A direct steam-heated ammonia distillation tower system and slag discharge method thereof

Abstract

The invention relates to a direct steam-heated ammonia still system and a slag discharge method thereof. The ammonia still system comprises an ammonia still, a still and ammonia still wastewater pump. The invention transfers the generation and deposition of tar residue from the bottom of the ammonia still to the still by adding a still outside the ammonia still. During the operation of the ammonia still, there is no need to perform slag discharge operation regularly, no blockage of the venting pipeline occurs, no shutdown treatment is required, and continuous and stable operation of the ammonia still is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of gas purification in the coking industry, and in particular to an ammonia still system using direct steam heating in an ammonia still unit and a slag discharge method thereof. Background Art

[0002] Ammonia is a nitrogen compound and a byproduct of the coal coking process. Generally, dry coal contains about 2% nitrogen, of which 40% to 50% enters the raw gas, most of which forms ammonia, and a small part forms hydrogen cyanide and pyridine.

[0003] Ammonia is a colorless gas with a strong pungent odor. It is highly soluble in water and its aqueous solution is called ammonia water.

[0004] The raw gas from the coke oven is a complex mixture of dry gas, water vapor and a series of chemical substances. After being processed by the gas purification device, tar, ammonia, benzene and other chemicals are recovered, and the clean gas is sent to users for use. After passing through the riser, the raw gas is sprayed with circulating ammonia water in the bridge pipe and the gas collecting pipe to cool to about 80°C. The amount of cooled tar is about 60%, which is sent to the gas-liquid separator for gas-liquid separation. After the tar-ammonia mixture is separated, it enters the air spray washing tower, and the ammonia water is used to continue to circulate and wash the coal powder entrained in the gas. Then the gas is pumped to the primary cooler, and indirectly cooled by circulating water and low-temperature water. Finally, the gas is cooled to 20°C~21°C and the purification effect of the gas is improved. After all the cooling mixed liquids are separated from oil, water and slag, the ammonia water is reused for circulating cooling. During this process, the circulating ammonia water collects the moisture contained in the raw coal gas (about 12% of the coal gas volume). The amount of circulating ammonia water gradually increases. The excess circulating ammonia water is called residual ammonia water. After being treated in the ammonia distillation unit of the coal gas purification device, it is sent to the wastewater treatment system.

[0005] The purpose of the ammonia evaporation unit is to decompose the volatile ammonium salts (such as ammonium carbonate, ammonium sulfide, etc.) in the raw ammonia water by heating the ammonia water, and to escape from the top of the tower in the form of carbon dioxide, hydrogen sulfide and ammonia in gaseous form; at the same time, in order to decompose the fixed ammonium salts (such as ammonium sulfate and ammonium chloride), sodium hydroxide solution is added to the middle section of the ammonia evaporation tower. There are two processes for the ammonia evaporation tower: direct steam heating and indirect steam heating. The direct steam heating method can simplify the process, reduce the tower bottom temperature, and is more energy-efficient.

[0006] Before being sent to the ammonia evaporation tower, the remaining ammonia water passes through the flotation detarrifier and the ceramic filter to remove impurities, but it still contains a small amount of tar. The tar enters the ammonia evaporation tower with the ammonia water and accumulates at the bottom of the ammonia evaporation tower to form tar residue. In the existing process, the ammonia evaporation tower is only vented, that is, vented to the tar residue pit. Since the tar residue contains precipitates such as fine coal powder, calcium hydroxide and magnesium hydroxide, and because of the direct steam heating, the bottom of the ammonia evaporation tower is in a boiling state, and the tar residue is deposited on the entire inner wall of the bottom of the tower, forming a thick and relatively solid tar residue layer, it is not easy to vent. It is often necessary to stop the work and manually clean the inner wall of the bottom of the tower. The ammonia evaporation tower needs to operate continuously for 365 days, so two ammonia evaporation towers need to be set up on site, one for operation and one for standby.

