculation line G5, a demister unit 14 and an EGR blower 47 are formed.

The demister unit 14 separates the exhaust gas from the exhaust gas from which harmful substances have been removed by water injection. The demister unit 14 is provided with a drain circulation line W1 for circulating drainage water to the water spraying unit 46 of the scrubber 42. [ The drain circulation line W1 is formed with a holding tank 49 and a pump 50 for temporarily storing waste water.

The EGR blower 47 leads the exhaust gas in the scrubber 42 from the exhaust gas recirculation line G5 to the demister unit 14. [

The exhaust gas recirculation line G7 has one end connected to the EGR blower 47 and the other end connected to the compressor 31 via a mixer And is sent to the compressor 31. In the exhaust gas recirculation line G7, an EGR outlet valve (an opening / closing valve or a flow rate adjusting valve) 41B is formed. Air from the suction line G6 and exhaust gas from the exhaust gas recirculation line G7 (recirculating gas) are mixed in a mixer to produce a combustion gas. Further, the mixer may be formed separately from the siren, and the siren may be configured to add the function of mixing the exhaust gas and the air without separately forming the mixer. The turbocharger 12 can supply the combustion gas compressed by the compressor 31 from the air supply line G1 to the engine main body 11 and the air cooler 48 Respectively. The air cooler 48 cools the combustion gas by heat-exchanging the combustion gas that has been compressed by the compressor 31 and has reached a high temperature.

3 to 5, the above-described demister unit 14 includes a casing 51, a baffle plate 52, a perforated plate 53, a demister support plate 54, A male main body 55, and a housing member 56. Fig.

The casing (51) has a hollow rectangular shape and is configured as a container for forming an internal space. That is, the casing 51 is formed in a box shape by a top portion 51a, left and right side wall portions 51b and 51c, a bottom portion 51d, an upstream side wall portion 51e, and a downstream side wall portion 51f. The casing 51 is provided with an inlet portion 61 through which exhaust gas and waste water are introduced at an upper portion of one end portion (right end portion in Fig. 3), and an inlet portion 61 at the other end portion And an outlet portion 62 through which exhaust gas (fluid) is discharged is formed. The casing 51 is formed on the exhaust gas recycling line G5.

The obstruction plate 52 is disposed in the casing 51 along the vertical direction so as to face the inlet portion 61 to form the upstream side flow path 63 as a bending flow path. The upper surface of the obstruction plate 52 is fixed to the ceiling portion 51a of the casing 51 and fixed to the ceiling portion 51a of the casing 51. The left and right side portions of the obstruction plate 52 are fixed to the left and right sides of the casing 51 Side wall portions 51b and 51c, and an upstream-side flow path 63 is formed below the lower end portion.

In this case, the distance from the inlet portion 61 of the casing 51 to the plane portion 52a of the obstruction plate 52 is set to be equal to or smaller than the inner diameter of the inlet portion 61. Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 flows into the upstream side flow path 63 after colliding with the obstruction plate. That is, the exhaust gas introduced into the casing 51 from the inlet portion 61 flows downward in the vertical direction by the baffle plate, and then flows in the horizontal direction. The flow path area under the obstruction plate 52 is set larger than the flow path area when the flow path is introduced from the inlet portion 61 into the casing 51. Therefore, when the exhaust gas introduced into the casing 51 from the inlet portion 61 flows under the baffle plate 52, there is no case where the exhaust gas is reintegrated.

The perforated plate (53) is fixed horizontally in the casing (51). The perforated plate 53 is formed of a flat plate on which a plurality of through holes (not shown) are formed so as to allow exhaust gas and droplets to pass therethrough. The perforated plate 53 is horizontally arranged at a position above the bottom 51d of the casing 51 by a predetermined height and the outer periphery of the perforated plate 53 is formed in the side wall portions 51b and 51c of the casing 51 and the front and rear wall portions 51e and 51f so as to form a storage portion 64 between the perforated plate 53 and the bottom portion 51d. The reservoir portion 64 is formed with a drainage passage 64a at a lower portion thereof.

The demister support plate 54 is arranged horizontally above the perforated plate 53 by a predetermined height at the exit portion 62 than the baffle plate 52. [ The demister support plate 54 is formed of a flat plate through which exhaust gas or liquid droplets can not pass and is fixed in close contact with the rear wall portion 51f of the casing 51. The left and right side portions of the demister support plate 54 are fixed to the casing 51 And the other end is spaced apart from the obstruction plate 52 by a predetermined distance, and an upstream-side flow path 63 is formed at the other end. In this case, the lower end of the baffle plate 52 is positioned lower than the lower surface of the demister support plate 54 in the vertical direction.

