Ammonia detoxification device and method

Abstract

To suppress leakage of ammonia-containing gas remaining in a pipeline after atmospheric discharge has ended, in a configuration where the ammonia-containing gas sent through the pipeline to an ammonia detoxification device is discharged into the atmosphere after removal of the ammonia component using the detoxification device.SOLUTION: An ammonia detoxification device for detoxifying ammonia-containing gas at a pressure higher than atmospheric pressure in an ammonia supply system includes: a storage tank that stores detoxification liquid for ammonia, and has a discharge port at its top; a spray nozzle that opens to a gas phase part located vertically between the liquid surface of the detoxification liquid in the storage tank and the discharge port; an underwater nozzle that opens into the detoxification liquid; an in-gas nozzle that opens into the gas phase part; and an ammonia-containing gas system in which ammonia-containing gas flows from the ammonia supply system to the underwater nozzle and the in-gas nozzle.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an ammonia abatement device and method for removing ammonia components from an ammonia-containing gas. [Background technology]

[0002] Conventionally, facilities that use ammonia have been equipped with an ammonia abatement device, and an ammonia-containing gas is released into the atmosphere after the ammonia component is separated and removed in the ammonia abatement device. Patent Document 1 discloses this type of ammonia abatement device.

[0003] The ammonia detoxification device disclosed in Patent Document 1 includes a storage tank that stores an aqueous sulfuric acid solution that is an absorbing solution for ammonia, a vent stack disposed at the top of the storage tank, and an ammonia-containing gas blowing pipe having an inlet disposed at the bottom of the storage tank. When an ammonia-containing gas is blown into the bottom of the storage tank through the ammonia-containing gas blowing pipe, the ammonia in the gas is absorbed and removed by the absorbing solution. The gas from which the ammonia has been removed is released into the atmosphere through the vent stack. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-239130 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a configuration in which the ammonia-containing gas sent to the ammonia detoxification device through a pipe is released into the atmosphere after the ammonia component is removed in a detoxification tank storing an ammonia detoxification liquid, when the inflow of new ammonia-containing gas into the pipe is stopped, the pressure inside the pipe gradually decreases and eventually converges to a pressure equivalent to the pressure at the ammonia-containing gas inlet in the detoxification tank. The ammonia-containing gas inlet in the detoxification tank is in the detoxification liquid, so it is higher than atmospheric pressure. As a result, even after the release into the atmosphere from the ammonia detoxification device is completed, the pressure inside the pipe is maintained at a higher pressure than atmospheric pressure. In other words, the pressure inside the pipe is higher than the atmosphere, and there remains a risk of ammonia-containing gas leaking from the pipe.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to relate to a technology for suppressing leakage of ammonia-containing gas remaining in piping after release into the atmosphere is completed in a configuration in which an ammonia-containing gas is sent through piping to an ammonia detoxification device, and the ammonia component is removed in the detoxification device before the gas is released into the atmosphere. [Means for solving the problem]

[0007] In order to solve the above problems, an ammonia detoxification apparatus according to one embodiment of the present disclosure is an ammonia detoxification apparatus that detoxifies an ammonia-containing gas at a pressure higher than atmospheric pressure in an ammonia supply system, A storage tank for storing an ammonia detoxifying liquid and having a discharge port at its top; A water spray nozzle that opens into a gas phase portion between the liquid level of the abatement liquid in the storage tank and the discharge port in the vertical direction; an underwater nozzle opening into the abatement liquid; an air nozzle opening in the gas phase portion; and an ammonia-containing gas system through which the ammonia-containing gas flows from the ammonia supply system to the underwater nozzle and the air nozzle.

[0008] In order to solve the above problems, an ammonia detoxification method according to one embodiment of the present disclosure is an ammonia detoxification method for detoxifying an ammonia-containing gas at a pressure higher than atmospheric pressure in an ammonia supply system, comprising: The ammonia-containing gas is blown into the ammonia detoxifying liquid in a storage tank through a submerged blowing pipe connected to the ammonia supply system; Spraying water onto a gas phase portion between the liquid level of the abatement liquid in the storage tank and a discharge port at the top of the storage tank in the vertical direction; and and blowing the ammonia-containing gas through an air blowing pipe connected to the ammonia supply system so that the gas comes into contact with the water sprayed into the gas phase portion. Effect of the Invention

[0009] According to the present disclosure, in a configuration in which ammonia-containing gas sent through piping to an ammonia detoxification device is released into the atmosphere after the ammonia components are removed in the detoxification device, leakage of ammonia-containing gas remaining in the piping after the release into the atmosphere is completed can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic configuration diagram of an ammonia supply system equipped with an ammonia detoxification device according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic diagram of an ammonia detoxification device according to one embodiment of the present disclosure. [Diagram 3] FIG. 3 is a schematic configuration diagram of an ammonia detoxification device according to the first modification. [Figure 4] FIG. 4 is a schematic diagram of an ammonia detoxification device according to the second modification. [Diagram 5] FIG. 5 is a timing chart of the ammonia detoxification process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic configuration diagram of an ammonia supply system 100 equipped with an ammonia detoxification device 2 according to an embodiment of the present disclosure.

[0012] The ammonia supply system 100 disclosed in Fig. 1 is a flow path for an ammonia-containing gas to be supplied to the ammonia combustion burner 5, and is composed of piping and the like. The ammonia combustion burner 5 is an example of an ammonia-using device, and the ammonia-using device is not limited to the ammonia combustion burner 5. In addition, the ammonia-containing gas may be any gas containing ammonia, and the concentration of ammonia in the ammonia-containing gas is not limited.

