Water treatment equipment

Abstract

The present invention provides a water treatment device that can select whether to discharge washing water used for washing exhaust gas from a ship internal combustion engine to the outside of the ship. The water treatment device of one embodiment of the present invention treats washing water containing foreign matter removed by washing exhaust gas from a ship internal combustion engine, and comprises: a foreign matter removal system that separates washing water into residue containing foreign matter and washing waste water and removes foreign matter from washing water, a storage tank that stores residue and washing waste water, a washing waste water discharge pipe for discharging washing waste water, a first drain pipe and a second drain pipe, and a drainage path branch valve that branches the washing waste water discharge pipe into the first drain pipe and the second drain pipe. When the ship internal combustion engine is operated by alternative fuel, the drainage path branch valve connects the washing waste water discharge pipe with the first drain pipe connected to the outside of the ship, and when the ship internal combustion engine is operated by fossil fuel, the drainage path branch valve connects the washing waste water discharge pipe with the second drain pipe connected to the storage tank.

Description

Technical Field

[0001] The present invention relates to a water treatment device for treating washing water of exhaust gas of a marine internal combustion engine mounted on a ship. Background Art

[0002] Conventionally, in the field of ships, an exhaust gas cleaning device (scrubber) for cleaning exhaust gas discharged from a ship internal combustion engine is well known. Generally, a scrubber sprays cleaning water on the exhaust gas to remove foreign matter such as sulfur oxides and particulate matter (PM) such as coal dust in the exhaust gas, thereby cleaning the exhaust gas. Such a scrubber is provided in an exhaust gas recirculation (EGR) system, for example, which is a method for reducing nitrogen oxides in the exhaust gas.

[0003] The EGR system cleans part of the exhaust gas discharged from the marine internal combustion engine through a scrubber, mixes the cleaned exhaust gas with fresh air (newly taken in air) and recirculates it to the marine internal combustion engine. Thus, the EGR system suppresses the generation of nitrogen oxides caused by the combustion of fuel in the combustion chamber of the marine internal combustion engine, and reduces the content of nitrogen oxides in the exhaust gas (i.e., the emission of nitrogen oxides).

[0004] On the other hand, water used for washing exhaust gas in a scrubber (hereinafter referred to as washing water) is generally subjected to treatment such as removal of foreign matter after washing the exhaust gas and is used again for washing the exhaust gas. Therefore, a water treatment device for removing foreign matter from washing water is applied to the scrubber (for example, see Patent Document 1).

[0005] In the water treatment device, foreign matter is removed from the washing water by, for example, using a centrifuge or a filter, and the washing water is separated from the foreign matter. The washing water after the foreign matter is removed is used again for cleaning the exhaust gas. However, even the washing water after the foreign matter is removed, washing water that is divided into the object of drainage will be produced according to its properties. Even after the foreign matter is removed, foreign matter from the exhaust gas of the ship internal combustion engine that has not been removed cleanly may remain in the washing water of such a drainage object. In particular, in the case where the ship internal combustion engine is a fossil fuel-only internal combustion engine that burns fossil fuels such as diesel fuel to operate, foreign matter containing a large amount of carbon components such as coal and oil that has not been removed cleanly will remain in the washing water of the drainage object. As a method for disposing of the washing water, it can be considered to discharge it from the ship to the sea (dumping it in the sea). However, in order to dump the washing water in the sea, it is necessary to reduce the amount of carbon components contained in the washing water as the object of drainage to the standard for dumping in the sea (hereinafter referred to as the discharge standard). The washing water containing foreign matter containing a large amount of carbon components as described above exceeds the discharge standard, so it cannot be dumped in the sea. Therefore, the wash water that cannot be dumped at sea is temporarily stored in a tank on board the ship and unloaded and disposed of (for example, disposed of as industrial waste) at an appropriate time.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-118903

[0009] Technical problem to be solved by the invention

[0010] In recent years, in the field of ships, in order to reduce the emission of greenhouse gases (GHG: Greenhouse Gas), ship internal combustion engines (ship internal combustion engines corresponding to alternative fuels) that can use alternative fuels instead of fossil fuels have been continuously developed. The alternative fuel mentioned here is, for example, a decarbonized fuel that does not contain carbon components, such as ammonia or hydrogen. In the ship internal combustion engine corresponding to the alternative fuel, for example, there is the following situation: since fossil fuels and alternative fuels are burned together (mixed combustion), the content of carbon components in the exhaust gas is less than that of the ship internal combustion engine that burns only fossil fuels, and the exhaust gas contains almost no foreign matter containing carbon components. In this case, since the washing water after cleaning the exhaust gas contains almost no foreign matter containing carbon, according to the discharge standard, the washing water of the discharge object does not need to be temporarily stored in a tank inside the ship and can be discarded at sea.

[0011] However, in the above-mentioned conventional water treatment apparatus, even if the wash water contains almost no carbonaceous foreign matter, it is not possible to dump the wash water into the sea, but the wash water to be discharged has to be temporarily stored in a tank inside the ship, as in the case of a fossil fuel-only marine internal combustion engine. Summary of the invention

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a water treatment device that can select whether to discharge wash water to be discharged overboard for washing exhaust gas from a marine internal combustion engine.

[0013] Technical means for solving technical problems

[0014] In order to solve the above-mentioned technical problems and achieve the purpose, the water treatment device of the present invention is used for cleaning the exhaust gas discharged from the internal combustion engine of the ship, and treats the washing water containing the foreign matter removed from the exhaust gas, and comprises: a foreign matter removal system, which separates the washing water into a residue containing the foreign matter and a washing wastewater containing less foreign matter than the residue, thereby removing the foreign matter from the washing water; a storage tank, which stores the residue and the washing wastewater; a washing wastewater discharge pipe, which is used to discharge the washing wastewater from the foreign matter removal system; a first drain pipe, which is used to discharge the washing wastewater to the outside of the ship; and a second drain pipe. a water pipe, the second drain pipe is used to discharge the washing waste water into the storage tank; and a drain branch valve, the drain branch valve branches the washing waste water discharge pipe to the first drain pipe and the second drain pipe, and connects the washing waste water discharge pipe to the first drain pipe or the second drain pipe selectively, when the ship's internal combustion engine is operating with an alternative fuel that at least burns a decarbonized fuel, the drain branch valve connects the washing waste water discharge pipe with the first drain pipe, and when the ship's internal combustion engine is operating with a fossil fuel that burns a fossil fuel, the drain branch valve connects the washing waste water discharge pipe with the second drain pipe.

[0015] In addition, the water treatment device of the present invention in the above invention comprises: a residue discharge pipe, which is used to discharge the residue from the foreign matter removal system; a first residue pipe, which is used to discharge the residue to the outside of the ship; a second residue pipe, which is used to discharge the residue to the storage tank; and a residue path branch valve, which branches the residue discharge pipe to the first residue pipe and the second residue pipe, and connects the residue discharge pipe to the first residue pipe or the second residue pipe selectively, and when the ship's internal combustion engine is operating with the alternative fuel, the residue path branch valve connects the residue discharge pipe with the first residue pipe, and when the ship's internal combustion engine is operating with the fossil fuel, the residue path branch valve connects the residue discharge pipe with the second residue pipe.

[0016] In addition, the water treatment device of the present invention in the above invention also includes a control device, which determines whether the operation mode of the ship internal combustion engine is the alternative fuel operation or the fossil fuel operation. In the case of the alternative fuel operation, the control device controls the opening of the drainage path branch valve in such a way that the washing wastewater discharge pipe is connected to the first drain pipe. In the case of the fossil fuel operation, the control device controls the opening of the drainage path branch valve in such a way that the washing wastewater discharge pipe is connected to the second drain pipe.

[0017] In addition, the water treatment device of the present invention in the above invention also includes a control device, which determines whether the operation mode of the ship internal combustion engine is the alternative fuel operation or the fossil fuel operation. In the case of the alternative fuel operation, the control device controls the opening of the residue path branch valve in a manner that connects the residue discharge pipe with the first residue pipe. In the case of the fossil fuel operation, the control device controls the opening of the residue path branch valve in a manner that connects the residue discharge pipe with the second residue pipe.

[0018] Effects of the Invention

[0019] According to the present invention, it is possible to select whether to discharge washing water to be discharged overboard for washing exhaust gas from a marine internal combustion engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram showing a configuration example of a water treatment device according to Embodiment 1 of the present invention.