The demister main body 55 is disposed in the casing 51 on the downstream side in the flow direction of the exhaust gas from the upstream side flow path 63 to remove mist from the exhaust gas. Although not shown, the demister main body 55 is formed with a plurality of bent passages through which exhaust gas can pass, and is formed as a plate-like body as a whole along the vertical direction. The demister main body 55 is provided on the other end portion of the demister support plate 54 and the upper end portion thereof is in close contact with the ceiling portion 51a of the casing 51, And is in close contact with the side wall portions 51b and 51c.

The demister main body 55 is arranged so as to face the obstruction plate 52. The demister main body 55 has an upstream side flow path 63 on the upstream side and a downstream side of the demister main body 55 on the downstream side And the flow path 65 is formed. That is, the upstream-side flow passage 63 is formed on the lower surface of the front wall portion 51e, the side wall portions 51b, 51c, the obstruction plate 52, the perforated plate 53, and the demister support plate 54 of the casing 51 And the downstream passage 65 is formed between the side wall portions 51b and 51c and the rear wall portion 51f of the casing 51 and the upper surface of the demister support plate 54. [ The exhaust gas introduced into the casing 51 from the inlet portion 61 passes through the upstream side flow path 63 and reaches the demister main body 55. After passing through the demister main body 55, Side flow path 65 and is discharged from the outlet portion 62. [

The housing member 56 accommodates a droplet generated by collision of the exhaust gas introduced into the casing 51 from the inlet portion 61 against the obstruction plate 52. [ The housing member 56 is formed on the flat surface portion 52a opposite to the inlet portion 61 of the obstruction plate 52. [ The housing member 56 is formed on the flat surface portion 52a of the baffle plate 52 so as to be positioned below the entrance portion 61 in the vertical direction.

The housing member 56 is formed on the flat surface portion 52a of the baffle plate 52 along the left and right direction and is constituted by two housing member bodies 66 and 67. The receiving member main body 66 extends from the intermediate position in the lateral direction on the flat surface portion 52a of the baffle plate 52 toward one side wall portion 51b, And extends from the intermediate position in the lateral direction on the flat surface portion 52a of the plate 52 toward the other side wall portion 51c. Each of the housing member main bodies 66 and 67 is inclined downward toward the side wall portions 51b and 51c of the casing 51. [

The housing member 56 (the housing member bodies 66 and 67) is composed of a bottom portion 68 and a side portion 69 formed along the flow direction of the liquid droplet, as shown in detail in Fig. The bottom portion 68 is fixed so as to be in horizontal contact with the flat portion 52a of the interference plate 52 so that the side portion 69 is perpendicular to the other side portion of the bottom portion 68 And they are fixed in close contact with each other. Therefore, the housing member 56 (the housing member main bodies 66 and 67) is formed into a coaxial section by the flat portion 52a, the bottom portion 68 and the side portion 69 of the baffle plate 52 The receiving passage 70 along the left and right direction of the obstruction plate 52 is formed.

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 The receiving member 56 can accommodate the droplet in the receiving passage 70. [0050]

Drainage passages 71 and 72 for discharging the liquid droplets accommodated in the receiving channel 70 of the housing member 56 to the reservoir portion 64 of the casing 51 are formed as shown in Figs. The housing member main bodies 66 and 67 extend from the central position of the inlet portion 61 in the left and right direction toward the left and right side wall portions 51b and 51c and have a front end portion and left and right side wall portions 51b, 51c, thereby forming the drainage passages 71, 72 therein. Therefore, the liquid contained in the receiving channel 70 of the housing member 56 flows downward in the inclined direction of the receiving channel 70, so that it can be flowed from the drain channels 71 and 72 to the holding portion 64 have.

As shown in Fig. 3, a downward plate 57 is formed below the demister main body 55. As shown in Fig. The underside plate 57 is formed of a flat plate through which exhaust gas or droplets can not pass and is fixed to the underside of the demister support plate 54 by being brought into close contact with the underside of the demister support plate 54 Respectively. The receiving plate 57 is arranged so that the flat portion thereof follows the edge of the demister supporting plate 54 in a stepwise manner. In this case, the lower end of the receiving plate 57 is located at the same position as the lower end of the obstruction plate 52 in the vertical direction, or at the upper position in the vertical direction. The exhaust gas flowing through the upstream side flow path 53 is guided from the area below the demister support plate 54 to the upstream side of the demister main body 55 by the water receiving plate 57.