[0007] The Chinese utility model patent with authorization announcement number CN209210559U discloses a "residual ammonia water tar removal device", in which a tar residue precipitation barrel is provided at the outlet of the vent pipe at the bottom of the ammonia distillation tower using a direct steam heating process for tar residue precipitation. However, due to the use of direct steam heating, the bottom of the ammonia distillation tower is in a boiling state, and the tar residue is dispersed on the bottom and the wall of the tower. The tar residue is discharged from the vent pipe at the bottom of the tower, which cannot solve the problem of slag hanging at the bottom of the ammonia distillation tower, and the problem of easy blockage of the vent pipe is not solved. Summary of the invention

[0008] The present invention provides a direct steam-heated ammonia still system and a slag discharge method thereof. By adding a steam-blowing kettle outside the ammonia still, the generation and deposition of tar residues are transferred from the bottom of the ammonia still to the steam-blowing kettle. During the operation of the ammonia still, there is no need to perform slag discharge operation regularly, the venting pipeline will not be blocked, and there is no need to stop the operation for treatment, thereby ensuring the continuous and stable operation of the ammonia still.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A direct steam-heated ammonia distillation tower system comprises an ammonia distillation tower; further comprising a distillation and blowing kettle and an ammonia distillation wastewater pump; the distillation and blowing kettle is arranged at the outer lower part of the ammonia distillation tower; a direct steam inlet is arranged at the lower part of the distillation and blowing kettle, a distillation and blowing steam outlet and ammonia distillation wastewater inlet are arranged at the top, and an ammonia distillation wastewater outlet is arranged at the bottom; a direct steam inlet and a distillation and blowing steam inlet are arranged at the lower part of the ammonia distillation tower, and a first ammonia distillation wastewater outlet and a second ammonia distillation wastewater outlet are arranged at the bottom; the direct steam inlet of the distillation and blowing kettle is connected to a steam main pipe through a steam pipeline 1, and the direct steam inlet of the ammonia distillation tower is connected to the steam main pipe through a steam pipeline 2; the distillation and blowing steam outlet of the distillation and blowing kettle is connected to the distillation and blowing steam inlet of the ammonia distillation tower through a steam pipeline 2; the ammonia distillation wastewater outlet 1 of the ammonia distillation tower is connected to the ammonia distillation wastewater inlet of the distillation and blowing kettle through ammonia distillation wastewater pipeline 1; the ammonia distillation wastewater outlet of the distillation and blowing kettle is connected to the inlet of the ammonia distillation wastewater pump through ammonia distillation wastewater pipeline 2, and the outlet of the ammonia distillation wastewater pump is connected to the ammonia distillation wastewater pipeline; the ammonia distillation wastewater outlet 2 is connected to the ammonia distillation wastewater pipeline 2 through ammonia distillation wastewater pipeline 3.

[0011] The steam-blowing kettle is a horizontal kettle.

[0012] A direct steam heating pipe is provided at the direct steam inlet of the steam-blowing kettle. The direct steam heating pipe is connected to the kettle body of the steam-blowing kettle by a flange. The direct steam heating pipe is arranged horizontally, one end of which is connected to the steam pipeline 1, and the other end extends into the steam-blowing kettle.

[0013] An ammonia wastewater pipe is arranged at the ammonia wastewater inlet of the distillation and blowing kettle, and the ammonia wastewater pipe is connected to the kettle body of the distillation and blowing kettle by a flange. The ammonia wastewater pipe is arranged vertically, one end of which is connected to the ammonia wastewater pipeline 1, and the other end extends into the distillation and blowing kettle.

[0014] The kettle body of the steam-blowing kettle is provided with a sealing head at one end corresponding to the direct steam inlet, and the kettle body and the sealing head are connected through a flange.

[0015] The lower part of the ammonia distillation tower is also provided with an ammonia distillation wastewater return port, which is connected to the outlet of the ammonia distillation wastewater pump through an ammonia distillation wastewater pipeline 4.

[0016] The steam pipe one is provided with valve one, the steam pipe two is provided with valve two; the steam blowing pipe is provided with valve three; the ammonia evaporation wastewater pipe one is provided with valve four, the ammonia evaporation wastewater pipe two is provided with valve five, the ammonia evaporation wastewater pipe three is provided with valve six, the ammonia evaporation wastewater pipe four is provided with valve seven; the ammonia evaporation wastewater pipe is provided with valve eight.