[0021] Figure 2 This is a flowchart illustrating a control procedure of the flow of washing water in the water treatment device according to Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram showing a configuration example of a water treatment device according to Embodiment 2 of the present invention.

[0023] Figure 4 This is a flowchart illustrating a control procedure of the flow of residues in the water treatment apparatus according to Embodiment 2 of the present invention.

[0024] Explanation of symbols

[0025] 1 Collection tank

[0026] 2 Circulatory system

[0027] 3 Foreign matter removal system

[0028] 4 Hydrometer

[0029] 5 Branch valve

[0030] 6 Washing waste water discharge pipe

[0031] 7. First Drain

[0032] 8 Second drain pipe

[0033] 9 Drainage branch valve

[0034] 10. 10A water treatment device

[0035] 11.11B residue discharge pipe

[0036] 12. First residue pipe

[0037] 13 Second residue pipe

[0038] 14 Residue line branch valve

[0039] 15 Waste slag tank

[0040] 16 Clean water supply department

[0041] 17 pH adjustment unit

[0042] 18. Level detection unit

[0043] 19.19A control device

[0044] 21 Circulation pipe

[0045] 22 Circulation pump

[0046] 31 Branch pipe

[0047] 32 outlet pipe

[0048] 33 Confluence pipe

[0049] 34 Centrifuge

[0050] 100 EGR system

[0051] 101 Scrubber

[0052] 101a Injection unit

[0053] 102 Defogger

[0054] 103 EGR Blower

[0055] 104 Recovery tube

[0056] 105 Pump

[0057] 110 Internal combustion engines for ships

[0058] Ls Liquid level DETAILED DESCRIPTION

[0059] Hereinafter, with reference to the drawings, a preferred embodiment of the water treatment device of the present invention is described in detail. In addition, this embodiment does not limit the present invention. In addition, the drawings are schematic, and it is necessary to note that the relationship between the dimensions of the elements, the proportion of the elements, etc. may be different from the actual. The drawings may contain parts with different dimensional relationships and proportions. In addition, in each drawing, the same components are marked with the same symbols.

[0060] (Implementation Method 1)

[0061] The structure of the water treatment device according to Embodiment 1 of the present invention will be described. Figure 1 1 is a schematic diagram showing a configuration example of a water treatment device according to Embodiment 1 of the present invention. The water treatment device 10 according to Embodiment 1 of the present invention treats wash water obtained by washing exhaust gas discharged from an internal combustion engine 110 for a ship.

[0062] For example Figure 1As shown, the water treatment device 10 includes a collection tank 1 for storing washing water after exhaust gas cleaning, a circulation system 2 for circulating the washing water, and a foreign matter removal system 3 for removing foreign matter in the washing water. In addition, the water treatment device 10 includes a hydrometer 4 for measuring the specific gravity of the washing water, a branch valve 5 and a washing waste water discharge pipe 6 for discharging the washing water (washing water to be discharged) with excessively increased specific gravity from the foreign matter removal system 3, and a first discharge pipe 7, a second discharge pipe 8, and a drainage channel branch valve 9 for discharging the washing water to be discharged to the outside or inside of the ship. In addition, the water treatment device 10 includes a residue discharge pipe 11 for discharging the residue containing foreign matter removed from the washing water from the foreign matter removal system 3, and a waste residue tank 15 for storing the residue and the like. In addition, the water treatment device 10 includes a clean water replenishing unit 16 for replenishing clean water to the collection tank 1, a pH adjusting unit 17 for adjusting the pH of the washing water, a level detection unit 18 for detecting the liquid level Ls of the washing water in the collection tank 1, and a control device 19. In addition, Figure 1 In the figure, the flow and piping of fluids such as washing water and exhaust gas are appropriately indicated by solid arrows. The electrical signal lines are appropriately indicated by single-point dashed lines. This is also the case in other figures.

[0063] In addition, if Figure 1 As shown, the water treatment device 10 is applied to a scrubber 101 for cleaning the exhaust gas discharged from the ship internal combustion engine 110 using wash water. In the first embodiment, the scrubber 101 is a component of the EGR system 100, which recirculates a part of the exhaust gas from the ship internal combustion engine 110 as recirculation gas to the ship internal combustion engine 110. Hereinafter, when the exhaust gas is mentioned, it means the exhaust gas discharged from the ship internal combustion engine 110 unless otherwise specified.

[0064] The ship internal combustion engine 110 used as the object in the present embodiment 1 is, for example, a type of internal combustion engine that operates by burning at least one of fossil fuel and alternative fuel in a combustion chamber, and is installed in the engine room of the ship. The operation mode of such a type of ship internal combustion engine 110 includes a fossil fuel operation mode that operates using only fossil fuel as a combustion fuel and an alternative fuel operation mode that operates using at least alternative fuel as a combustion fuel. For example, the alternative fuel operation mode can be listed as: an operation mode that operates by mixing and burning fossil fuel and alternative fuel, and an operation mode that operates by burning only alternative fuel. In addition, fossil fuel is a fuel obtained by refining from petroleum (crude oil), such as heavy oil or light oil. Alternative fuel is a fuel that can replace fossil fuel, for example, a decarbonized fuel that does not contain carbon components, such as ammonia fuel or hydrogen fuel.

[0065] In the above-mentioned ship internal combustion engine 110, for example, when operating in a fossil fuel operation mode, foreign matter containing a large amount of carbon components such as coal is contained in the exhaust gas. In this case, the washing water used for washing the exhaust gas contains foreign matter containing a large amount of carbon components removed from the exhaust gas, for example, exceeding the discharge regulation (hereinafter referred to as foreign matter containing carbon components). On the other hand, when the ship internal combustion engine 110 is operated in an alternative fuel operation mode, the amount of carbon components contained in the foreign matter in the exhaust gas is less than that of the exhaust gas in the fossil fuel operation mode. In this case, the washing water used for washing the exhaust gas contains almost or no carbon components derived from the exhaust gas, and the amount of carbon components contained in the foreign matter in the washing water is, for example, below the discharge regulation.

[0066] As foreign matter in the above-mentioned washing water (foreign matter originating from exhaust gas), for example, coal (coal dust), unburned oil and sulfur oxides can be cited. That is, as the components contained in the foreign matter, carbon components such as coal, oil (hydrocarbons), and components other than carbon components such as sulfur oxides can be cited. In this specification, foreign matter that contains less carbon components than the exhaust gas in the fossil fuel operation mode and does not contain carbon components exceeding the prescribed degree of discharge is defined as foreign matter not containing carbon components. In this embodiment 1, the water treatment device 10 has a case where washing water containing foreign matter containing carbon components is treated according to the operation mode of the ship internal combustion engine 110, and there is also a case where washing water containing foreign matter not containing carbon components is treated. In the following, foreign matter containing carbon components originating from exhaust gas and foreign matter not containing carbon components may be collectively referred to and abbreviated as foreign matter. In addition, when referring to a ship, unless otherwise specified, it means a ship equipped with the ship internal combustion engine 110.

[0067] In detail, Figure 1 In the water treatment device 10 shown, the collection tank 1 is a tank for recovering washing water. Figure 1 As shown in FIG. 1 , the collecting tank 1 is connected to the lower part of the demister 102 of the EGR system 100 via the recovery pipe 104 (at Figure 1 In addition, the demister 102 is a component of the EGR system 100, such as Figure 1 The collection tank 1 is connected to the scrubber 101 as shown. The collection tank 1 recovers the washing water used for washing the exhaust gas in the scrubber 101 from the demister 102 through the recovery pipe 104. For example Figure 1 As shown, a pump 105 is provided in the recovery pipe 104. After the used washing water flows from the scrubber 101 into the demister 102, it flows into the collection tank 1 through the recovery pipe 104 due to the action of the pump 105. The collection tank 1 temporarily stores the washing water recovered in this way.

[0068] The circulation system 2 is a system for circulating the washing water from the collection tank 1 toward the scrubber 101. Figure 1 As shown, the circulation system 2 includes a circulation pipe 21 and a circulation pump 22 .