In the above description, the housing member 56 (the housing member main bodies 66 and 67) is formed by the flat portion 52a, the bottom portion 68 and the side portion 69 of the baffle plate 52, And a receiving channel 70 that forms a section of a spiral phase. However, the present invention is not limited to this configuration. 7A to 7D are cross-sectional views showing modified examples of the accommodation channel.

As shown in Fig. 7A, the housing member 81 is constituted by a bottom portion 82 formed along the flow direction of the liquid droplet. One side of the bottom portion 82 is horizontally tightly fixed so as to be perpendicular to the flat portion 52a of the obstruction plate 52. The accommodating member 81 is formed with the receiving passage 83 along the lateral direction of the obstruction plate 52 by the planar portion 52a and the bottom portion 82 of the obstructing plate 52 . 7B, the housing member 84 is constituted by a bottom portion 85 formed along the flow direction of the liquid droplet. The bottom part 85 is fixed to the flat surface part 52a of the obstruction plate 52 at one side and is inclined upward from the horizontal direction at the other end part and the upper surface of the flat part 52a and the upper surface of the bottom part 85 The angle is set to a predetermined angle (acute angle). The accommodating member 84 is formed with the receiving passage 86 along the lateral direction of the obstruction plate 52 by the flat portion 52a and the bottom portion 85 of the obstruction plate 52 .

As shown in Fig. 7C, the housing member 87 is constituted by a curved bottom portion 88 formed along the flow direction of the liquid droplet. One side of the curved bottom portion 88 is tightly fixed to the flat portion 52a of the interference plate 52 so as to be perpendicular thereto and the other side portion is extended and projected so as to curve upward. Therefore, the receiving member 87 is formed by the flat surface portion 52a of the baffle plate 52 and the curved bottom portion 88 so that the receiving passage 89 along the lateral direction of the baffle plate 52 is formed do. 7 (d), the housing member 90 is constituted by the concave portion 91 formed along the flow direction of the liquid droplet. The concave portion 91 is formed by bending the baffle plate 52 and the receiving channel 92 along the left and right direction of the baffle plate 52 is formed by the concave portion 91. In this case, it is preferable to arrange the flat surface portion 52b below the concave portion 91 on the right side of the plane portion 52a above the concave portion 91, that is, on the inlet side (see Fig. 3) .

In the above description, the housing member 56 is composed of two housing member main bodies 66 and 67, and the housing member main bodies 66 and 67 are connected to the side wall portions 51b, 51c. However, the present invention is not limited to this configuration. 8 and 9 are longitudinal sectional views showing a modified example of the demister unit according to the first embodiment.

8, the housing member 101 accommodates a droplet generated by collision of the exhaust gas introduced into the casing 51 from the inlet portion 61 with the obstruction plate 52. As shown in Fig. The housing member 101 is formed on the flat surface portion 52a opposite to the inlet portion 61 of the baffle plate 52. [ The housing member 101 is formed on the flat surface portion 52a of the baffle plate 52 so as to be positioned below the inlet portion 61 in the vertical direction. The housing member 101 is formed on the flat surface portion 52a of the baffle plate 52 along the left and right direction and extends from one side wall portion 51b of the casing 51 to the other side wall portion 51c And is inclined downward toward the other side wall portion 51c.

A drainage flow path 102 is formed in the housing 51 for discharging the droplets received by the housing member 101 to the storage portion 64 of the casing 51. One end of the housing member 101 is in close contact with the side wall portion 51b of the casing 51 but a gap is formed between the other end portion and the side wall portion 51c and the drainage passage 102 is formed there.

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 The receiving member 101 can accommodate this droplet. Since the droplets contained in the housing member 101 flow downward in the inclined direction of the housing member 101, the droplets can flow from the drainage passage 102 to the storage portion 64.

9, the housing member 111 accommodates a droplet generated when the exhaust gas introduced into the casing 51 from the inlet portion 61 collides against the obstruction plate 52. As shown in Fig. The housing member 111 is formed on the flat surface portion 52a facing the inlet portion 61 of the baffle plate 52. [ The housing member 111 is formed on the flat surface portion 52a of the baffle plate 52 so as to be positioned below the inlet portion 61 in the vertical direction. The housing member 111 is composed of three housing member bodies 112, 113 and 114 and is formed on the flat surface portion 52a of the baffle plate 52 along the left and right direction. Each of the housing member bodies 112, 113, and 114 is offset in the left-right direction (horizontal direction) of the baffle plate 52 and spaced apart at a predetermined interval in the vertical direction, and partly overlapped in the vertical direction. Each of the housing member bodies 112, 113 and 114 is inclined downward from the one side wall portion 51b of the casing 51 toward the other side wall portion 51c.