[0013] The ammonia supply system 100 includes a supply main pipe 13 connected to a gas source 12, and a shutoff valve 16 is disposed in the supply main pipe 13 for opening and closing the flow path of the supply main pipe 13. One or more supply branch pipes 14 are connected downstream of the shutoff valve 16 of the supply main pipe 13. The supply branch pipe 14 is connected to an ammonia combustion burner 5, and the ammonia-containing gas that flows from the supply main pipe 13 to the supply branch pipe 14 is supplied to the ammonia combustion burner 5. The supply branch pipe 14 is disposed with a burner valve 17 for opening and closing the flow path of the supply branch pipe 14.

[0014] A release pipe 15 is connected downstream of the shutoff valve 16 of the supply main pipe 13. The release pipe 15 is used when releasing the ammonia-containing gas remaining in the ammonia supply system 100. A release valve 18 for opening and closing the flow path of the release pipe 15 is disposed in the release pipe 15. An ammonia detoxification device 2 is connected to the most downstream of the release pipe 15.

[0015] In the ammonia supply system 100 having the above configuration, when an ammonia-containing gas is being supplied to the ammonia combustion burner 5, the shutoff valve 16 and the burner valve 17 are opened, and the release valve 18 is closed. When the supply of the ammonia-containing gas to the ammonia combustion burner 5 is stopped, the shutoff valve 16 and the burner valve 17 are closed, and the release valve 18 is opened.

[0016] When the ammonia supply system 100 switches from supplying ammonia-containing gas to stopping the supply, ammonia-containing gas at a pressure higher than atmospheric pressure remains in the downstream portion of the shutoff valve 16 of the supply main pipe 13 and in the upstream portion of the burner valve 17 of the supply branch pipe 14. This ammonia-containing gas flows through the release pipe 15 to the ammonia detoxification device 2 by opening the release valve 18. In the ammonia detoxification device 2, ammonia is removed from the ammonia-containing gas, and the gas is released into the atmosphere as ammonia-detoxified gas.

[0017] Configuration of ammonia detoxification device 2 Here, a detailed description will be given of the configuration of the ammonia detoxification device 2. Fig. 2 is a schematic configuration diagram of the ammonia detoxification device 2 according to one embodiment of the present disclosure.

[0018] The ammonia detoxification device 2 shown in Figure 2 comprises a storage tank 21 in which an ammonia detoxification liquid 22 is stored, spray nozzles 31, 32 that spray water into the gas phase portion 24 of the storage tank 21, submerged nozzles 46A, 46B that spray ammonia-containing gas into the gas phase portion 24 of the storage tank 21, an air nozzle 47 that sprays ammonia-containing gas into the gas phase portion 24 of the storage tank 21, and an ammonia-containing gas system 4 in which ammonia-containing gas flows from a discharge pipe 15 to the submerged nozzles 46A, 46B and the air nozzle 47.

[0019] The detoxifying liquid 22 stored in the storage tank 21 is a liquid that traps ammonia, and is, for example, an aqueous sulfuric acid solution. When the ammonia-containing gas is blown into the detoxifying liquid 22, the ammonia in the ammonia-containing gas is absorbed into the detoxifying liquid 22 by the following reaction. NH3+H2O→NH4OH 2NH4OH+H2SO4→(NH4)2SO4+2H2O

[0020] An outlet 25 opens at the top of the storage tank 21. Inside the storage tank 21, there is a gas phase section 24 between the liquid level 23 of the abatement liquid 22 and the outlet 25 in the vertical direction. The gas phase section 24 is in communication with the outside through the outlet 25, and is at approximately atmospheric pressure. The gas from which the ammonia component has been removed in the gas phase section 24 is released from the storage tank 21 to the atmosphere through the outlet 25.

[0021] The first sprinkler nozzle 31 is disposed in the gas phase section 24 of the storage tank 21. The first sprinkler nozzle 31 is preferably disposed in the upper half of the gas phase section 24, more preferably directly below the outlet 25. The first sprinkler nozzle 31 is connected to a water supply pipe 30. Water supplied to the first sprinkler nozzle 31 through the water supply pipe 30 is sprinkled from the first sprinkler nozzle 31 to the gas phase section 24. The first sprinkler nozzle 31 is preferably a nozzle that sprays water so as to diffuse it over a wide range. The water sprayed from the first sprinkler nozzle 31 comes into contact with ammonia gas floating in the gas phase section 24, absorbs the ammonia, and becomes ammonia water in which the ammonia is dissolved, and falls into the abatement liquid 22.

[0022] 2, the submersible nozzles 46A, 46B include a first submersible nozzle 46A and a second submersible nozzle 46B that open at different height levels within the detoxifying liquid 22. At least one first submersible nozzle 46A is disposed at the bottom of the storage tank 21. At least one second submersible nozzle 46B is disposed below the liquid level 23 of the storage tank 21 and above the first submersible nozzle 46A. However, the ammonia detoxifying device 2 only needs to be equipped with at least one submersible nozzle 46A, 46B that opens into the detoxifying liquid 22, and may be equipped with three or more submersible nozzles.

[0023] The ammonia-containing gas system 4 is composed of a main pipe 40 connected to the release pipe 15 of the ammonia supply system 100, and blowing pipes 41, 42 connected to the main pipe 40. Ammonia-containing gas flows into the main pipe 40 from the release pipe 15. By opening and closing a release valve 18 provided in the release pipe 15, it is possible to switch between allowing and stopping the inflow of ammonia-containing gas from the release pipe 15 to the main pipe 40. The release valve 18 may be provided in the main pipe 40. In addition, the main pipe 40 may be a part of the release pipe 15.

