Removal device, control device for removal device, and removal method

Abstract

To flexibly respond to changes in a processing condition of a removal target.SOLUTION: A removal device comprises: a tank that receives a removal target; a flow path including a plurality of pipes connected to the tank for circulating liquid and a connection pipe that connects the plurality of pipes to each other; a fine bubble generating device that is provided in each of the plurality of pipes and generates a processing liquid by generating bubbles in the liquid; and a flow path switching unit that switches the connections of the flow path so that each fine bubble generating device is connected to the tank either in series or in parallel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a removal device, a control device for the removal device, and a removal method. [Background technology]

[0002] There is known a removal device that removes substances to be removed from waste generated from a source such as a plant. In the removal device, there is a technology that uses a fine bubble generator to generate a treatment liquid containing fine bubbles, thereby improving the treatment efficiency of the substances to be removed by the treatment liquid. Patent Documents 1 and 2 disclose fine bubble generators.

[0003] Patent Document 3 discloses a technology in which, in a wet ammonia washing device that removes ammonia from basic gases generated in a fertilizer manufacturing plant, multiple fine bubble generators are connected in series to produce a treatment liquid containing fine bubbles of carbon dioxide, and the produced treatment liquid is used to remove ammonia. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-217585 [Patent Document 2] JP 2017-94300 A [Patent Document 3] International Publication No. 2022 / 049769 Summary of the Invention [Problem to be solved by the invention]

[0005] During operation of the removal device, various changes in the situation occur, such as fluctuations in the amount of substances to be removed, fluctuations in the operating status of the removal device, and the occurrence of unintended problems. It is desirable to be able to respond flexibly to such changes in the situation.

[0006] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a removal device, a control device for the removal device, and a removal method that can flexibly respond to changes in the processing status of objects to be removed. [Means for solving the problem]

[0007] The removal device according to the present disclosure comprises a tank for receiving the material to be removed, a flow path including a plurality of pipes connected to the tank for circulating a liquid, and connecting pipes for connecting the plurality of pipes together, fine bubble generators disposed in each of the plurality of pipes for generating bubbles in the liquid to produce a treatment liquid, and a flow path switching unit for switching the connection of the flow path so that each of the fine bubble generators is connected in series or in parallel to the tank.

[0008] The control device of the removal device according to the present disclosure is a control device that controls the removal device according to the present disclosure, and includes an information acquisition unit that acquires the status of the removal process of the object to be removed in the removal device, and a switching control unit that controls the flow path switching unit of the removal device based on the status of the removal process of the object to be removed in the removal device.

[0009] The removal method according to the present disclosure is a removal method in which a target substance to be removed is supplied to a tank and removed using a treatment liquid containing gas bubbles, and includes the steps of receiving the target substance to be removed into the tank, circulating the liquid through a flow path connected to the tank, generating gas bubbles in the liquid using at least some of a plurality of fine bubble generators arranged in the flow path to produce a treatment liquid, and switching the connection of the flow path so that at least some of the plurality of fine bubble generators are connected in series or in parallel to the tank based on the status of the removal process of the target substance to be removed. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to flexibly respond to changes in the processing status of the object to be removed. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a removal device according to the first embodiment. [Figure 2] FIG. 2 is a schematic configuration diagram illustrating the treatment liquid generating unit according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing the series mode in which fine bubble generators are connected in series. [Figure 4] FIG. 4 is a diagram showing an example of a parallel mode in which fine bubble generators are connected in parallel. [Figure 5] FIG. 5 is a diagram showing an example of a parallel mode in which all fine bubble generators are connected in parallel. [Figure 6] FIG. 6 is a diagram showing an example of a mixed mode in which the series-connected paths of fine bubble generators are connected in parallel. [Figure 7] FIG. 7 is a flowchart showing a method for removing an object to be removed according to the embodiment. [Figure 8] FIG. 8 is a graph showing the tendency of change in the amount of ammonia absorbed into water when the carbon dioxide content is changed. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations in which the respective embodiments are combined.

[0013] [First embodiment] FIG. 1 is a schematic diagram showing the configuration of a removal device according to the first embodiment.

[0014] The removal device 1 is a removal device that removes a substance to be removed from effluent generated from an emission source such as a plant. The substance to be removed is not particularly limited. The substance to be removed is a predetermined component contained in the effluent. The effluent may be a gas, a liquid, or a suspension such as sludge.

[0015] The removal device 1 uses a fine bubble generator 22 to generate a treatment liquid PL containing fine bubbles, thereby improving the treatment efficiency of the object to be removed with the treatment liquid PL. The treatment liquid PL is a liquid containing fine bubbles. Fine bubbles are minute air bubbles. Fine bubbles are formed in a liquid. Fine bubbles are bubbles with a diameter of less than 100 micrometers. The gas enclosed in the fine bubbles is not particularly limited. When used to remove an object to be removed, it is desirable to enclose a gas with a composition appropriate for the object to be removed.

[0016] As an example, the substance to be removed is ammonia. The effluent containing the substance to be removed is exhaust gas (gas) generated at the source of the emission, specifically a basic gas containing ammonia. An example of the source of the emission is a fertilizer manufacturing plant. As an example, the gas enclosed in the fine bubbles is a gas containing carbon dioxide as a main component. The liquid in which the fine bubbles are formed is mainly water. In the embodiment, an example will be described in which the removal device 1 is a wet ammonia removal device that removes ammonia in exhaust gas by bringing a treatment liquid PL, in which fine bubbles of carbon dioxide have been generated in water, into gas-liquid contact with the exhaust gas.

[0017] As shown in FIG. 1, the removal device 1 includes a tank 2, a pump 3, a treatment liquid generator 4, and a control device 5.

[0018] The tank 2 is a container having an internal space 2A through which exhaust gas containing the substance to be removed flows. The tank 2 is connected to an exhaust gas introduction line 6. The exhaust gas introduction line 6 introduces exhaust gas into the internal space 2A of the tank 2. In other words, the tank 2 receives a basic gas containing ammonia. This allows the tank 2 to receive the substance to be removed (ammonia).

[0019] The tank 2 is connected to an exhaust line 9 for discharging the exhaust gas that has come into gas-liquid contact with the processing liquid PL from the internal space 2A. The tank 2 sends the treated exhaust gas, from which the removal target has been removed within the tank 2, to the exhaust line 9. The tank 2 has a nozzle 10 for spraying makeup water into the internal space 2A and a nozzle 11 for spraying the processing liquid PL into the internal space 2A. The nozzle 10 is connected to a makeup water supply line 12, through which the makeup water is supplied. The makeup water is not particularly limited, but may be water, for example. Carbonated water may also be used as the makeup water. The nozzle 11 is connected to a supply line 13 for the processing liquid PL, through which the processing liquid PL is supplied from the processing liquid generator 4. A tray 2B is provided in the internal space 2A. The tray 2B is formed, for example, of a perforated plate. The nozzle 11 sprays the processing liquid PL toward the tray 2B within the internal space 2A.

[0020] The tank 2 is connected to a circulation line 7A for extracting and circulating the processing liquid PL supplied to the internal space 2A. The tank 2 is connected to a pump 3 via the circulation line 7A. The tank 2 is also connected to a discharge line 8 for discharging a portion of the processing liquid PL.