A drain passage 115 is formed in the housing 51 for discharging the droplets received by the housing member 111 to the storage portion 64 of the casing 51. The housing member 111 is formed such that one end of the housing member main body 112 is in close contact with the side wall portion 51b of the casing 51 but a gap is formed between the other end portion of the housing member main body 114 and the side wall portion 51c And a drainage flow path 115 is formed therein.

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 The receiving member 111 can accommodate this droplet. That is, the liquid droplets flowing down the plane portion 52a of the obstruction plate 52 flow sequentially along with the receiving member main bodies 112, 113, and 114, 64).

Hereinafter, the operation of the EGR system of the first embodiment will be described. When the combustion air is supplied into the cylinder 21 from the scavenging trunk 22, the engine body 11 compresses the combustion air by the piston, and the fuel is spontaneously ignited by the injection of the high-temperature air, Burned. Then, the generated combustion gas is discharged as exhaust gas from the exhaust manifold 23 to the exhaust line G2. The exhaust gas discharged from the engine body 11 is discharged to the exhaust line G3 after rotating the turbine 32 in the turbocharger 12 and the EGR inlet valve 41A is closed , The entire amount is discharged from the exhaust line G3 to the outside.

On the other hand, when the EGR inlet valve 41A is opened, a part of the exhaust gas flows from the exhaust line G3 to the exhaust gas recirculation line G4. The exhaust gas flowing into the exhaust gas recirculation line (G4) is removed by the scrubber (42) to contain harmful substances such as SOx and sold-out. That is, when the exhaust gas passes through the venturi section 44 at a high speed, the scrubber 42 injects water from the water spraying section 46 to cool the exhaust gas by the water, Etc. are dropped together with water to remove them. Then, the water containing SOx, sold-out, etc. flows into the demister unit 14 together with the EGR gas.

The exhaust gas from which harmful substances have been removed by the scrubber 42 is discharged to the gas discharge line G5 and the scrubber cleansing water is separated by the demister unit 14, (12). This exhaust gas is mixed with the air sucked from the suction line G6 to be a combustion gas and compressed by the compressor 31 of the turbocharger 12 and then cooled in the air cooler 48, (G1) to the engine body (11).

Here, the processing by the demister unit 14 will be described. 3 to 5, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the flat surface portion 52a of the obstruction plate 52 on the front surface, And the contained mist is adhered to the flat surface portion 52a of the obstruction plate 52 as a droplet. Then, the droplet adhered to the flat surface portion 52a of the baffle plate 52 flows downward along the flat surface portion 52a by its own weight, and is accommodated in the accommodating member 56. The liquid contained in the housing member 56 is solid in the housing channel 70 and flows toward the side face portions 51b and 51c of the casing 51 by inclination of the housing member bodies 66 and 67. The droplets flowing to the respective side portions 51b and 51c of the casing 51 are discharged to the storage portion 64 through the respective drainage passages 71 and 72 and discharged to the outside by the drainage passage 64a .

On the other hand, the exhaust gas from which some of the mist is removed is separated by the planar portion 52a of the baffle 52 and the ceiling portion 51a, the side wall portions 51b, 51b, and the front wall portion 51e of the casing 51 And flows into the upstream-side flow path 63. As shown in Fig. The exhaust gas flowing into the upstream side flow path 63 flows horizontally by the perforated plate 53 and flows upward by the receiving plate 57 to reach the demister main body 55. At this time, the exhaust gas flowing through the upstream-side flow path 63 passes under the obstruction plate 52, but the droplet adhered to the obstruction plate 52 is received in the receiving member 56, , 72 to the storage portion 64, so that it does not fall into the upstream-side flow path 63. Therefore, the exhaust gas flowing through the upstream-side flow path 63 is suppressed from contacting with water, but the mist removed from the exhaust gas is prevented from flowing back into the exhaust gas. Further, the exhaust gas flows through the curved upstream-side flow path 63, whereby the mist is removed by the centrifugal force. Further, when the exhaust gas passes through the demister main body 55, the remaining mist coalesces to become a droplet, and falls to the storage portion 64. Thereafter, the exhaust gas from which the mist is removed passes through the downstream passage 65 and is discharged from the outlet portion 62.