[0024] The blowing pipes 41, 42 include a submerged blowing pipe 41 for blowing the ammonia-containing gas into the abatement liquid 22, and an air blowing pipe 42 for blowing the ammonia-containing gas into the gas phase portion 24. The submerged blowing pipe 41 includes a first submerged blowing pipe 41A connected to a first submerged nozzle 46A, and a second submerged blowing pipe 41B connected to a second submerged nozzle 46B. The ammonia-containing gas flows from the mother pipe 40 through the first submerged blowing pipe 41A to the first submerged nozzle 46A, and is blown out from the first submerged nozzle 46A into the abatement liquid 22. The ammonia-containing gas also flows from the discharge pipe 15 through the second submerged blowing pipe 41B to the second submerged nozzle 46B, and is blown out from the second submerged nozzle 46B into the abatement liquid 22.

[0025] At least one of the first submerged nozzle 46A and the second submerged nozzle 46B may be equipped with a fine bubble generator. The fine bubble generator generates fine bubbles with diameters on the order of microns or less. Fine bubbles of ammonia-containing gas are blown out from the first submerged nozzle 46A and the second submerged nozzle 46B equipped with the fine bubble generator. The fine bubbles have a smaller bubble diameter than millibubbles and rise slowly in the abatement liquid 22. The fine bubbles of ammonia-containing gas have a larger contact area with the abatement liquid 22 and a longer contact time, accelerating the reaction between the ammonia contained in the ammonia-containing gas and the abatement liquid 22.

[0026] The first and second submersible blowing pipes 41A and 41B, as well as the first and second submersible nozzles 46A and 46B, are desirably made of a material having high corrosion resistance, since they are constantly submerged in the abatement liquid 22. An example of such a material is stainless steel.

[0027] At least one air nozzle 47 is disposed above the liquid level 23 of the storage tank 21 and below the discharge port 25. A second sprinkling nozzle 32 connected to the water supply pipe 30 is disposed near the air nozzle 47. Water supplied to the second sprinkling nozzle 32 through the water supply pipe 30 is sprinkled from the second sprinkling nozzle 32 to the gas phase section 24. The air nozzle 47 is connected to the main pipe 40 via the air blowing pipe 42. The ammonia-containing gas flows from the main pipe 40 through the air blowing pipe 42 to the air nozzle 47, and is blown out from the air nozzle 47 to the gas phase section 24.

[0028] The aerial nozzle 47 is disposed so that the ammonia-containing gas blown out from the aerial nozzle 47 collides with and mixes with the water blown out from the second watering nozzle 32. Since the ammonia in the ammonia-containing gas blown out from the aerial nozzle 47 rises in the gas phase section 24, it is desirable that the aerial nozzle 47 opens below the first watering nozzle 31 and the second watering nozzle 32. However, the second watering nozzle 32 may be omitted, and the aerial nozzle 47 may be disposed so that the ammonia-containing gas blown out from the aerial nozzle 47 collides with the water blown out from the first watering nozzle 31. Alternatively, the aerial nozzle 47 may be a nozzle with a mixer configured to mix and blow out the ammonia-containing gas supplied from the aerial blowing pipe 42 and the water supplied from the water supply pipe 30.

[0029] Among the first submerged nozzle 46A, the second submerged nozzle 46B, and the air nozzle 47, the first submerged nozzle 46A has a high efficiency of removing ammonia from the ammonia-containing gas. Therefore, the relationship is adjusted for at least one of the pipe diameter of the blowing pipe, the area of ​​the nozzle outlet (i.e., the aperture), and the number of nozzles so that the ammonia-containing gas flows preferentially to the first submerged nozzle 46A. For example, the first submerged blowing pipe 41A, the second submerged blowing pipe 41B, and the air blowing pipe 42 have different pipe diameters, with the first submerged blowing pipe 41A>the second submerged blowing pipe 41B>the air blowing pipe 42 being smaller in diameter. For example, the first submerged nozzle 46A, the second submerged nozzle 46B, and the air nozzle 47 have different total outlet areas, with the first submerged nozzle 46A>the second submerged nozzle 46B>and the air nozzle 47 being smaller in total outlet area. The total outlet area of ​​the first submersible nozzles 46A means the sum of the outlet areas of all the first submersible nozzles 46A connected to the first submersible blowing pipe 41A. The same applies to the total outlet area of ​​the second submersible nozzles 46B and the total outlet area of ​​the aerial nozzles 47. For example, the first submersible nozzles 46A, the second submersible nozzles 46B and the aerial nozzles 47 are different in number, with the number of nozzles decreasing in the order of first submersible nozzles 46A > second submersible nozzles 46B > aerial nozzles 47.

[0030] <Method for removing ammonia> Here, we will explain the ammonia detoxification method using the above-mentioned ammonia detoxification device 2. In the ammonia supply system 100, when the shutoff valve 16 and the burner valve 17 (see FIG. 1) are closed and the release valve 18 is opened, the ammonia-containing gas remaining in the ammonia supply system 100 and having a pressure higher than atmospheric pressure flows into the mother pipe 40.

