Dosing valve

Abstract

An invention is disclosed regarding a dosing valve for micro-flow control of an SCR system for a marine diesel engine. The disclosed dosing valve for micro-flow control of an SCR system for a marine diesel engine is characterized by comprising: a body forming an inlet opening to one side and an outlet opening to the other side, and forming an installation hole portion that is open to the outside while connecting the inlet and the outlet; a seat portion that is seated on a stepped portion formed at a set position of the installation hole portion and forms a through hole portion corresponding to the installation hole portion; a stem that is axially inserted into the installation hole portion and moves axially by an external force to control the fluid flowing from the inlet to the outlet by opening and closing the through hole portion; and a coupling portion that detachably connects the seat portion to the body.

Description

Technology Field

[0001] The present invention relates to a dosing valve for micro-flow control in an SCR system for a marine diesel engine, and more specifically, to a dosing valve for precise control injection of a reducing agent and urea in an SCR system for reducing NOx in a marine diesel engine. To achieve precise micro-seal setting, the seat portion is positioned correctly on the body and then firmly fixed to the body using a plug; the maintainability of the seat portion and plug is enhanced through a structure that allows the seat portion and plug to be separated from the body; and a guide sleeve is applied to the bonnet coupled to the upper side of the body to guide the reciprocating axial movement of the stem, thereby preventing eccentricity of the stem's center axis that interrupts the transfer of urea solution when a guide sleeve is placed on the upper side of the seat portion. Background Technology

[0002] Recently, international environmental pollution regulations have been significantly strengthened, and new conventions regulating the emission of air pollutants from ships are being enacted and adopted. At the 62nd Marine Environment Protection Committee (MEPC) in July 2011, the International Maritime Organization (IMO) amended Annex IV of the Convention on the Prevention of Marine Pollution (MARPOL IV) to introduce stringent Tier III regulations on nitrogen oxide (NOx) emissions, which entered into force on January 1, 2016. Consequently, newly constructed ships are now required to be equipped with flue gas denitrification systems in their engines to operate within Emission Control Areas (ECAs). Therefore, flue gas denitrification systems are becoming indispensable for ships.

[0003] In particular, since diesel engines operate under very lean fuel conditions with a high air-to-fuel ratio, they emit very little gaseous hydrocarbons and carbon monoxide. On the other hand, diesel engines emit relatively large amounts of nitrogen oxides (NOx) and particulate matter.

[0004] The emitted particulates are multiphase substances consisting of solid insoluble carbon soot particles, liquid hydrocarbons in the form of lubricating oil and non-combustion fuels, soluble organic fractions (SOF), or so-called "sulfates" of the form SO3 + H2O = H2SO4.

[0005] Both NOx and particulate matter are difficult-to-reduce diesel exhaust components, and recently, emission standards in the United States and Europe (EURO V regulations) have been set requiring a reduction of at least 50%, preferably 70-90%.

[0006] Currently, many technologies such as DPF, SCR, LNT, and LNC are being developed to purify exhaust gases harmful to the human body. Among these, SCR (Selective Catalytic Reduction) technology has proven to be highly successful in reducing NOx under lean exhaust conditions.

[0007] A conventional reducing agent dosing system comprises a reducing agent tank module filled with a reducing agent, a dosing valve that guides the precise control injection of urea solution, a dosing unit that mixes the reducing agent and air supplied through the tank module and the dosing valve, a nozzle that injects the reducing agent and air mixed through the dosing unit into a catalytic converter, and a controller that controls the ratio and injection amount of the reducing agent and air mixed through the dosing unit.

[0008] Related technologies include Korean registered patent No. 10-1195148 (Title of invention: System for reducing harmful substances in exhaust gas and a ship including the same, Registration date: 2012.10.29.) and Korean registered patent No. 10-1345118 (Title of invention: Method for manufacturing titanium oxide nanotubes by anodic oxidation in an aqueous electrolyte, Registration date: 2013.12.26.).

[0009] The technical configuration described above is provided as background technology to aid in understanding the present invention and does not constitute prior art widely known in the technical field to which the present invention belongs. The problem to be solved

[0010] In existing reducing agent dosing systems, the dosing valve is equipped for precise control of urea injection; however, there is a problem in that precision control failure occurs because the eccentricity of the seat inside the body is caused by the flow pressure of the urea entering the body.

[0011] Therefore, there is a need to improve this.