[0017] A slag discharge method for an ammonia distillation tower system with direct steam heating, wherein no liquid is stored at the bottom of the ammonia distillation tower, and ammonia distillation wastewater is directly discharged into a distillation and blowing kettle, which is directly heated by steam, and tar residue in the ammonia distillation wastewater is deposited in the distillation and blowing kettle. After the tar residue has been deposited for a period of time, the distillation and blowing kettle is deslagging off-line, and the system is switched to a mode of directly introducing steam heating into the bottom of the ammonia distillation tower; after the deslagging of the distillation and blowing kettle is completed, the system is switched back to a mode of directly introducing steam heating into the distillation and blowing kettle.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1) Compared with the conventional process of discharging the tar residue from the bottom of the ammonia distillation tower to the tar residue pit through the venting pipe, the shutdown caused by the tar residue blocking the venting pipe is avoided;

[0020] 2) The conventional tar slag pit was eliminated and a steam-blowing kettle was used, which can be used to clean the slag on site or after removal. The steam-blowing kettle adopts a closed structure, which is conducive to purifying the on-site environment;

[0021] 3) When the steam-blowing kettle is discharging slag, it can be temporarily switched to a mode of direct steam heating at the bottom of the ammonia distillation tower. The ammonia distillation tower does not need to be shut down, and continuous production can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a direct steam-heated ammonia distillation tower system according to the present invention.

[0023] In the figure: 1. Ammonia distillation tower 2. Distillation and blowing kettle 3. Ammonia distillation wastewater pump 4. Valve 1 5. Valve 2 6. Valve 3 7. Valve 4 8. Valve 5 9. Valve 6 10. Valve 7 11. Valve 8 A1. Direct steam inlet of ammonia distillation tower A2. Direct steam inlet of distillation and blowing kettle A3. Ammonia distillation wastewater inlet of distillation and blowing kettle A4. Distillation and blowing steam inlet A5. Ammonia distillation wastewater return port B1. Ammonia distillation wastewater outlet 1 B2. Ammonia distillation wastewater outlet 2 B3. Ammonia distillation wastewater outlet B4. Distillation and blowing steam outlet DETAILED DESCRIPTION

[0024] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0025] like Figure 1 As shown, the present invention discloses a direct steam-heated ammonia still system, comprising an ammonia still 1; a still 2 and an ammonia still wastewater pump 3; a still 2 is provided at the lower part of the ammonia still 1; a direct steam inlet A2 is provided at the lower part of the still 2, a still 3 and ammonia still wastewater inlet A3 is provided at the top, and an ammonia still wastewater outlet B3 is provided at the bottom; a direct steam inlet A1 and a still 4 and ammonia still wastewater inlet B1 and an ammonia still wastewater outlet B2 are provided at the lower part of the ammonia still 1; the direct steam inlet A2 of the still 2 is connected to the steam pipe A1 through the steam pipe B2; a steam inlet A3 is provided at the lower part of the ammonia still 1, and a steam inlet B4 and an ammonia still wastewater outlet B1 and an ammonia still wastewater outlet B2 are provided at the bottom; a steam inlet A2 of the still 2 is connected to the steam pipe A1 through the steam pipe B2; a steam inlet A3 of the still 2 is provided to the steam pipe B1 through the steam pipe B2; a steam inlet A4 of the still 2 is provided to the steam pipe B1 through the steam pipe B2; a steam inlet A2 of the still 2 is connected to the steam pipe A ... provided to the steam pipe A1; a steam inlet Main pipe, the direct steam inlet A1 of the ammonia distillation tower 1 is connected to the steam main pipe through the steam pipe 2; the steam outlet B4 of the distillation kettle 2 is connected to the steam inlet A4 of the ammonia distillation tower 1 through the steam pipe; the ammonia distillation wastewater outlet B1 of the ammonia distillation tower 1 is connected to the ammonia distillation wastewater inlet A3 of the distillation kettle 2 through the ammonia distillation wastewater pipe 1; the ammonia distillation wastewater outlet B3 of the distillation kettle 2 is connected to the inlet of the ammonia distillation wastewater pump 3 through the ammonia distillation wastewater pipe 2, and the outlet of the ammonia distillation wastewater pump 3 is connected to the ammonia distillation wastewater pipe; the ammonia distillation wastewater outlet B2 is connected to the ammonia distillation wastewater pipe 2 through the ammonia distillation wastewater pipe 3.