[0069] The inlet end of the circulation pipe 21 is connected to the lower part of the collection tank 1, and the outlet end is connected to the inlet end of the injection part 101a of the scrubber 101. The circulation pump 22 is provided in the middle of the circulation pipe 21. The circulation pump 22 presses the washing water flowing from the collection tank 1 into the circulation pipe 21 toward the scrubber 101. Thus, the circulation pump 22 generates a flow of washing water in the circulation pipe 21 from the collection tank 1 side toward the scrubber 101 side.

[0070] In the circulation system 2 having such a structure, the circulation pipe 21 conveys the washing water in the collection tank 1 to the injection part 101a of the scrubber 101 by the action of the circulation pump 22. The conveyed washing water is injected from the injection part 101a in the scrubber 101 and is used for washing (reusing) the exhaust gas in the scrubber 101. The washing water for washing the exhaust gas flows from the scrubber 101 into the demister 102 in a state containing foreign matter removed from the exhaust gas, and is then recovered to the collection tank 1 through the recovery pipe 104. In this way, the circulation system 2 repeatedly circulates the washing water between the collection tank 1 and the scrubber 101.

[0071] The foreign matter removal system 3 is a system that separates the washing water after the exhaust gas cleaning into a residue containing foreign matter and a washing wastewater containing less foreign matter than the residue, and removes foreign matter from the washing water. Figure 1 As shown, the foreign matter removal system 3 includes a branch pipe 31 , an outlet pipe 32 , a converging pipe 33 , and a centrifugal separator 34 .

[0072] The branch pipe 31 constitutes a pipe for extracting washing water from the circulation system 2. Figure 1 As shown, the inlet end of the branch pipe 31 is connected to the circulation pipe 21 of the circulation system 2, and the outlet end is connected to the inlet of the centrifuge 34. In the present embodiment 1, the branch pipe 31 branches from the circulation pipe 21 to connect the circulation pipe 21 with the centrifuge 34. The branch pipe 31 extracts a part of the washing water flowing in the circulation pipe 21, and guides the washing water extracted from the circulation pipe 21 to the centrifuge 34.

[0073] The outlet pipe 32 and the confluence pipe 33 constitute a pipe for returning the washing water after the foreign matter is removed by the centrifugal separator 34 to the circulation system 2. Figure 1As shown, the inlet end of the outlet pipe 32 is connected to the outlet portion of the centrifuge 34 and the outlet end is connected to the branch valve 5. The outlet pipe 32 receives the washing water after the foreign matter is removed from the centrifuge 34, and guides the received washing water to the branch valve 5. In addition, the outlet pipe 32 is connected to the junction pipe 33 and the washing waste water discharge pipe 6 via the branch valve 5 so as to be communicable. That is, the outlet pipe 32 and the junction pipe 33 are the pipes for setting the branch valve 5 in the pipes of the foreign matter removal system 3. In the present embodiment 1, the washing water guided to the branch valve 5 from the outlet pipe 32 flows into any one of the junction pipe 33 and the washing waste water discharge pipe 6 via the branch valve 5.

[0074] The confluence pipe 33 is a pipe for returning the washing water after the foreign matter is removed by the centrifugal separator 34 to the circulation system 2. Figure 1 As shown, the inlet end of the confluence pipe 33 is connected to the branch valve 5, and the outlet end is connected to the middle part of the circulation pipe 21 (for example, the downstream side of the flow direction of the washing water compared with the branch pipe 31). The confluence pipe 33 receives the washing water after the foreign matter is removed from the outlet pipe 32 through the branch valve 5, and returns the received washing water as the washing water used again for exhaust gas cleaning (washing water for reuse) to merge with the circulation pipe 21.

[0075] The centrifuge 34 is an example of a removal device for removing foreign matter from washing water in the foreign matter removal system 3. In the present embodiment 1, the centrifuge 34 receives washing water extracted from the circulation pipe 21 through the branch pipe 31, and removes foreign matter from the received washing water. At this time, the centrifuge 34 uses the difference in specific gravity between the received washing water and the foreign matter to separate (centrifuge) the washing water into residue containing foreign matter and washing wastewater containing less foreign matter than the residue. That is, the washing wastewater is the washing water after foreign matter is removed by the centrifuge 34. The centrifuge 34 sends the washing wastewater to the outlet pipe 32, and sends the residue containing the removed foreign matter to the residue discharge pipe 11. In the following, when the residue is mentioned, unless otherwise specified, it means the residue separated from the washing water as described above, and the residue contains the foreign matter removed from the washing water.

[0076] The hydrometer 4 measures the specific gravity of the washing water. Figure 1 As shown, the hydrometer 4 is provided in the branch pipe 31. The hydrometer 4 measures the specific gravity of the washing water flowing in the branch pipe 31 (i.e., the washing water drawn from the circulation pipe 21 through the branch pipe 31). The measurement of the specific gravity of the washing water by the hydrometer 4 may be performed continuously in a time series, may be performed intermittently at a predetermined time interval, or may be performed when the measurement is instructed by the control device 19. Whenever the hydrometer 4 measures the specific gravity of the washing water, it sends an electrical signal indicating the obtained specific gravity (measured value) of the washing water to the control device 19.

[0077] The branch valve 5 is a valve for allowing the washing water in the pipe of the foreign matter removal system 3 to flow toward the circulation pipe 21 side or the washing waste water discharge pipe 6 side. Figure 1 As shown, the branch valve 5 is composed of a three-way valve and the like, and is provided in the piping of the foreign matter removal system 3 (in the present embodiment 1, the piping is composed of the outlet pipe 32 and the confluence pipe 33). Specifically, the first opening of the three openings of the branch valve 5 is connected to the outlet end of the outlet pipe 32, the second opening is connected to the inlet end of the confluence pipe 33, and the third opening is connected to the inlet end of the washing wastewater discharge pipe 6. The branch valve 5 adjusts the openings by increasing the opening of one of the openings between the outlet pipe 32 and the confluence pipe 33 and the opening of the outlet pipe 32 and the washing wastewater discharge pipe 6 and reducing the opening of the other. In the present embodiment 1, the branch valve 5 adjusts the opening of one of the openings to be fully opened and the opening of the other to be fully closed. The opening adjustment is controlled by the control device 19, and based on this control, the branch valve 5 selectively determines the flow destination of the washing waste water from the outlet pipe 32 to be either the confluence pipe 33 (the circulation path side of the washing water) or the washing waste water discharge pipe 6 (the discharge path side of the washing water).

[0078] The washing waste water discharge pipe 6 is a pipe for discharging washing waste water from the foreign matter removal system 3. Figure 1 As shown, the inlet end of the washing wastewater discharge pipe 6 is connected to the branch valve 5 described above, and the outlet end is connected to the drainage path branch valve 9. The washing wastewater discharge pipe 6 branches from the piping of the foreign matter removal system 3 via the branch valve 5, and constitutes a part of the drainage path for discharging the washing wastewater. The washing wastewater discharge pipe 6 receives the washing wastewater that becomes the object of drainage, for example, due to excessive increase in specific gravity, from the washing wastewater sent from the centrifugal separator 34 through the outlet pipe 32 through the branch valve 5. The washing wastewater discharge pipe 6 allows the received washing wastewater to flow toward the first drainage pipe 7 or the second drainage pipe 8 via the drainage path branch valve 9.

[0079] The first drain pipe 7 is a pipe constituting a drainage path for discharging the washing wastewater to the outside of the ship. Figure 1 As shown, the inlet end of the first drain pipe 7 is connected to the drain branch valve 9, and is configured to branch from the washing wastewater discharge pipe 6 via the drain branch valve 9. Although not particularly shown, the outlet end of the first drain pipe 7 is connected to the outside of the ship (ocean, etc.). The first drain pipe 7 receives washing wastewater from the washing wastewater discharge pipe 6 via the drain branch valve 9, and flows the received washing wastewater toward the outside of the ship, thereby being able to discharge the washing wastewater to the outside of the ship (discarding it in the ocean).

[0080] The second drain pipe 8 is a pipe constituting a drainage path for discharging the washing waste water to the waste residue tank 15 in the ship. Figure 1As shown, the inlet end of the second drain pipe 8 is connected to the drain branch valve 9 and the outlet end is connected to the waste residue tank 15. That is, the second drain pipe 8 branches from the washing waste water discharge pipe 6 via the drain branch valve 9 and communicates with the waste residue tank 15. The second drain pipe 8 receives the washing waste water from the washing waste water discharge pipe 6 via the drain branch valve 9 and discharges the received washing waste water to the waste residue tank 15.