[0012] The present invention has been devised to improve upon the aforementioned problems, and aims to provide a dosing valve for micro-flow control of an SCR system for a marine diesel engine, which is used for the precise control injection of a reducing agent and urea in an SCR system for reducing NOx in marine diesel engines. This is achieved by positioning the seat portion correctly on the body and using a plug to firmly fix the seat portion to the body for precise fine-tightness setting, and by providing a structure in which the seat portion and the plug are separable from the body to increase maintainability of the seat portion and the plug.

[0013] The present invention aims to provide a dosing valve for micro-flow control of an SCR system for a marine diesel engine, which prevents the eccentricity of the stem's center axis that controls the transfer of urea solution by applying a guide sleeve to a bonnet coupled to the upper side of the body to guide the reciprocating axial movement of the stem, thereby preventing the eccentricity of the stem's center axis that controls the transfer of urea solution by placing a guide sleeve on the upper side of the seat portion. means of solving the problem

[0014] A dosing valve for micro-flow control of an SCR system for a marine diesel engine according to the present invention comprises: a body forming an inlet opening to one side and an outlet opening to the other side, and forming an installation hole portion that is open to the outside while connecting the inlet and the outlet; a seat portion that is seated on a stepped portion formed at a set position of the installation hole portion and forms a through hole portion corresponding to the installation hole portion; a stem that is axially inserted into the installation hole portion and moves axially by an external force to control the fluid flowing from the inlet to the outlet by opening and closing the through hole portion; and a coupling portion that detachably connects the seat portion to the body.

[0015] A dosing valve for micro-flow control of an SCR system for a marine diesel engine according to the present invention comprises: an eccentricity prevention member provided on the inner side of the body to prevent eccentricity of the central axis of the stem relative to the central axis of the installation hole portion due to the fluid flow pressure.

[0016] The above coupling portion includes: an expansion space portion that is extended and formed in a corresponding area of ​​the installation hole portion of the body to mount the seat portion; and a plug that is fixedly installed in the expansion space portion while stacked on the seat portion, forms a communication hole portion that guides the shaft insertion and axial movement of the stem, and forms a channel corresponding to the outlet to be connected to the communication hole portion.

[0017] The above body is characterized by having opening holes formed on both sides that are aligned in a straight line with the above installation hole, thereby detachably connecting a bonnet into which the above stem is inserted.

[0018] It includes a guide sleeve provided on the inner side of the above-mentioned eccentricity prevention part and the above-mentioned opening hole part, which guides the stem to reciprocate in the axial direction while maintaining its central axis. Effects of the invention

[0019] As explained above, unlike the prior art, the dosing valve for micro-flow control of an SCR system for a marine diesel engine according to the present invention is a dosing valve for precise control injection of a reducing agent and urea in an SCR system that reduces NOx to reduce nitrogen oxides (NOx) in a marine diesel engine. To achieve precise micro-tightness, the seat portion is seated in the correct position on the body and then a plug is used to firmly fix the seat portion to the body. Additionally, the maintainability of the seat portion and the plug can be increased through a structure in which the seat portion and the plug are separable from the body.

[0020] The present invention can prevent the eccentricity of the stem's center axis, which controls the transfer of urea solution, by applying a guide sleeve to the bonnet coupled to the upper side of the body to guide the reciprocating axial movement of the stem, thereby placing the guide sleeve on the upper side of the seat portion. Brief explanation of the drawing

[0021] FIG. 1 is a cross-sectional view showing the closed state of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention. FIG. 2 is a cross-sectional view showing the open state of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention. FIG. 3 is an exploded view of a key part of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention. FIG. 4 is an enlarged view of a key part showing the closed operation of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention. FIG. 5 is an enlarged view of a key part showing the open operation of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, an embodiment of a dosing valve for micro-flow control of an SCR system for a marine diesel engine according to the present invention will be described with reference to the attached drawings. In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of explanation. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intention or convention of the user or operator. Therefore, the definitions of these terms should be based on the content throughout this specification.

[0023] FIG. 1 is a cross-sectional view showing the closed state of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the open state of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention.

[0024] FIG. 3 is an exploded view of a key part of a dosing valve for micro-flow control of an SCR system for a marine diesel engine according to one embodiment of the present invention.

[0025] FIG. 4 is an enlarged view of a key part showing the closing operation of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention, and FIG. 5 is an enlarged view of a key part showing the opening operation of a dosing valve for microflow control of an SCR system for a marine diesel engine according to one embodiment of the present invention.