[0031] Most of the ammonia-containing gas that has flowed into the mother pipe 40 passes through the first submerged blowing pipe 41A and the second submerged blowing pipe 41B, and is blown out from the submerged nozzles 46A and 46B into the abatement liquid 22. The ammonia-containing gas blown into the abatement liquid 22 from the submerged nozzles 46A and 46B reacts with the abatement liquid 22 while rising toward the liquid surface 23, and ammonia is removed. The gas from which ammonia has been removed passes through the liquid surface 23 and moves to the gas phase 24. In this way, most of the ammonia in the ammonia-containing gas blown into the abatement liquid 22 is absorbed by the abatement liquid 22. Some ammonia may remain in the gas that has moved from the abatement liquid 22 to the gas phase 24. Since ammonia is lighter than air, the ammonia in the gas phase 24 rises and comes into contact with the water sprayed from the first water spray nozzle 31, dissolves in the water, and becomes ammonia water, which falls into the abatement liquid 22. The gas from which ammonia has been removed is released into the atmosphere through the outlet 25.

[0032] The remainder of the ammonia-containing gas that has flowed into the mother pipe 40 passes through the air blowing pipe 42 and is blown out from the air nozzle 47 into the gas phase section 24. The ammonia-containing gas blown into the gas phase section 24 from the air nozzle 47 comes into contact with the water sprayed out from the second sprinkler nozzle 32 (or the first sprinkler nozzle 31) and dissolves in the water to become ammonia water, which falls into the abatement liquid 22.

[0033] As described above, while the ammonia-containing gas is being detoxified by the ammonia detoxification device 2, there is no new inflow of ammonia-containing gas into the discharge pipe 15, so the pressure inside the discharge pipe 15 gradually drops. First, when the pressure inside the discharge pipe 15 drops to the water pressure at the outlet of the first submerged nozzle 46A, the blowing of the ammonia-containing gas from the first submerged nozzle 46A stops. Next, when the pressure inside the discharge pipe 15 drops to the water pressure at the outlet of the second submerged nozzle 46B, the blowing of the ammonia-containing gas from the second submerged nozzle 46B stops. Finally, when the pressure inside the discharge pipe 15 drops to the air pressure at the outlet of the air nozzle 47, that is, atmospheric pressure, the blowing of the ammonia-containing gas from the air nozzle 47 stops. In this way, even after the blowing of the ammonia-containing gas from the first submerged nozzle 46A and the second submerged nozzle 46B stops, the blowing of the ammonia-containing gas from the air nozzle 47 into the storage tank 21 continues until the pressure inside the discharge pipe 15 becomes atmospheric pressure. In this way, the pressure inside the discharge pipe 15 can be automatically lowered to atmospheric pressure without relying on the power of a blower, etc. When the pressure inside the discharge pipe 15 becomes atmospheric pressure, leakage of gas to the atmosphere from the discharge pipe 15, the connection between the discharge pipe 15 and the main pipe 40, the connection between the main pipe 40 and each blowing pipe, etc. is suppressed.

[0034] [Modifications] Modifications 1 and 2 of the ammonia detoxification apparatus 2 according to the above embodiment will be described. The ammonia detoxification apparatus 2 according to modifications 1 and 2 differ from the ammonia detoxification apparatus 2 according to the above embodiment in that the flow path of the ammonia-containing gas is operated by a valve so that the nozzle from which the ammonia-containing gas is blown can be selected from among the first submerged nozzle 46A, the second submerged nozzle 46B, and the aerial nozzle 47. In the description of the modifications, members that are the same as or similar to those in the above embodiment are given the same reference numerals in the drawings, and detailed description thereof will be omitted.

[0035] Fig. 3 is a schematic diagram of an ammonia detoxification apparatus 2 according to Modification 1. In the ammonia detoxification apparatus 2 according to Modification 1 shown in Fig. 3, the second submerged blowing pipe 41B is provided with a first valve 51 for opening and closing a flow path of the second submerged blowing pipe 41B. The air blowing pipe 42 is provided with a second valve 52 for opening and closing a flow path of the air blowing pipe 42. The water supply pipe 30 is provided with a sprinkler valve 53. The discharge pipe 15 is provided with a pressure sensor 55 for detecting the pressure inside the pipe.

[0036] Fig. 4 is a schematic configuration diagram of an ammonia detoxification apparatus 2 according to Modification 2. The ammonia detoxification apparatus 2 according to Modification 2 shown in Fig. 4 differs from the embodiment and Modification 1 in that a control device 60 operates a flow path for an ammonia-containing gas with a valve.

[0037] In the ammonia detoxification device 2 shown in FIG. 4, the second submerged blowing pipe 41B is provided with a first valve 51 for opening and closing the flow path of the second submerged blowing pipe 41B. The air blowing pipe 42 is provided with a second valve 52 for opening and closing the flow path of the air blowing pipe 42. The water supply pipe 30 is provided with a water sprinkling valve 53 for switching between supplying and stopping water to the first water sprinkling nozzle 31 and the second water sprinkling nozzle 32. The first valve 51, the second valve 52, the release valve 18, and the water sprinkling valve 53 are electrically connected to the control device 60, and these valves are opened and closed upon receiving a command from the control device 60. The release pipe 15 is provided with a pressure sensor 55 for detecting the pressure inside the pipe. The pressure sensor 55 is electrically connected to the control device 60, and the control device 60 opens and closes the valve based on the detection value of the pressure sensor 55 to operate the flow path of the ammonia-containing gas.

[0038] <Method for removing ammonia> Here, the ammonia detoxification method using the ammonia detoxification device 2 according to the modified example 1 and the modified example 2 will be described with reference to the timing chart of ammonia detoxification in Fig. 5. The ammonia detoxification method is common to the modified example 1 and the modified example 2, but in the modified example 1, each valve is manually opened and closed, whereas in the modified example 2, the opening and closing operation of each valve is controlled by the control device 60. Although not specifically stated, in the ammonia detoxification method using the ammonia detoxification device 2 according to the modified example 2, the opening and closing operations of the first valve 51, the second valve 52, the release valve 18, and the sprinkler valve 53 are controlled by the control device 60, which is configured to monitor the detection value of the pressure sensor 55 during processing and to issue an operation command to each valve based on the detection value.