As described above, the demister unit of the first embodiment includes the casing 51 having the hollow shape and having the inlet portion 61 and the outlet portion 62 of the exhaust gas, the inlet portion 61 in the casing 51, Side flow path 63 formed in the casing 51 so as to be opposed to the upstream side flow path 63 in the flow direction of the exhaust gas so as to flow from the exhaust gas The mist body 55 is formed to remove the mist and the housing member 56 for housing the droplet generated by collision of the exhaust gas with the obstruction plate 52 is formed.

Therefore, the droplet generated by collision of the exhaust gas with the obstruction plate 52 flows down through the plane portion 52a of the obstruction plate 52 by its own weight and is accommodated in the housing member 56, Is prevented from flowing back into the exhaust gas without introducing the droplet again as mist, and the mist removal efficiency can be improved as a result.

In the demister unit according to the first embodiment, the receiving channel 56 is provided with the receiving channel 70 along the left-right direction of the baffle plate 52. The droplet adhered to the obstruction plate 52 flows through the flat surface portion 52a of the obstruction plate 52 by its own weight and is received in the accommodation passage 70. The liquid drops received by the accommodation passage 70 It can be gathered at a predetermined point.

In the demister unit of the first embodiment, the bottom portion 68 and the side portion 69 are formed as the receiving flow path 56 along the flow direction of the liquid droplet. Therefore, it is possible to appropriately accommodate a large amount of droplets without overflowing from the accommodation channel 70.

The receiving channel 70 is inclined downward toward the side wall portions 51b and 51c of the casing 51 in the demister unit of the first embodiment. Therefore, it is possible to appropriately flow the accommodated droplets to the side wall portions 51b and 51c of the casing 51 along the inclined direction of the accommodation channel 70, and to discharge them.

In the demister unit of the first embodiment, the housing member 56 is formed on the flat surface portion 52a opposite to the inlet portion 61 of the obstruction plate 52. [ Therefore, the droplets generated by colliding with the flat surface portion 52a of the obstruction plate 52 can be properly accommodated by the accommodating member 56. [

The demister unit according to the first embodiment forms the drainage passages 71 and 72 for draining the droplets accommodated in the accommodation passage 70 to the lower portion 64 of the lower portion of the casing 51. The droplet adhered to the obstruction plate 52 flows down through the flat portion 52a of the obstruction plate 52 due to its own weight and is accommodated in the accommodation passage 70. The amount of the liquid contained in the accommodation passage 70, It flows to the storage portion 64 by the drainage flow paths 71 and 72 to appropriately drain the droplet so that the contact with the exhaust gas flowing through the upstream side flow path 63 can be suppressed.

The drainage passages 71 and 72 are formed between the end portion of the accommodation channel 70 and the side wall portions 51b and 51c of the casing 51 in the demister unit of the first embodiment. Therefore, by discharging the droplets along the side wall portions 51b, 51c of the casing 51, it is possible to suppress the contact between the generated droplet and the exhaust gas flowing through the upstream-side flow path 63, have.

In the EGR system of the first embodiment, an exhaust gas recirculation line G4 for recirculating a part of the exhaust gas discharged from the engine body 11 to the engine body as a part of the combustion gas, and an exhaust gas recirculation line The scrubber 42 for removing harmful substances by spraying water against the exhaust gas flowing through the scrubber 42 and the demister unit 14 for introducing the exhaust gas discharged from the scrubber 42 are formed.

Therefore, in the demister unit 14, the droplets generated by colliding the exhaust gas with the obstruction plate 52 flow down through the flat surface portion 52a of the obstruction plate 52 by their own weight and are accommodated in the accommodating member 56 Therefore, the exhaust gas flowing through the upstream-side flow path 63 is prevented from flowing back into the mist-based exhaust gas removed from the exhaust gas without introducing the droplet again as a mist. As a result, .

[Second Embodiment]

Fig. 10 is a vertical sectional view showing the inlet portion of the demister unit according to the second embodiment, Fig. 11 is a sectional view showing the receiving channel, and Fig. 12 is a vertical sectional view showing a modification of the demister unit according to the second embodiment. Members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

10, the demister unit 120 includes a casing 51, a baffle plate 52, a perforated plate 53, a demister support plate 54, A male main body 55, and a plurality of accommodating members 121, 122. The casing 51, the obstruction plate 52, the perforated plate 53, the demister support plate 54, and the demister main body 55 are the same as those in the first embodiment, and a description thereof will be omitted.