[0026] Referring to FIGS. 1 to 5, a dosing valve (100) for micro-flow control of an SCR system for a marine diesel engine according to one embodiment of the present invention includes a body (110), a seat portion (120), a stem (130), a bonnet (140), a housing (150), an actuator (160), a coupling portion (170), and an eccentricity prevention portion (180).

[0027] The dosing valve (100) according to the present invention can be applied to various fields, such as for a ship's diesel engine, and plays a role in controlling the flow of fluid, particularly urea solution.

[0028] In detail, the body (110) forms the main outer shape of the dosing valve (100) according to the present invention and forms an inlet (112) that is opened to one side, particularly to one side circumferential surface, and an outlet (114) that is opened to the other side, particularly to the other side circumferential surface.

[0029] In addition, the body (110) forms an installation hole (116) that is open to the outside, particularly to the upper side, while connecting the inlet (112) and the outlet (114). Thus, fluid passes through the body (110) in a set amount through the inlet (112), the installation hole (116), and the outlet (114), or the transfer is interrupted.

[0030] Of course, the body (110) can be applied in various shapes and various materials.

[0031] At this time, the body (110) may have the inlet (112) and the outlet (114) arranged in a straight line, or they may be arranged offset from each other with respect to the straight line.

[0032] Then, the seat portion (120) is seated on a stepped portion (118) formed at a set position of the installation hole portion (116) and externally fixed. In addition, the seat portion (120) forms a through hole portion (122) corresponding to the installation hole portion (116). At this time, the center line of the installation hole portion (116) and the center line of the through hole portion (122) are aligned.

[0033] Of course, the seat portion (120) can be made of various materials having various shapes and rigidities.

[0034] Additionally, the stem (130) is axially inserted into the installation hole (116) and moves axially by an external force to open and close the through hole (122). Thus, the stem (130) directly controls the fluid flowing from the inlet (112) to the outlet (114).

[0035] And, the hood (140) is detachably connected to one side, particularly the upper side, of the body (110) by a fastening member (144). At this time, the hood (140) is formed with an opening hole (142) that is connected in a straight line with the installation hole (116) and is open on both sides.

[0036] Thus, the stem (130) moves back and forth along the axial direction while being supported in contact with the bonnet (140) and the seat portion (120). Of course, the bonnet (140) can be made of various materials having various shapes and rigidities.

[0037] In particular, the stem (130) may include a main shaft (132), a sub-shaft (134), and an axle pin (136).

[0038] The main shaft (132), sub-shaft (134), and shaft diameter pin (136) are formed with a cross-sectional shape corresponding to the circular installation hole (116) and the through hole (122).

[0039] And, the diameter (a) of the main shaft (132) is formed to be larger than the diameter (b) of the sub-shaft (134), and the diameter (b) of the sub-shaft (134) is formed to be larger than the diameter of the shaft pin (136)(c). (a>b>c)

[0040] In addition, the diameter of the main shaft (132) is made to be the same or similar in size to the inner diameter of the opening hole (142) of the bonnet (140), so that the main shaft (132) is supported by the bonnet (140) and stably guided to move in a straight line.

[0041] The subshaft (134) and the shaft pin (136) serve to block the through hole (122) of the seat portion (120) when the dosing valve (100) is in a closed state.

[0042] At this time, the diameter (b) of the subshaft (134) and the diameter (b) of the through hole portion (122) are made to be the same or nearly similar, so that when the dosing valve (100) is set to be blocked, the subshaft (134) comes into full contact with the inner surface of the through hole portion (122) in the circumferential direction, thereby blocking the through hole portion (122) of the seat portion (120).

[0043] In this case, the main shaft (132) and sub-shaft (134), having different diameters, are connected by an inclined surface (135). When the sub-shaft (134) blocks the inner side of the through-hole portion (122), the inclined surface (135) is in contact with the upper side of the seat portion (120) along the corresponding side of the seat portion (120), particularly along the edge of the through-hole portion (122). Thus, the sealing force of the through-hole portion (122) of the seat portion (120) is increased by the inclined surface (135) of the stem (130).

[0044] And, when the dosing valve (100) is set to open, the stem (130) moves in a predetermined direction (upward direction) along the axial direction, so that the subshaft (134) is positioned outside the through hole portion (122), and the shaft pin (136) with a diameter (c) smaller than the diameter (b) of the through hole portion (122) is positioned inside the through hole portion (122), so that the through hole portion (122) becomes open. Accordingly, the fluid is guided to be transferred through the inlet (112) and the through hole portion (122) to the outlet (114).