[0039] In the ammonia supply system 100, when the release process of the ammonia-containing gas is started based on the ON of the purge command, the shutoff valve 16 and the burner valve 17 (see FIG. 1) are closed and the release valve 18 is opened. As a result, the ammonia-containing gas remaining in the ammonia supply system 100 and having a higher pressure than the atmospheric pressure flows into the main pipe 40 through the release pipe 15. With the opening of the release valve 18, the sprinkler valve 53 is opened. With the opening of the sprinkler valve 53, sprinkling from the first sprinkler nozzle 31 and the second sprinkler nozzle 32 is started.

[0040] The first valve 51 and the second valve 52 are closed in advance. Therefore, immediately after starting the purging of the ammonia-containing gas, the ammonia-containing gas flows only into the first submerged blowing pipe 41A, and is blown out from the first submerged nozzle 46A into the abatement liquid 22. At this time, blowing of the ammonia-containing gas from the second submerged nozzle 46B and the aerial nozzle 47 is stopped.

[0041] When the ammonia detoxification process progresses in the ammonia detoxification device 2 and the pressure inside the discharge pipe 15 detected by the pressure sensor 55 becomes equal to or lower than the first pressure threshold value P1, the first valve 51 is opened. The height from the first submerged nozzle 46A to the liquid level 23 is Hd, the height from the second submerged nozzle 46B to the liquid level 23 is Hs, the density of the detoxification liquid 22 is ρ, and the gravitational acceleration is g. ρ, g, Hd, and Hs are known or controlled values ​​and are given to the control device 60 in advance. The water pressure at the outlet of the first submerged nozzle 46A is represented by ρgHd, and the water pressure at the outlet of the second submerged nozzle 46B is represented by ρgHs. The first pressure threshold value P1 is ρgHd×n1. Here, n1 is a variable that is equal to or greater than 1 and equal to or less than 1.1. In other words, the first pressure threshold value P1 is equal to or slightly higher than the water pressure at the outlet of the first submerged nozzle 46A. The control device 60 can calculate the first pressure threshold value P1 using a given value of n1. The value of n1 may be stored in advance in a memory connected to the control device 60, input at the appropriate time through an input device connected to the control device 60, or sent to the control device 60 remotely through a communication line.

[0042] When the first valve 51 is opened, the ammonia-containing gas is blown out from the second submersible nozzle 46B through the second submersible blowing pipe 41B into the abatement liquid 22. As the pressure inside the discharge pipe 15 of the ammonia supply system 100 further drops, the blowing out of the ammonia-containing gas from the first submersible nozzle 46A automatically stops. However, in order to prevent backflow of the abatement liquid 22 into the first submersible blowing pipe 41A, an additional on-off valve may be provided in the first submersible blowing pipe 41A, and the on-off valve may be closed to forcibly stop the blowing out of the ammonia-containing gas from the first submersible nozzle 46A.

[0043] When the ammonia-containing gas detoxification process further progresses in the ammonia detoxification device 2 and the pressure inside the discharge pipe 15 of the ammonia supply system 100 detected by the pressure sensor 55 becomes equal to or lower than the second pressure threshold value P2, the first valve 51 is closed and the second valve 52 is opened. The second pressure threshold value P2 is expressed as ρgHs×n2. Here, n2 is a variable between 1 and 1.1. In other words, the second pressure threshold value P2 is equal to or slightly higher than the water pressure at the outlet of the second underwater nozzle 46B. The control device 60 can calculate the second pressure threshold value P2 using a given value of n2. The value of n2 may be stored in advance in a memory connected to the control device 60, input at any time through an input device connected to the control device 60, or sent remotely to the control device 60 through a communication line.

[0044] When the second valve 52 is opened, the ammonia-containing gas is blown out from the air nozzle 47 through the air blowing pipe 42 into the gas phase section 24. In order to prevent backflow of the abatement liquid 22 into the second submerged blowing pipe 41B, the first valve 51 is closed to forcibly stop blowing of the ammonia-containing gas from the second submerged nozzle 46B.

[0045] When the pressure inside the discharge pipe 15 drops to the air pressure at the outlet of the air nozzle 47, i.e., atmospheric pressure, the blowing of the ammonia-containing gas from the air nozzle 47 automatically stops. After the pressure inside the discharge pipe 15 drops to atmospheric pressure, the discharge valve 18 and the second valve 52 are closed, and then the water sprinkler valve 53 is closed, and the discharge process ends.

[0046] As described above, in the ammonia detoxification devices 2 according to the first and second modifications, the flow path of the ammonia-containing gas is operated with a valve, and as the pressure inside the discharge pipe 15 decreases, the nozzle that blows out the ammonia-containing gas is switched in this order from the first submerged nozzle 46A, to the second submerged nozzle 46B, and then to the aerial nozzle 47. This increases the proportion of the ammonia-containing gas being treated that is blown out from the first submerged nozzle 46A as much as possible, enabling efficient ammonia detoxification.

