JP7214346B2 - water treatment equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water treatment apparatus for treating cleaning water of exhaust gas from a marine diesel engine mounted on a ship.

2. Description of the Related Art Conventionally, in the field of ships, an exhaust gas cleaning device (scrubber) for cleaning exhaust gas discharged from a marine diesel engine is known. In general, a scrubber injects cleaning water into the exhaust gas, thereby removing foreign matter such as sulfur oxides (SOx) and fine particles (PM) such as dust in the exhaust gas to clean the exhaust gas. Such scrubbers are provided, for example, in Exhaust Gas Recirculation (EGR) systems, which is one method of reducing nitrogen oxides (NOx) in exhaust gases.

The EGR system scrubs a portion of the exhaust gas discharged from the marine diesel engine with a scrubber, mixes the cleaned exhaust gas with air, and recirculates it to the marine diesel engine. As a result, the EGR system suppresses the generation of NOx due to the combustion of fuel in the combustion chamber of the marine diesel engine, thereby reducing the NOx content in the exhaust gas (that is, the amount of NOx emissions).

On the other hand, the water used for cleaning the exhaust gas in the scrubber (hereinafter referred to as scrubber water as appropriate) is used again for cleaning the exhaust gas while adjusting the pH (neutralization) and removing foreign matter after cleaning the exhaust gas. (see, for example, Patent Documents 1 to 3). For this reason, the scrubber is applied with a water treatment device that performs treatments such as adjustment of pH and removal of foreign matter from the scrubber water.

In the water treatment apparatus, the pH of the scrubber water is adjusted by injecting a chemical solution having a high alkaline value such as NaOH (hereinafter referred to as an alkaline solution as appropriate) into the scrubber water. In addition, the removal of foreign matter from the scrubber water may be performed, for example, by using a centrifugal separator to separate the scrubber water and the foreign matter by utilizing the difference in specific gravity. and foreign matter without using the difference in specific gravity.

Japanese Patent No. 5968954 Japanese Patent No. 5859463 Japanese Patent No. 5784719

By the way, in adjusting the pH of the scrubber water, by-products such as Na ₂ SO ₄ are produced in the scrubber water due to the neutralization reaction of the scrubber water caused by the injection of alkaline solution. As this by-product increases, the specific gravity of the scrubber water increases. This increase in the specific gravity reduces the difference in specific gravity between the scrubber water and the foreign matter, thereby causing a decrease in the ability of the centrifuge to separate the scrubber water and the foreign matter. Due to this, in the water treatment apparatus, there arises a problem that it becomes difficult to remove the foreign matter from the scrubber water. On the other hand, even if the foreign matter is removed from the scrubber water by a filtration device or the like without using the difference in specific gravity between the scrubber water and the foreign matter, the concentration of by-products in the scrubber water increases as the specific gravity of the scrubber water increases. exceeds the limit value (solubility), and by-products such as Na ₂ SO ₄ cannot be completely dissolved in the scrubber water and precipitate out. Due to this, by-products (precipitates) adhere to the inner wall of the pipe, causing problems such as obstructing the flow of scrubber water and clogging the liquid injection part of the scrubber. In order to solve these problems, conventionally, the scrubber water whose specific gravity has increased is periodically discharged out of the ship, such as the sea, and the scrubber water remaining in the ship is replenished with fresh water so that it can be used in the scrubber. Liquid specific gravity control is performed to lower the specific gravity of the scrubber water.

In the above-mentioned liquid specific gravity control, the scrubber water to be discharged overboard must comply with predetermined discharge regulations, for example, must have a pH of 6.5 or more, and must have a polycyclic aromatic hydrocarbon (PAH) concentration of 2250 μg. /L or less and the turbidity is 25 NTU or less. For this reason, centrifugal separation processing for removing foreign matter from the scrubber water to be discharged may not be sufficient in one stage, and may have to be performed in multiple stages (two or more stages) using a plurality of centrifugal separators. In addition, an inspection device for inspecting whether the scrubber water to be discharged satisfies the above-mentioned emission regulations is necessary, and furthermore, the scrubber water to be discharged is distributed between these devices or outboard. Piping, etc. are required.

On the other hand, foreign matter (also called residue) removed from the scrubber water cannot be discharged overboard due to emission regulations, regardless of its properties. Therefore, the foreign matter is temporarily stored in a tank, landed at an appropriate timing, and disposed of (for example, disposed of as industrial waste).

As described above, in the conventional technology, two types of discharged objects, namely, scrubber water discharged overboard and foreign substances discharged on land and discarded, are generated in the ship that require different handling for discharge. For this reason, in the limited space of the ship, it is necessary to install the equipment and piping necessary for discharging the scrubber water overboard and the equipment and piping necessary for the temporary storage of foreign objects to be landed. And there is a problem that the configuration of piping becomes complicated. As a result, the manufacturing cost of the ship increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water treatment system in which the devices and piping necessary for discharging scrubber water and foreign matter can be easily constructed in a ship. do.

In order to solve the above-described problems and achieve the object, a water treatment apparatus according to the present invention is a water treatment apparatus applied to a scrubber for cleaning exhaust gas discharged from a marine diesel engine using scrubber water. , a collecting tank for collecting the scrubber water used for cleaning the exhaust gas in the scrubber, a fresh water replenishment system for replenishing the collecting tank with fresh water for diluting the scrubber water, and from the collecting tank A circulation system for circulating the scrubber water toward the scrubber, and a removal device for removing foreign matter in the scrubber water, extracting the scrubber water from the circulation system and removing the foreign matter from the extracted scrubber water. A foreign matter removal system for returning the scrubber water removed by a device to the circulation system, a foreign matter discharge pipe for discharging the foreign matter from the foreign matter removal system, and the foreign matter discharged through the foreign matter discharge pipe. a storage tank for storing the scrubber water, a hydrometer for measuring the specific gravity of the scrubber water, and when the measured specific gravity is equal to or higher than a predetermined reference value, the scrubber water is discharged from the foreign matter removal system to the storage tank and a control device for controlling the flow of the scrubber water.

In the above invention, the water treatment apparatus according to the present invention further includes a level detector for detecting the liquid level of the scrubber water in the collecting tank, and the control device controls the detected liquid level. is less than a predetermined low level, controlling the fresh water replenishment system to start replenishing fresh water to the collecting tank; and controlling the fresh water replenishment system so as to stop replenishment of fresh water to the tank.

Further, the water treatment apparatus according to the present invention, in the above invention, includes a branch valve provided in the piping of the foreign matter removal system, a scrubber water discharge pipe branching from the piping of the foreign matter removal system through the branch valve, wherein, when the measured specific gravity is equal to or greater than the reference value, the control device operates the branch valve so that the scrubber water is discharged from the foreign matter removal system through the scrubber water discharge pipe to the storage tank. It is characterized by controlling the degree of opening.

Further, in the water treatment apparatus according to the present invention, in the above invention, when the detected liquid level is lower than a predetermined low level, the control device controls the branch valve to close the scrubber water discharge pipe. is characterized by controlling the opening of the

Further, in the water treatment apparatus according to the present invention, in the above invention, when the measured specific gravity is less than the reference value, the controller controls the opening degree of the branch valve so as to close the scrubber water discharge pipe. is characterized by controlling

Further, in the water treatment apparatus according to the present invention, in the above invention, the outlet end of the scrubber water discharge pipe is connected to an intermediate portion of the foreign matter discharge pipe, and the scrubber water in the scrubber water discharge pipe is connected to the foreign matter discharge pipe. It is characterized in that it is discharged to the storage tank through a discharge pipe.

Further, in the water treatment apparatus according to the present invention, in the above invention, the foreign matter removal system extracts the scrubber water from the circulation system, and a first pipe leading the extracted scrubber water to the removal device; a second pipe for returning the scrubber water after the removal of foreign matter by the removal device to the circulation system, wherein the second pipe is a pipe of the foreign matter removal system in which the branch valve is provided. It is characterized by

Further, in the water treatment apparatus according to the present invention, in the above invention, when the measured specific gravity is equal to or higher than the reference value, the control device controls the storage tank through the foreign matter discharge pipe from the removal device together with the foreign matter. and controlling the removal device so as to increase the flow rate of the scrubber water discharged to the above compared to when the measured specific gravity is less than the reference value.

In the water treatment apparatus according to the present invention, in the above invention, when the detected liquid level is below a predetermined low level, the liquid level is reduced from the removal device to the foreign matter discharge pipe together with the foreign matter. The removing device is controlled so as to reduce the flow rate of the scrubber water discharged to the storage tank, compared to when the measured specific gravity is equal to or greater than the reference value.

Further, in the water treatment apparatus according to the present invention, in the above invention, when the measured specific gravity is less than the reference value, the controller controls the storage tank through the foreign matter discharge pipe from the removal device together with the foreign matter. and controlling the removal device so as to reduce the flow rate of the scrubber water discharged to the above compared to when the measured specific gravity is equal to or greater than the reference value.

Further, in the water treatment apparatus according to the present invention, in the above invention, the removal device is a centrifugal separator that removes foreign matter in the scrubber water by utilizing a difference in specific gravity from the scrubber water. .

Advantageous Effects of Invention According to the water treatment apparatus of the present invention, it is possible to easily configure the apparatus and piping necessary for discharging scrubber water and foreign matter in a ship.

FIG. 1 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 1 of the present invention. FIG. 2 is a flow diagram illustrating one treatment procedure for scrubber water treatment by the water treatment apparatus according to Embodiment 1 of the present invention. FIG. 3 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 2 of the present invention. FIG. 4 is a flow diagram illustrating one treatment procedure for scrubber water treatment by the water treatment apparatus according to Embodiment 2 of the present invention. FIG. 5 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 3 of the present invention. FIG. 6 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 4 of the present invention. FIG. 7 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 5 of the present invention. FIG. 8 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 6 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of a water treatment device according to the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment. Also, it should be noted that the drawings are schematic, and the dimensional relationship of each element, the ratio of each element, and the like may differ from the actual ones. Even between the drawings, there are cases where portions with different dimensional relationships and ratios are included. Moreover, in each drawing, the same code|symbol is attached|subjected to the same component.