[0045] At this time, when the dosing valve (100) is set to open, the shaft pin (136) is maintained in a position inside the through hole (122) of the seat portion (120), so that when the stem (130) moves toward the seat portion (120) along the axial direction, the subshaft (134) can stably enter the through hole (122). Of course, the shaft pin (136) can be formed in various shapes.

[0046] In addition, the stem (130), particularly the main shaft (132), is inserted into the opening hole (142) and a portion of it protrudes to the outside of the bonnet (140).

[0047] And, the hood (140) is detachably connected to the housing (150) on the other side by a fastening member (144). The housing (150) can be applied in various shapes and various materials.

[0048] The housing (150) inserts the corresponding portion that protrudes outward from the hood (140). At this time, the housing (150) is provided with a holder (156) in the internal space (154).

[0049] At this time, the stem (130), particularly the main shaft (132), forms a flange (133) at the other end, i.e., the upper end, and the holder (156) receives the flange (133) and sets the allowable movement distance of the flange (133). Thus, the stem (130) reciprocates along the axial direction by the set distance. Of course, the holder (156) can be modified into various shapes and may be made of a proximity sensor, etc.

[0050] In addition, the housing (150) may be provided with an actuator (160) connected to the other side either integrally or detachably. The actuator (160) is connected to the flange (133) of the stem (130), that is, the main shaft (132), and serves to move the flange (133) in one direction and the other. At this time, the actuator (160) serves to reciprocate the stem (130) in the axial direction and can be applied in various ways, and the configuration connected to the flange (133) can be applied in various ways and is not illustrated in detail.

[0051] The hood (140) can be detachably coupled to the housing (150) by a fastening member (144) with a portion of the other side inserted into the internal space (154) through one side of the housing (150).

[0052] In particular, the bonnet (140) is provided with a packing member (146) on the inner surface of the opening hole (142). The packing member (146) maintains contact with the entire circumferential surface in the circumferential direction of the main shaft (132) of the stem (130) that reciprocates in the axial direction.

[0053] Therefore, the fluid flowing in through the inlet (112) of the body (110) is not leaked to the outside of the body (110) through the installation hole (116) by the packing member (146).

[0054] Meanwhile, the connecting part (170) is provided to detachably connect the sheet part (120) to the body (110).

[0055] In addition, the eccentricity prevention part (180) is provided on the inner side of the body (110) to prevent eccentricity of the central axis of the stem (130) relative to the central axis of the installation hole part (116) due to fluid flow pressure.

[0056] More specifically, the connecting part (170) may include an expansion space part (172) and a plug (174).

[0057] The expansion space (172) is formed by expanding the corresponding area of ​​the installation hole (116) of the body (110) to mount the seat portion (120). At this time, the center lines of the installation hole portion (116) and the expansion space portion (172) are made to be the same, and the bottom surface of the expansion space portion (172), which has a diameter larger than the diameter of the installation hole portion (116), becomes a stepped portion (118) on which the seat portion (120) can be seated.

[0058] In addition, the expansion space (172) is formed to be open toward the upper side of the body (110) to facilitate mounting of the seat portion (120) and the plug (174).

[0059] The plug (174) is fixedly installed in the expansion space (172) while stacked on the seat portion (120), and forms a communication hole portion (175) that guides the axial insertion and axial movement of the stem (130).

[0060] At this time, the seat portion (120) forms a first ledge portion (124) along the outer circumferential surface, and the plug (174) forms a second ledge portion (177) in the circumferential direction on the inner surface of the communication hole portion (175). Additionally, when the plug (174) is laminated to the seat portion (120), the first ledge portion (124) and the second ledge portion (177) come into contact. Furthermore, the plug (174) may be detachably connected to the seat portion (120) by a bolt, or may be fixed by being forcibly fitted onto the inner surface of the expansion space portion (172). Accordingly, the seat portion (120) maintains a fixed position at a set location of the body (110).

[0061] In addition, the plug (174) is formed to connect a channel (176) corresponding to the outlet (114) to the communication hole (175).

[0062] In particular, the plug (174) forms one or more channels (176) open along the circumference, and each channel (176) is formed to be connected to a communication hole (175). As the fluid discharged through the channels (176) is temporarily stored in the expansion space (172), it is stably guided to be discharged to the outside of the body (110) through the outlet (114).

[0063] Thus, the fluid is transferred to the outlet (114) through the inlet (112), installation hole (116), penetration hole (122), communication hole (175), and channel (176).

[0064] Of course, the plug (174) can be deformed into various shapes and can be made of various materials that have rigidity.

[0065] Additionally, the eccentricity prevention part (180) may include a guide sleeve (182).