[0081] The drainage branch valve 9 is a valve for allowing the washing waste water discharged from the foreign matter removal system 3 through the washing waste water discharge pipe 6 to flow to the first drainage pipe 7 connected to the outside of the ship or the second drainage pipe 8 connected to the waste residue tank 15 inside the ship. Figure 1 As shown, the drain branch valve 9 is composed of a three-way valve and the like, and branches the washing wastewater discharge pipe 6 to the first drain pipe 7 and the second drain pipe 8. That is, the first opening of the three openings of the drain branch valve 9 is connected to the outlet end of the washing wastewater discharge pipe 6, the second opening is connected to the inlet end of the first drain pipe 7, and the third opening is connected to the inlet end of the second drain pipe 8. The drain branch valve 9 adjusts the openings by increasing the opening of one of the openings between the washing wastewater discharge pipe 6 and the first drain pipe 7 and the opening of the washing wastewater discharge pipe 6 and the second drain pipe 8 and reducing the opening of the other. In the first embodiment, the drain branch valve 9 adjusts the opening of one of the openings to be fully opened and the opening of the other to be fully closed. For example, the opening adjustment is controlled by the control device 19, and based on the control, the drain branch valve 9 connects the washing wastewater discharge pipe 6 to either the first drain pipe 7 or the second drain pipe 8. When the ship's internal combustion engine 110 is operated with alternative fuel, such a drain branch valve 9 connects the washing waste water discharge pipe 6 with the first drain pipe 7. When the ship's internal combustion engine 110 is operated with fossil fuel, such a drain branch valve 9 connects the washing waste water discharge pipe 6 with the second drain pipe 8.

[0082] In addition, the alternative fuel operation is the operation of the ship internal combustion engine 110 by burning at least the alternative fuel (decarbonized fuel). In this case, the operation mode of the ship internal combustion engine 110 is the above-mentioned alternative fuel operation mode. The fossil fuel operation is the operation of the ship internal combustion engine 110 by burning only the fossil fuel. In this case, the operation mode of the ship internal combustion engine 110 is the above-mentioned fossil fuel operation mode.

[0083] The residue discharge pipe 11 is a pipe for discharging the residue including the foreign matter removed from the washing water as described above from the foreign matter removal system 3. Figure 1As shown, the inlet end of the residue discharge pipe 11 is connected to the residue discharge outlet of the centrifugal separator 34, and the outlet end is connected to the waste residue tank 15. The residue discharge pipe 11 receives the residue (e.g., waste residue-like residue) containing foreign matter removed from the washing water by the centrifugal separator 34 from the centrifugal separator 34, discharges the received residue from the foreign matter removal system 3, and sends it to the waste residue tank 15.

[0084] The waste residue tank 15 is an example of a storage tank for storing the residue and washing waste water discharged from the foreign matter removal system 3. Figure 1 As shown, the slag tank 15 is provided at a lower position than the centrifuge 34, and as described above, is connected to the slag discharge pipe 11. In the first embodiment, the slag tank 15 collectively stores the slag discharged through the slag discharge pipe 11 and the washing waste water discharged through the second drain pipe 8 until the cargo is unloaded from the ship.

[0085] The clean water replenishing unit 16 replenishes clean water for increasing or diluting the washing water into the collection tank 1. The clean water replenishing unit 16 includes, for example, a clean water tank, a replenishing pipe, and a replenishing pump (all not shown). Figure 1 As shown, it is configured to be able to replenish clean water to the collection tank 1 through a replenishing pipe. As the clean water replenished from the clean water replenishing unit 16 to the collection tank 1, for example, clean water loaded from outside the ship, clean water produced in the ship, and discharge water discharged from the ship internal combustion engine 110 can be listed. In this embodiment 1, the clean water replenishing unit 16 obtains the liquid level Ls of the washing water in the collection tank 1 from the level detection unit 18, and controls the timing and replenishment amount of the clean water replenished to the collection tank 1 in a manner that the obtained liquid level Ls converges within a predetermined threshold level range. Clean water is replenished by the clean water replenishing unit 16, so that the washing water in the collection tank 1 increases and is diluted. As a result, the specific gravity of the washing water is reduced.

[0086] The pH adjustment unit 17 is used to adjust (neutralize) the pH of the washing water in the collection tank 1. The pH adjustment unit 17 includes, for example, an alkali liquid tank, a supply pipe, a supply pump, and a pH meter (all not shown). Figure 1 As shown, it is configured to be able to supply alkali solution to the collection tank 1 through a supply pipe. Here, every time the washing water is used for washing the exhaust gas in the scrubber 101, the content of foreign matter such as sulfur oxides removed from the exhaust gas in the washing water increases. Therefore, the acidification of the washing water is promoted. Therefore, as a liquid for adjusting the pH of the washing water, an alkali solution that is a highly alkaline liquid is used. As the alkali solution, for example, sodium hydroxide can be cited. Sulfur oxides in foreign matter in the washing water are removed by the action of the pH adjustment unit 17.

[0087] In the present embodiment 1, the pH adjustment unit 17 measures the pH of the washing water in the collection tank 1, and supplies an alkaline solution to the collection tank 1 when the obtained pH measurement value is less than a predetermined threshold value. As a result, the washing water in the collection tank 1 is neutralized by the alkaline solution, and the pH of the washing water rises. In addition, when the obtained pH measurement value is greater than a predetermined threshold value, the pH adjustment unit 17 stops supplying the alkaline solution to the collection tank 1. The above-mentioned pH threshold is set to a range in which various components such as the piping in contact with the washing water in the water treatment device 10 will not be corroded, or a range in which the removal performance of sulfur oxides in the scrubber 101 will not be impaired. On the other hand, as the neutralization reaction of the washing water and the alkaline solution proceeds, the content of by-products such as Na2SO4 generated in the washing water increases. As a result, the specific gravity of the washing water increases.

[0088] The level detection unit 18 detects the liquid level Ls of the washing water in the collection tank 1. Figure 1 As shown, the level detection unit 18 is provided in the collection tank 1 in such a manner that a detection element is provided at each position of the low level and the high level in the height direction of the collection tank 1. When the liquid surface level Ls of the washing water in the collection tank 1 becomes a position lower than the detection element of the low level, the level detection unit 18 detects that the liquid surface level Ls is less than the low level. In this case, the level detection unit 18 sends an electrical signal indicating that the liquid surface level Ls is less than the low level to the clean water replenishing unit 16. On the other hand, when the liquid surface level Ls becomes a high position above the detection element of the high level, the level detection unit 18 detects that the liquid surface level Ls is above the high level. In this case, the level detection unit 18 sends an electrical signal indicating that the liquid surface level Ls is above the high level to the clean water replenishing unit 16.

[0089] In the present embodiment 1, the above-mentioned low level and high level are respectively threshold levels of the liquid surface pre-set within the range between the lower limit level and the upper limit level on the equipment specifications of the collection tank 1. That is, the low level is a threshold level that is above the lower limit level of the collection tank 1 and less than the above-mentioned high level. The high level is a threshold level that is higher than the above-mentioned low level and below the upper limit level of the collection tank 1. When the washing water in the collection tank 1 is increased (diluted) by clean water so that the liquid surface level Ls rises from a state lowered to less than the low level to a state higher than the high level, the specific gravity of the washing water is reduced to a degree that does not hinder the separation of the washing water and foreign matter by the centrifuge 34. These low levels and high levels are pre-set to enable the above-mentioned situation to be achieved.

[0090] The control device 19 controls the flow of washing water in the water treatment device 10. Specifically, the control device 19 is composed of a CPU, a memory, and a sequence generator for executing various programs. When controlling the flow of washing water, the control device 19 receives electrical signals from the hydrometer 4 and the ship internal combustion engine 110, respectively, and controls the branch valve 5 and the drainage channel branch valve 9, respectively, based on these electrical signals.