(Embodiment 1)
A configuration of a water treatment apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 1 of the present invention. A water treatment apparatus 10 according to Embodiment 1 of the present invention is for treating cleaning water of exhaust gas from a marine diesel engine 110 mounted on a ship. It comprises a collecting tank 1 for storing water, a circulation system 2 for circulating the scrubber water, and a foreign matter removal system 3 for removing foreign matter in the scrubber water. Further, the water treatment device 10 includes a specific gravity meter 4 for measuring the specific gravity of the scrubber water, a scrubber water discharge pipe 5 for discharging scrubber water whose specific gravity has increased excessively, a pipe of the foreign matter removal system 3 and the scrubber water discharge. A branch valve 6 interposed between the pipe 5, a foreign matter discharge pipe 7 for discharging foreign matter removed from the scrubber water, a check valve 8 for preventing backflow in the foreign matter discharge pipe 7, and foreign matter and a sludge tank 9 for storing such as. Further, the water treatment device 10 includes a fresh water supply system 11 for supplying fresh water to the collecting tank 1 , a chemical supply system 12 for adjusting the pH of the scrubber water, and a liquid level of the scrubber water in the collecting tank 1 . A level detector 13 for detecting Ls, a pH meter 14 for measuring the pH of the scrubber water, and a controller 15 are provided.

Further, as shown in FIG. 1, the water treatment device 10 is applied to a scrubber 101 that cleans exhaust gas discharged from a marine diesel engine 110 using scrubber water. In Embodiment 1, the scrubber 101 is one component of the EGR system 100 that recirculates part of the exhaust gas from the marine diesel engine 110 to the marine diesel engine 110 as recirculated gas. Hereinafter, exhaust gas means exhaust gas discharged from the marine diesel engine 110 .

In FIG. 1, the distribution and piping of fluids such as scrubber water and exhaust gas are appropriately illustrated by solid-line arrows. Electrical signal lines are appropriately illustrated by dashed-dotted lines. This also applies to the following.

A collecting tank 1 is a tank for collecting scrubber water. As shown in FIG. 1 , the collecting tank 1 is arranged below a demister 102 connected to a scrubber 101 in the EGR system 100 and communicates with the demister 102 via a recovery pipe 104 . The collecting tank 1 collects the scrubber water used for cleaning the exhaust gas in the scrubber 101 from the demister 102 through the collection pipe 104 . At this time, the used scrubber water flows from the scrubber 101 into the demister 102 and into the collecting tank 1 through the recovery pipe 104 by the action of gravity, for example. The collecting tank 1 temporarily stores the scrubber water thus collected.

The circulation system 2 is a system for circulating scrubber water from the collecting tank 1 toward the scrubber 101 . As shown in FIG. 1, the circulation system 2 includes a circulation pipe 2a, a circulation pump 2b, and a regulation valve 2c.

The circulation pipe 2 a has an inlet end connected to the bottom of the collecting tank 1 and an outlet end connected to the inlet end of the injection pipe 101 a of the scrubber 101 . The circulation pump 2b is provided in the middle of the circulation pipe 2a. The circulation pump 2 b pressure-feeds the scrubber water that has flowed from the collecting tank 1 into the circulation pipe 2 a toward the scrubber 101 . Thereby, the circulation pump 2b generates a flow of scrubber water from the collecting tank 1 side to the scrubber 101 side in the circulation pipe 2a. The regulating valve 2c is provided in the middle of the circulation pipe 2a and downstream of the circulation pump 2b in the flow direction of the scrubber water. The adjustment valve 2c adjusts the flow rate of the scrubber water flowing through the circulation pipe 2a by controlling the degree of opening. The degree of opening of this adjustment valve 2c may be controlled by the control device 15, controlled by another control device (not shown), or manually controlled.

In the circulation system 2 having such a configuration, the circulation pipe 2a sends the scrubber water in the collecting tank 1 to the injection pipe 101a of the scrubber 101 by the action of the circulation pump 2b. The scrubber water sent to the injection pipe 101 a is injected from a liquid injection part such as an injection nozzle of the scrubber 101 and used (reused) for cleaning the exhaust gas in the scrubber 101 . The scrubber water used for cleaning the exhaust gas flows from the scrubber 101 into the demister 102 in a state containing foreign matter (soot dust, SOx, etc.) removed from the exhaust gas, and is then collected in the collecting tank 1 through the collection pipe 104. be. Thus, the circulation system 2 repeatedly circulates scrubber water between the collecting tank 1 and the scrubber 101 .

The foreign matter removal system 3 extracts scrubber water from the circulation system 2 , removes foreign matter in the extracted scrubber water, and returns the scrubber water after removing the foreign matter to the circulation system 2 . Such a foreign matter removal system 3 includes a branch pipe 3a, an outlet pipe 3b, a junction pipe 3c, and a centrifuge 3d, as shown in FIG.

The branch pipe 3a constitutes a pipe for extracting scrubber water from the circulation system 2 (first pipe in the foreign matter removal system 3). As shown in FIG. 1, the branch pipe 3a has an inlet end connected to the circulation pipe 2a of the circulation system 2 and an outlet end connected to the inlet of the centrifuge 3d. In the first embodiment, the branch pipe 3a branches off from the circulation pipe 2a at a position between the circulation pump 2b and the regulating valve 2c to allow the circulation pipe 2a and the centrifuge 3d to communicate with each other. The branch pipe 3a extracts a part of the scrubber water flowing through the circulation pipe 2a and guides the scrubber water extracted from the circulation pipe 2a to the centrifuge 3d.

The outlet pipe 3b and the confluence pipe 3c constitute a pipe (second pipe in the foreign matter removal system 3) for returning the scrubber water after the foreign substances have been removed by the centrifuge 3d to the circulation system 2. As shown in FIG. 1, the outlet tube 3b is connected at its inlet end to the outlet of the centrifuge 3d and at its outlet end to the branch valve 6. As shown in FIG. The outlet pipe 3 b receives scrubber water from the centrifugal separator 3 d after removing foreign substances by the centrifugal separator 3 d and guides the received scrubber water to the branch valve 6 . In addition, the outlet pipe 3b is connected to the confluence pipe 3c and the scrubber water discharge pipe 5 through the branch valve 6 so as to be able to communicate therewith. That is, the second pipe (the outlet pipe 3b and the confluence pipe 3c) in the foreign matter removal system 3 is the pipe provided with the branch valve 6 among the pipes of the foreign matter removal system 3. As shown in FIG. In Embodiment 1, the scrubber water guided from the outlet pipe 3 b to the branch valve 6 flows through the branch valve 6 into either the confluence pipe 3 c or the scrubber water discharge pipe 5 .

The confluence pipe 3c is a pipe for returning the scrubber water to the circulation system 2 after foreign matter has been removed by the centrifuge 3d. As shown in FIG. 1, the confluence pipe 3c has an inlet end connected to the branch valve 6 and an outlet end connected to an intermediate portion of the circulation pipe 2a (for example, downstream of the adjustment valve 2c in the flow direction of the scrubber water). be. The confluence pipe 3c receives the scrubber water from the outlet pipe 3b through the branch valve 6 after removing the foreign matter, and returns the received scrubber water to the circulation pipe 2a.

The centrifugal separator 3 d is an example of a removal device that removes foreign matter in the scrubber water in the foreign matter removal system 3 . In Embodiment 1, the centrifugal separator 3d receives scrubber water extracted from the circulation pipe 2a through the branch pipe 3a (first pipe), and removes foreign substances in the received scrubber water. At this time, the centrifugal separator 3d exerts a centrifugal force on the received scrubber water, and separates and removes the foreign matter from the scrubber water using the difference in specific gravity between the scrubber water and the foreign matter. The centrifugal separator 3 d sends out the scrubber water from which foreign matter has been removed to the outlet pipe 3 b and sends out the foreign matter (residue) removed from the scrubber water to the foreign matter discharge pipe 7 .

A specific gravity meter 4 measures the specific gravity of the scrubber water. In this embodiment, the hydrometer 4 is provided in the branch pipe 3a, as shown in FIG. 1, for example. The hydrometer 4 measures the specific gravity of the scrubber water flowing through the branch pipe 3a (that is, the scrubber water extracted from the circulation pipe 2a through the branch pipe 3a). The measurement of the specific gravity of the scrubber water by the hydrometer 4 may be performed continuously along the time series, may be performed intermittently at predetermined time intervals, or may be measured as instructed by the control device 15. may be done in some cases. The specific gravity meter 4 transmits an electric signal indicating the obtained specific gravity (measured value) of the scrubber water to the control device 15 each time the specific gravity of the scrubber water is measured.

The scrubber water discharge pipe 5 is a pipe for discharging scrubber water whose specific gravity has increased excessively, and branches from the pipe of the foreign matter removal system 3 via a branch valve 6 . In the first embodiment, as shown in FIG. 1, the scrubber water discharge pipe 5 has an inlet end connected to the branch valve 6 and an outlet end connected to the middle portion of the foreign matter discharge pipe 7 . The scrubber water discharge pipe 5 receives the scrubber water from the outlet pipe 3 b via the branch valve 6 after removing the foreign matter, and circulates the received scrubber water toward the sludge tank 9 . At this time, the scrubber water in the scrubber water discharge pipe 5 joins the foreign matter discharge pipe 7 from the scrubber water discharge pipe 5 and is discharged to the sludge tank 9 through the foreign matter discharge pipe 7 .

The branch valve 6 is a valve for causing the scrubber water in the piping of the foreign matter removal system 3 to flow to the circulation pipe 2a side or the scrubber water discharge pipe 5 side. As shown in FIG. 1, the branch valve 6 is configured by a three-way valve or the like, and is provided in the piping of the foreign matter removal system 3 (the second piping configured by the outlet pipe 3b and the confluence pipe 3c in the first embodiment). . Specifically, of the three openings of the branch valve 6, the first opening is connected to the outlet end of the outlet pipe 3b, and the second opening is connected to the inlet end of the confluence pipe 3c. , the inlet end of the scrubber water discharge pipe 5 is connected to the third opening. The branch valve 6 has an opening degree between the outlet pipe 3b and the merging pipe 3c and an opening degree between the outlet pipe 3b and the scrubber water discharge pipe 5. Each of these openings is adjusted by, for example, decreasing the opening. In the first embodiment, the branch valve 6 adjusts one of these openings to fully open, thereby adjusting the other opening to fully close. This opening degree adjustment is controlled by the control device 15, and based on this control, the branch valve 6 directs the flow of the scrubber water from the outlet pipe 3b to the confluence pipe 3c (circulation pipe 2a side) and the scrubber water discharge pipe 5 (sludge). tank 9 side).