[0066] The guide sleeve (182) is provided on the inner side of the opening hole (142) of the hood (140). At this time, when the hood (140) is combined with the body (110), the guide sleeve (182) comes into contact with the plug (174).

[0067] At this time, as the body (110) is firmly connected to the hood (140) by the fastening member (144), the guide sleeve (182) presses the plug (174) toward the seat portion (120) over a relatively wide surface area, thereby keeping the seat portion (120) in a fixed position while being secured by the plug (174).

[0068] In particular, as the guide sleeve (182) maintains contact with the entire circumferential surface of the main shaft (132) of the stem (130) together with the plug (174), the stem (130) is guided to reciprocate in the axial direction while maintaining its central axis.

[0069] That is, the plug (174) and the guide sleeve (182) are positioned on the upper and lower sides in the axial direction of the stem (130) to guide the linear reciprocating movement of the stem (130), thereby preventing the stem (130) from becoming eccentric due to fluid flow pressure with respect to the central axis of the installation hole (116) and the opening hole (142).

[0070] At this time, the guide sleeve (182) is mounted in the opening hole (142) so as to be exposed to one side of the hood (140), and the guide sleeve (182) forms an expanded surface area (184), and the expanded surface area (184) is exposed to the outside of the hood (140).

[0071] Thus, when the hood (140) is joined to the body (110), the expanded contact portion (184) of the guide sleeve (182) comes into contact with the plug (174). As a result, leakage of fluid through the gap between the expanded contact portion (184) and the plug (174) is prevented to the maximum extent.

[0072] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom.

[0073] Therefore, the true technical scope of protection of the present invention should be determined by the claims below. Explanation of the symbols

[0074] 100: Dosing valve 110: Body 112: Inlet 114: Outlet 116: Installation hole 118: Step ledge 120: Seat section 122: Through-hole section 124: First jaw 130: Stem 132: Main shaft 133: Flange 134: Subshaft 135: Inclined surface 136: Shaft pin 140: Hood 142: Opening hole 150: Housing 160: Actuator 170: Connection part 172: Expansion space section 174: Plug 175: Chimney hole 176: Channel 177: Second jaw section 180: Eccentricity prevention section 182: Guide Sleeve 184: Extended Interview Section

Claims

Claim 1 A body forming an inlet opening to one side and an outlet opening to the other side, and forming an installation hole portion that is open to the outside while connecting the inlet and the outlet; a seat portion that is seated on a stepped portion formed at a set position of the installation hole portion and forms a through hole portion corresponding to the installation hole portion; a stem that is axially inserted into the installation hole portion and moves axially by an external force to control fluid flowing from the inlet to the outlet by opening and closing the through hole portion; and a coupling portion that detachably connects the seat portion to the body, wherein the stem comprises: a main shaft; and a sub-shaft having a diameter smaller than that of the main shaft and having a diameter equal to or similar to that of the through hole portion, and which contacts the inner surface of the through hole portion in a circumferential direction in a closed state. A dosing valve for micro-flow control of an SCR system for a marine diesel engine, characterized by including a shaft diameter pin having a smaller diameter than the subshaft and located on the inner side of the through hole portion in the open state, wherein the main shaft and the subshaft are connected by an inclined surface, and in the closed state, the inclined surface is formed to contact the upper side of the seat portion along the edge of the through hole portion. Claim 2 A dosing valve for micro-flow control of an SCR system for a marine diesel engine, characterized in that, in claim 1, it includes an eccentricity prevention member provided on the inner side of the body to prevent eccentricity of the central axis of the stem relative to the central axis of the installation hole portion due to the fluid flow pressure. Claim 3 A dosing valve for micro-flow control of an SCR system for a marine diesel engine according to claim 1, wherein the coupling portion comprises: an expansion space portion formed by expanding in a corresponding area of ​​the installation hole portion of the body to mount the seat portion; and a plug that is fixedly installed in the expansion space portion while stacked on the seat portion, forms a communication hole portion that guides the axial insertion and axial movement of the stem, and forms a channel corresponding to the outlet to be connected to the communication hole portion. Claim 4 A dosing valve for micro-flow control of an SCR system for a marine diesel engine, characterized in that, in claim 2, the body has an opening hole formed open on both sides that is aligned with the installation hole, thereby detachably connecting a bonnet into which the stem is axially inserted, and includes an eccentricity prevention part and a guide sleeve provided on the inner side of the opening hole part, which guides the stem to reciprocate in the axial direction while maintaining a central axis.

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