[0026] The steam-blowing kettle 2 is a horizontal kettle.

[0027] A direct steam heating pipe is provided at the direct steam inlet A2 of the steam-blowing kettle 2. The direct steam heating pipe is connected to the kettle body of the steam-blowing kettle 2 by a flange. The direct steam heating pipe is arranged horizontally, one end of which is connected to the steam pipe 1, and the other end extends into the steam-blowing kettle 2.

[0028] An ammonia wastewater pipe is provided at the ammonia wastewater inlet A3 of the distillation and blowing kettle 2. The ammonia wastewater pipe is connected to the kettle body of the distillation and blowing kettle 2 by a flange. The ammonia wastewater pipe is vertically arranged, one end of which is connected to the ammonia wastewater pipeline 1, and the other end extends into the distillation and blowing kettle 2.

[0029] The kettle body of the steam-blowing kettle 2 is provided with a head at one end corresponding to the direct steam inlet A2, and the kettle body and the head are connected by a flange.

[0030] The lower part of the ammonia distillation tower 1 is also provided with an ammonia distillation wastewater return port A5, which is connected to the outlet of the ammonia distillation wastewater pump 3 through an ammonia distillation wastewater pipeline 4.

[0031] The steam pipe one is provided with a valve one 4, the steam pipe two is provided with a valve two 5; the steam blowing pipe is provided with a valve three 6; the ammonia evaporation wastewater pipe one is provided with a valve four 7, the ammonia evaporation wastewater pipe two is provided with a valve five 8, the ammonia evaporation wastewater pipe three is provided with a valve six 9, the ammonia evaporation wastewater pipe four is provided with a valve seven 10; the ammonia evaporation wastewater pipe is provided with a valve eight 11.

[0032] A slag discharge method for an ammonia distillation tower system with direct steam heating, wherein no liquid is stored at the bottom of the ammonia distillation tower, and ammonia distillation wastewater is directly discharged into a distillation and blowing kettle 2, which is directly heated by steam, and tar residue in the ammonia distillation wastewater is deposited in the distillation and blowing kettle 2. After the tar residue has been deposited for a period of time, the distillation and blowing kettle 2 is deslagging off-line, and the system is switched to a mode of directly introducing steam heating into the bottom of the ammonia distillation tower; after the deslagging of the distillation and blowing kettle 2 is completed, the system is switched back to a mode of directly introducing steam heating into the distillation and blowing kettle 2.

[0033] The present invention adopts a steam-blowing kettle for heating, and the deposition position of the tar residue is transferred from the bottom of the ammonia distillation tower to the steam-blowing kettle, which effectively protects the ammonia distillation tower; and the present invention can switch back to the bottom of the ammonia distillation tower for direct steam heating operation in a short period of time, so as to realize the slag cleaning operation of the steam-blowing kettle without stopping the operation.

[0034] The following embodiments are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0035] [Example]

[0036] In this embodiment, a direct steam heating ammonia distillation tower system includes an ammonia distillation tower 1, a distillation and blowing kettle 2, an ammonia distillation wastewater pump 3, valve one 4, valve two 5, valve three 6, valve four 7, valve five 8, valve six 9, valve seven 10, and valve eight 11.

[0037] Firstly, a horizontal steam blowing kettle 2 is added on the ground below the ammonia distillation tower 1 to replace the direct steam heating function of the bottom of the ammonia distillation tower 1. The ammonia distillation tower 1 is an empty tower with no liquid at the bottom.

[0038] In order to make the steam-blowing kettle 2 have the function of direct steam heating and steam-blowing, and to facilitate manual slag removal, the top of the steam-blowing kettle 2 is provided with a steam-blowing steam outlet B4 and an ammonia steam wastewater inlet A3, a direct steam inlet A2 is provided on one side of the lower part of the steam-blowing kettle 2, and an ammonia steam wastewater outlet B3 is provided on the bottom. The direct steam heating pipe inserted horizontally from the direct steam inlet extends to the other end of the steam-blowing kettle 2, and the ammonia steam wastewater pipe inserted vertically from the ammonia steam wastewater inlet A3 extends to the bottom of the steam-blowing kettle 2. Both the direct steam heating pipe and the ammonia steam wastewater pipe can be pulled out of the steam-blowing kettle 2. The steam-blowing kettle 2 is provided with a head on one side corresponding to the direct steam heating pipe, and the head is connected to the kettle body by a flange, which is convenient for manual slag removal after disassembly.