The foreign matter discharge pipe 7 is a pipe for discharging foreign matter removed from the scrubber water from the foreign matter removal system 3 . As shown in FIG. 1, the foreign matter discharge pipe 7 is connected at its inlet end to the residue discharge port of the centrifuge 3d and connected to the sludge tank 9 at its outlet end. The foreign matter discharge pipe 7 receives foreign matter (for example, sludge-like residue) removed from the scrubber water by the centrifuge 3 d and discharges the received foreign matter to the sludge tank 9 . Further, in Embodiment 1, the scrubber water discharge pipe 5 is connected to the intermediate portion of the foreign matter discharge pipe 7 as described above. The foreign matter discharge pipe 7 discharges the scrubber water flowing from the scrubber water discharge pipe 5 to the sludge tank 9 .

The check valve 8 is a valve for preventing foreign matters, scrubber water, and other objects to be discharged from flowing in the foreign matter discharge pipe 7 from the sludge tank 9 side to the centrifugal separator 3 d side (that is, reverse flow). As shown in FIG. 1 , the check valve 8 is provided in the middle of the foreign matter discharge pipe 7 and closer to the centrifugal separator 3 d than the confluence of the scrubber water discharge pipe 5 and the foreign matter discharge pipe 7 . The check valve 8 prevents the foreign matter sent from the centrifuge 3d to the foreign matter discharge pipe 7 to flow back to the centrifuge 3d side, and prevents the scrubber water that joins the foreign matter discharge pipe 7 from the scrubber water discharge pipe 5 to be centrifuged. It prevents backflow to the separator 3d side.

The sludge tank 9 is a storage tank that stores at least foreign matter discharged through the foreign matter discharge pipe 7 . As shown in FIG. 1, the sludge tank 9 is provided below the centrifuge 3d, and is connected to the foreign matter discharge pipe 7 as described above. In the first embodiment, the sludge tank 9 collects and stores the foreign substances and scrubber water discharged through the foreign substance discharge pipe 7 and the like until they are unloaded from the ship.

The fresh water supply system 11 is a system for supplying the collecting tank 1 with fresh water for diluting the scrubber water. As shown in FIG. 1, the fresh water supply system 11 includes a fresh water tank 11a, a supply pipe 11b, and a supply pump 11c. The fresh water tank 11a is a tank that stores fresh water. The fresh water stored in the fresh water tank 11a includes, for example, fresh water loaded from outside the ship, fresh water produced inside the ship, drain water discharged from the marine diesel engine 110, and the like. The supply pipe 11b is a pipe that guides fresh water from the fresh water tank 11a to the collecting tank 1. As shown in FIG. Specifically, the supply pipe 11b has an inlet end connected to the fresh water tank 11a and an outlet end connected to the collecting tank 1 . The replenishment pump 11c is provided in the middle of the replenishment pipe 11b, and generates a fresh water flow from the fresh water tank 11a side to the collecting tank 1 side in the replenishment pipe 11b.

The fresh water replenishing system 11 having such a configuration replenishes the collecting tank 1 with fresh water from the fresh water tank 11a through the replenishing pipe 11b by the action of the replenishing pump 11c. As a result, the scrubber water in the collecting tank 1 is diluted while being increased, and the specific gravity of the scrubber water is lowered. In the first embodiment, the control device 15 controls each timing of starting and stopping fresh water replenishment by the fresh water replenishment system 11 (that is, operation timing of the replenishment pump 11c).

The chemical supply system 12 is a system for supplying the collecting tank 1 with a chemical for adjusting (neutralizing) the pH of the scrubber water. In the first embodiment, every time the scrubber water is used for cleaning the exhaust gas in the scrubber 101, the content of foreign matter such as SOx removed from the exhaust gas is increased, thereby advancing the acidification of the scrubber water. Therefore, a chemical solution having a high alkaline value (alkaline solution) is used as the chemical solution for adjusting the pH of the scrubber water.

As shown in FIG. 1, the chemical solution supply system 12 includes an alkaline solution tank 12a, a supply pipe 12b, and a supply pump 12c. The alkaline liquid tank 12a is a tank that stores an alkaline liquid such as NaOH. The supply pipe 12b is a pipe that guides the alkaline solution from the alkaline solution tank 12a to the collecting tank 1. As shown in FIG. Specifically, the supply pipe 12b has an inlet end connected to the alkaline liquid tank 12a and an outlet end connected to the collecting tank 1 . The supply pump 12c is provided in the middle of the supply pipe 12b and causes the alkaline solution to flow from the side of the alkaline solution tank 12a toward the side of the collecting tank 1 in the supply pipe 12b.

The chemical solution supply system 12 having such a configuration supplies the alkaline solution from the alkaline solution tank 12a to the collecting tank 1 through the supply pipe 12b by the action of the supply pump 12c. As a result, the scrubber water in the collecting tank 1 is neutralized with the alkaline solution, and the pH of this scrubber water rises. On the other hand, as the neutralization reaction between the scrubber water and the alkaline solution progresses, the content of by-products such as Na ₂ SO ₄ generated in the scrubber water increases, so the specific gravity of the scrubber water increases. . In Embodiment 1, the control device 15 controls the timing of starting and stopping the supply of the alkaline solution by the chemical solution supply system 12 (that is, the operation timing of the supply pump 12c).

The level detector 13 detects the liquid level Ls of the scrubber water in the collecting tank 1 . For example, as shown in FIG. 1, the level detector 13 is provided on the collecting tank 1 in such a manner as to have detectors at each of the low level and high level positions in the height direction of the collecting tank 1 . The level detector 13 detects that the liquid level Ls is below the low level when the liquid level Ls of the scrubber water in the collecting tank 1 is lower than the low level detector. In this case, the level detector 13 transmits to the control device 15 an electrical signal indicating that the liquid level Ls is below the low level. On the other hand, the level detector 13 detects that the liquid level Ls is higher than the high level when the liquid level Ls is higher than the high level detector. In this case, the level detector 13 transmits to the control device 15 an electrical signal indicating that the liquid level Ls is higher than the high level.

In the first embodiment, the above-mentioned low level and high level are respectively threshold levels of the liquid surface which are set in advance in the range between the lower limit level and the upper limit level in the equipment specifications of the collecting tank 1 . That is, the low level is a threshold level equal to or higher than the lower limit level of the collecting tank 1 and lower than the high level. The high level is a threshold level above the low level and below the upper level of the collecting tank 1 . When the scrubber water in the collecting tank 1 is increased (diluted) with fresh water from a state in which the liquid level Ls is lowered below the low level to a state in which the liquid level Ls is raised to a high level or higher, the specific gravity of this scrubber water is , to the extent that the separation process of scrubber water and foreign matter by the centrifuge 3d is not hindered. These low and high levels are preset to achieve the above events.

A pH meter 14 measures the pH of the scrubber water. As shown in FIG. 1, the pH meter 14 is provided in the collecting tank 1, for example, in such a manner that it has a detector at the bottom of the collecting tank 1 (for example, at a portion lower than the low level described above). A pH meter 14 measures the pH of this scrubber water via a detector immersed in the scrubber water in the collecting tank 1 . The measurement of the pH of the scrubber water by the pH meter 14 may be performed continuously along the time series, may be performed intermittently at predetermined time intervals, or may be measured as instructed by the control device 15. may be done in some cases. Each time the pH meter 14 measures the pH of the scrubber water, the pH meter 14 transmits an electrical signal indicating the obtained pH (measurement value) of the scrubber water to the control device 15 .

The control device 15 is a device that performs control necessary for water treatment of scrubber water by the water treatment device 10 . In the first embodiment, the water treatment of the scrubber water by the water treatment device 10 includes, for example, specific gravity control and pH adjustment of the scrubber water. Specifically, the control device 15 is composed of a CPU, a memory, a sequencer, and the like for executing various programs. The control device 15 receives electric signals from each of the hydrometer 4, the level detector 13 and the pH meter 14 during specific gravity control and pH adjustment of the scrubber water, and based on these electric signals, the branch valve 6, It controls each of the replenishment pump 11c and the supply pump 12c.

For example, in controlling the specific gravity of the scrubber water, the control device 15 compares the specific gravity of the scrubber water measured by the hydrometer 4 with a preset reference value, and based on the comparison result, controls the flow of the scrubber water. to control. In the first embodiment, when the measured specific gravity of the scrubber water is equal to or higher than the reference value, the control device 15 controls the scrubber water so that the scrubber water is discharged from the foreign matter removal system 3 to the sludge tank 9, i.e., the scrubber water The opening degree of the branch valve 6 is controlled so that the discharge pipe 5 is opened. After that, based on the level detector 13 detecting that the liquid level Ls of the scrubber water is below the low level, the controller 15 adjusts the opening degree of the branch valve 6 so as to close the scrubber water discharge pipe 5 . to control. In addition, the control device 15 controls the fresh water replenishment system 11 (specifically, the fresh water replenishment system 11 (specifically, the Controls replenishment pump 11c). As the reference value preset in the control device 15 as described above, for example, the upper limit of the specific gravity range of the scrubber water that does not interfere with the separation process of the scrubber water and the foreign matter by the centrifugal separator 3d. Used. Hereinafter, the reference value means a predetermined reference value preset for the specific gravity of the scrubber water as described above, unless otherwise specified.

In addition, in adjusting the pH of the scrubber water, the control device 15 compares the pH of the scrubber water measured by the pH meter 14 with a preset pH threshold, and based on the comparison result, adjusts the pH of the collecting tank 1. The chemical solution supply system 12 is controlled to start or stop the supply of the alkaline solution. The pH threshold value is set, for example, within a range that does not corrode each member of the water treatment device 10 such as piping that contacts the scrubber water, or within a range that does not impair the SOx removal performance of the scrubber 101 .

On the other hand, the EGR system 100 recirculates a portion of the exhaust gas emitted from the marine diesel engine 110 mounted on the ship as recirculated gas to the marine diesel engine 110, thereby reducing the NOx content in the exhaust gas. It is a system for As shown in FIG. 1 , EGR system 100 includes scrubber 101 , demister 102 and EGR blower 103 .