The accommodation flow paths 121 and 122 are formed in parallel (two in this embodiment) in the vertical direction. Each of the housing members 121 and 122 houses a droplet generated by collision of the exhaust gas introduced into the casing 51 from the inlet portion 61 against the obstruction plate 52. [ The housing members 121 and 122 are formed in a plane portion 52a opposite to the inlet portion 61 of the obstruction plate 52 and below the inlet portion 61 in the vertical direction.

Each of the receiving members 121 and 122 has substantially the same configuration as that of the receiving member 56 (see Fig. 5) of the first embodiment and extends from the center position in the left- 51b, and 51c, as well as the receiving member main bodies 123, 124, 125, and 126 that are inclined downward. 11, the receiving members 121 and 122 (the receiving member main bodies 123, 124, 125, and 126) are composed of a bottom portion and side portions formed along the flow direction of the liquid droplet, Receiving passages 127, 128 along the left-right direction of the seat portion 52 are formed. The amount of protrusion of the baffle plate 52 from the flat surface portion 52a of the receiving member 122 on the lower side is set larger than that of the receiving member 121 on the upper side. That is, the housing member 122 on the lower side largely protrudes toward the inlet portion 61 side than the housing member 121 on the upper side. 10, drainage passages 71 and 72 for discharging the liquid drops contained in the receiving passages 127 and 128 of the housing members 121 and 122 to the storage portion 64 of the casing 51 are formed .

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 It flows downward. At this time, the accommodating members 121 and 122 can accommodate the droplets in the accommodating flow paths 127 and 128. Since the droplets received by the receiving passages 127 and 128 of the receiving members 121 and 122 flow downward in the inclined direction of the receiving passages 127 and 128, 64).

In the above description, the housing members 121 and 122 are constituted by two housing member bodies 123, 124, 125 and 126, and the housing member bodies 123, 124, 125, and 126 And is inclined downward toward the side wall portions 51b and 51c of the casing 51, the present invention is not limited to this configuration.

As shown in Fig. 12, a plurality of (two in this embodiment) receiving channels 131 and 132 are formed in parallel in the vertical direction. Each of the housing members 131 and 132 accommodates the droplets generated by collision of the exhaust gas introduced into the casing 51 from the inlet portion 61 against the obstruction plate 52. The accommodating members 131 and 132 are formed as planar portions 52a opposed to the inlet portion 61 of the obstruction plate 52 and below the inlet portion 61 in the vertical direction. The housing members 131 and 132 are formed on the flat surface portion 52a of the baffle plate 52 in the left and right direction and extend from one side wall portion 51b of the casing 51 to the other side wall portion 51c And is formed to be inclined downward toward the other side wall portion 51c. A drainage flow path 102 is formed in the housing 51 to flow the droplets received by the housing members 131 and 132 to the storage portion 64 of the casing 51.

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 It flows downward. At this time, the accommodating members 131 and 132 can accommodate this droplet. Since the droplets received by the receiving members 131 and 132 flow downward in the oblique direction, they can flow from the drainage channel 102 to the storage unit 64. [

In this embodiment, even if the amount of protrusion from the flat portion 52a of the interference plate 52 in the upper housing member 121, 131 and the lower housing member 122, 132 is the same And the projecting amount of the lower receiving members 122 and 132 may be larger than the projecting amount of the upper receiving members 121 and 131. [ In addition, the number of the housing members is not limited to two but may be three or more.

Thus, in the demister unit according to the second embodiment, the accommodating members 121, 122 (131, 132) for accommodating the droplets generated by collision of the exhaust gas with the obstruction plate 52 are formed in a plurality .

Therefore, the droplets generated by the collision of the exhaust gas with the obstruction plate 52 flow down through the flat portion 52a of the obstruction plate 52 by their own weight and are accommodated in the accommodation members 121, 122 (131, 132) , The mist flowing through the upstream-side flow path 63 does not flow again into the mist as the mist, and the mist removed from the exhaust gas is prevented from flowing back into the exhaust gas. As a result, the mist removal efficiency is improved can do. A plurality of the accommodating members 121 and 122 (131 and 132) are arranged in parallel in the vertical direction so that the exhaust gas collides with the flat surface portion 52a of the obstruction plate 52 to securely accommodate droplets have.