[0021] The internal space 2A of the tank 2 includes an upper region into which the exhaust gas is introduced and a lower region in which the processing liquid PL is stored. In the upper region, the exhaust gas comes into gas-liquid contact with the processing liquid PL sprayed from the nozzle 11, causing ammonia (the substance to be removed) in the exhaust gas to be absorbed and removed by the processing liquid PL. The processing liquid PL that has absorbed the ammonia and the make-up water sprayed from the nozzle 10 accumulate in the lower region of the internal space 2A. The processing liquid PL that has absorbed the ammonia is diluted with the make-up water. The processing liquid PL is discharged from the lower region to the circulation line 7A and / or the discharge line 8. Excess processing liquid PL is sent to the discharge line 8, and the amount of liquid in the tank 2 is controlled. A discharge control valve 14 is provided in the discharge line 8.

[0022] The circulation line 7A connects the tank 2 and the pump 3. The pump 3 is connected to the processing liquid generation unit 4 via the circulation line 7B. A supply control valve 15 is provided in the circulation line 7A. The supply control valve 15 is capable of opening and closing the circulation line 7A and controlling the opening degree. The pump 3 sucks the processing liquid PL from the tank 2 via the circulation line 7A and sends the sucked processing liquid PL to the circulation line 7B. In this way, the pump 3 sends the processing liquid PL from the tank 2 to the processing liquid generation unit 4.

[0023] The processing liquid generating unit 4 generates the processing liquid PL from the liquid (diluted processing liquid PL) sent from the pump 3 and the enclosed gas (carbon dioxide gas) supplied from the gas source 16. The processing liquid PL is formed by forming fine bubbles of the enclosed gas in the liquid. The processing liquid generating unit 4 is connected to the tank 2 via a supply line 13. The processing liquid generating unit 4 supplies the generated processing liquid from the supply line 13 into the tank 2 by the discharge pressure of the pump 3. As a result, in the embodiment, the removal device 1 circulates the processing liquid PL between the tank 2 and the processing liquid generating unit 4 by the pump 3 while diluting it.

[0024] (Processing liquid generating unit) Fig. 2 is a schematic diagram showing the configuration of the treatment liquid generating unit according to the first embodiment. For convenience, Figs. 2 to 6 show a simplified configuration between the tank 2 and the treatment liquid generating unit 4 shown in Fig. 1. The treatment liquid generating unit 4 includes a flow path 21, a fine bubble generator 22, and a flow path switching unit 23.

[0025] The flow path 21 is connected to the tank 2. The outlet of the flow path 21 is connected to the tank 2 via a supply line 13. In an embodiment in which the treatment liquid PL is circulated, the inlet of the flow path 21 is connected to the tank 2 via a circulation line 7A and a circulation line 7B.

[0026] The flow path 21 includes a plurality of pipes 24 through which the liquid flows. The flow path 21 includes a connecting pipe 25 that connects the plurality of pipes 24 together. The flow path 21 has a structure in which the plurality of pipes 24 are connected by the connecting pipes 25. The flow path 21 includes an inlet pipe 24A and an outlet pipe 24B. The inlet pipe 24A is a distribution pipe that connects the plurality of pipes 24 in parallel. The inlet pipe 24A is connected to the circulation line 7B. The inlet pipe 24A receives the liquid (diluted treatment liquid PL) sent from the pump 3 and distributes it to each pipe 24. The outlet pipe 24B is a collecting pipe that connects the plurality of pipes 24 in parallel. The outlet pipe 24B is connected to the supply line 13. The outlet pipe 24B receives the treatment liquid PL from each pipe 24 and sends it to the tank 2 via the supply line 13.

[0027] The pipes 24 allow a liquid to circulate. Note that the "liquid" flowing through the pipes 24 here is a concept that encompasses water (diluted treatment liquid PL) before the enclosed gas is blown in, and the treatment liquid PL after fine bubbles have been formed. The multiple pipes 24 are arranged in parallel to one another. Each pipe 24 has two ends, one end and the other end. Each pipe 24 is separately connected to an inlet pipe 24A. Each pipe 24 is separately connected to an outlet pipe 24B. One fine bubble generator 22 is disposed in each of the multiple pipes 24. The number of the multiple pipes 24 is N. N is a natural number equal to or greater than 2. The number N of the multiple pipes 24 is preferably equal to or greater than 4. The multiple pipes 24 are connected by connecting pipes 25.

[0028] The connecting pipe 25 allows a liquid (treatment liquid PL) to flow. The connecting pipe 25 has two ends, one end and the other end. The connecting pipe 25 connects two adjacent pipes 24. Note that adjacent here refers to adjacent in the fluid circuit shown in FIG. 2, and the two pipes 24 connected by the connecting pipe 25 do not necessarily have to be adjacent in space. By connecting each of the two adjacent pipes 24, all of the pipes 24 communicate with each other via the connecting pipe 25. One connecting pipe 25 is provided between two adjacent pipes 24. The number of connecting pipes 25 is N-1.

[0029] The connecting pipe 25 connects the downstream of the fine bubble generator 22 in one of the multiple pipes 24 with the upstream of the fine bubble generator 22 in another of the pipes 24. Therefore, when a liquid flows from one pipe 24 to another of the pipes 24 through the connecting pipe 25, the liquid passes through the fine bubble generator 22 in the one pipe 24 and the fine bubble generator 22 in the other of the pipes 24.

[0030] As described above, the fine bubble generators 22 are disposed in each of the multiple pipes 24. The fine bubble generators 22 generate bubbles in the liquid to produce the treatment liquid PL. Each of the fine bubble generators 22 is connected to the gas source 16 via the gas supply line 16A. The fine bubble generators 22 generate fine bubbles in the liquid introduced through the pipes 24 using the enclosed gas supplied from the gas supply line 16A. That is, the fine bubble generators 22 generate carbon dioxide bubbles in the liquid passing through the pipes 24 to produce the treatment liquid PL. The liquid introduced through the pipes 24 is make-up water at the beginning of operation of the removal device 1, and becomes diluted treatment liquid PL after circulation of the treatment liquid PL begins.

[0031] The fine bubble generator 22 generates bubbles (fine bubbles) with a diameter of 100 micrometers or less. Even if the generated bubbles include some bubbles outside the range, as long as the average bubble size is within the range, the bubble generator is considered to be generating bubbles of a size within the range. Here, the diameter of a bubble is the diameter equivalent to its volume, i.e., the diameter of a sphere with the same volume as the bubble. The bubble diameter can be measured using a nanoparticle analyzer (NANOSIGHT, manufactured by Malvern).

[0032] The configuration of the fine bubble generator 22 is not particularly limited. The fine bubble generator 22 may be any device that can produce the treatment liquid PL from a sealed gas (here, carbon dioxide) supplied via the gas supply line 16A and a liquid (here, make-up water or treatment liquid PL). Devices that use an ejector system, a cavitation system, a swirl flow system, or a pressurized dissolution system may be used as the fine bubble generator. In this embodiment, all of the fine bubble generators 22 arranged in each pipe 24 have the same configuration, but each pipe 24 may be provided with a fine bubble generator 22 using a different bubble generation system.

[0033] Each fine bubble generator 22 generates a treatment liquid PL with a predetermined air bubble content for a predetermined supply amount (flow rate). The air bubble content is the volume ratio (%) of air bubbles to a unit volume of treatment liquid PL. There are limits to the amount of liquid (flow rate) supplied to the fine bubble generator 22 and the amount of bubbles generated. If the limit of the amount of liquid supplied is exceeded, even if the amount of enclosed gas is increased, large bubbles will be generated, reducing the efficiency of fine bubble generation. It is most efficient to operate each fine bubble generator 22 at the limit (or rated value) of the amount of bubbles relative to the amount of liquid. Thus, simply increasing or decreasing the amount of liquid supplied and the amount of enclosed gas does not allow the fine bubble generator 22 to freely control the amount of liquid and the air bubble content of the treatment liquid PL to be generated. Therefore, it is important to be able to control the amount of liquid and the air bubble content of the treatment liquid PL according to the operating status of the removal device 1. In the embodiment, the flow path switching unit 23 switches the connection of the flow path 21 in which multiple fine bubble generators 22 are arranged, making it possible to change the number and connection form of the fine bubble generators 22 used to generate the treatment liquid PL, thereby making it possible to control the liquid volume and bubble content of the treatment liquid PL.