The scrubber 101 is for cleaning part of the exhaust gas discharged from the marine diesel engine 110 for use as recirculated gas, and the water treatment device 10 according to the first embodiment is applied. As shown in FIG. 1, part of the exhaust gas is supplied to the scrubber 101 from a marine diesel engine 110 through a pipe or the like. The scrubber 101 includes a liquid injection unit such as a nozzle for injecting scrubber water onto the exhaust gas to be cleaned. This liquid injection part is configured to be supplied with scrubber water through the injection pipe 101a. The scrubber 101 injects scrubber water from the liquid injection part to part of the exhaust gas (recirculated gas) supplied from the marine diesel engine 110 side, thereby removing dust, SOx, etc. from the recirculated gas. Clean the recirculated gas by removing foreign matter. Of the exhaust gas discharged from the marine diesel engine 110, the remaining exhaust gas that is not sent to the scrubber 101 is discharged out of the ship through a chimney through a pipe or the like.

The demister 102 is a hollow rectangular housing and is connected to the outlet of the scrubber 101 . A recovery pipe 104 leading to the above-described collecting tank 1 is connected to the lower portion (bottom portion) of the demister 102 . Into the demister 102, the recirculated gas cleaned by the scrubber water injection in the scrubber 101 and the scrubber water used for cleaning the recirculated gas flow. The demister 102 separates the recycle gas after washing and the scrubber water after use. Of these recirculated gas and scrubber water, the recirculated gas is sent to the EGR blower 103 from the gas discharge port of the demister 102, and the scrubber water is recovered from the bottom of the demister 102 through the recovery pipe 104 into the collecting tank 1.

The EGR blower 103 is provided above the demister 102 as shown in FIG. The EGR blower 103 sends the recirculated gas sent from the demister 102 to the marine diesel engine 110 through a pipe or the like. The recirculated gas sent out from the EGR blower 103 is sent to the combustion chamber of the marine diesel engine 110 together with air (fresh air) and used as combustion gas when the marine diesel engine 110 is operated.

Next, the procedure of water treatment performed on the scrubber water by the water treatment device 10 will be described. FIG. 2 is a flow diagram illustrating one treatment procedure for scrubber water treatment by the water treatment apparatus according to Embodiment 1 of the present invention. The above-described water treatment apparatus 10 (see FIG. 1) performs specific gravity control, which is one of the water treatments of scrubber water, by performing the processes of steps S101 to S107 shown in FIG.

Specifically, in controlling the specific gravity of the scrubber water by the water treatment device 10, as shown in FIG. 2, the control device 15 first determines whether or not the specific gravity of the scrubber water is equal to or higher than a reference value (step S101). .

In step S101, the controller 15 compares the specific gravity of the scrubber water measured by the hydrometer 4 with a reference value. Then, when the measured value of the specific gravity is equal to or higher than the reference value, the controller 15 determines that the specific gravity of the scrubber water is equal to or higher than the reference value. This corresponds to the fact that the specific gravity of the scrubber water repeatedly circulating between the water treatment device 10 and the scrubber 101 is equal to or higher than the reference value.

When the measured specific gravity of the scrubber water is equal to or higher than the reference value (step S101, Yes), the controller 15 controls the opening of the branch valve 6 so as to open the scrubber water discharge pipe 5 (step S102). In step S<b>102 , the controller 15 controls the opening of the branch valve 6 so that the scrubber water is discharged from the foreign matter removal system 3 through the scrubber water discharge pipe 5 to the sludge tank 9 . At this time, the control device 15 controls the opening degree of the branch valve 6 so that the scrubber water discharge pipe 5 side of the branch valve 6 is fully opened and the junction pipe 3c side is fully closed. Based on this opening degree control, the branch valve 6 selectively switches the flow destination of the scrubber water from the outlet pipe 3b from the confluence pipe 3c side to the scrubber water discharge pipe 5 side.

At the stage of step S102, circulation of the scrubber water is continuously performed between the collecting tank 1 and the scrubber 101 through the circulation pipe 2a and the like. In parallel with this, a part of the scrubber water extracted from the circulation pipe 2a to the branch pipe 3a is sequentially discharged to the sludge tank 9 through the scrubber water discharge pipe 5 without returning from the junction pipe 3c to the circulation pipe 2a. . As a result, the amount of scrubber water stored in the collecting tank 1 decreases, and the liquid level Ls of this scrubber water drops accordingly.

After executing step S102, the control device 15 determines whether or not the liquid level Ls of the scrubber water in the collecting tank 1 is below the low level (step S103). In step S103, the control device 15 determines whether or not the liquid level Ls is below the low level based on the detection result of the liquid level Ls by the level detector 13. FIG.

Specifically, when the controller 15 does not receive from the level detector 13 an electrical signal indicating that the liquid level Ls is less than the low level, the liquid level Ls is not less than the low level (low level above) (step S103, No). In this case, the control device 15 repeats the process of step S103.

On the other hand, when the controller 15 receives from the level detector 13 an electrical signal indicating that the liquid level Ls is less than the low level, it determines that the liquid level Ls is less than the low level. If the detected liquid level Ls is less than the low level (step S103, Yes), the controller 15 controls the opening of the branch valve 6 so as to close the scrubber water discharge pipe 5 (step S104).

In step S104, the control device 15 controls the opening degree of the branch valve 6 so as to stop discharging the scrubber water through the scrubber water discharge pipe 5 described above. At this time, the control device 15 controls the opening degree of the branch valve 6 so that the scrubber water discharge pipe 5 side of the branch valve 6 is fully closed and the junction pipe 3c side is fully open. Based on this opening degree control, the branch valve 6 selectively switches the flow destination of the scrubber water from the outlet pipe 3b from the scrubber water discharge pipe 5 side to the confluence pipe 3c side.

At the stage of step S104, in parallel with the circulation of the scrubber water between the collecting tank 1 and the scrubber 101, part of the scrubber water extracted from the circulation pipe 2a to the branch pipe 3a is centrifuged. After the foreign matter is removed by the machine 3d, it returns to the circulation pipe 2a through the junction pipe 3c without being discharged from the scrubber water discharge pipe 5. As a result, the amount of scrubber water in the collecting tank 1 is suppressed, and accordingly the decrease in the liquid level Ls of the scrubber water is suppressed.

Subsequently, the control device 15 controls the fresh water supply system 11 to start supplying fresh water to the collecting tank 1 (step S105). In step S105, the controller 15 controls the supply pump 11c to start supplying fresh water to the collecting tank 1 when the liquid level Ls detected by the level detector 13 is below the low level as a trigger. do. At this time, the control device 15 sends an electric signal instructing activation to the replenishment pump 11c to activate the replenishment pump 11c. Due to the action of the activated replenishment pump 11c, fresh water in the fresh water tank 11a begins to be replenished to the collecting tank 1 through the replenishment pipe 11b. This replenishment of fresh water continues until the control device 15 stops the replenishment pump 11c.

At the stage of step S105, the scrubber water is not discharged from the scrubber water discharge pipe 5 to the sludge tank 9 in parallel with the circulation of the scrubber water between the collecting tank 1 and the scrubber 101 described above. Fresh water is sequentially replenished in the tank 1 . As a result, the amount of scrubber water in the collecting tank 1 is increased, and along with this, the liquid level Ls of this scrubber water rises. Further, the scrubber water in the collecting tank 1 is diluted by replenishment of fresh water, and accordingly the specific gravity of this scrubber water is lowered.

After executing step S105, the control device 15 determines whether or not the liquid surface level Ls of the scrubber water in the collecting tank 1 is higher than the high level (step S106). In step S106, the control device 15 determines whether or not the liquid level Ls is higher than the high level based on the detection result of the liquid level Ls by the level detector 13. FIG.

Specifically, when the control device 15 does not receive from the level detector 13 an electrical signal indicating that the liquid level Ls is higher than the high level, the liquid level Ls is not higher than the high level (high level is less than) (step S106, No). In this case, the control device 15 repeats the process of step S106.

On the other hand, when the control device 15 receives from the level detector 13 an electrical signal indicating that the liquid level Ls is higher than the high level, it determines that the liquid level Ls is higher than the high level. If the detected liquid level Ls is higher than the high level (step S106, Yes), the control device 15 controls the fresh water supply system 11 to stop supplying fresh water to the collecting tank 1 (step S107). .

In step S107, the control device 15 controls the replenishment pump 11c to stop replenishment of fresh water to the collecting tank 1. FIG. At this time, the control device 15 stops the supply pump 11c by transmitting an electric signal instructing the stop to the supply pump 11c. As a result, the replenishment of fresh water by the action of the replenishment pump 11c is stopped.

At the stage of step S107, since the supply of fresh water to the collecting tank 1 is stopped, the increase in scrubber water in the collecting tank 1 (dilution with fresh water) is stopped. The surface level Ls stops rising. After executing step S107, the control device 15 returns to the above-described step S101, and repeats the processing after step S101.

On the other hand, in step S101 described above, if the specific gravity of the scrubber water measured by the hydrometer 4 is less than the reference value, the control device 15 determines that the scrubber water that is repeatedly circulating between the water treatment device 10 and the scrubber 101 is not equal to or greater than the reference value (step S101, No). In this case, the control device 15 repeats the process of step S101.

On the other hand, in the first embodiment, the water treatment device 10 performs pH adjustment, which is one of the scrubber water treatments, in parallel with the specific gravity control of the scrubber water illustrated in steps S101 to S107 shown in FIG. conduct.

In adjusting the pH of the scrubber water, the controller 15 compares the pH of the scrubber water measured by the pH meter 14 with a preset pH threshold. The control device 15 controls the chemical solution supply system 12 to start supplying the alkaline solution to the collecting tank 1 when the pH value measured by the pH meter 14 is less than the threshold value. At this time, the control device 15 transmits an electric signal instructing activation to the supply pump 12c to activate the supply pump 12c. Due to the action of the activated supply pump 12c, the alkaline solution in the alkaline solution tank 12a begins to be supplied to the collecting tank 1 through the supply pipe 12b. The supply of the alkaline solution is continued until the control device 15 stops the supply pump 12c.

On the other hand, the controller 15 controls the chemical solution supply system 12 to stop supplying the alkaline solution to the collecting tank 1 when the pH value measured by the pH meter 14 is equal to or higher than the threshold value. At this time, the control device 15 stops the supply pump 12c by transmitting an electrical signal instructing the stop to the supply pump 12c. As a result, the supply of the alkaline liquid by the action of the supply pump 12c is stopped. At this stage, the scrubber water in the collecting tank 1 is sufficiently neutralized by the supplied alkaline solution, whereby the pH of this scrubber water is at an appropriate value (for example, about 6.5 to 7.5). is adjusted to By adjusting the pH of the scrubber water as described above, it is possible to prevent corrosion of devices such as the water treatment device 10 and the EGR system 100 through which the scrubber water flows, and piping. Furthermore, it is possible to prevent a situation in which the performance of the scrubber 101 for removing SOx from the exhaust gas is impaired.