[0047] [Summary] The ammonia detoxification device 2 according to the first aspect of the present disclosure comprises: An ammonia detoxification device 2 that detoxifies an ammonia-containing gas at a pressure higher than atmospheric pressure in an ammonia supply system 100, A storage tank 21 for storing an ammonia detoxifying liquid 22 and having a discharge port 25 at the top; Sprinkler nozzles 31, 32 opening into a gas phase portion 24 between a liquid level 23 of the detoxifying liquid 22 in the storage tank 21 and a discharge port 25 in the vertical direction; Submerged nozzles 46A, 46B opening into the abatement liquid 22; an air nozzle 47 opening into the gas phase section 24; and an ammonia-containing gas system 4 that supplies an ammonia-containing gas from an ammonia supply system 100 to the submerged nozzles 46A, 46B and the air nozzle 47.

[0048] According to the ammonia abatement device 2 having the above-mentioned configuration, the ammonia-containing gas in the ammonia supply system 100 is blown out from both the submerged nozzles 46A, 46B and the aerial nozzle 47. The ammonia-containing gas blown out from the submerged nozzles 46A, 46B into the abatement liquid 22 has the ammonia contained therein absorbed and separated into the abatement liquid 22 while rising through the abatement liquid 22, and the gas from which the ammonia has been removed flows into the gas phase section 24 and is released into the atmosphere through the outlet 25. The ammonia-containing gas blown out from the aerial nozzle 47 into the gas phase section 24 mixes with the water sprayed out from the watering nozzles 31, 32, and the ammonia dissolves in the water to become ammonia water, which falls into the abatement liquid 22, and the gas from which the ammonia has been removed is released into the atmosphere through the outlet 25. As the ammonia detoxification process proceeds, the pressure inside the ammonia supply system 100 (in the embodiment, the discharge pipe 15) drops below the pressure at the outlet of the submerged nozzles 46A, 46B, and the blowing of the ammonia-containing gas from the submerged nozzles 46A, 46B stops, but the blowing from the air nozzle 47 continues until the pressure inside the ammonia supply system 100 reaches atmospheric pressure. When the pressure inside the ammonia supply system 100 reaches atmospheric pressure, the flow of the ammonia-containing gas into the storage tank 21 and the release of the detoxified gas to the atmosphere end. Therefore, after the release to the atmosphere ends, the pressure inside the ammonia supply system 100 and the ammonia-containing gas system 4 connected to the ammonia supply system 100 is approximately the same as atmospheric pressure, and the leakage of the ammonia-containing gas remaining in these piping to the outside is suppressed.

[0049] The ammonia detoxification apparatus 2 relating to the second item of the present disclosure is the ammonia detoxification apparatus 2 relating to the first item, in which the underwater nozzles 46A, 46B include a first underwater nozzle 46A opening at the bottom of the storage tank 21 and a second underwater nozzle 46B opening vertically between the first underwater nozzle 46A and the liquid level 23 of the detoxification liquid 22.

[0050] In the ammonia detoxification device 2 configured as described above, the second submersible nozzle 46B continues to blow out the ammonia-containing gas even after the first submersible nozzle 46A stops blowing out the ammonia-containing gas. Therefore, compared to the case where only the first submersible nozzle 46A is provided, a larger amount of ammonia-containing gas can be blown out into the detoxification liquid 22, and the efficiency of the ammonia detoxification process can be improved.

[0051] The ammonia detoxification apparatus 2 relating to the third item of the present disclosure is the ammonia detoxification apparatus 2 relating to the second item, in which the total nozzle outlet area of ​​the submerged nozzles 46A, 46B and the aerial nozzle 47 that open at the same height in the vertical direction is smaller the higher those nozzles are located in the vertical direction.

[0052] According to the ammonia detoxification device 2 having the above-mentioned configuration, the nozzles disposed vertically lower tend to blow out the ammonia-containing gas more easily, and the ammonia-containing gas is preferentially blown out from the nozzles disposed vertically lower.

[0053] The ammonia detoxification apparatus 2 according to the fourth item of the present disclosure is an ammonia detoxification apparatus 2 according to any one of the first to third items, in which the underwater nozzles 46A, 46B are equipped with fine bubble generators that atomize the ammonia-containing gas that is blown out.

[0054] In the ammonia detoxification device 2 configured as described above, the bubbles of the ammonia-containing gas blown out from the underwater nozzles 46A, 46B into the detoxification liquid 22 are made finer, and the efficiency of the ammonia detoxification process can be improved by increasing the contact area between the ammonia-containing gas and the detoxification liquid 22 and increasing the residence time of the ammonia-containing gas in the detoxification liquid 22.

[0055] The ammonia detoxification device 2 relating to the fifth item of the present disclosure is an ammonia detoxification device 2 relating to any one of the first to fourth items, in which the aerial nozzle 47 is arranged so as to spray ammonia-containing gas toward the water sprayed from the water spray nozzles 31, 32.

[0056] In the ammonia detoxification device 2 having the above configuration, the ammonia-containing gas blown into the gas phase section 24 immediately mixes with the water blown from the water spray nozzles 31 and 32, and the ammonia in the ammonia-containing gas dissolves in the water and is separated from the ammonia-containing gas. Therefore, the efficiency of the ammonia detoxification process can be improved.

[0057] The ammonia detoxification device 2 according to a sixth item of the present disclosure is an ammonia detoxification device 2 according to any one of the first to fourth items, in which the air nozzle 47 is configured to mix the ammonia-containing gas with water and spray it out.

[0058] In the ammonia detoxification device 2 having the above configuration, the ammonia-containing gas is blown out into the gas phase section 24 in a state where it is mixed with water such as spray water, so that the ammonia in the ammonia-containing gas is immediately dissolved in the water and separated from the ammonia-containing gas. This makes it possible to improve the efficiency of the ammonia detoxification treatment.