[0039] The bottom of the ammonia distillation tower 1 is not provided with a vent pipe, but is provided with an ammonia distillation wastewater outlet 1 B1 and an ammonia distillation wastewater outlet 2 B2. The ammonia distillation wastewater outlet 1 B1 is connected to the ammonia distillation wastewater inlet A3 of the distillation and blowing kettle 2, and is used to empty the ammonia distillation wastewater at the bottom of the ammonia distillation tower 1 during the ammonia distillation operation.

[0040] A steam inlet A4 and an ammonia evaporation wastewater return port A5 are provided on the tower side wall above the highest liquid level at the bottom of the tower at the lower part of the ammonia evaporation tower 1. The steam inlet A4 is used to connect to the steam outlet B4 on the top of the steam evaporation kettle 2 through a steam pipeline. The ammonia evaporation wastewater return port A5 is used to return the ammonia evaporation wastewater discharged from the steam evaporation kettle 2 during the system switching process to the ammonia evaporation tower 1 through the ammonia evaporation wastewater pump 3 when the steam evaporation kettle 2 performs an offline slag discharge operation.

[0041] The ammonia wastewater discharged from the ammonia wastewater outlet B2 of the ammonia still 1 and the ammonia wastewater outlet B3 of the still 2 share a common ammonia wastewater pump 3, that is, no matter the still 2 is directly heated by steam or the bottom of the ammonia still 1 is directly heated by steam, the same ammonia wastewater pump 3 is used to deliver the ammonia wastewater to the ammonia wastewater pipeline.

[0042] External direct steam is connected to the direct steam inlet A1 of the ammonia still 1 and the direct steam inlet A2 of the steam-blowing kettle 2 at the same time, which can provide heat to the ammonia still 1 and the steam-blowing kettle 2.

[0043] The specific operation process is as follows:

[0044] 1. During normal production, valve 2 5, valve 6 9 and valve 7 10 are closed, and the other valves are opened; all the ammonia distillation wastewater in the ammonia distillation tower 1 is discharged into the distillation and blowing kettle 2 through the ammonia distillation wastewater pipeline 1, and the steam in the steam main pipe is passed into the distillation and blowing kettle 2 through the steam pipeline 1 and the direct steam heating pipe to heat the distillation and blowing kettle 2; the tar residue in the ammonia distillation wastewater is deposited at the bottom of the distillation and blowing kettle 2; the ammonia distillation wastewater in the distillation and blowing kettle 2 is pumped out by the ammonia distillation wastewater pump 3 and sent to the ammonia distillation wastewater pipeline;

[0045] 2. When the tar residue in the distillation and blowing kettle 2 is deposited to a certain thickness and needs to be cleaned, switch the system; close valve 4 7; open valve 6 9 and valve 7 10, and pump the ammonia wastewater at the bottom of the ammonia distillation tower through the ammonia wastewater pump 3 during the switching process and then send it back to the ammonia distillation tower 1;

[0046] 3. After the system switching is completed, close valve 1 4, valve 3 6, valve 4 7, valve 5 8 and valve 7 10, and open the other valves; the steam blowing kettle 2 is cleaned offline; the steam in the steam main pipe enters the ammonia distillation tower 1 through the steam pipe 2 to heat the bottom of the tower, and the ammonia distillation wastewater in the ammonia distillation tower 1 is pumped out by the ammonia distillation wastewater pump 3 and sent to the ammonia distillation wastewater pipeline;