[0034] The flow path switching unit 23 switches the connection of the flow path 21. The flow path switching unit 23 includes a plurality of valves. The plurality of valves include a first valve 26 arranged upstream of the fine bubble generator 22, a second valve 27 arranged downstream of the fine bubble generator 22, and a connecting pipe valve 28 arranged in the connecting pipe 25. The first valve 26 and the second valve 27 are arranged in each of the plurality of pipes 24. In each pipe 24, the fine bubble generator 22 is arranged between the first valve 26 and the second valve 27. The number of first valves 26 and second valves 27 is the same as the number N of pipes 24. The connecting pipe valve 28 is arranged in each of the plurality of connecting pipes 25. The number of connecting pipe valves 28 is the same as the number N-1 of the connecting pipes 25. The first valve 26, the second valve 27, and the connecting pipe valve 28 are each an opening / closing valve that can be switched between fully open and fully closed. The first valve 26, the second valve 27, and the connecting pipe valve 28 can each be controlled to open and close individually.

[0035] Opening or closing the first valve 26 of any of the pipes 24 allows for switching between communication between the fine bubble generator 22 of that pipe 24 and the inlet pipe 24A. Opening or closing the second valve 27 of any of the pipes 24 allows for switching between communication between the fine bubble generator 22 of that pipe 24 and the outlet pipe 24B. Opening or closing the connecting pipe valve 28 of any of the connecting pipes 25 allows for switching between communication between the outlet of the fine bubble generator 22 of one pipe 24 and the inlet of the fine bubble generator 22 of the other pipe 24.

[0036] The flow path switching unit 23 can change the liquid flow path in the flow path 21 in various ways by switching the open / closed combination of these valve groups (first valve 26, second valve 27, and connecting pipe valve 28). The flow path switching unit 23 can select which fine bubble generator 22 to connect to the tank 2 by switching the open / closed combination of the valve groups. In this embodiment, the flow path switching unit 23 switches the connection of the flow path 21 so that each fine bubble generator 22 is connected to the tank 2 in series or in parallel.

[0037] The flow path switching unit 23 can be switched between a series mode in which one path through which the liquid passes through two or more fine bubble generators 22 is connected to the tank 2, and a parallel mode in which multiple paths through which the liquid passes through one fine bubble generator 22 are connected in parallel to the tank 2.

[0038] Fig. 3 is a diagram showing a series mode in which fine bubble generators are connected in series. Fig. 4 is a diagram showing an example of a parallel mode in which fine bubble generators are connected in parallel. For ease of explanation, Figs. 3 and 4 show an example in which the number of pipes 24, N, is 4 and the number of connecting pipes 25, (N-1), is 3. Below, the four pipes 24 are referred to as pipes 24-1, 24-2, 24-3, and 24-4, respectively. The three connecting pipes 25 are referred to as connecting pipes 25-1, 25-2, and 25-3, respectively.

[0039] In the serial mode, the flow path switching unit 23 opens the first valve 26 of one of the pipes 24, the second valve 27 of the other pipe 24, and the connecting pipe valve 28 of the connecting pipe 25 between the two pipes 24, and closes the other valves.

[0040] In the example of FIG. 3, the first valve 26 of the pipe 24-1, the second valve 27 of the pipe 24-2, and the connecting pipe valve 28 of the connecting pipe 25-1 are open. The other valves are closed. As a result, the flow path switching unit 23 connects the fine bubble generator 22 of the pipe 24-1 and the fine bubble generator 22 of the pipe 24-2 in series with the tank 2 (outlet pipe 24B). As a result, a series connection path in which the liquid passing through the inlet pipe 24A passes through the two fine bubble generators 22 of the pipes 24-1 and 24-2 is connected to the tank 2. By passing the liquid through two or more fine bubble generators 22, the bubble content of the treatment liquid PL can be increased. Thus, in the series mode, the concentration of carbon dioxide (filled gas) in the treatment liquid PL supplied to the tank 2 increases. Since the absorption of ammonia by the treatment liquid PL is promoted, exhaust gas with a higher ammonia concentration can be treated.

[0041] 3, pipes 24-3 and 24-4 can be treated as standby systems. If an abnormality occurs in the series connection path formed by pipes 24-1 and 24-2, the flow path switching unit 23 closes the valves on pipes 24-1 and 24-2, and connects the series connection path passing through the two fine bubble generators 22 via pipes 24-3 and 24-4 to the tank 2. In this case, the first valve 26 on pipe 24-3, the second valve 27 on pipe 24-4, and the connecting pipe valve 28 on connecting pipe 25-3 are open. The other valves are closed.

[0042] 3, the flow path switching unit 23 can change the number of fine bubble generators 22 connected in series. For example, the first valve 26 of the pipe 24-1, the second valve 27 of the pipe 24-3, and the connecting pipe valves 28 of the connecting pipes 25-1 and 25-2 are opened, and the other valves are closed. As a result, a series connection path through which the liquid passes through the three fine bubble generators 22 of the pipes 24-1, 24-2, and 24-3 is connected to the tank 2. The first valve 26 of the pipe 24-1, the second valve 27 of the pipe 24-4, and the connecting pipe valves 28 of the connecting pipes 25-1, 25-2, and 25-3 are opened, and the other valves are closed. As a result, a series connection path through which the liquid passes through the four fine bubble generators 22 of the pipes 24-1, 24-2, 24-3, and 24-4 is connected to the tank 2.

[0043] In the parallel mode, the flow path switching unit 23 opens the first valves 26 and the second valves 27 of any of the pipes 24 and closes the other valves. In the parallel mode, the flow path switching unit 23 closes all of the connecting pipe valves 28.

[0044] In the example of FIG. 4, the first valves 26 and the second valves 27 of the pipes 24-1 and 24-2 are open. The other valves are closed. This causes the flow path switching unit 23 to connect the fine bubble generator 22 of the pipe 24-1 and the fine bubble generator 22 of the pipe 24-2 in parallel to the tank 2 (outlet pipe 24B). As a result, two paths through which the liquid passing through the inlet pipe 24A passes through one fine bubble generator 22 are connected in parallel to the tank 2. By forming multiple paths through which the liquid passes through one fine bubble generator 22, the amount (flow rate) of the treated liquid PL can be increased. Furthermore, in the parallel mode, pressure loss is reduced compared to the serial mode, enabling operation with a reduced load on the pump 3. Thus, in the parallel mode, the supply amount of the treated liquid PL supplied to the tank 2 is improved. Since the amount of the treated liquid PL increases, the amount of exhaust gas treated per hour increases.

[0045] In Fig. 4, pipes 24-3 and 24-4 can be treated as standby systems. If an abnormality occurs in the series path formed by pipes 24-1 or 24-2, the flow path switching unit 23 closes the valve of the abnormal pipe 24, thereby maintaining a parallel connection of two or more fine bubble generators 22 via pipes 24-3 and / or 24-4. For example, the first valves 26 and second valves 27 of pipes 24-3 and 24-4 are opened, and the other valves are closed. This switches the parallel connection from pipes 24-1 and 24-2 to pipes 24-3 and 24-4.