[0091] For example, the control device 19 compares the specific gravity of the washing water measured by the hydrometer 4 with a predetermined reference value set in advance, and controls the branch valve 5 based on the comparison result. In the present embodiment 1, when the specific gravity of the washing water measured is greater than the above-mentioned reference value, the control device 19 controls the opening of the branch valve 5 in such a manner that the outlet pipe 32 is connected to the washing waste water discharge pipe 6. Thus, the control device 19 controls the flow of the washing waste water in such a manner that the washing waste water is discharged from the foreign matter removal system 3 to the washing waste water discharge pipe 6 (i.e., the drainage path side) as a drainage object. In addition, when the specific gravity of the washing water measured is less than the above-mentioned reference value, the control device 19 controls the opening of the branch valve 5 in such a manner that the outlet pipe 32 is connected to the confluence pipe 33. Thus, the control device 19 controls the flow of the washing waste water in such a manner that the washing waste water is sent (returned) from the foreign matter removal system 3 to the circulation pipe 21 of the circulation system 2 as a reuse object.

[0092] In addition, as the reference value pre-set in the control device 19 as described above, for example, an upper limit value within the range of specific gravity of the washing water that does not hinder the separation of the washing water and foreign matter by the centrifugal separator 34 is used. Hereinafter, when the reference value is mentioned, unless otherwise specified, it means the prescribed reference value pre-set according to the specific gravity of the washing water as described above.

[0093] In addition, the control device 19 determines whether the operation mode of the ship internal combustion engine 110 is the alternative fuel operation or the fossil fuel operation based on the electrical signal received from the ship internal combustion engine 110. In the case of alternative fuel operation, the control device 19 controls the opening of the drainage path branch valve 9 in such a way that the washing wastewater discharge pipe 6 is connected to the first drainage pipe 7. Thus, the control device 19 controls the flow of the washing wastewater in such a way that the washing wastewater is discharged outside the ship. In the case of fossil fuel operation, the control device 19 controls the opening of the drainage path branch valve 9 in such a way that the washing wastewater discharge pipe 6 is connected to the second drainage pipe 8. Thus, the control device 19 controls the flow of the washing wastewater in such a way that the washing wastewater is discharged to the waste residue tank 15 in the ship.

[0094] In addition, the operation mode of the ship internal combustion engine 110 is switched to the above-mentioned alternative fuel operation mode or fossil fuel operation mode according to the operation of the operator on the operation unit (not shown) of the ship internal combustion engine 110. Whenever the operation mode of the ship internal combustion engine 110 (hereinafter, may be abbreviated as the engine operation mode) is switched in this way, an electrical signal indicating that the engine operation mode is the alternative fuel operation mode, or an electrical signal indicating that the engine operation mode is the fossil fuel operation mode is transmitted from the operation unit or the control device of the ship internal combustion engine 110 to the control device 19.

[0095] On the other hand, the EGR system 100 is a system for reducing the content of nitrogen oxides in the exhaust gas by recirculating part of the exhaust gas discharged from the ship internal combustion engine 110 mounted on the ship to the ship internal combustion engine 110 as recirculation gas. Figure 1 As shown, the EGR system 100 includes a scrubber 101 , a defogger 102 , and an EGR blower 103 .

[0096] The scrubber 101 is used to clean the exhaust gas by using a part of the exhaust gas discharged from the ship internal combustion engine 110 as recirculation gas. Figure 1 As shown, a part of the exhaust gas is transported from the ship internal combustion engine 110 to the scrubber 101 through piping or the like. The scrubber 101 is provided with an injection unit 101a such as a nozzle for injecting washing water to the exhaust gas to be cleaned. The injection unit 101a is configured to be supplied with washing water through the circulation pipe 21. The scrubber 101 injects washing water from the injection unit 101a to a part of the exhaust gas (recirculation gas) transported from the ship internal combustion engine 110 side, thereby removing foreign matter such as coal dust and sulfur oxides from the recirculation gas and cleaning the recirculation gas. In addition, the remaining exhaust gas discharged from the ship internal combustion engine 110 that is not transported to the scrubber 101 is discharged to the outside of the ship from the chimney through piping or the like.

[0097] The demister 102 is a hollow rectangular shell connected to the outlet of the scrubber 101. In addition, a recovery pipe 104 connected to the above-mentioned collection tank 1 is connected to the lower part (bottom) of the demister 102. The recirculating gas cleaned by the injection of washing water in the scrubber 101 and the washing water used for washing the recirculating gas flow into such a demister 102. The demister 102 separates the cleaned recirculating gas from the used washing water. These recirculating gases and the recirculating gas in the washing water are sent to the EGR blower 103 from the gas exhaust port of the demister 102, and the washing water is recovered to the collection tank 1 from the lower part of the demister 102 through the recovery pipe 104.

[0098] like Figure 1As shown, the EGR blower 103 is provided on the upper part of the demister 102. The EGR blower 103 delivers the recirculation gas delivered from the demister 102 to the ship internal combustion engine 110 through piping, etc. The recirculation gas delivered from the EGR blower 103 is delivered to the combustion chamber of the ship internal combustion engine 110 together with the air (fresh air), and is used as combustion gas when the ship internal combustion engine 110 is operated.

[0099] Next, a control procedure of the flow of wash water by water treatment device 10 will be described. Figure 2 This is a flowchart illustrating a control procedure of the flow of washing water in the water treatment device according to the first embodiment of the present invention. Figure 1 ), the control device 19 performs Figure 2 The flow of washing water is controlled by each process of steps S101 to S106 shown.

[0100] In detail, regarding the control of the flow of washing water based on the water treatment device 10, as shown in FIG. Figure 2 As shown, control device 19 first determines whether the specific gravity of the washing water is greater than or equal to a reference value (step S101).

[0101] In step S101, the control device 19 compares the specific gravity of the washing water measured by the hydrometer 4 with the reference value. Then, when the measured value of the specific gravity is greater than the reference value, the control device 19 determines that the specific gravity of the washing water is greater than the reference value. This is equivalent to the specific gravity of the washing water repeatedly circulated between the water treatment device 10 and the scrubber 101 being greater than the reference value.

[0102] When the measured specific gravity of the washing water is greater than the reference value (step S101, yes), the control device 19 controls the opening of the branch valve 5 in such a manner as to open the washing wastewater discharge pipe 6 (step S102). In step S102, the control device 19 controls the opening of the branch valve 5 in such a manner as to fully open the washing wastewater discharge pipe 6 side of the branch valve 5 and fully close the confluence pipe 33 side. Based on this opening control, the branch valve 5 selectively switches the flow destination of the washing wastewater from the outlet pipe 32 from the confluence pipe 33 side to the washing wastewater discharge pipe 6 side. The control device 19 controls the flow of washing water by controlling the opening of the branch valve 5 so as to discharge the washing wastewater in the outlet pipe 32 (the washing water after foreign matter is removed by the centrifuge 34) as the drainage object from the foreign matter removal system 3 to the washing wastewater discharge pipe 6 side.

[0103] In the stage of step S102, the washing water is continuously circulated between the collection tank 1 and the scrubber 101 through the circulation pipe 21 and the like. In parallel with this, a portion of the washing water drawn from the circulation pipe 21 to the branch pipe 31 is not returned to the circulation pipe 21 from the confluence pipe 33, but is discharged from the foreign matter removal system 3 through the washing waste water discharge pipe 6. As a result, the storage amount of the washing water in the collection tank 1 is reduced, and with this, the liquid level Ls of the washing water is lowered. When the liquid level Ls of the washing water in the collection tank 1 is less than the low level, the clean water replenishing unit 16 replenishes clean water into the collection tank 1. As a result, the liquid level Ls of the washing water rises. When the liquid level Ls of the washing water is above the high level, the clean water replenishing unit 16 stops replenishing clean water into the collection tank 1.

[0104] After executing step S102, the control device 19 determines the engine operation mode (step S103). In step S103, the control device 19 determines whether the engine operation mode is the alternative fuel operation mode or the fossil fuel operation mode based on the electrical signal (electrical signal indicating the engine operation mode) from the marine internal combustion engine 110.

[0105] Specifically, when the marine internal combustion engine 110 is operated for alternative fuel operation, the control device 19 receives an electrical signal indicating that the engine operation mode is the alternative fuel operation mode from the marine internal combustion engine 110. The control device 19 determines that the current engine operation mode is the alternative fuel operation mode based on the received electrical signal.