As described above, in the water treatment device 10 according to the first embodiment of the present invention, the scrubber water used for cleaning the exhaust gas in the scrubber 101 is recovered in the collecting tank 1, and the recovered scrubber water is circulated. The system 2 circulates from the collecting tank 1 toward the scrubber 101, and the foreign matter removal system 3 removes foreign matter in the scrubber water extracted from the circulation system 2 and returns the scrubber water after the foreign matter removal to the circulation system 2, The removed foreign matter is discharged from the foreign matter removal system 3 to the sludge tank 9 through the foreign matter discharge pipe 7, and when the specific gravity of the scrubber water measured by the specific gravity meter 4 is equal to or higher than a predetermined reference value, the scrubber A branch valve interposed between the piping of the foreign matter removal system 3 and the scrubber water discharge pipe 5 so that the water is discharged from the foreign matter removal system 3 through the scrubber water discharge pipe 5 into the sludge tank 9 . 6 is controlled, and a fresh water replenishing system 11 appropriately replenishes the collecting tank 1 with fresh water for diluting the scrubber water.

With the above configuration, while the scrubber water whose specific gravity has increased above the reference value is stored in the sludge tank 9 without being discharged overboard such as the sea, the specific gravity of this scrubber water can be controlled to be lower than the reference value. . For this reason, scrubber water, which has conventionally been discharged overboard, is collected and stored in a sludge tank 9 together with foreign matters (residues), and these scrubber water and foreign matters to be discharged are discharged from the ship and disposed of. can be done. As a result, it is necessary to install devices for discharging scrubber water overboard (for example, highly functional purification devices, inspection and monitoring devices, etc. to satisfy emission regulations) and piping in the limited space inside the ship. Since the equipment for discharging scrubber water such as the scrubber water discharge pipe 5 can be combined with the equipment for discharging foreign matter to be landed and disposed of, the equipment and piping necessary for discharging scrubber water and foreign matter can be easily installed in the ship. configuration, which in turn reduces the cost of manufacturing the vessel.

Further, in the water treatment apparatus 10 according to Embodiment 1 of the present invention, the level detector 13 detects the liquid level Ls of the scrubber water in the collecting tank 1, and the detected liquid level Ls reaches a predetermined low level. If it is less than Ls, the control device 15 controls the fresh water supply system 11 to start supplying fresh water to the collecting tank 1, and if the detected liquid level Ls is equal to or higher than a predetermined high level, the collecting tank The fresh water replenishment system 11 is controlled by the control device 15 so as to stop replenishment of fresh water to 1 . For this reason, it is possible to prevent excessive reduction or increase in the amount of scrubber water in the collecting tank 1, and for the scrubber water with increased specific gravity in the collecting tank 1, the amount of fresh water to be replenished necessary for reducing the specific gravity is reduced. can be efficiently injected after sufficiently reducing the amount of this scrubber water.

Further, in the water treatment apparatus 10 according to Embodiment 1 of the present invention, when the liquid surface level Ls of the scrubber water detected by the level detector 13 is below a predetermined low level, the scrubber water discharge pipe 5 is closed. , the control device 15 controls the opening of the branch valve 6 . Therefore, the scrubber water in the collecting tank 1 can be prevented from being excessively reduced as the scrubber water is discharged from the scrubber water discharge pipe 5 to the sludge tank 9. Therefore, the scrubber water in the collecting tank 1 can be replenished with clean water without waste by eliminating the reduction in the amount of scrubber water that accompanies discharge of the scrubber water.

Further, in the water treatment apparatus 10 according to Embodiment 1 of the present invention, the outlet end of the scrubber water discharge pipe 5 is connected to the middle portion of the foreign matter discharge pipe 7 so that the scrubber water flows from the scrubber water discharge pipe 5 to the foreign matter discharge pipe 7 . The piping is configured so that the sludge is discharged to the sludge tank 9 through. Therefore, the foreign matter discharge pipe 7 for discharging foreign matter to the sludge tank 9 can be shared as part of the discharge path for discharging the scrubber water to the sludge tank 9 . As a result, it is possible to reduce the size of the scrubber water discharge pipe 5 that replaces the pipe for discharging the scrubber water overboard, and to simplify the structure of the piping for discharging the scrubber water and foreign matter leading to the sludge tank 9 as much as possible. can.

Further, in the water treatment apparatus 10 according to Embodiment 1 of the present invention, the foreign matter removal system 3 is extracted through the first pipe (branch pipe 3a) for extracting scrubber water from the circulation system 2 and the first pipe. A centrifuge 3d for removing foreign matter in the scrubber water, and a second pipe (outlet pipe 3b and confluence pipe 3c) for returning the scrubber water after the foreign matter has been removed by the centrifuge 3d to the circulation system 2. A branch valve 6 to which the scrubber water discharge pipe 5 is connected is provided in the second pipe (specifically, between the outlet pipe 3b and the confluence pipe 3c). Therefore, among the piping of the foreign matter removing system 3, the piping can be configured such that the scrubber water discharge pipe 5 branches from between the outlet pipe 3b and the merging pipe 3c via the branch valve 6. As a result, the scrubber water can be introduced into the scrubber water discharge pipe 5 leading to the sludge tank 9 without excessively varying the flow rate of the scrubber water (the scrubber water to be centrifuged) flowing into the centrifuge 3d. . As a result, the scrubber water whose specific gravity has increased above the reference value can be discharged to the sludge tank 9 through the scrubber water discharge pipe 5 while ensuring stable operation of the centrifuge 3d.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described. In the first embodiment described above, when the scrubber water surface level Ls in the collecting tank 1 is below the low level in the scrubber water specific gravity control, the scrubber water discharge pipe 5 is closed to discharge the scrubber to the sludge tank 9. Although the discharge of water has been stopped, in the second embodiment, when the specific gravity of the scrubber water is less than the reference value, the scrubber water discharge pipe 5 is closed to stop the discharge of the scrubber water to the sludge tank 9. .

FIG. 3 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 2 of the present invention. As shown in FIG. 3, the water treatment device 20 according to the second embodiment includes a control device 25 instead of the control device 15 of the water treatment device 10 according to the first embodiment. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

In controlling the specific gravity of the scrubber water, the controller 25 compares the specific gravity of the scrubber water measured by the hydrometer 4 with a preset reference value, and controls the flow of the scrubber water based on the result of this comparison. That is, the opening degree of the branch valve 6 is controlled so as to open and close the scrubber water discharge pipe 5 . The control device 25 is the same as the control device 15 in Embodiment 1 described above, except that it controls the opening degree of the branch valve 6 based on the result of comparison between the specific gravity of the scrubber water and the reference value.

Next, the procedure of water treatment performed on the scrubber water by the water treatment device 20 will be described. FIG. 4 is a flow diagram illustrating one treatment procedure for scrubber water treatment by the water treatment apparatus according to Embodiment 2 of the present invention. The water treatment device 20 (see FIG. 3) performs specific gravity control, which is one of the water treatments of the scrubber water, by performing the processes of steps S201 to S207 shown in FIG.

Specifically, in controlling the specific gravity of the scrubber water by the water treatment device 20, as shown in FIG. 4, the control device 25 first determines whether or not the specific gravity of the scrubber water is equal to or higher than a reference value (step S201). . At this time, the control device 25 performs the process of step S201 in the same manner as step S101 in the first embodiment described above.

When the specific gravity of the scrubber water measured by the specific gravity meter 4 is equal to or higher than the reference value (step S201, Yes), the control device 25 controls the opening degree of the branch valve 6 so as to open the scrubber water discharge pipe 5 (step S202). At this time, the control device 25 performs the process of step S202 in the same manner as step S102 in the first embodiment described above.

At the stage of step S202, the scrubber water is sequentially discharged to the sludge tank 9 through the scrubber water discharge pipe 5, similarly to the stage of step S102 in the first embodiment described above. The storage amount decreases, and along with this, the surface level Ls of this scrubber water decreases.

After executing step S202, the control device 25 determines whether or not the liquid surface level Ls of the scrubber water in the collecting tank 1 is below the low level (step S203). At this time, the control device 25 performs the process of step S203 in the same manner as step S103 in the first embodiment described above.

That is, when the liquid level Ls is not less than the low level (step S203, No), the control device 25 repeats the process of step S203. On the other hand, when the liquid level Ls is less than the low level (step S203, Yes), the controller 25 controls the fresh water supply system 11 to start supplying fresh water to the collecting tank 1 (step S204). At this time, the control device 25 performs the process of step S204 in the same manner as step S105 in the first embodiment described above.

At the stage of step S204, in parallel with the circulation of the scrubber water between the collecting tank 1 and the scrubber 101, part of the scrubber water extracted from the circulation pipe 2a to the branch pipe 3a is continuously , and is discharged to the sludge tank 9 through the scrubber water discharge pipe 5. At the same time, the collecting tank 1 is replenished with fresh water. In the second embodiment, the amount of clean water replenished is controlled to be greater than the amount of scrubber water discharged from the scrubber water discharge pipe 5 to the sludge tank 9 . Therefore, the amount of scrubber water in the collecting tank 1 is increased, and the liquid surface level Ls of this scrubber water rises accordingly. Further, the scrubber water in the collecting tank 1 is diluted by replenishment of fresh water, and accordingly the specific gravity of this scrubber water is lowered.

After executing step S204, the control device 25 determines whether or not the liquid surface level Ls of the scrubber water in the collecting tank 1 is higher than the high level (step S205). At this time, the control device 25 performs the process of step S205 in the same manner as step S106 in the first embodiment described above.

That is, when the liquid level Ls is not equal to or higher than the high level (step S205, No), the control device 25 repeats the process of step S205. On the other hand, when the liquid level Ls is higher than the high level (step S205, Yes), the control device 25 controls the fresh water supply system 11 to stop supplying fresh water to the collecting tank 1 (step S206). At this time, the control device 25 performs the process of step S206 in the same manner as step S107 in the first embodiment described above.

At the stage of step S206, since the supply of fresh water to the collecting tank 1 is stopped, the increase in scrubber water in the collecting tank 1 (dilution with fresh water) is stopped. The surface level Ls stops rising. After executing step S206, the control device 25 returns to the above-described step S201, and repeats the processing after step S201.