[0046] 4, the number of parallel connections of the fine bubble generators 22 (the number of systems connected to the tank 2) can also be increased. For example, the first valves 26 and second valves 27 of the pipes 24-1, 24-2, and 24-3 are each opened. The other valves are closed. As a result, three paths through which the liquid separately passes through the fine bubble generators 22 of the pipes 24-1, 24-2, and 24-3 are connected in parallel to the tank 2.

[0047] Fig. 5 is a diagram showing an example of parallel mode in which all fine bubble generators 22 are connected in parallel. In Fig. 4, the first valves 26 and second valves 27 of pipes 24-1, 24-2, 24-3, and 24-4 are open. The other valves (connecting pipe valves 28) are closed. As a result, four paths through which liquid separately passes through the fine bubble generators 22 of pipes 24-1, 24-2, 24-3, and 24-4 are connected in parallel to the tank 2.

[0048] Even in the same parallel mode, by increasing the number of parallel connections from the two-system connection in Fig. 4 to the three-system connection or the four-system connection in Fig. 5, it is possible to increase the amount of processing liquid PL supplied to the tank 2 while maintaining the bubble content of the processing liquid PL. Conversely, by decreasing the number of parallel connections, it is possible to decrease the amount of processing liquid PL supplied to the tank 2 without changing the bubble content of the processing liquid PL.

[0049] In this embodiment, the flow path switching unit 23 can switch the paths through which two or more liquids pass through the fine bubble generators 22 to a mixed mode in which multiple paths are connected in parallel to the tank 2. The mixed mode is a mode in which the direct mode and the parallel mode are used in combination.

[0050] FIG. 6 is a diagram showing an example of a mixed mode in which the series-connected paths of the fine bubble generator 22 are connected in parallel.

[0051] In the mixed mode, the flow path switching unit 23 forms a plurality of serially connected paths through which two or more liquids pass through the fine bubble generator 22 by using a piping group consisting of a plurality of pipes 24 and a connecting pipe 25. The flow path switching unit 23 then closes the connecting pipe valves 28 of the connecting pipes 25 that connect the piping groups that make up the serially connected paths, thereby connecting each of the serially connected paths to the tank 2 in parallel.

[0052] 6, the flow path switching unit 23 forms a first serial connection path using a first piping group consisting of piping 24-1, piping 24-2, and connecting pipe 25-1. Specifically, the first valve 26 of piping 24-1, the second valve 27 of piping 24-2, and the connecting pipe valve 28 of connecting pipe 25-1 are opened. The second valve 27 of piping 24-1 and the first valve 26 of piping 24-2 are closed. As a result, the flow path switching unit 23 forms a first serial connection path in which the liquid passes through the fine bubble generator 22 of piping 24-1 and the fine bubble generator 22 of piping 24-2.

[0053] The flow path switching unit 23 forms a second serial connection path using a second piping group consisting of piping 24-3, piping 24-4, and connecting pipe 25-3. Specifically, the first valve 26 of piping 24-3, the second valve 27 of piping 24-4, and the connecting pipe valve 28 of connecting pipe 25-3 are opened. The second valve 27 of piping 24-3 and the first valve 26 of piping 24-4 are closed. As a result, the flow path switching unit 23 forms a second serial connection path in which the liquid passes through the fine bubble generator 22 of piping 24-3 and the fine bubble generator 22 of piping 24-4.

[0054] Then, the connecting pipe valve 28 of the connecting pipe 25-2 between the first and second pipe groups is closed. As a result, the flow path switching unit 23 connects the first and second series connection paths in parallel to the tank 2 (outlet pipe 24B). As a result, two series connection paths, through which the liquid passing through the inlet pipe 24A passes through the two fine bubble generators 22, are connected to the tank 2 in parallel. By forming multiple series connection paths, it is possible to increase the amount (flow rate) of the treatment liquid PL while increasing the bubble content of the treatment liquid PL. In the mixed mode, it is possible to increase the treatment amount of exhaust gas with a high ammonia concentration.

[0055] The mixed mode can be implemented when the number N of pipes 24 is 4 or more. Increasing the number N of pipes 24 enables even more diverse path configurations. For example, when the number N of pipes 24 is 6, the flow path switching unit 23 can configure three parallel systems of series-connected paths through which the liquid passes through two fine bubble generators 22. Furthermore, when the number N of pipes 24 is 6, the flow path switching unit 23 can configure two parallel systems of series-connected paths through which the liquid passes through three fine bubble generators 22.

[0056] (Control device) As shown in FIG. 1 , the control device 5 controls the removal device 1. The control device 5 is electrically connected to the pump 3, the supply control valve 15, and the discharge control valve 14. The control device 5 controls the operation of the pump 3 and the aperture of the supply control valve 15 and the discharge control valve 14. The control device 5 controls the flow rate of the liquid from the pump 3 to the processing liquid generator 4 by controlling the operation of the pump 3 and the aperture of the supply control valve 15. In this embodiment, the liquid delivered from the pump 3 passes through the processing liquid generator 4 and is sent to the tank 2, so the discharge flow rate of the pump 3 may be considered to be equal to the supply amount of the processing liquid PL to the tank 2.

[0057] The control device 5 is electrically connected to the processing liquid generation unit 4. Specifically, the control device 5 is electrically connected to each valve (each of the first valves 26, each of the second valves 27, each of the connecting pipe valves 28) constituting the flow path switching unit 23 of the processing liquid generation unit 4. The control device 5 controls the opening and closing of each valve (each of the first valves 26, each of the second valves 27, each of the connecting pipe valves 28). In other words, the control device 5 controls the flow path switching unit 23 to switch the connection of the flow path 21.

[0058] The control device 5 has an arithmetic processing device including a processor such as a CPU (Central Processing Unit), a storage device including a memory and storage such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an interface including an input / output circuit. The arithmetic processing device performs arithmetic processing according to a computer program stored in the storage device.

[0059] The control device 5 includes an information acquisition unit 31 and a switching control unit 32. The information acquisition unit 31 and the switching control unit 32 are functional blocks realized on a computer program executed by an arithmetic processing unit. The control device 5 may be configured by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The information acquisition unit 31 and the switching control unit 32 may be realized by dedicated hardware (arithmetic processing unit).

[0060] The information acquiring unit 31 acquires the status of the removal process of the removal target in the removal device 1. That is, the information acquiring unit 31 acquires the operating status of the removal device 1. The status of the removal process of the removal target includes at least one of information on the flow rate of the removal target to the tank 2, the flow rate of the fluid flowing through the flow path 21, and the concentration of the removal target supplied to the tank 2.

[0061] The control device 5 is electrically connected to a gas flow sensor 33 that measures the flow rate of the substances to be removed into the tank 2. The gas flow sensor 33 is provided in the exhaust gas introduction line 6. The gas flow sensor 33 measures the flow rate of the exhaust gas passing through the exhaust gas introduction line 6. The flow rate of the substances to be removed can be determined from the flow rate of the exhaust gas. The information acquisition unit 31 acquires information about the flow rate of the substances to be removed based on the output signal of the gas flow sensor 33.