[0106] When it is determined that the engine operation mode is the alternative fuel operation mode (step S103, alternative fuel), the control device 19 controls the opening of the drainage path branch valve 9 to open the first drainage pipe 7 (step S104). Thereafter, the control device 19 returns to the above-mentioned step S101 and repeats the processing after step S101.

[0107] In step S104, the control device 19 controls the opening of the drain branch valve 9 in such a manner that the first drain pipe 7 side of the drain branch valve 9 is fully opened and the second drain pipe 8 side is fully closed. Based on this opening control, the drain branch valve 9 switches the flow destination of the washing waste water from the washing waste water discharge pipe 6 from the second drain pipe 8 side to the first drain pipe 7 side. That is, the drain branch valve 9 cuts off the connection between the washing waste water discharge pipe 6 and the second drain pipe 8, and connects the washing waste water discharge pipe 6 with the first drain pipe 7. The control device 19 controls the flow of washing water by controlling the opening of the drain branch valve 9 in such a manner that the washing waste water in the alternative fuel operation mode is discharged to the outside of the ship through the washing waste water discharge pipe 6 and the first drain pipe 7 (dumping at sea).

[0108] Here, when the engine operation mode is the alternative fuel operation mode, the foreign matter contained in the washing wastewater after washing the exhaust gas from the ship internal combustion engine 110 is a foreign matter that does not contain carbon components as described above. That is, the washing wastewater does not contain foreign matter containing carbon components as defined above in the present invention. The washing wastewater that does not contain foreign matter containing carbon components is clean wastewater that can be dumped at sea in accordance with the discharge regulations.

[0109] On the other hand, when the ship internal combustion engine 110 is operated to perform fossil fuel operation, the control device 19 receives an electrical signal indicating that the engine operation mode is the fossil fuel operation mode from the ship internal combustion engine 110. In the above-mentioned step S103, the control device 19 determines that the current engine operation mode is the fossil fuel operation mode based on the received electrical signal.

[0110] When it is determined that the engine operation mode is the fossil fuel operation mode (step S103, fossil fuel), the control device 19 controls the opening of the drainage path branch valve 9 to open the second drainage pipe 8 (step S105). Thereafter, the control device 19 returns to the above-mentioned step S101 and repeats the processing after step S101.

[0111] In step S105, the control device 19 controls the opening of the drain branch valve 9 in such a manner that the first drain pipe 7 side of the drain branch valve 9 is completely closed and the second drain pipe 8 side is completely opened. Based on this opening control, the drain branch valve 9 selectively switches the flow destination of the washing waste water from the washing waste water discharge pipe 6 from the first drain pipe 7 side to the second drain pipe 8 side. That is, the drain branch valve 9 cuts off the connection between the washing waste water discharge pipe 6 and the first drain pipe 7, and connects the washing waste water discharge pipe 6 with the second drain pipe 8. The control device 19 controls the flow of washing water in such a manner that the washing waste water in the fossil fuel operation mode is discharged to the waste residue tank 15 in the ship through the washing waste water discharge pipe 6 and the second drain pipe 8 through the opening control of the drain branch valve 9.

[0112] Here, when the engine operation mode is the fossil fuel operation mode, the washing wastewater used for washing the exhaust gas from the ship internal combustion engine 110 contains foreign matter containing carbon components. The washing wastewater containing foreign matter containing carbon components cannot be dumped into the ocean, but is temporarily stored in the waste slag tank 15 and disposed of after unloading.

[0113] On the other hand, in the above step S101, when the specific gravity of the washing water measured by the hydrometer 4 is less than the reference value, the control device 19 determines that the specific gravity of the washing water repeatedly circulated between the water treatment device 10 and the scrubber 101 is not greater than the reference value (step S101, No). In this case, the control device 19 controls the opening of the branch valve 5 in a manner to close the washing wastewater discharge pipe 6 (step S106). After that, the control device 19 returns to the above step S101 and repeats the processing after step S101.

[0114] In step S106, the control device 19 controls the opening of the branch valve 5 so that the washing wastewater discharge pipe 6 side of the branch valve 5 is completely closed and the confluence pipe 33 side is completely opened. Based on this opening control, the branch valve 5 switches the flow destination of the washing wastewater from the outlet pipe 32 from the washing wastewater discharge pipe 6 side to the confluence pipe 33 side. The control device 19 controls the flow of washing water by controlling the opening of the branch valve 5 so that the washing wastewater in the outlet pipe 32 is sent from the foreign matter removal system 3 to the circulation system 2 as washing water to be reused.

[0115] In the stage of step S106, in parallel with the circulation of the washing water between the collection tank 1 and the scrubber 101, a portion of the washing water drawn from the circulation pipe 21 to the branch pipe 31 passes through the centrifugal separator 34 to remove foreign matter, and then is not discharged from the washing waste water discharge pipe 6 but returns to the circulation pipe 21 through the confluence pipe 33. As a result, the reduction of the washing water in the collection tank 1 is suppressed, and accordingly, the reduction of the liquid level Ls of the washing water is suppressed.

[0116] As described above, the water treatment device 10 of the first embodiment of the present invention includes: a foreign matter removal system 3 for separating washing water used for washing exhaust gas from a ship internal combustion engine 110 into residue and washing waste water and removing foreign matter from the washing water; a washing waste water discharge pipe 6 for discharging washing waste water from the foreign matter removal system 3; a first drain pipe 7 for discharging washing waste water to the outside of the ship; a second drain pipe 8 for discharging washing waste water to a storage tank in the ship; and a drain branch valve 9 for branching the washing waste water discharge pipe 6 into the first drain pipe 7 and the second drain pipe 8 so that the washing waste water discharge pipe 6 is connected to either the first drain pipe 7 or the second drain pipe 8. In addition, in the water treatment device 10, when the ship internal combustion engine 110 is operated by alternative fuel, the drain branch valve 9 connects the washing waste water discharge pipe 6 to the first drain pipe 7, and when the ship internal combustion engine 110 is operated by fossil fuel, the drain branch valve 9 connects the washing waste water discharge pipe 6 to the second drain pipe 8.

[0117] Through the above-mentioned structure, the drainage path of the washing waste water can be switched to any one of a drainage path for discharging the waste water outside the ship (discarding at sea) and a drainage path for discharging the waste water inside the ship (storing) according to the operation mode (alternative fuel operation mode or fossil fuel operation mode) of the ship internal combustion engine 110. Therefore, for the washing waste water (washing water of the drainage object) used for cleaning the exhaust gas from the ship internal combustion engine 110, it can be selected whether to discharge the waste water outside the ship. Specifically, it is not necessary to store the washing waste water that does not contain foreign matter containing carbon components in the alternative fuel operation mode in the storage tank inside the ship, but it can be discarded at sea, and it is possible to store the washing waste water that contains foreign matter containing carbon components in the fossil fuel operation mode in the storage tank inside the ship without discarding it at sea.

[0118] (Implementation Method 2)

[0119] Next, the structure of the water treatment device according to Embodiment 2 of the present invention will be described. Figure 3 Schematic diagram showing a structural example of a water treatment device according to Embodiment 2 of the present invention. Figure 3 As shown, the water treatment device 10A of the second embodiment is provided with a residue discharge pipe 11B instead of the residue discharge pipe 11 of the water treatment device 10 of the first embodiment, a control device 19A instead of the control device 19, and a first residue pipe 12, a second residue pipe 13, and a residue path branch valve 14. The other structures are the same as those of the first embodiment, and the same symbols are marked on the same components.

[0120] The residue discharge pipe 11B is a pipe for discharging the residue generated by the foreign matter removal system 3 (specifically, the centrifugal separator 34) from the foreign matter removal system 3. Figure 3 As shown, the inlet end of the residue discharge pipe 11B is connected to the residue discharge outlet of the centrifugal separator 34, and the outlet end is connected to the residue path branch valve 14. The residue discharge pipe 11B receives the residue (e.g., waste residue-like residue) containing foreign matter removed from the washing water by the centrifugal separator 34 from the centrifugal separator 34. The residue discharge pipe 11B discharges the received residue from the foreign matter removal system 3 and flows toward the first residue pipe 12 or the second residue pipe 13 via the residue path branch valve 14.