[0059] The ammonia detoxification apparatus 2 relating to the seventh item of the present disclosure is an ammonia detoxification apparatus 2 relating to any of the first to sixth items, in which the ammonia-containing gas system 4 includes a mother pipe 40 connected to the ammonia supply system 100, submerged blowing pipes 41A, 41B connecting the mother pipe 40 and submerged nozzles 46A, 46B, and an air blowing pipe 42 connecting the mother pipe 40 and air nozzle 47.

[0060] The ammonia detoxification apparatus 2 according to the eighth item of the present disclosure is the ammonia detoxification apparatus 2 according to the seventh item, in which the ammonia-containing gas system 4 includes a first valve 51 for opening and closing the underwater blowing pipe 41B and a second valve 52 for opening and closing the air blowing pipe 42.

[0061] In the ammonia detoxification device 2 having the above configuration, the nozzle from which the ammonia-containing gas is blown out can be selected by opening and closing the first valve 51 and the second valve 52. Therefore, it is possible to increase the amount of ammonia-containing gas blown out into the detoxification liquid 22, thereby improving the efficiency of the ammonia detoxification process.

[0062] The ammonia detoxification apparatus 2 according to the ninth item of the present disclosure is the ammonia detoxification apparatus 2 according to the seventh or eighth item, further comprising a pressure sensor 55 for detecting the pressure inside the pipe of the ammonia supply system 100, and a control device 60 for controlling the opening and closing operations of the first valve 51 and the second valve 52 based on the pressure inside the pipe detected by the pressure sensor 55. When the pressure inside the pipe falls below a predetermined pressure threshold P2, the control device 60 is configured to switch from a state in which the first valve 51 is opened and the second valve 52 is closed, and ammonia-containing gas is blown out from the underwater nozzle 46B, to a state in which the second valve 52 is opened and the first valve 51 is closed, and ammonia-containing gas is blown out from the air nozzle 47.

[0063] According to the ammonia detoxification device 2 having the above-mentioned configuration, the flow path of the ammonia-containing gas is automatically operated by opening and closing the first valve 51 and the second valve 52 by the control device 60 so that a larger amount of ammonia-containing gas is blown out into the detoxification liquid 22 and the release of the ammonia-containing gas is continued until the pressure inside the ammonia supply system 100 becomes atmospheric pressure.

[0064] The ammonia detoxification apparatus 2 according to the tenth item of the present disclosure is the ammonia detoxification apparatus 2 according to the ninth item, wherein the pressure threshold P2 is a value obtained by multiplying the water pressure at the outlet of the underwater nozzle 46B by a variable greater than or equal to 1 and less than or equal to 1.1.

[0065] According to the ammonia detoxification device 2 having the above-mentioned configuration, the timing at which the nozzle for blowing out the ammonia-containing gas is switched from the submerged nozzle 46B to the aerial nozzle 47 can be adjusted by adjusting the variables.

[0066] The ammonia detoxification apparatus 2 according to an eleventh item of the present disclosure is the ammonia detoxification apparatus 2 according to the ninth or tenth item, further comprising a sprinkler valve 53 for switching between supplying and stopping water to the sprinkler nozzles 31, 32, and a release valve 18 for switching between allowing and stopping the inflow of ammonia-containing gas from the ammonia supply system 100, and the control device 60 is configured to control the opening and closing operations of the release valve 18 and the sprinkler valve 53 so that the sprinkler valve 53 opens and closes in conjunction with the opening and closing of the release valve 18.

[0067] According to the ammonia detoxification device 2 having the above-mentioned configuration, the sprinkling of water into the storage tank 21 can be automatically started in synchronization with the inflow of the ammonia-containing gas into the storage tank 21.

[0068] The ammonia detoxification method according to the twelfth aspect of the present disclosure is a method for detoxifying an ammonia-containing gas having a higher pressure than atmospheric pressure in an ammonia supply system 100, comprising: Injecting the ammonia-containing gas into the ammonia detoxifying liquid 22 in the storage tank 21 through underwater injection pipes 41A and 41B connected to the ammonia supply system 100; Water is sprayed onto a gas phase portion 24 between a liquid level 23 of the detoxifying liquid 22 in the storage tank 21 and a discharge port 25 at the top of the storage tank 21 in the vertical direction; and The ammonia-containing gas is blown into the gas phase section 24 through an air blowing pipe 42 connected to an ammonia supply system 100 so as to come into contact with the water sprayed therein.

[0069] According to the above-mentioned ammonia abatement method, the ammonia-containing gas in the ammonia supply system 100 is blown out into both the abatement liquid 22 and the gas phase section 24. The ammonia-containing gas blown out into the abatement liquid 22 has the ammonia contained therein absorbed and separated into the abatement liquid 22 while rising through the abatement liquid 22, and the gas from which the ammonia has been removed flows out to the gas phase section 24 and is released into the atmosphere through the outlet 25. The ammonia-containing gas blown out into the gas phase section 24 mixes with the sprayed water, and the ammonia in the ammonia-containing gas is dissolved in the water and separated, and the gas from which the ammonia has been removed is released into the atmosphere through the outlet 25. As the ammonia detoxification process proceeds in this manner, the pressure inside the ammonia supply system 100 drops, and the blowing of the ammonia-containing gas into the detoxification liquid 22 stops, but the blowing of the ammonia-containing gas into the gas phase section 24 continues until the pressure inside the ammonia supply system 100 reaches atmospheric pressure, and when the pressure inside the ammonia supply system 100 reaches atmospheric pressure, the flow of the ammonia-containing gas into the storage tank 21 and the release of the detoxified gas into the atmosphere end. Therefore, after the release into the atmosphere ends, the pressure inside the ammonia supply system 100 and the ammonia-containing gas system 4 connected to the ammonia supply system 100 becomes approximately the same as atmospheric pressure, and leakage of the ammonia-containing gas remaining in these piping to the outside is suppressed.