On the other hand, in step S201 described above, when the specific gravity of the scrubber water measured by the hydrometer 4 is less than the reference value (step S201, No), the control device 25 closes the scrubber water discharge pipe 5. is controlled (step S207). At this time, the control device 25 performs the process of step S207 in the same manner as step S104 in the first embodiment described above. After that, the control device 25 returns to step S201 and repeats the processing after step S201.

At the stage of step S207, in parallel with the circulation of the scrubber water between the collecting tank 1 and the scrubber 101, part of the scrubber water extracted from the circulation pipe 2a to the branch pipe 3a is centrifuged. After the foreign matter is removed by the machine 3d, it returns to the circulation pipe 2a through the junction pipe 3c without being discharged from the scrubber water discharge pipe 5. As a result, the amount of scrubber water in the collecting tank 1 is suppressed, and accordingly the decrease in the liquid level Ls of the scrubber water is suppressed.

On the other hand, in the second embodiment, the water treatment device 20 performs pH adjustment, which is one of the scrubber water treatments, in parallel with the specific gravity control of the scrubber water illustrated in steps S201 to S207 shown in FIG. conduct. The processing executed by the control device 25 in adjusting the pH of the scrubber water is the same as the pH adjustment of the scrubber water in the first embodiment described above.

As described above, in the water treatment device 20 according to the second embodiment of the present invention, the branch valve 6 is opened to close the scrubber water discharge pipe 5 when the scrubber water level Ls is below the low level. When the specific gravity of the scrubber water measured by the hydrometer 4 is less than the reference value, the control device 25 controls the opening of the branch valve 6 so as to close the scrubber water discharge pipe 5 instead of controlling the specific gravity of the scrubber water. , and others are configured in the same manner as in the first embodiment. For this reason, the same effect as the first embodiment described above is obtained, and the scrubber water whose specific gravity has increased to the reference value or more is discharged as much as possible to the sludge tank 9 through the scrubber water discharge pipe 5, thereby reducing the specific gravity. As a result, the scrubber water from which foreign substances are easily removed by centrifugal separation can be efficiently circulated between the collecting tank 1 and the scrubber 101 .

(Embodiment 3)
Next, Embodiment 3 of the present invention will be described. In the first embodiment described above, the outlet end of the scrubber water discharge pipe 5 is connected to the middle portion of the foreign matter discharge pipe 7, and the scrubber water is discharged from the scrubber water discharge pipe 5 through the foreign matter discharge pipe 7 to the sludge tank 9. In Embodiment 3, a scrubber water discharge pipe independent of the foreign matter discharge pipe 7 is connected to the sludge tank 9, and the scrubber water is directly discharged to the sludge tank 9 through this independent scrubber water discharge pipe.

FIG. 5 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 3 of the present invention. As shown in FIG. 5, the water treatment apparatus 30 according to Embodiment 3 includes an independent scrubber water discharge pipe 35 instead of the scrubber water discharge pipe 5 of the water treatment apparatus 10 according to Embodiment 1 described above. Further, in this water treatment apparatus 30, the foreign matter discharge pipe 7 is not provided with the above-described check valve 8 (see FIG. 1). Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

The scrubber water discharge pipe 35 is a pipe independent of the foreign matter discharge pipe 7 and configured to directly lead to the sludge tank 9 without passing through the foreign matter discharge pipe 7 . Specifically, as shown in FIG. 5, the scrubber water discharge pipe 35 has an inlet end connected to the branch valve 6 and an outlet end connected to the sludge tank 9 . The scrubber water discharge pipe 35 receives the scrubber water from the outlet pipe 3b through the branch valve 6 after removing the foreign matter, and discharges the received scrubber water directly to the sludge tank 9. The scrubber water discharge pipe 35 is the same as the scrubber water discharge pipe 5 in Embodiment 1 described above, except that the outlet end is connected to the sludge tank 9 .

As described above, in the water treatment apparatus 30 according to the third embodiment of the present invention, the outlet end of the scrubber water discharge pipe 35 is connected to the sludge tank 9, and the scrubber water whose specific gravity has increased to a reference value or more is The sludge is directly discharged to the sludge tank 9 through the scrubber water discharge pipe 35 without passing through the foreign matter discharge pipe 7, and the rest of the configuration is the same as that of the first embodiment. Therefore, even though the foreign matter discharge pipe 7 and the scrubber water discharge pipe 35 are connected to the sludge tank 9 as mutually independent pipes, the same effects as those of the first embodiment can be obtained.

(Embodiment 4)
Next, Embodiment 4 of the present invention will be described. In the first embodiment described above, the fresh water and the alkaline liquid are appropriately fed into the collecting tank 1 by the action of the pump. there is

FIG. 6 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 4 of the present invention. As shown in FIG. 6, a water treatment apparatus 40 according to the fourth embodiment includes a fresh water replenishment system 41 instead of the fresh water replenishment system 11 of the water treatment apparatus 10 according to the first embodiment. A chemical solution supply system 42 is provided instead. The fresh water replenishment system 41 includes a replenishment pipe 41b in place of the replenishment pipe 11b of the fresh water replenishment system 11 in Embodiment 1 described above, and a replenishment valve 41c in place of the replenishment pump 11c. The chemical solution supply system 42 includes a supply pipe 42b instead of the supply pipe 12b of the chemical solution supply system 12 in Embodiment 1 described above, and a supply valve 42c instead of the supply pump 12c. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

The fresh water replenishment system 41 replenishes the collecting tank 1 with fresh water for diluting the scrubber water by the action of gravity or the like. 41b and a supply valve 41c. The supply pipe 41b is a pipe that guides fresh water from the fresh water tank 11a to the collecting tank 1, and is inclined downward from the fresh water tank 11a toward the collecting tank 1, as shown in FIG. The supply pipe 41b is configured in the same manner as the supply pipe 11b in Embodiment 1, except that it is inclined in this way. The replenishment valve 41c is a valve that opens and closes the replenishment pipe 41b, and as shown in FIG. 6, is provided in the middle of the replenishment pipe 41b. The replenishment valve 41c is opened to allow fresh water to flow through the replenishment pipe 41b, and closed to prevent fresh water from flowing through the refill pipe 41b.

The fresh water supply system 41 having such a configuration supplies fresh water from the fresh water tank 11a to the collecting tank 1 through the supply pipe 41b by the action of gravity when the supply valve 41c is opened. Further, the fresh water supply system 41 stops supplying fresh water to the collecting tank 1 when the supply valve 41c is closed.

In the fourth embodiment, the control device 15 controls the degree of opening of the supply valve 41c described above. That is, in step S105 of steps S105 and S107 shown in FIG. 2, the control device 15 controls the replenishment valve 41c so as to start replenishing the collecting tank 1 with fresh water. At this time, the control device 15 controls the opening degree of the replenishment valve 41c so that it is in an open state (for example, fully open), thereby opening the replenishment pipe 41b and starting replenishment of fresh water to the collecting tank 1. . The replenishment valve 41c maintains this open state to continue replenishment of fresh water to the collecting tank 1 until the control device 15 controls the degree of opening thereof so as to be closed. On the other hand, in step S107, the control device 15 controls the replenishment valve 41c so as to stop replenishment of fresh water to the collecting tank 1. FIG. At this time, the control device 15 controls the degree of opening of the replenishment valve 41c so that it is in a closed state (for example, fully closed), thereby closing the replenishment pipe 41b and stopping replenishment of fresh water to the collecting tank 1. Let

The chemical solution supply system 42 supplies the chemical solution (alkaline solution) for adjusting the pH of the scrubber water to the collecting tank 1 by the action of gravity or the like. ), a supply pipe 42b, and a supply valve 42c. The supply pipe 42b is a pipe that guides the alkaline solution from the alkaline solution tank 12a to the collecting tank 1, and is inclined downward from the alkaline solution tank 12a toward the collecting tank 1, as shown in FIG. The supply pipe 42b is configured in the same manner as the supply pipe 12b in Embodiment 1, except that it is inclined in this way. The supply valve 42c is a valve that opens and closes the supply pipe 42b, and as shown in FIG. 6, is provided in the middle of the supply pipe 42b. The supply valve 42c is opened to allow the alkaline liquid to flow through the supply pipe 42b, and is closed to disable the alkaline liquid to flow through the supply pipe 42b.

When the supply valve 42c is opened, the chemical solution supply system 42 having such a configuration supplies the alkaline solution from the alkaline solution tank 12a to the collecting tank 1 through the supply pipe 42b by the action of gravity. Further, the chemical solution supply system 42 stops supplying the alkaline solution to the collecting tank 1 when the supply valve 42c is closed.

In the fourth embodiment, the control device 15 controls the opening degree of the supply valve 42c described above. That is, in adjusting the pH of the scrubber water, when the pH of the scrubber water measured by the pH meter 14 is less than the threshold value, the control device 15 operates the supply valve 42c to start supplying the alkaline liquid to the collecting tank 1. Control. At this time, the control device 15 controls the opening degree of the supply valve 42c so that the supply valve 42c is opened (for example, fully opened), thereby opening the supply pipe 42b and starting the supply of the alkaline solution to the collecting tank 1. Let The supply valve 42c maintains this open state to continue supplying the alkaline liquid to the collecting tank 1 until the control device 15 controls the degree of opening to the closed state. On the other hand, the controller 15 controls the supply valve 42c to stop supplying the alkaline solution to the collecting tank 1 when the pH of the scrubber water measured by the pH meter 14 is equal to or higher than the threshold. At this time, the control device 15 controls the degree of opening of the supply valve 42c so that it is closed (for example, fully closed), thereby closing the supply pipe 42b and replenishing the collecting tank 1 with the alkaline solution. stop.

As described above, in the water treatment apparatus 40 according to Embodiment 4 of the present invention, the fresh water supply system 41 starts and stops supply of fresh water to the collecting tank 1, and the chemical supply system 42 supplies the collecting tank 1 with water. The start and stop of the supply of the alkaline solution to the tank are performed by the opening and closing of the valve and the action of gravity. For this reason, the same advantages as those of the first embodiment described above are obtained, and the action of the pump is not required for replenishing fresh water or supplying alkaline liquid to the collecting tank 1, thereby reducing the power required for the pump. consumption can be saved.