[0062] The control device 5 is electrically connected to a flow rate sensor 34 that measures the flow rate of the fluid flowing through the flow path 21. The flow rate sensor 34 is provided between the pump 3 and the tank 2. In FIG. 1, the flow rate sensor 34 is provided in the circulation line 7B that connects the pump 3 and the treatment liquid generator 4. The flow rate sensor 34 measures the flow rate of the fluid (diluted treatment liquid PL) passing through the circulation line 7B. The flow rate sensor 34 may be provided in the supply line 13 that connects the treatment liquid generator 4 and the tank 2. In that case, the flow rate sensor 34 measures the flow rate of the treatment liquid PL sent from the treatment liquid generator 4 to the tank 2. The flow rate sensor 34 may be provided in each of the multiple pipes 24 as long as it is possible to determine the total flow rate of the treatment liquid PL sent to the tank 2. The information acquisition unit 31 acquires information about the flow rate of the fluid flowing through the flow path 21 based on the output signal of the flow rate sensor 34.

[0063] The control device 5 is connected to a concentration sensor 35 that measures the concentration of the substance to be removed supplied to the tank 2. The concentration sensor 35 is provided in the tank 2. The concentration sensor 35 measures the concentration of the substance to be removed (ammonia) contained in the treatment liquid PL stored in the tank 2. The concentration of ammonia contained in the exhaust gas supplied to the tank 2 can be determined from the concentration of ammonia absorbed in the treatment liquid PL. The information acquisition unit 31 acquires information on the concentration of the substance to be removed supplied to the tank 2 based on the output signal of the concentration sensor 35.

[0064] Information on the flow rate of the substance to be removed, information on the flow rate of the fluid flowing through the flow path 21, and information on the concentration of the substance to be removed supplied to the tank 2 may be acquired based on measurement results from measurement means other than the above-mentioned sensors. This information may be acquired directly from the measurement results of the sensors, or may be acquired indirectly by calculation from the measurement results of the sensors. Furthermore, this information may be absolute values ​​of the flow rate or concentration, or relative values, i.e., values ​​indicating the amount of fluctuation of the flow rate or concentration relative to a reference level.

[0065] The information acquisition unit 31 outputs the acquired information to the switching control unit 32 as the status of the removal process of the removal object in the removal device 1.

[0066] The switching control unit 32 controls the flow path switching unit 23 of the removal device 1 based on the status of the removal process of the removal target in the removal device 1. The switching control unit 32 controls the opening and closing of the valve group (first valve 26, second valve 27, and connecting pipe valve 28) that constitutes the flow path switching unit 23. The switching control unit 32 individually controls the opening and closing of each of the first valves 26, second valves 27, and connecting pipe valves 28. In this way, the switching control unit 32 controls the flow path switching unit 23 to switch to any one of the series mode, parallel mode, and mixed mode. The switching control unit 32 determines the number of series connections in the series mode, the number of parallel connections (number of systems) in the parallel mode, and the number of systems and the number of series connections for each system in the mixed mode. The switching control unit 32 also determines whether the status of the removal process of the removal target in the removal device 1 satisfies the mode switching condition. If the status of the removal process satisfies the mode switching condition, the switching control unit 32 controls the flow path switching unit 23 to change from the current mode to another mode. The mode switching condition is satisfied, for example, when an index value indicating the status of the removal process reaches a predetermined threshold value.

[0067] As an example, the mode switching condition is that the flow rate of the substance to be removed exceeds a threshold value. When the flow rate of the substance to be removed into the tank 2 exceeds the threshold value, the switching control unit 32 controls the flow path switching unit 23 to connect the fine bubble generators 22 in parallel. In this embodiment, the flow rate of the substance to be removed can be determined from the flow rate of the exhaust gas passing through the exhaust gas introduction line 6. That is, the switching control unit 32 controls each valve to change the connection state of the flow path 21 to the parallel mode as the flow rate of the exhaust gas into the tank 2 increases. When the connection state of the flow path 21 is in the parallel mode, the switching control unit 32 controls each valve to increase the number of parallel connections (number of systems).

[0068] For example, one fine bubble generator 22 generates a predetermined amount (0.5 Vm) of air at a predetermined bubble content (a%). 3) (a and V are constants) of treatment liquid PL. For ease of explanation, it is assumed that when the fine bubble generators 22 are connected in series, the liquid volume remains the same, but the bubble content doubles according to the number of series connections. In the series mode shown in Figure 3, the discharge volume of the pump 3 per unit time is 0.5Vm 3 The treatment liquid generating unit 4 generates 2a%, 0.5Vm by two fine bubble generators 22. 3 The processing liquid PL is generated.

[0069] Assume that the flow rate of the exhaust gas (substance to be removed) increases during operation of the removal device 1 and exceeds the threshold value in the series mode. The switching control unit 32 controls the flow path switching unit 23 to switch to the two-parallel parallel mode shown in FIG. 4. In the parallel mode of FIG. 4, the discharge amount of the pump 3 per unit time is Vm 3 and two parallel fine bubble generators 22 produce a % and Vm 3 When the amount of processing liquid PL to be produced is further increased, the switching control unit 32 controls the flow path switching unit 23 to operate in a 4-parallel parallel mode as shown in FIG. 5. In the parallel mode of FIG. 5, the discharge amount of the pump 3 is set to 2Vm 3 The four parallel fine bubble generators 22 produce a % and 2Vm 3 The processing liquid PL is generated.

[0070] In addition, when the amount of absorption of the substance to be removed (ammonia) is insufficient and the bubble content in the treatment liquid PL is the expected amount, the switching control unit 32 controls the flow path switching unit 23 to switch to the parallel mode. Also, when the bubble content in the treatment liquid PL is lower than expected and the effect of increased pressure loss due to the series connection of the fine bubble generators 22 is significant, the switching control unit 32 controls the flow path switching unit 23 to switch to the parallel mode. Even when the bubble content is lower than expected, it is possible to ensure removal capacity by increasing the amount of absorption liquid.

[0071] Furthermore, for example, the mode switching condition is that the flow rate of the fluid flowing through the flow path 21 is below a threshold value. When the flow rate of the fluid flowing through the flow path 21 is below the threshold value, the switching control unit 32 controls the flow path switching unit 23 to connect the fine bubble generators 22 in parallel. When the flow rate of the fluid flowing through the flow path 21, i.e., the amount of treatment liquid PL produced, decreases, the switching control unit 32 controls each valve to change the connection state of the flow path 21 to the parallel mode. When the connection state of the flow path 21 is in the parallel mode, the switching control unit 32 controls each valve to increase the number of parallel connections (number of systems).

[0072] Suppose that during operation in the serial mode shown in Fig. 3, the discharge amount of the treatment liquid PL falls below a threshold due to a decrease in the performance of the pump 3 or the like. The switching control unit 32 controls the flow path switching unit 23 to switch to the two-parallel parallel mode shown in Fig. 4. By switching from the serial mode to the parallel mode, the pressure loss in the flow path 21 decreases, and the discharge amount of the treatment liquid PL can be increased. As a result, the flow rate of the fluid flowing through the flow path 21 can be maintained within an allowable range, and the production amount of the treatment liquid PL can be controlled within an allowable range.

[0073] Also, suppose that, during operation in the serial mode shown in Fig. 3, there is no problem with the operation of the pump 3, and the flow rate of the treatment liquid PL falls below the threshold. In this case, there is a possibility that an abnormality has occurred in one of the fine bubble generators 22 on the liquid path. The switching control unit 32 controls the flow path switching unit 23 to switch from the serial connection path in use (pipes 24-1 and 24-2) in Fig. 3 to the spare serial connection path (pipes 24-3 and 24-4) to continue the serial mode. This allows the flow rate of the treatment liquid PL to be controlled within an allowable range.