[Third embodiment]

13 is a longitudinal sectional view showing an inlet portion of the demister unit according to the third embodiment. Members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

13, the demister unit 140 includes a casing 51, a baffle plate 52, a perforated plate 53, a demister support plate 54, A male main body 55, and a housing member 141. Fig. The casing 51, the obstruction plate 52, the perforated plate 53, the demister support plate 54, and the demister main body 55 are the same as those in the first embodiment, and a description thereof will be omitted.

The accommodating flow path 141 accommodates a droplet generated by collision of the exhaust gas introduced into the casing 51 from the inlet portion 61 against the obstruction plate 52. The housing member 141 is formed as a flat surface portion 52a facing the entrance portion 61 of the obstruction plate 52 and below the entrance portion 61 in the vertical direction.

Each housing member 141 is composed of a plurality of housing member main bodies 142, 143 inclined to have a V-shape. A collection portion 144 is formed in the lower connection portion of each of the housing member main bodies 142 and 143. That is, each of the housing member main bodies 142 and 143 is formed with a receiving passage, which is not shown, and the receiving passage is opened at the position of the collecting portion 144. A piping section 145 is formed below the collecting section 144 of the housing member 141 and serves as a drain passage through which the stored liquid droplets flow into the storage section 64 of the casing 51.

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 It flows downward. At this time, the receiving member 141 can receive the droplets by the respective receiving member main bodies 142 and 143. [ The liquid collected by each of the receiving member bodies 142 and 143 of the receiving member 141 flows downward in the oblique direction and is joined to each of the collecting portions 144, Through each piping section 145 to the storage section 64.

As described above, in the demister unit according to the third embodiment, the housing member 141 for housing the droplets generated by the collision of the exhaust gas with the obstruction plate 52 is formed, A piping section 145 is formed as a drain passage through which the enemy is discharged from the catch section 135 to the lower storage section 64 of the lower portion of the casing 51. [

The droplet adhered to the obstruction plate 52 flows down through the flat surface portion 52a of the obstruction plate 52 by its own weight and is accommodated in the accommodating member 141, It flows from the collecting portion 144 to the storage portion 64 through the piping portion 145 and drains the droplets appropriately to prevent contact with the exhaust gas flowing through the upstream side flow path 63. [ The droplet accommodated in the drainage channel 141 by the drainage channel 141 is formed into a piping section 145 communicating with the reservoir section 64 from the reservoir section 144, (64), and contact between the generated droplet and exhaust gas flowing through the upstream-side flow path (63) can be prevented.

[Fourth Embodiment]

FIG. 14 is a vertical sectional view showing a demister unit of the fourth embodiment, and FIG. 15 is a vertical sectional view showing an inlet unit of the demister unit. Members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

14 and 15, the demister unit 150 includes a casing 51, a baffle plate 52, a perforated plate 53, a demister support plate 54, A demister main body 55, and a housing member 151. As shown in Fig. The casing 51, the obstruction plate 52, the perforated plate 53, the demister support plate 54, and the demister main body 55 are the same as those in the first embodiment, and a description thereof will be omitted.

The receiving channel 151 receives a droplet generated by collision of the exhaust gas introduced into the casing 51 from the inlet 61 with the obstruction plate 52. The housing member 151 is formed in the lower portion of the baffle plate 52 in the vertical direction.

Each housing member 151 is composed of a bottom portion 152 and both side portions 153 and 154 formed along the flow direction of the liquid droplet. The bottom portion 152 is horizontally arranged so as to be orthogonal to the flat portion 52a below the baffle plate 52 and the both side portions 153 and 154 are arranged such that the lower end portion is orthogonal to each side of the bottom portion 152. [ So as to be vertically fixed. The receiving member 151 is formed by the bottom portion 152 and the both side portions 153 and 154 so as to form a receiving channel 155 along the left and right direction in the jamming plate 52, do. The bottom 152 of the housing member 151 is connected to the lower end of the obstruction plate 52 via the stay 156 so that the housing member 151 is disposed below the obstruction plate 52 do. The housing member 151 is formed with drainage passages 157 and 158 for discharging the droplets stored on the end side to the storage portion 64 of the casing 51. [

Therefore, the exhaust gas introduced into the casing 51 from the inlet portion 61 collides with the obstruction plate 52 to generate a liquid droplet. The liquid droplet passes through the flat portion 52a of the obstruction plate 52 It flows downward. At this time, the accommodating member 151 can accommodate a droplet that the receiving channel 155 flows down from the lower end of the obstructing plate 52. The droplets contained in the receiving channel 155 of the housing member 151 can be discharged from the drain channels 157 and 158 to the storing portion 64.