[0121] The first residue pipe 12 is a pipe that constitutes a discharge path for discharging the residue generated by the foreign matter removal system 3 to the outside of the ship. Figure 3As shown, the inlet end of the first residue pipe 12 is connected to the residue path branch valve 14, and is configured to branch from the residue discharge pipe 11B via the residue path branch valve 14. Although not particularly shown, the outlet end of the first residue pipe 12 is connected to the outside of the ship (ocean, etc.). The first residue pipe 12 receives residue from the residue discharge pipe 11B via the residue path branch valve 14, and flows the received residue toward the outside of the ship. The residue can be discharged to the outside of the ship (discarded in the ocean) through the first residue pipe 12.

[0122] The second residue pipe 13 is a pipe constituting a discharge path for discharging the residue generated by the foreign matter removal system 3 to the waste residue tank 15 in the ship. Figure 3 As shown, the inlet end of the second residue pipe 13 is connected to the residue path branch valve 14 and the outlet end is connected to the waste residue tank 15. That is, the second residue pipe 13 branches from the residue discharge pipe 11B via the residue path branch valve 14 and communicates with the waste residue tank 15. The second residue pipe 13 receives residue from the residue discharge pipe 11B via the residue path branch valve 14 and discharges the received residue into the waste residue tank 15.

[0123] The residue branch valve 14 is a valve for allowing the residue discharged from the foreign matter removal system 3 through the residue discharge pipe 11B to flow to the first residue pipe 12 connected to the outside of the ship or the second residue pipe 13 connected to the waste residue tank 15 in the ship. Figure 3 As shown, the residue path branch valve 14 is composed of a three-way valve and the like, and branches the residue discharge pipe 11B to the first residue pipe 12 and the second residue pipe 13. That is, the first opening of the three openings of the residue path branch valve 14 is connected to the outlet end of the residue discharge pipe 11B, the second opening is connected to the inlet end of the first residue pipe 12, and the third opening is connected to the inlet end of the second residue pipe 13. The residue path branch valve 14 adjusts the openings by increasing the opening of one of the openings between the residue discharge pipe 11B and the first residue pipe 12 and the opening of the residue discharge pipe 11B and the second residue pipe 13 and reducing the opening of the other. In the second embodiment, the residue path branch valve 14 adjusts the opening of one of the openings to be fully opened and the opening of the other to be fully closed. For example, the opening adjustment is controlled by the control device 19A, and based on the control, the residue path branch valve 14 connects the residue discharge pipe 11B to either the first residue pipe 12 or the second residue pipe 13. When the ship internal combustion engine 110 is operated with alternative fuel, such a residue path branch valve 14 connects the residue discharge pipe 11B to the first residue pipe 12, and when the ship internal combustion engine 110 is operated with fossil fuel, such a residue path branch valve 14 connects the residue discharge pipe 11B to the second residue pipe 13.

[0124] The control device 19A controls the flow of washing water and residue in the water treatment device 10A. Specifically, the control device 19A is composed of a CPU, a memory, and a sequencer for executing various programs. When controlling the flow of residue, the control device 19A receives an electrical signal from the ship internal combustion engine 110, and controls the above-mentioned residue path branch valve 14 based on the received electrical signal. In addition, when controlling the flow of washing water, the control device 19A controls the above-mentioned branch valve 5 and the drainage path branch valve 9 respectively, similarly to the control device 19 in the above-mentioned embodiment 1.

[0125] For example, the control device 19A determines whether the operation mode of the ship internal combustion engine 110 is the alternative fuel operation or the fossil fuel operation based on the electrical signal received from the ship internal combustion engine 110. In the case of alternative fuel operation, the control device 19A controls the opening of the residue path branch valve 14 in such a way that the residue discharge pipe 11B is connected to the first residue pipe 12. Thus, the control device 19A controls the flow of residue in such a way that the residue from the foreign matter removal system 3 is discharged to the outside of the ship. In the case of fossil fuel operation, the control device 19A controls the opening of the residue path branch valve 14 in such a way that the residue discharge pipe 11B is connected to the second residue pipe 13. Thus, the control device 19A controls the flow of residue in such a way that the residue from the foreign matter removal system 3 is discharged to the waste residue tank 15 in the ship.

[0126] Next, a description will be given of a procedure for controlling the flow of residues by the water treatment apparatus 10A. Figure 4 This is a flowchart illustrating a control procedure for the flow of residues in a water treatment device according to Embodiment 2 of the present invention. Figure 3 ), the control device 19A performs Figure 4 The processes of steps S201 to S203 shown are used to control the flow of the residue to be discharged.

[0127] Specifically, in the control of the flow of the residue in the water treatment device 10A, as shown in FIG. Figure 4 As shown, the control device 19A first determines the operation mode (engine operation mode) of the marine internal combustion engine 110 (step S201). In step S201, the control device 19A performs the same operation as step S103 in the above-mentioned first embodiment (see Figure 2 ) Similarly, based on the electrical signal from the ship internal combustion engine 110, it is determined whether the engine operation mode is the alternative fuel operation mode or the fossil fuel operation mode.

[0128] When it is determined that the engine operation mode is the alternative fuel operation mode (step S201, alternative fuel), the control device 19A controls the opening of the residue path branch valve 14 so as to open the first residue pipe 12 (step S202). Thereafter, the control device 19A returns to the above-mentioned step S201 and repeats the processing after step S201.

[0129] In step S202, the control device 19A controls the opening of the residue path branch valve 14 in such a manner that the first residue pipe 12 side of the residue path branch valve 14 is fully opened and the second residue pipe 13 side is fully closed. Based on this opening control, the residue path branch valve 14 switches the flow destination of the residue from the residue discharge pipe 11B from the second residue pipe 13 side to the first residue pipe 12 side. That is, the residue path branch valve 14 cuts off the connection between the residue discharge pipe 11B and the second residue pipe 13, and connects the residue discharge pipe 11B with the first residue pipe 12. The control device 19A controls the flow of the residue in the alternative fuel operation mode by controlling the opening of the residue path branch valve 14 so that the residue is discharged to the outside of the ship (dumped at sea) through the residue discharge pipe 11B and the first residue pipe 12.

[0130] Here, when the engine operation mode is the alternative fuel operation mode, the residue separated and removed from the washing water used for washing the exhaust gas does not contain foreign matter containing carbon components, as in the case of the above-mentioned washing waste water. Such residues that do not contain foreign matter containing carbon components can be disposed of in the ocean according to the discharge regulations.

[0131] On the other hand, in the above-mentioned step S201, when it is determined that the engine operation mode is the fossil fuel operation mode (step S201, fossil fuel), the control device 19A controls the opening degree of the residue path branch valve 14 so as to open the second residue pipe 13 (step S203). Thereafter, the control device 19A returns to the above-mentioned step S201 and repeats the processing after the step S201.

[0132] In step S203, the control device 19A controls the opening of the residue path branch valve 14 in such a manner that the first residue pipe 12 side of the residue path branch valve 14 is completely closed and the second residue pipe 13 side is completely opened. Based on this opening control, the residue path branch valve 14 switches the flow destination of the residue from the residue discharge pipe 11B from the first residue pipe 12 side to the second residue pipe 13 side. That is, the residue path branch valve 14 cuts off the connection between the residue discharge pipe 11B and the first residue pipe 12, and connects the residue discharge pipe 11B with the second residue pipe 13. The control device 19A controls the flow of the residue in the fossil fuel operation mode through the residue discharge pipe 11B and the second residue pipe 13 to discharge the residue to the waste residue tank 15 in the ship.

[0133] Here, when the engine operation mode is the fossil fuel operation mode, the residue separated and removed from the washing water used for washing the exhaust gas contains foreign matter containing carbon components, similarly to the above-mentioned washing waste water. Such residue containing foreign matter containing carbon components cannot be dumped into the ocean, but is temporarily stored in the waste residue tank 15 and disposed of after unloading.

[0134] In addition, the control device 19A controls the flow of washing water in parallel with the control of the flow of the above-mentioned residue. The control sequence of the flow of washing water by the control device 19A is the same as that of steps S101 to S106 in the above-mentioned embodiment 1 (see Figure 2 )same.