(Embodiment 5)
Next, Embodiment 5 of the present invention will be described. In Embodiment 1 described above, the branch valve 6 for connecting the scrubber water discharge pipe 5 is provided in the pipe on the outlet side of the centrifuge 3d (the second pipe in the foreign matter removal system 3), and foreign matter is removed by the centrifuge 3d. The subsequent scrubber water was appropriately discharged from the scrubber water discharge pipe 5 to the sludge tank 9, but in the fifth embodiment, the branch valve 6 is connected to the pipe on the inlet side of the centrifugal separator 3d (the first The scrubber water before flowing into the centrifuge 3 d is appropriately discharged from the scrubber water discharge pipe 5 to the sludge tank 9 .

FIG. 7 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 5 of the present invention. As shown in FIG. 7, a water treatment apparatus 50 according to Embodiment 5 includes a foreign matter removal system 53 instead of the foreign matter removal system 3 of the water treatment apparatus 10 according to Embodiment 1 described above, and a foreign matter removal system 53 instead of the control device 15. A control device 55 is provided at the end. The foreign matter removing system 53 includes an outlet pipe 53b instead of the outlet pipe 3b and the junction pipe 3c of the foreign matter removing system 3 in the first embodiment. Further, in the fifth embodiment, the branch valve 6 is provided in the middle of the first pipe (that is, the branch pipe 3a) in the foreign substance removal system 53. As shown in FIG. The scrubber water discharge pipe 5 branches off from the branch pipe 3a via this branch valve 6. As shown in FIG. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

In the foreign matter removal system 53, the outlet pipe 53b is a pipe (second pipe in the foreign matter removal system 53) for returning the scrubber water after the foreign matter has been removed by the centrifuge 3d to the circulation system 2. As shown in FIG. 7, the outlet pipe 53b has an inlet end connected to an outlet portion of the centrifuge 3d and an outlet end connected to an intermediate portion of the circulation pipe 2a (for example, downstream of the adjustment valve 2c in the flow direction of the scrubber water). ). The outlet pipe 53b receives the scrubber water from the centrifuge 3d after the removal of foreign substances by the centrifuge 3d, and returns the received scrubber water to the circulation pipe 2a.

When controlling the specific gravity of the scrubber water, if the specific gravity of the scrubber water measured by the hydrometer 4 is greater than or equal to the reference value, the controller 55 adjusts the opening of the branch valve 6 in step S102 (see FIG. 2). , the opening is controlled to an intermediate opening degree in which both the scrubber water discharge pipe 5 side and the branch pipe 3a side are in an open state. As a result, part of the scrubber water in the branch pipe 3a is discharged to the sludge tank 9 through the scrubber water discharge pipe 5, and the remaining scrubber water flows into the centrifuge 3d through the branch pipe 3a. centrifuged (removing foreign matter). Further, when the specific gravity of the scrubber water measured by the specific gravity meter 4 is less than the reference value, the controller 55 fully closes the scrubber water discharge pipe 5 side and the branch pipe 3a in step S104 (see FIG. 2). The opening degree of the branch valve 6 is controlled so that the side is fully opened. As a result, the scrubber water in the branch pipe 3a is not discharged from the scrubber water discharge pipe 5 to the sludge tank 9, but is flowed into the centrifuge 3d and subjected to centrifugal separation (removal of foreign substances). The control device 55 is the same as the control device 15 in Embodiment 1 except that the opening degree of the branch valve 6 is controlled to an intermediate opening degree or the like as described above.

As described above, in the water treatment apparatus 50 according to the fifth embodiment of the present invention, among the pipes of the foreign matter removal system 53, the first pipe (branch pipe) for extracting scrubber water from the circulation pipe 2a of the circulation system 2 3a) is provided with a branch valve 6, and the scrubber water discharge pipe 5 is branched from the first pipe via this branch valve 6, and the scrubber water is discharged to the sludge tank 9 through this scrubber water discharge pipe 5. In this case, the opening degree of the branch valve 6 is controlled to an intermediate opening degree so that both the scrubber water discharge pipe 5 side and the first pipe side are open, and the rest is configured in the same manner as in the first embodiment. ing. For this reason, although the piping configuration is such that the scrubber water before foreign substances are removed by the centrifuge 3d can be discharged from the scrubber water discharge pipe 5 to the sludge tank 9, the same effects as those of the first embodiment described above can be achieved. can enjoy.

(Embodiment 6)
Next, Embodiment 6 of the present invention will be described. In the first embodiment described above, when the specific gravity of the scrubber water is equal to or higher than the reference value, the scrubber water is discharged to the sludge tank 9 through the scrubber water discharge pipe 5. However, in the sixth embodiment, the scrubber water is It is discharged from the centrifugal separator 3 d to the sludge tank 9 through the foreign matter discharge pipe 7 without passing through the water discharge pipe 5 .

FIG. 8 is a schematic diagram showing one configuration example of a water treatment apparatus according to Embodiment 6 of the present invention. As shown in FIG. 8, a water treatment apparatus 60 according to the sixth embodiment includes a foreign matter removal system 63 instead of the foreign matter removal system 3 of the water treatment apparatus 10 according to the first embodiment described above, and a foreign matter removal system 63 instead of the control device 15. A control device 65 is provided at the end. The foreign matter removing system 63 includes an outlet pipe 53b similar to that of the fifth embodiment instead of the outlet pipe 3d and the junction pipe 3c of the foreign matter removing system 3 in the first embodiment. Further, the foreign matter removal system 63 is not provided with the scrubber water discharge pipe 5 and the branch valve 6 described above, and the scrubber water is discharged from the centrifuge 3d through the foreign matter discharge pipe 7 into the sludge tank 9. It is configured. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

In controlling the specific gravity of the scrubber water, the controller 65 compares the specific gravity of the scrubber water measured by the hydrometer 4 with a preset reference value, and controls the flow of the scrubber water based on the result of this comparison. That is, it controls the flow rate of the scrubber water discharged from the centrifuge 3 d to the sludge tank 9 through the foreign matter discharge pipe 7 together with the foreign matter. The control device 65 is the same as the control device 15 in Embodiment 1 described above, except for controlling the flow rate of the scrubber water discharged from the centrifuge 3d to the sludge tank 9 in controlling the specific gravity of the scrubber water. .

In the sixth embodiment, the control device 65 performs each process other than steps S102 and S104 (steps S101, S103, and S105 to S107) of steps S101 to S107 shown in FIG. go to

In step S102, instead of controlling the opening degree of the branch valve 6 to open the scrubber water discharge pipe 5, the scrubber water is discharged from the centrifuge 3d to the sludge tank 9 through the foreign matter discharge pipe 7. control the flow rate of the scrubber water so that Specifically, when the specific gravity of the scrubber water measured by the specific gravity meter 4 is equal to or higher than the reference value, the control device 65 controls the scrubber water discharged from the centrifuge 3d through the foreign matter discharge pipe 7 into the sludge tank 9 together with the foreign matter. The centrifuge 3d is controlled so that the flow rate is increased more than when the specific gravity of the scrubber water is less than the reference value. At this time, the control device 65 may increase the flow rate of the scrubber water discharged together with the foreign matter by increasing the amount of foreign matter discharged from the centrifuge 3d at one time, or may increase the flow rate of the scrubber water discharged from the centrifuge 3d. The flow rate of scrubber water discharged with the foreign matter may be increased by increasing the frequency of discharge of the foreign matter.

After step S102 is executed, the scrubber water, which is larger than the scrubber water returning to the circulation pipe 2a through the outlet pipe 53b, is sequentially discharged from the centrifuge 3d to the sludge tank 9 through the foreign substance discharge pipe 7 together with the foreign substances. be. At this time, the flow rate of the scrubber water discharged from the centrifuge 3d is adjusted so that the flow rate of the scrubber water from the outlet pipe 53b to the circulation pipe 2a becomes zero (so as not to return to the circulation pipe 2a). ) may be controlled.

On the other hand, in step S104, instead of controlling the opening degree of the branch valve 6 so as to close the scrubber water discharge pipe 5 described above, the controller 65 controls the flow of scrubber water from the centrifuge 3d to the sludge tank 9 in the sixth embodiment. Control the flow rate of scrubber water from the centrifuge 3d so as to stop the discharge of . Specifically, when the liquid level Ls of the scrubber water detected by the level detector 13 is less than a predetermined low level, the control device 65 sends the liquid from the centrifuge 3 d to the sludge tank 9 through the foreign matter discharge pipe 7 together with the foreign matter. The centrifugal separator 3d is controlled so as to reduce the flow rate of the discharged scrubber water below that when the specific gravity of the scrubber water measured by the hydrometer 4 is equal to or higher than the reference value. At this time, the control device 65 may reduce the flow rate of the scrubber water discharged together with the foreign matter by reducing the amount of foreign matter discharged from the centrifuge 3d at one time, or may reduce the flow rate of the scrubber water discharged from the centrifuge 3d. The flow rate of scrubber water discharged with the contaminants may be reduced by reducing the frequency of discharge of the contaminants.

After step S104 is executed, from the centrifuge 3d, a larger amount of scrubber water than the scrubber water discharged to the sludge tank 9 together with the foreign matter through the foreign matter discharge pipe 7 is sequentially supplied to the circulation pipe 2a through the outlet pipe 53b. return.

On the other hand, in the sixth embodiment, the control device 65 may perform substantially the same processing as steps S201 to S207 shown in FIG. That is, the control device 65 may perform each process other than steps S202 and S207 (each process of steps S201 and S203 to S206) among steps S201 to S207 in the same manner as in the second embodiment.

In step S202, instead of controlling the opening degree of the branch valve 6 to open the scrubber water discharge pipe 5, the scrubber water is discharged from the centrifuge 3d to the sludge tank 9 through the foreign matter discharge pipe 7. control the flow rate of the scrubber water so that The process of step S202 is the same as step S102 in the sixth embodiment described above.

Further, in step S207, instead of controlling the opening degree of the branch valve 6 so as to close the scrubber water discharge pipe 5 described above, the controller 65 controls the flow of scrubber water from the centrifuge 3d to the sludge tank 9 in the sixth embodiment. Control the flow rate of scrubber water from the centrifuge 3d so as to stop the discharge of . Specifically, when the specific gravity of the scrubber water measured by the hydrometer 4 is the reference value, the control device 65 controls the flow rate of the scrubber water discharged from the centrifuge 3d to the sludge tank 9 through the foreign matter discharge pipe 7 together with the foreign matter. is less than when the specific gravity of the scrubber water is equal to or higher than the reference value. The processing of this step S207 is the same as that of step S104 in the sixth embodiment described above.