[0070] The functions performed by the controller 60 described herein may be implemented in circuitry or processing circuitry, including general purpose processors, application specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), CPUs (Central Processing Units), conventional circuits, and / or combinations thereof, programmed to perform the described functions. Processors include transistors and other circuits and are considered to be circuitry or processing circuitry. A processor may be a programmed processor that executes a program stored in a memory. In this specification, a circuitry, unit, or means is hardware that is programmed to perform or executes the described functions. The hardware may be any hardware disclosed in this specification or any hardware that is programmed to perform or is known to perform the described functions. If the hardware is a processor, which is considered to be a type of circuitry, the circuitry, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0071] The above discussion of the present disclosure has been presented for purposes of illustration and description, and is not intended to limit the present disclosure to the form disclosed herein. For example, in the above detailed description, various features of the present disclosure are grouped together in one embodiment for the purpose of streamlining the present disclosure, but some of the features may be combined. In addition, the features included in the present disclosure may be combined into alternative embodiments, configurations, or aspects other than those discussed above. [Explanation of symbols]

[0072] 2: Ammonia removal device 4: Ammonia-containing gas system 18: Release valve 21:Storage tank 22: Harm removal liquid 23:Liquid level 24: Gas phase section 25: Outlet 31, 32: Watering nozzle 40: Main pipe 41: Underwater blowing pipe 41A: No. 1 underwater blowing pipe 41B: 2nd submersible blow pipe 42: Air blowing pipe 46A: First underwater nozzle 46B: 2nd underwater nozzle 47: Air nozzle 51: First valve 52: Second valve 53: Water sprinkler valve 55: Pressure sensor 60: Control device 100: Ammonia supply system

Claims

1. An ammonia detoxification device for detoxifying an ammonia-containing gas having a higher pressure than atmospheric pressure in an ammonia supply system, A storage tank for storing an ammonia detoxifying liquid and having a discharge port at its top; A water spray nozzle that opens into a gas phase portion between the liquid level of the abatement liquid in the storage tank and the discharge port in the vertical direction; an underwater nozzle opening into the abatement liquid; an air nozzle opening in the gas phase portion; an ammonia-containing gas system through which the ammonia-containing gas flows from the ammonia supply system to the underwater nozzle and the air nozzle; Ammonia abatement device.

2. The underwater nozzles include a first underwater nozzle that opens to the bottom of the storage tank, and a second underwater nozzle that opens between the first underwater nozzle and the liquid level of the abatement liquid in the vertical direction. The ammonia detoxification device according to claim 1 .

3. In the underwater nozzles and the air nozzles, the total nozzle outlet area of ​​the nozzles opening at the same height in the vertical direction is smaller the higher the nozzle is located in the vertical direction. The ammonia detoxification device according to claim 2 .

4. The underwater nozzle is equipped with a fine bubble generator that atomizes the ammonia-containing gas that is blown out. The ammonia detoxification device according to claim 1 .

5. The aerial nozzle is arranged to spray the ammonia-containing gas toward the water sprayed from the water spray nozzle. The ammonia detoxification device according to claim 1 .

6. The air nozzle is configured to mix the ammonia-containing gas with water and eject the mixed gas. The ammonia detoxification device according to claim 1 .

7. The ammonia-containing gas system includes a mother pipe connected to the ammonia supply system, a submerged blowing pipe connecting the mother pipe and the submerged nozzle, and an air blowing pipe connecting the mother pipe and the air nozzle. The ammonia detoxification device according to claim 1 .

8. The ammonia-containing gas system includes a first valve for opening and closing the underwater blowing pipe and a second valve for opening and closing the air blowing pipe. The ammonia detoxification device according to claim 7.

9. a pressure sensor for detecting a pressure inside the pipe of the ammonia supply system; a control device that controls opening and closing operations of the first valve and the second valve based on the pressure in the pipe detected by the pressure sensor, The control device is configured to switch from a state in which the first valve is opened and the second valve is closed, and the ammonia-containing gas is blown out from the underwater nozzle, to a state in which the second valve is opened and the first valve is closed, and the ammonia-containing gas is blown out from the air nozzle, when the pressure inside the pipe becomes equal to or lower than a predetermined pressure threshold. The ammonia detoxification device according to claim 8.

10. The pressure threshold is the water pressure at the outlet of the underwater nozzle multiplied by a variable between 1 and 1.1, The ammonia detoxification device according to claim 9.

11. A water sprinkler valve for switching between supplying and stopping water to the water sprinkler nozzle; A release valve that switches between allowing and stopping the inflow of the ammonia-containing gas from the ammonia supply system, The control device is configured to control the opening and closing operations of the release valve and the sprinkler valve so that the sprinkler valve opens and closes in conjunction with the opening and closing of the release valve. The ammonia detoxification device according to claim 9.

12. 1. An ammonia detoxification method for detoxifying an ammonia-containing gas having a higher pressure than atmospheric pressure in an ammonia supply system, comprising: The ammonia-containing gas is blown into the ammonia detoxifying liquid in a storage tank through a submerged blowing pipe connected to the ammonia supply system; Spraying water onto a gas phase portion between the liquid level of the abatement liquid in the storage tank and a discharge port at the top of the storage tank in the vertical direction; and The ammonia-containing gas is blown into the gas phase through an air blowing pipe connected to the ammonia supply system so as to come into contact with the water sprayed into the gas phase. Ammonia detoxification method.

Images