[0135] As described above, the water treatment device 10A of the second embodiment of the present invention includes: a residue discharge pipe 11B for discharging residue from the foreign matter removal system 3; a first residue pipe 12 for discharging residue to the outside of the ship; a second residue pipe 13 for discharging residue to a storage tank inside the ship; and a residue path branching valve 14 for branching the residue discharge pipe 11B into the first residue pipe 12 and the second residue pipe 13 and connecting the residue discharge pipe 11B to either the first residue pipe 12 or the second residue pipe 13, and also includes the same components as those of the first embodiment. In addition, in the water treatment device 10A, when the ship internal combustion engine 110 is operated with alternative fuel, the residue path branching valve 14 connects the residue discharge pipe 11B with the first residue pipe 12, and when the ship internal combustion engine 110 is operated with fossil fuel, the residue path branching valve 14 connects the residue discharge pipe 11B with the second residue pipe 13.

[0136] Through the above-mentioned structure, the same effect as the above-mentioned embodiment 1 can be obtained, and the discharge path of the residue can be switched to any one of a discharge path for discharge to the outside of the ship (dumping at sea) and a discharge path for discharge (storage) in a storage tank inside the ship according to the operation mode (alternative fuel operation mode or fossil fuel operation mode) of the ship internal combustion engine 110. Therefore, in addition to the above-mentioned washing wastewater, it is also possible to choose whether to discharge the residue separated and removed from the washing water after cleaning the exhaust gas to the outside of the ship. Specifically, in the alternative fuel operation mode, the washing wastewater and residue that do not contain foreign matter containing carbon components do not need to be stored in the storage tank inside the ship, and can be dumped at sea. In the fossil fuel operation mode, the washing wastewater and residue that contain foreign matter containing carbon components can be stored in the storage tank inside the ship without dumping at sea.

[0137] In the above-mentioned embodiments 1 and 2, the opening degree control of the branch valve 5 and the drainage branch valve 9 is automatically performed by the control device 19 and 19A, but the present invention is not limited to this. For example, the opening degree control of the branch valve 5 and the drainage branch valve 9 can also be manually controlled by the operator.

[0138] In the second embodiment, the opening degree of the residue path branch valve 14 is automatically controlled by the control device 19A, but the present invention is not limited thereto. For example, the opening degree of the residue path branch valve 14 may be manually controlled by an operator.

[0139] In addition, in the above-mentioned embodiments 1 and 2, when the washing wastewater is discharged from the foreign matter removal system 3, the washing wastewater discharge pipe side of the branch valve 5 is fully opened and the confluence pipe side (circulation system side) is fully closed, but the present invention is not limited to this. For example, when the washing wastewater is discharged from the foreign matter removal system 3, both the washing wastewater discharge pipe side and the confluence pipe side of the branch valve 5 may be opened (intermediate opening).

[0140] In the above-mentioned embodiments 1 and 2, the specific gravity of the washing water in the piping (branch pipe 31, etc.) on the inlet side of the centrifuge 34 is measured by the hydrometer 4, but the present invention is not limited to this. For example, the specific gravity of the washing water measured by the hydrometer 4 may be measured in the piping (outlet pipe 32, etc.) on the outlet side of the centrifuge 34. Alternatively, the specific gravity of the washing water measured by the hydrometer 4 may be measured in the flow path of the washing water outside the foreign matter removal system such as the circulation pipe 21, the recovery pipe 104 or the collection tank 1.

[0141] In addition, in the above-mentioned embodiments 1 and 2, the second drain pipe 8 and the residue discharge pipes 11 and 11B and the second residue pipe 13 are respectively connected to the waste residue tank 15, but the present invention is not limited thereto. For example, the second drain pipe 8 and the residue discharge pipes 11 and 11B may be merged and connected to the waste residue tank 15, or the second drain pipe 8 and the second residue pipe 13 may be merged and connected to the waste residue tank 15.

[0142] In the above-mentioned embodiments 1 and 2, the scrubber 101 of the EGR system 100 is illustrated as an example of a scrubber to which the water treatment device of the present invention is applied, but the present invention is not limited thereto. For example, the water treatment device of the present invention may also be applied to an exhaust gas cleaning device (scrubber) other than the EGR system.

[0143] In addition, in the above-mentioned embodiments 1 and 2, the centrifugal separator 34 is exemplified as a device for separating washing water into residue and washing wastewater to remove foreign matter, but the present invention is not limited thereto. For example, the device for separating washing water into residue and washing wastewater to remove foreign matter may be a device for removing foreign matter from washing water by utilizing the specific gravity difference between washing water and foreign matter, or may be a device for removing foreign matter from washing water without utilizing the specific gravity difference between washing water and foreign matter (e.g., a filtering device, etc.). That is, in the present invention, the type of the device is not particularly limited.

[0144] In the above-mentioned embodiments 1 and 2, the openings of the branch valve 5 and the drainage branch valve 9 are controlled by a single control device (control device 19 of embodiment 1 or control device 19A of embodiment 2), but the present invention is not limited thereto. For example, the opening of the branch valve 5 may be controlled by a control device (not shown) different from the above-mentioned control devices 19 and 19A according to the specific gravity of the washing water. In this case, the control devices 19 and 19A may be appropriately repeated. Figure 2 The processing sequence of steps S103 to S105 in steps S101 to S106 shown in FIG. 1 (ie, the processing sequence for controlling the opening degree of the drain passage branch valve 9 according to the engine operation mode).

[0145] In addition, the above-mentioned embodiments 1 and 2 do not limit the present invention. The mode of appropriately combining the above-mentioned constituent elements is also included in the present invention. In addition, other embodiments, examples and application technologies implemented by those skilled in the art based on the above-mentioned embodiments 1 and 2 are also included in the scope of the present invention.

Claims

1. A water treatment device for cleaning exhaust gas discharged from an internal combustion engine for a ship, treating wash water containing foreign matter removed from the exhaust gas, characterized in that: have: a foreign matter removal system for separating the wash water into a residue containing the foreign matter and a wash wastewater containing less foreign matter than the residue, thereby removing the foreign matter from the wash water; A waste residue tank storing the residue and the washing wastewater; a washing waste water discharge pipe for discharging the washing waste water from the foreign matter removal system; a first drain pipe, the first drain pipe being used to discharge the washing wastewater outboard; a second drain pipe, the second drain pipe being used to discharge the washing waste water into the waste residue tank; as well as a drainage branch valve, the drainage branch valve branches the washing wastewater discharge pipe to the first drain pipe and the second drain pipe, and connects the washing wastewater discharge pipe to either the first drain pipe or the second drain pipe, When the ship's internal combustion engine performs alternative fuel operation in which at least decarbonized fuel is burned, the drain channel branch valve connects the washing wastewater discharge pipe with the first drain pipe. When the ship's internal combustion engine performs fossil fuel operation in which fossil fuel is burned, the drain channel branch valve connects the washing wastewater discharge pipe with the second drain pipe.

2. The water treatment device according to claim 1, characterized in that: have: a residue discharge pipe for discharging the residue from the foreign matter removal system; a first residue pipe, the first residue pipe being used to discharge the residue outboard of the ship; a second residue pipe, the second residue pipe being used to discharge the residue into the waste residue tank; as well as a residue path branching valve, the residue path branching valve branches the residue discharge pipe to the first residue pipe and the second residue pipe, and connects the residue discharge pipe to either the first residue pipe or the second residue pipe, When the ship internal combustion engine is operating with the alternative fuel, the residue path branch valve connects the residue discharge pipe with the first residue pipe, and when the ship internal combustion engine is operating with the fossil fuel, the residue path branch valve connects the residue discharge pipe with the second residue pipe.

3. The water treatment device according to claim 1 or 2, characterized in that: A control device is also provided for determining whether the operation mode of the ship internal combustion engine is the alternative fuel operation or the fossil fuel operation. In the case of the alternative fuel operation, the control device controls the opening of the drain path branch valve in such a way that the washing waste water discharge pipe is connected to the first drain pipe. In the case of the fossil fuel operation, the control device controls the opening of the drain path branch valve in such a way that the washing waste water discharge pipe is connected to the second drain pipe.

4. The water treatment device according to claim 2, characterized in that: A control device is also provided for determining whether the operation mode of the ship internal combustion engine is the alternative fuel operation or the fossil fuel operation. In the case of the alternative fuel operation, the control device controls the opening of the residue path branch valve in such a way that the residue discharge pipe is connected to the first residue pipe. In the case of the fossil fuel operation, the control device controls the opening of the residue path branch valve in such a way that the residue discharge pipe is connected to the second residue pipe.

Images