In addition, in the sixth embodiment, the water treatment device 60 performs pH adjustment, which is one of water treatments of the scrubber water, in parallel with the above-described specific gravity control of the scrubber water. The processing executed by the control device 65 in adjusting the pH of the scrubber water is the same as the pH adjustment of the scrubber water in the first embodiment.

As described above, in the water treatment device 60 according to Embodiment 6 of the present invention, when controlling the specific gravity of the scrubber water, the flow rate of the scrubber water discharged from the centrifuge 3d to the sludge tank 9 through the foreign matter discharge pipe 7 is are controlled, and the rest is configured in the same manner as in the first embodiment. Therefore, the same effect as the first embodiment described above can be obtained, and the scrubber water discharge pipe 5 and the branch valve 6 need not be provided in the foreign matter removal system 63, and the scrubber water having an excessively increased specific gravity can be The waste can be directly discharged from the centrifuge 3 d to the sludge tank 9 through the foreign matter discharge pipe 7 without passing through the discharge pipe 5 .

In the above-described Embodiments 1, 3 to 5, when the scrubber water level Ls in the collecting tank 1 is below the low level, the branch valve 6 is opened so as to close the scrubber water discharge pipes 5 and 35. (hereinafter referred to as scrubber water discharge stop control as appropriate), and then controls the fresh water replenishment systems 11 and 41 so as to start replenishing fresh water to the collecting tank 1 (hereinafter referred to as fresh water replenishment start control). appropriately), but the present invention is not limited to this. For example, when the scrubber water level Ls is less than the low level, fresh water replenishment start control may be performed first, and then scrubber water discharge stop control may be performed, or these controls may be performed in parallel. and (simultaneously).

In the first to fourth embodiments described above, when the scrubber water is discharged to the sludge tank 9, the scrubber water discharge pipe side of the branch valve 6 is fully opened and the confluence pipe side (circulation system side) is fully closed. The invention is not limited to this. For example, when the scrubber water is discharged to the sludge tank 9, both the scrubber water discharge pipe side and the confluence pipe side of the branch valve 6 may be opened (intermediate opening).

In the fifth embodiment described above, when the scrubber water is discharged to the sludge tank 9, both the scrubber water discharge pipe side and the branch pipe side of the branch valve 6 are opened (intermediate opening). It is not limited to this. For example, when the scrubber water is discharged to the sludge tank 9, the scrubber water discharge pipe side of the branch valve 6 is fully opened and the branch pipe side is fully closed so that the scrubber water flows into the centrifuge 3d (centrifugal separation of the scrubber water). process) may be suspended.

Further, in the above-described Embodiments 1 to 6, the specific gravity of the scrubber water in the pipes (branch pipes 3a, etc.) on the inlet side of the centrifuge 3d is measured by the hydrometer 4, but the present invention is limited to this. not to be For example, the measurement of the specific gravity of the scrubber water by the hydrometer 4 may be performed in the pipes (outlet pipes 3b, 53b, confluence pipe 3c, etc.) on the outlet side of the centrifuge 3d. Alternatively, the measurement of the specific gravity of the scrubber water by the hydrometer 4 may be performed in a scrubber water flow path other than the foreign matter removal system, such as the circulation pipe 2a, the recovery pipe 104, or the collecting tank 1.

Further, in Embodiments 3 to 5 described above, the specific gravity control of the scrubber water is performed in the same manner as in Embodiment 1, but the present invention is not limited to this. For example, in the third to fifth embodiments described above, the specific gravity control of the scrubber water (see steps S201 to S207 in FIG. 4) similar to that in the second embodiment may be performed. That is, the water treatment apparatus according to the present invention may be an appropriate combination of Embodiments 1 to 5 described above.

Further, in the first to sixth embodiments described above, the scrubber 101 of the EGR system 100 is illustrated as an example of a scrubber to which the water treatment device according to the present invention is applied, but the present invention is not limited to this. For example, the water treatment device according to the present invention may be applied to an exhaust gas cleaning device (scrubber) other than an EGR system.

Further, in the first to sixth embodiments described above, the centrifugal separator 3d was exemplified as a device for removing foreign matter in the scrubber water, but the present invention is not limited to this. For example, the removal device for removing foreign matter in the scrubber water may be one that removes the foreign matter from the scrubber water by using the specific gravity difference between the scrubber water and the foreign matter, or uses the specific gravity difference between the scrubber water and the foreign matter. It may also be a device that removes foreign matter from the scrubber water without cleaning (for example, a filtration device, etc.). That is, in the present invention, the type of removal device is not particularly limited. Further, the specific gravity of the scrubber water at which by-products start to precipitate when the pH of the scrubber water is adjusted is greater than the specific gravity of the scrubber water that affects the separation performance of the centrifugal separator 3d between the scrubber water and foreign matter. For this reason, when the removal device removes foreign matter from the scrubber water without using the difference in specific gravity between the scrubber water and the foreign matter, the criteria for determining whether or not to discharge the scrubber water to the sludge tank 9 The value (reference value in the scrubber water specific gravity control described above) may be set to a higher value than when the removing device is the centrifuge 3d.

Further, in Embodiments 1 to 5 described above, the pH of the scrubber water in the collecting tank 1 is measured by the pH meter 14, but the present invention is not limited to this. For example, the pH measurement of the scrubber water by the pH meter 14 may be performed in a scrubber water distribution route other than the collecting tank 1, such as the circulation pipe 2a, the piping in the foreign matter removal system, or the recovery pipe 104.

Moreover, the present invention is not limited to the first to sixth embodiments described above. The present invention also includes those configured by appropriately combining the respective constituent elements described above. In addition, other embodiments, examples, operation techniques, etc. made by those skilled in the art based on the above-described Embodiments 1 to 6 are all included in the scope of the present invention.

Reference Signs List 1 collecting tank 2 circulation system 2a circulation pipe 2b circulation pump 2c regulating valve 3, 53, 63 foreign matter removal system 3a branch pipe 3b, 53b outlet pipe 3c confluence pipe 3d centrifuge 4 hydrometer 5, 35 scrubber water discharge pipe 6 Branch valve 7 Foreign matter discharge pipe 8 Check valve 9 Sludge tank 10, 20, 30, 40, 50, 60 Water treatment device 11, 41 Fresh water supply system 11a Fresh water tank 11b, 41b Supply pipe 11c Supply pump 12, 42 Chemical solution supply system 12a alkaline liquid tank 12b, 42b supply pipe 12c supply pump 13 level detector 14 pH meter 15, 25, 55, 65 controller 41c supply valve 42c supply valve 100 EGR system 101 scrubber 101a injection pipe 102 demister 103 EGR blower 104 recovery pipe 110 marine diesel engine Ls liquid level

Claims (10)

A water treatment device applied to a scrubber that cleans exhaust gas emitted from a marine diesel engine using scrubber water,
a collecting tank for collecting the scrubber water used for cleaning the exhaust gas in the scrubber;
a fresh water replenishment system for replenishing the collecting tank with fresh water for diluting the scrubber water;
a circulation system having a circulation pipe for sending the scrubber water from the collecting tank to the scrubber, and circulating the scrubber water between the collecting tank and the scrubber through the circulation pipe;
a removing device for removing foreign substances in the scrubber water; a first pipe for extracting the scrubber water from the circulation pipe of the circulation system and guiding the extracted scrubber water to the removing device; a foreign matter removal system having a second line for returning said later scrubber water to said circulation pipe of said circulation system;
a branch valve provided in the piping of the foreign matter removal system;
a scrubber water discharge pipe branching from the pipe of the foreign matter removal system via the branch valve;
a foreign matter discharge pipe for discharging the foreign matter from the foreign matter removal system;
a storage tank for storing the foreign matter discharged through the foreign matter discharge pipe;
a hydrometer for measuring the specific gravity of the scrubber water flowing through the first pipe;
a control device for controlling the flow of the scrubber water so that the scrubber water is discharged from the foreign matter removal system to the storage tank when the measured specific gravity is equal to or greater than a predetermined reference value;
with
When the measured specific gravity is equal to or greater than the reference value, the controller adjusts the opening of the branch valve so that the scrubber water is discharged from the foreign matter removal system through the scrubber water discharge pipe to the storage tank. A water treatment device characterized by controlling . A level detector that detects the surface level of the scrubber water in the collecting tank,
The control device controls the fresh water replenishment system to start replenishing fresh water to the collecting tank when the detected liquid level is less than a predetermined low level, and 2. The water treatment apparatus according to claim 1, wherein the fresh water replenishment system is controlled so as to stop replenishment of fresh water to the collecting tank when is equal to or higher than a predetermined high level. 3. The control device according to claim 2 , wherein the controller controls the opening of the branch valve so as to close the scrubber water discharge pipe when the detected liquid level is below a predetermined low level. water treatment equipment. 3. The control device according to claim 1 , wherein when the measured specific gravity is less than the reference value, the control device controls the opening degree of the branch valve so as to close the scrubber water discharge pipe. Water treatment equipment. an outlet end of the scrubber water discharge pipe is connected to an intermediate portion of the foreign matter discharge pipe;
The water treatment apparatus according to any one of claims 1 to 4 , wherein the scrubber water in the scrubber water discharge pipe is discharged to the storage tank through the foreign matter discharge pipe. The water treatment apparatus according to any one of claims 1 to 5 , wherein the second pipe is a pipe provided with the branch valve among the pipes of the foreign substance removal system. When the measured specific gravity is equal to or greater than the reference value, the control device adjusts the flow rate of the scrubber water discharged from the removal device to the storage tank through the foreign matter discharge pipe together with the foreign matter to the measured specific gravity 3. The water treatment apparatus according to claim 1 or 2, wherein said removing device is controlled so as to increase more than when is less than said reference value. The control device measures the flow rate of the scrubber water discharged from the removal device to the storage tank through the foreign matter discharge pipe together with the foreign matter when the detected liquid level is less than a predetermined low level. 8. The water treatment apparatus according to claim 7 , wherein the removal device is controlled so as to reduce the specific gravity more than the reference value or more. When the measured specific gravity is less than the reference value, the control device adjusts the flow rate of the scrubber water discharged from the removing device to the storage tank through the foreign matter discharge pipe together with the foreign matter to the measured specific gravity 8. The water treatment apparatus according to claim 7 , wherein said removing device is controlled so as to reduce the amount of water than when is equal to or greater than said reference value. The water treatment apparatus according to any one of claims 1 to 9 , wherein the removal device is a centrifugal separator that removes foreign matter in the scrubber water by using a difference in specific gravity from the scrubber water. .

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