[0047] 4. After the steam-blowing kettle 2 is cleaned, it is put back online and the system switches back to normal production mode.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A slag removal method for a direct steam-heated ammonia still system, the direct steam-heated ammonia still system comprising an ammonia still; characterized in that: It also includes a steam blowing kettle and an ammonia distillation wastewater pump; the steam blowing kettle is arranged outside and below the ammonia distillation tower; the lower part of the steam blowing kettle is provided with a direct steam inlet, the top is provided with a steam blowing steam outlet and ammonia distillation wastewater inlet, and the bottom is provided with an ammonia distillation wastewater outlet; the lower part of the ammonia distillation tower is provided with a direct steam inlet and a steam blowing steam inlet, and the bottom is provided with ammonia distillation wastewater outlet 1 and ammonia distillation wastewater outlet 2; the direct steam inlet of the steam blowing kettle is connected to the steam main pipe through a steam pipe 1, and the direct steam inlet of the ammonia distillation tower is connected to the steam main pipe through a steam pipe 2; the steam blowing steam outlet of the steam blowing kettle is connected to the steam blowing steam inlet of the ammonia distillation tower through a steam blowing steam pipe; the ammonia distillation wastewater outlet 1 of the ammonia distillation tower is connected to the ammonia distillation wastewater inlet of the steam blowing kettle through an ammonia distillation wastewater pipe 1; the ammonia distillation wastewater outlet of the steam blowing kettle is connected to the inlet of the ammonia distillation wastewater pump through an ammonia distillation wastewater pipe 2, and the outlet of the ammonia distillation wastewater pump is connected to the ammonia distillation wastewater pipe; the ammonia distillation wastewater outlet 2 is connected to the ammonia distillation wastewater pipe 2 through an ammonia distillation wastewater pipe 3; The slag discharge method of the ammonia evaporation tower system with direct steam heating is as follows: no liquid is stored in the bottom of the ammonia evaporation tower, the ammonia evaporation wastewater is directly discharged into the distillation and blowing kettle, the distillation and blowing kettle is directly heated by steam, and the tar residue in the ammonia evaporation wastewater is deposited in the distillation and blowing kettle. After the tar residue is deposited for a period of time, the distillation and blowing kettle is offline for slag cleaning, and the system is switched to a mode of directly introducing steam heating into the bottom of the ammonia evaporation tower; after the slag cleaning of the distillation and blowing kettle is completed, the system is switched back to a mode of directly introducing steam heating into the distillation and blowing kettle.

2. The slag removal method of a direct steam-heated ammonia still system according to claim 1, characterized in that: The steam-blowing kettle is a horizontal kettle.

3. The slag removal method of a direct steam-heated ammonia distillation tower system according to claim 1, characterized in that: A direct steam heating pipe is provided at the direct steam inlet of the steam-blowing kettle. The direct steam heating pipe is connected to the kettle body of the steam-blowing kettle by a flange. The direct steam heating pipe is arranged horizontally, one end of which is connected to the steam pipeline 1, and the other end extends into the steam-blowing kettle.

4. The slag discharge method of a direct steam-heated ammonia still system according to claim 1, characterized in that: An ammonia wastewater pipe is arranged at the ammonia wastewater inlet of the distillation and blowing kettle, and the ammonia wastewater pipe is connected to the kettle body of the distillation and blowing kettle by a flange. The ammonia wastewater pipe is arranged vertically, one end of which is connected to the ammonia wastewater pipeline 1, and the other end extends into the distillation and blowing kettle.

5. The slag discharge method of a direct steam-heated ammonia still system according to claim 1, characterized in that: The kettle body of the steam-blowing kettle is provided with a sealing head at one end corresponding to the direct steam inlet, and the kettle body and the sealing head are connected through a flange.

6. The slag removal method of a direct steam-heated ammonia distillation tower system according to claim 1, characterized in that: The lower part of the ammonia distillation tower is also provided with an ammonia distillation wastewater return port, which is connected to the outlet of the ammonia distillation wastewater pump through an ammonia distillation wastewater pipeline 4.

7. The slag removal method of a direct steam-heated ammonia distillation tower system according to claim 1, characterized in that: The steam pipe one is provided with valve one, the steam pipe two is provided with valve two; the steam blowing pipe is provided with valve three; the ammonia evaporation wastewater pipe one is provided with valve four, the ammonia evaporation wastewater pipe two is provided with valve five, the ammonia evaporation wastewater pipe three is provided with valve six, the ammonia evaporation wastewater pipe four is provided with valve seven; the ammonia evaporation wastewater pipe is provided with valve eight.

Images