[0074] Furthermore, for example, the mode switching condition is that the concentration of the substance to be removed exceeds a threshold value. The switching control unit 32 controls the flow path switching unit 23 to connect the fine bubble generators 22 in series based on the concentration of the substance to be removed supplied to the tank 2 exceeding the threshold value. Suppose that during operation in the parallel mode shown in FIG. 4, the concentration of the substance to be removed in the exhaust gas increases and exceeds the threshold value for the parallel mode. The switching control unit 32 controls the flow path switching unit 23 to switch to the two-series series mode shown in FIG. 3. In the series mode of FIG. 3, the discharge amount of the pump 3 per unit time is 0.5 Vm 3 By connecting two fine bubble generators 22 in series, 3 The processing liquid PL is generated by increasing the bubble content in the processing liquid PL. Even if the concentration of ammonia (substance to be removed) increases, the amount of ammonia absorbed can be increased.

[0075] When the bubble content in the treatment liquid PL is to be further increased, the switching control unit 32 controls the flow path switching unit 23 to increase the number of series connections. For example, if the number of series connections is set to 4, the bubble content is 4a%, 0.5Vm 3 The processing liquid PL is generated.

[0076] Also, assume that the concentration of ammonia in the exhaust gas exceeds the threshold value, and the flow rate of the exhaust gas (ammonia) also exceeds the threshold value. In this case, the switching control unit 32 controls the flow path switching unit 23 to enter the mixed mode shown in Figure 6. In the mixed mode of Figure 6, the discharge rate of the pump 3 is 2Vm 3 By connecting two fine bubble generators 22 in series, the air temperature is 2a%, 0.5Vm per system. 3 The processing liquid PL is generated in the two series-connected paths. 3 Even if both the ammonia concentration and flow rate increase, it is possible to increase the amount of exhaust gas with a high ammonia concentration by operating at a high load in the mixed mode.

[0077] (Removal method) 7 is a flowchart showing a method for removing a removal target according to an embodiment. The method for removing a removal target according to an embodiment will be described. The removal method is a method for removing a removal target supplied to a tank 2 by a processing liquid PL containing bubbles. The removal method is carried out by a control device 5 controlling a removal device 1 according to an embodiment.

[0078] The removal device 1 receives the material to be removed into the tank 2 (step S1). The removal device 1 receives exhaust gas from the emission source via the exhaust gas introduction line 6. Make-up water is supplied into the tank 2 from the make-up water supply line 12.

[0079] The removal device 1 circulates the liquid through the flow path 21 connected to the tank 2 (step S2). The control device 5 drives the pump 3 and controls the opening of the supply control valve 15 to send the liquid to the flow path 21 of the treatment liquid production unit 4. The pump 3 sucks the liquid accumulated in the tank 2 via the circulation line 7A and sends it out to the circulation line 7B.

[0080] The treatment liquid generating unit 4 generates treatment liquid PL by generating bubbles in the liquid using at least some of the multiple fine bubble generators 22 arranged in the flow path 21 (step S3). The control device 5 controls the opening and closing of each valve constituting the flow path switching unit 23 to set the flow path 21 to one of parallel mode, serial mode, or mixed mode. The liquid delivered from the pump 3 flows into the treatment liquid generating unit 4 through the circulation line 7B. The fine bubble generator 22 blows the enclosed gas (carbon dioxide gas) supplied from the gas source 16 into the liquid passing through the pipe 24, generating fine bubbles of the enclosed gas. In this way, the treatment liquid generating unit 4 generates treatment liquid PL. The treatment liquid generating unit 4 sends the generated treatment liquid PL to the supply line 13 using the discharge pressure from the pump 3.

[0081] The processing liquid PL flows into the tank 2 through the supply line 13 and is sprayed into the internal space 2A from the nozzle 11. The processing liquid PL comes into gas-liquid contact with the exhaust gas introduced into the tank 2 and absorbs ammonia (the substance to be removed) contained in the exhaust gas. This removes the ammonia from the exhaust gas. The ammonia reacts with carbon dioxide to become ammonium carbonate, which is then incorporated into the processing liquid PL. The processing liquid PL accumulates in the lower region of the tank 2 and is diluted with make-up water. The control device 5 controls the opening and closing of the discharge control valve 14, causing a portion of the processing liquid PL to be discharged from the discharge line 8.

[0082] The pump 3 sends the diluted processing liquid PL that has accumulated in the lower region of the tank 2 to the processing liquid generator 4. The processing liquid generator 4 generates the processing liquid PL by forming fine bubbles of the enclosed gas in the liquid (diluted processing liquid PL) sent from the pump 3. The generated processing liquid PL is sent to the tank 2 via a supply line 13. As a result, the processing liquid PL circulates while being diluted with make-up water.

[0083] Based on the status of the ammonia (substance to be removed) removal process, the control device 5 switches the connection of the flow paths 21 so that at least some of the multiple fine bubble generators 22 are connected in series or in parallel to the tank 2. That is, the control device 5 determines whether the status of the ammonia (substance to be removed) removal process satisfies the mode switching condition (step S4).

[0084] As described above, the control device 5 determines whether various mode switching conditions are satisfied, such as whether the flow rate of the substance to be removed into the tank 2 exceeds a threshold, whether the flow rate of the fluid flowing through the flow path 21 is below a threshold, and whether the concentration of the substance to be removed supplied to the tank 2 exceeds a threshold. If any of the mode switching conditions is satisfied, the control device 5 controls the flow path switching unit 23 to switch the connection of the flow path 21 so that the flow path 21 is in a mode corresponding to the mode switching condition (step S5).

[0085] As a result, in the removal method according to the embodiment, by switching the connection of the flow path 21 in response to fluctuations in the operating status of the removal device 1, it is possible to generate the processing liquid PL in accordance with the operating status and supply it to the tank 2. Note that the start timing of step S1, in which the object to be removed is received in the tank 2, is arbitrary, and may be after step S2 or step S3.

[0086] (Effect of fine bubble content on removal effect) As described above, in this embodiment, the bubble content in the treatment liquid PL can be changed by switching the number of series-connected fine bubble generators 22. Here, we will explain how the ammonia removal effect is affected by changes in the bubble content of fine bubbles containing carbon dioxide as the enclosed gas.

[0087] Figure 8 is a graph showing the tendency of change in the amount of ammonia absorbed into water when the carbon dioxide content is changed. The graph in Figure 8 shows the change in the amount of ammonia absorbed into water when a mixed gas of air, ammonia gas, and carbon dioxide gas is supplied to the gas phase region of a tank containing water. The horizontal axis of the graph represents the flow rate ratio (liquid / gas) of the liquid phase (water) to the gas (mixed gas) in logarithm, and the vertical axis represents the ratio of the partial pressure at the time of measurement to the initial partial pressure of ammonia gas (ammonia gas partial pressure / initial partial pressure). The partial pressure ratio on the vertical axis represents the amount of ammonia absorbed, and a smaller value on the vertical axis indicates a larger amount absorbed (i.e., a higher removal effect of the substance to be removed).

[0088] Each curve in the graph represents the results when the carbon dioxide partial pressure in the mixed gas is varied. Curves 40A, 40B, 40C, 40D, and 40E represent different partial pressures of carbon dioxide in the gas phase. The magnitude of the carbon dioxide partial pressures is as follows: Curve 40A > Curve 40B > Curve 40C > Curve 40D > Curve 40E. From each curve, it can be seen that the greater the amount of carbon dioxide in the gas phase, the greater the ammonia removal effect. As the partial pressure of carbon dioxide in the gas phase increases, the amount of carbon dioxide dissolved in the water increases. This increase in the amount of carbon dioxide dissolved in the water increases the amount of ammonia absorbed by the water. Similar to increasing the partial pressure of carbon dioxide in Figure 8, increasing the bubble content in the treatment liquid PL can enhance the ammonia removal effect in the treatment liquid PL. Because carbon dioxide has a low solubility in water, the amount of carbon dioxide that can be dissolved in the treatment liquid PL is limited. In this embodiment, the carbon dioxide in the gas phase is retained in the treatment liquid PL as fine bubbles, effectively increasing the amount of carbon dioxide in the treatment liquid PL.