As described above, in the demister unit according to the fourth embodiment, the receiving member 151 for receiving the droplet generated by the collision of the exhaust gas with the obstruction plate 52 is formed below the baffle plate 52 in the vertical direction .

Therefore, the liquid droplets generated by the collision of the exhaust gas against the obstruction plate 52 flow down the planar portion 52a of the obstruction plate 52 by its own weight and are accommodated in the housing member 151, 63 do not introduce the liquid droplets again as mist, and the mist removed from the exhaust gas is prevented from flowing back into the exhaust gas, and as a result, the mist removal efficiency can be improved. In addition, since the housing member 151 is formed below the obstruction plate 52, the droplet can be effectively accommodated.

Although the housing member 151 is disposed below the obstruction plate 52 in the fourth embodiment, the accommodating member may be disposed below the flat surface portion 52a of the obstruction plate 52. [

In the above-described embodiment, the housing member is inclined in the first to third embodiments and the housing member is horizontal in the fourth embodiment. However, in the housing member of the present invention, Or may be partially inclined.

The shape of the casing 51 and the positions of the inlet portion 61 and the outlet portion 62 are not limited to the respective embodiments and the inlet portion 61 and the obstruction plate 52 ) Are opposed to each other. Further, although the disturbing plate 52 is disposed along the vertical direction, it may be inclined.

In the above-described embodiment, the marine diesel engine has been described using a main engine, but the invention is also applicable to a diesel engine used as a generator.

10: Marine diesel engine
11: Engine body
12: Supercharger
13: EGR system
14, 120, 140, 150: Demister Unit
41A: EGR inlet valve
41B: EGR outlet valve
42: Scrubber
47: EGR blower
48: Air cooler (cooler)
51: casing
52: interference plate
53: Perforated plate
54: Demister support
55: Demister body
56, 81, 84, 87, 90, 101, 111, 121, 122, 131, 132, 141, 151:
61:
62:
63: upstream side flow path
64:
65: downstream side flow path
66, 67, 112, 113, 114, 123, 124, 125, 126, 142, 143:
68, 82, 85, 152:
69, 153, 154: side
70, 83, 86, 89, 92, 127, 128, 155:
71, 72, 102, 115:
88: Curved bottom
91:
144: Housekeeper
145: Piping part (drainage flow path)
G4: Exhaust gas recirculation line
G5: Gas discharge line
G6: Suction line
G7: Exhaust gas supply line
W1: Drain circulation line

Claims (11)

A casing having a hollow shape and having an inlet portion and an outlet portion,
A baffle plate disposed in the casing so as to face the inlet, thereby forming a bending passage;
A mist body disposed on the downstream side in the flow direction of the fluid than the bending flow path in the casing to remove mist from the fluid,
And a receiving member for receiving the droplet generated by the fluid colliding with the disturbing plate. The method according to claim 1,
Wherein the receiving member is a receiving channel along the left-right direction of the baffle plate. 3. The method of claim 2,
Wherein the receiving passage has a bottom portion and a side portion formed along the flow direction of the liquid droplet. The method according to claim 2 or 3,
And the receiving channel is formed to be inclined downward toward the inner wall surface of the casing. 5. The method according to any one of claims 1 to 4,
And the receiving member is formed in a plane portion opposed to the inlet portion of the obstruction plate. 6. The method according to any one of claims 1 to 5,
And the receiving member is formed in a lower portion in the vertical direction of the baffle plate. 7. The method according to any one of claims 2 to 6,
Wherein the receiving members are formed in a plurality of parallel in the vertical direction. 8. The method according to any one of claims 2 to 7,
And a drainage passage through which the droplet received by the receiving member flows to the lower portion of the casing is formed. 9. The method of claim 8,
And said drainage passage is formed between an end of said housing member and an inner wall surface of said casing. 9. The method of claim 8,
Wherein the drainage passage is a pipe portion communicating with the storage portion from the collection portion of the housing member. An exhaust gas recirculation line for recirculating a part of the exhaust gas discharged from the engine to the engine as a part of the combustion gas;
A scrubber for removing harmful substances by spraying water against the exhaust gas flowing through the exhaust gas recirculation line,
The exhaust gas recirculation system according to any one of claims 1 to 10, wherein the exhaust gas discharged from the scrubber is introduced.

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