[0089] As described above, according to the first aspect of the present disclosure, there is provided a removal device 1 comprising: a tank 2 for receiving a material to be removed; a flow path 21 including a plurality of pipes 24 connected to the tank 2 for circulating a liquid; and a connecting pipe 25 connecting the plurality of pipes 24 together; fine bubble generators 22 disposed in each of the plurality of pipes 24 for generating bubbles in the liquid to produce a treatment liquid PL; and a flow path switching unit 23 for switching the connection of the flow path 21 so that each fine bubble generator 22 is connected in series or in parallel to the tank 2.

[0090] According to this configuration, the connection of the flow paths 21 can be switched so that the fine bubble generators 22 arranged in each of the multiple pipes 24 are connected in series or in parallel to the tank 2. If the fine bubble generators 22 are connected in series, the bubble content in the treatment liquid PL can be increased. If the fine bubble generators 22 are connected in parallel, the supply amount of the treatment liquid PL can be increased. This allows for flexible response to changes in the treatment status of ammonia (the substance to be removed).

[0091] According to the second aspect of the present disclosure, in the removal device 1 according to the first aspect, the connecting pipe 25 connects the downstream of the fine bubble generator 22 in one of the multiple pipes 24 with the upstream of the fine bubble generator 22 in the other pipes 24, and the flow path switching unit 23 includes multiple valves that switch between opening and closing the multiple pipes 24 and the connecting pipe 25. As a result, when the connecting pipe 25 is opened, a path can be formed that connects the fine bubble generator 22 in one pipe 24 in series with the fine bubble generator 22 in the other pipes 24. When the connecting pipe 25 is closed, a path can be formed that connects the fine bubble generator 22 in one pipe 24 in parallel with the fine bubble generator 22 in the other pipes 24. Therefore, with a relatively simple configuration in which multiple pipes 24 are connected with the connecting pipe 25, a flow path 21 can be constructed in which the fine bubble generators 22 can be connected in series or in parallel.

[0092] According to the third aspect of the present disclosure, in the removal device 1 of the second aspect, the multiple valves include a first valve 26 arranged upstream of the fine bubble generator 22, a second valve 27 arranged downstream of the fine bubble generator 22, and a connecting pipe valve 28 arranged in the connecting pipe 25. This makes it possible to switch between series and parallel connections and to change the number of series connections or parallel connections (number of systems) by combining the open / close states of the first valve 26, the second valve 27, and the connecting pipe valve 28. Since various connection states of the fine bubble generator 22 can be realized depending on the treatment status of the ammonia (substance to be removed), the bubble content in the treatment liquid PL and the supply amount can be precisely controlled.

[0093] According to a fourth aspect of the present disclosure, in the removal device 1 according to any one of the first to third aspects, the number of the multiple pipes 24 is four or more, and the flow path switching unit 23 is switchable between a series mode in which one path through two or more fine bubble generators 22 for liquid is connected to the tank 2, a parallel mode in which multiple paths through one fine bubble generator 22 for liquid are connected in parallel to the tank 2, and a mixed mode in which multiple paths through two or more fine bubble generators 22 for liquid are connected in parallel to the tank 2. This makes it possible to realize a mixed mode in which multiple series-connected paths are connected in parallel, in addition to the series mode and parallel mode. Therefore, the production of the treatment liquid PL can be more flexibly adjusted according to the treatment status of the ammonia (substance to be removed).

[0094] According to the fifth aspect of the present disclosure, in the removal device 1 according to any one of the first to fourth aspects, the fine bubble generator 22 generates bubbles of 100 micrometers or less, thereby forming fine bubbles that can promote the removal of ammonia (the target of removal).

[0095] According to a sixth aspect of the present disclosure, in the removal device 1 according to any one of the first to fifth aspects, the tank 2 receives a basic gas containing ammonia as the substance to be removed, and the fine bubble generator 22 generates carbon dioxide bubbles in the liquid passing through the pipe 24 to produce the treatment liquid PL. This makes it possible to provide a wet ammonia removal device that can effectively remove ammonia and flexibly respond to changes in the ammonia removal situation.

[0096] According to a seventh aspect of the present disclosure, there is provided a control device 5 for a removal device 1 that controls a removal device 1 relating to any of the first to sixth aspects, the control device 5 including an information acquisition unit 31 that acquires the status of the removal process of the object to be removed in the removal device 1, and a switching control unit 32 that controls the flow path switching unit 23 of the removal device 1 based on the status of the removal process of the object to be removed in the removal device 1.

[0097] According to this configuration, the connection of the flow path 21 can be switched so that the fine bubble generator 22 provided in the removal device 1 is connected in series or in parallel to the tank 2. If the fine bubble generators 22 are connected in series, the bubble content in the treatment liquid PL can be increased. If the fine bubble generators 22 are connected in parallel, the supply amount of the treatment liquid PL can be increased. This allows for flexible response to changes in the treatment status of ammonia (the substance to be removed).

[0098] According to an eighth aspect of the present disclosure, in the control device 5 of the removal device 1 according to the seventh aspect, the status of the removal process of the removal target includes information on at least one of the flow rate of the removal target relative to the tank 2, the flow rate of the fluid flowing through the flow path 21, and the concentration of the removal target supplied to the tank 2. This allows for more flexible adjustment of the production of the treatment liquid PL according to the flow rate of the removal target, the flow rate of the fluid (the amount of treatment liquid PL produced), the concentration of the removal target, etc.

[0099] According to the ninth aspect of the present disclosure, in the control device 5 of the removal device 1 of the eighth aspect, the switching control unit 32 controls the flow path switching unit 23 to connect the fine bubble generators 22 in parallel when the flow rate of the material to be removed into the tank 2 exceeds a threshold value. As a result, when the flow rate of the material to be removed increases, the fine bubble generators 22 are connected in parallel, thereby making it possible to increase the amount of treatment liquid PL supplied to the tank 2 in accordance with the increase in the flow rate of the material to be removed.

[0100] According to the tenth aspect of the present disclosure, in the control device 5 of the removal device 1 according to the eighth or ninth aspect, the switching control unit 32 controls the flow path switching unit 23 to connect the fine bubble generators 22 in parallel when the flow rate of the fluid flowing through the flow path 21 falls below a threshold value. As a result, when the supply rate of the treatment liquid PL is insufficient, the fine bubble generators 22 are connected in parallel, thereby making it possible to increase the supply rate of the treatment liquid PL to the tank 2 in response to an increase in the flow rate of the material to be removed.

[0101] According to an eleventh aspect of the present disclosure, in the control device 5 of the removal device 1 according to any of the eighth to tenth aspects, the switching control unit 32 controls the flow path switching unit 23 to connect the fine bubble generators 22 in series when the concentration of the substance to be removed supplied to the tank 2 exceeds a threshold value. As a result, when the concentration of the substance to be removed increases, the fine bubble generators 22 are connected in series, thereby making it possible to increase the bubble content of the treatment liquid PL in accordance with the increase in the concentration of the substance to be removed.

[0102] According to a twelfth aspect of the present disclosure, there is provided a removal method for removing a target object to be removed, which is supplied to a tank 2, by a treatment liquid PL containing gas bubbles, the removal method comprising the steps of: receiving the target object to be removed into the tank 2; circulating the liquid through a flow path 21 connected to the tank 2; generating gas bubbles in the liquid by at least some of a plurality of fine bubble generators 22 arranged in the flow path 21 to produce the treatment liquid PL; and switching the connection of the flow path 21 so that at least some of the plurality of fine bubble generators 22 are connected in series or in parallel to the tank 2 based on the status of the removal process of the target object to be removed.

[0103] According to this configuration, the connection of the flow path 21 can be switched so that the multiple fine bubble generators 22 arranged in the flow path 21 are connected in series or in parallel to the tank 2. If the fine bubble generators 22 are connected in series, the bubble content in the treatment liquid PL can be increased. If the fine bubble generators 22 are connected in parallel, the supply amount of the treatment liquid PL can be increased. This allows for flexible response to changes in the treatment status of ammonia (the substance to be removed).

[0104] In the above-described embodiment, an example was shown in which the object to be removed was ammonia contained in exhaust gas (basic gas) from an emission source such as a fertilizer manufacturing plant, but the present invention is not limited to this configuration. The object to be removed is not limited to ammonia, and may be any component contained in the gas introduced into the tank. Therefore, in the above-described embodiment, an example was shown in which the removal device 1 is a wet ammonia removal device that removes ammonia from exhaust gas, but the removal device 1 may be other than a wet ammonia removal device.

[0105] The object to be removed may be a solid (solid matter). Fine bubbles have the property of adsorbing to substances due to the surface of the fine bubbles being electrically charged. For example, tank 2 receives sludge containing various solid matters. The object to be removed is the solid matter contained in the sludge. By introducing the treatment liquid PL containing fine bubbles into tank 2, removable solid matters can be efficiently removed from the sludge. The object to be removed may be a liquid.

[0106] In the above embodiment, an example has been shown in which the connecting pipe 25 connects two adjacent pipes 24 in the fluid circuit, but the present invention is not limited to this configuration. The connecting pipe 25 may also be connected to a pipe 24 other than the adjacent pipe 24. For example, in FIG. 3, a connecting pipe may be added that connects pipes 24-1 and 24-3. This connecting pipe connects the downstream side of the fine bubble generator 22 in pipe 24-1 to the upstream side of the fine bubble generator 22 in pipe 24-3. In this case, it is possible to selectively construct a series connection path between pipes 24-1 and 24-2 and a series connection path between pipes 24-1 and 24-3.

[0107] In the above-described embodiment, the flow path 21 is shown as being composed of N pipes 24 and N-1 connecting pipes 25, which can be switched between a series connection and a parallel connection of the fine bubble generator 22. However, the present invention is not limited to this configuration. The removal device 1 may have multiple sets of flow paths 21, each composed of N pipes 24 and N-1 connecting pipes 25. For example, multiple sets of N=4 flow paths 21 as shown in FIG. 3 may be provided. In this case, multiple sets of N=4 flow paths 21 are provided in parallel between the inlet pipe 24A and the outlet pipe 24B. This allows multiple systems of up to four flow paths 21 in series or four in parallel.

[0108] In the above-described embodiment, an example has been shown in which the treatment liquid PL is circulated by the pump 3, but this configuration is not limited to this. The removal device 1 does not have to circulate the treatment liquid PL. In this case, the treatment liquid generator 4 is connected to the makeup water supply line 12 and generates the treatment liquid PL by forming fine bubbles of an enclosed gas in the makeup water. The treatment liquid PL is sent to the tank 2, absorbs the substances to be removed, and is then discharged through the discharge line 8. In this case, the circulation line 7A does not have to be provided. If the supply pressure of the makeup water supply line 12 is sufficient, the pump 3 does not have to be provided, and a supply control valve 15 may be provided in the makeup water supply line 12 to control the flow rate of the makeup water to the treatment liquid generator 4. [Explanation of symbols]

[0109] 1 Removal device 2 Tanks 5. Control device 21 Flow path 22 Fine bubble generator 23 Flow path switching section 24, 24-1, 24-2, 24-3, 24-4 Piping 25, 25-1, 25-2, 25-3 connecting pipe 26 First valve 27 Second valve 28 Connecting pipe valve 31 Information Acquisition Department 32 Switching control section PL processing solution

Claims

1. a tank for receiving the material to be removed; a flow path including a plurality of pipes connected to the tank and through which a liquid flows, and a connecting pipe connecting the plurality of pipes to each other; a fine bubble generator disposed in each of the plurality of pipes, the fine bubble generator generating bubbles in the liquid to produce a treatment liquid; and a flow path switching unit that switches the connection of the flow paths so that each of the fine bubble generators is connected in series or in parallel to the tank. removal device.

2. The connecting pipe connects a downstream side of the fine bubble generator in one of the plurality of pipes to an upstream side of the fine bubble generator in another of the plurality of pipes, the flow path switching unit includes a plurality of valves that switch between opening and closing of the plurality of pipes and the connection pipes, The removal device of claim 1 .

3. The plurality of valves include a first valve arranged upstream of the fine bubble generator, a second valve arranged downstream of the fine bubble generator, and a connecting pipe valve arranged in the connecting pipe. The removal device of claim 2 .

4. The number of the plurality of pipes is four or more, The flow path switching unit is a serial mode in which one path through which liquid passes through two or more of the fine bubble generators is connected to the tank; a parallel mode in which a plurality of paths through which liquid passes through one fine bubble generator are connected in parallel to the tank; a mixed mode in which a plurality of paths through which liquid passes through two or more of the fine bubble generators are connected in parallel to the tank; It is possible to switch the connection to The removal device of claim 1 .

5. The fine bubble generator generates bubbles with a diameter of 100 micrometers or less. The removal device of claim 1 .

6. the tank receives a basic gas containing ammonia as the substance to be removed; The fine bubble generator generates carbon dioxide bubbles in the liquid passing through the pipe to produce the treatment liquid. The removal device of claim 1 .

7. A control device for controlling the removal device according to claim 1, an information acquisition unit that acquires a status of a removal process of the removal object in the removal device; a switching control unit that controls a flow path switching unit of the removal device based on a status of removal processing of the removal object in the removal device, Control device for removal device.

8. the status of the removal process of the removal target substance includes information on at least one of a flow rate of the removal target substance to the tank, a flow rate of the fluid flowing through the flow path, and a concentration of the removal target substance supplied to the tank; The control device for a removal device according to claim 7.

9. The switching control unit controls the flow path switching unit to connect the fine bubble generators in parallel based on the fact that the flow rate of the substance to be removed into the tank exceeds a threshold value. The control device for a removal device according to claim 8 .

10. The switching control unit controls the flow path switching unit to connect the fine bubble generators in parallel when the flow rate of the fluid flowing through the flow path falls below a threshold. The control device for a removal device according to claim 8 .

11. The switching control unit controls the flow path switching unit to connect the fine bubble generators in series based on the concentration of the substance to be removed supplied to the tank exceeding a threshold value. The control device for a removal device according to claim 8 .

12. A removal method for removing a target substance supplied to a tank using a processing liquid containing air bubbles, comprising: receiving the object to be removed into the tank; passing a liquid through a flow path connected to the tank; generating bubbles in the liquid by at least some of the fine bubble generators arranged in the flow path to produce a treatment liquid; switching the connection of the flow paths so that at least some of the fine bubble generators are connected in series or in parallel to the tank based on the status of the removal process of the object to be removed; Equipped with Removal method.

Images