Energy-saving and consumption-reducing ammonia evaporation system

Abstract

The utility model discloses an energy -conserving and consumption -reducing ammonia evaporation system, set up dilute liquid distillation tower in ammonia evaporation system, and the liquid outlet of dilute liquid distillation tower is communicated to the liquid pipeline of mother liquor, the ash milk import of pre -ash bucket, the liquid inlet of the upper portion of preheating decomposition section of ammonia evaporation tower. The waste dilute liquid of dilute liquid distillation tower is used to the tower of warm tower, the work of stopping tower of ammonia evaporation system, can satisfy the requirement of the steam amount of ammonia evaporation tower tray efficiency, has improved the working efficiency of warm tower stopping tower, avoided the blockage of sand liquid pipeline, and realized waste dilute liquid recycling, reduced energy consumption. In addition, set up two stage flasher, and flash steam is used as supplementary steam and enters dilute liquid distillation tower and is recycled, saves primary steam, further realizes energy -conserving and consumption -reducing.

Description

Technical Field

[0001] This utility model relates to the field of ammonia-soda process for producing soda ash, and specifically to an energy-saving and consumption-reducing ammonia stripping system. Background Technology

[0002] In the ammonia-soda process for producing soda ash, the ammonia stripping tower is a key energy-consuming piece of equipment, accounting for one-third of the total energy consumption. Therefore, energy management of the ammonia stripping system has become a key research and development area. The main task of the ammonia stripping tower is to use steam distillation to remove ammonia and carbon dioxide from the mother liquor and transport it to an absorption tower to prepare ammonia brine, thereby recovering the ammonia and carbon dioxide. A conventional ammonia stripping system mainly includes the ammonia stripping tower, a pre-ash tank, an ammonia condenser, an ammonia cooler, and a distillation tower.

[0003] Because the lime slurry added to the pre-ash bucket contains a lot of sand, and Ca(OH)2 reacts with SO4 in the mother liquor... 2- During ammonia stripping, sulfate scale easily forms with calcium in the ash slurry, adhering to the walls of the ammonia stripping tower, sieve plates, or pre-ash tank, narrowing the gas-liquid passage and affecting the stripping effect. Therefore, periodic shutdown and cleaning are necessary. The traditional start-up process for ammonia stripping towers primarily involves using steam to preheat the tower itself, the pre-ash tank, the ammonia condenser, and the ammonia cooler; this process is called tower warming. The traditional shutdown procedure involves sequentially adding mother liquor and ash slurry, then using steam to remove ammonia from the remaining liquid in the stripping tower and pre-ash tank, and finally adding circulating water from the top of the stripping tower to boil off any remaining ammonia. Traditional tower start-up and shutdown methods have the following disadvantages: (1) High steam consumption: Since the low-pressure steam temperature is between 150 and 170°C, in order to prevent the equipment from heating up too quickly and causing damage to the internal components, it is required to slowly introduce steam in the early stage of tower heating. This makes the tower heating time relatively long, which is also an important reason for high steam consumption. In addition, in order to prevent the pre-ash tank from stirring and swaying, a large amount of circulating water is usually added to the pre-ash tank during start-up. Adding circulating water will increase the steam consumption. (2) High ammonia loss: During the start-up stage, the initial steam volume is only 30m³. 3 / h, when the tower is shut down, the pre-ash tank discharges the mixing liquid into the tower, at which time the estimated flow rate is 20~30m³ / h. 3 The low tray efficiency during these two stages leads to high ammonia consumption during start-up and shutdown. Furthermore, after the mother liquor and ash slurry are introduced into the ammonia stripping tower, the operating procedures typically require opening the valve on the sand slurry pipeline in the pre-ash tank after waste liquid appears at the bottom of the tower to feed the sand slurry into the stripping tower. However, due to the sedimentation process in the pre-ash tank, the sand slurry pipeline frequently becomes clogged during start-up, resulting in a long processing time, high difficulty, and significant ammonia loss. The most common method is to use high-pressure circulating water to pump water counter-currently along the sand slurry pipeline, which not only affects key economic indicators such as ammonia content and excess ash in the waste liquid but also increases steam consumption. Therefore, a new energy-saving and consumption-reducing ammonia stripping system needs to be developed. Utility Model Content

[0004] The purpose of this invention is to provide an energy-saving and consumption-reducing ammonia stripping system, which can effectively reduce steam consumption and has good economic and environmental benefits.

[0005] This utility model is implemented by the following technical solution: An energy-saving and consumption-reducing ammonia stripping system includes an ammonia condenser, an ammonia stripping tower, a pre-ash tank, an ammonia cooler, a condensate tank, and an absorption tower. The outlet of the mother liquor pipeline is connected to the cold medium inlet of the ammonia condenser, and the cold medium outlet of the ammonia condenser is connected to the liquid inlet at the upper part of the preheating decomposition section of the ammonia stripping tower. The outlet of the preheating decomposition section of the ammonia stripping tower is connected to the liquid inlet of the pre-ash tank, the air outlet at the top of the pre-ash tank is connected to the air inlet of the preheating decomposition section of the ammonia stripping tower, and the outlet at the lower part of the pre-ash tank is connected to the liquid inlet of the ash-adding distillation section of the ammonia stripping tower. The outlet of the ash-adding distillation section is connected to the inlet of the pre-ash tank at the top; the sand liquid outlet at the bottom of the pre-ash tank is connected to the liquid inlet of the ash-adding distillation section of the ammonia stripping tower; the outlet of the top of the ammonia stripping tower is connected to the heat medium inlet of the ammonia condenser; the heat medium outlet of the ammonia condenser is connected to the heat medium inlet of the ammonia cooler; the gas phase outlet of the heat medium of the ammonia cooler is connected to the inlet of the absorption tower; the liquid phase outlet of the heat medium of the ammonia cooler is connected to the liquid inlet of the condensate tank; and the outlet of the top of the condensate tank is connected to the inlet of the absorption tower. The outlet of the condensate tank is connected to a distillation tower via a condensate pump; the outlet of the distillation tower is connected to the mother liquor pipeline; the outlet of the distillation tower is connected to the ash slurry inlet of the pre-ash tank; and the outlet of the distillation tower is connected to the inlet at the top of the preheating and decomposition section of the ammonia stripping tower.

[0006] Furnace gas condensate and ammonia stripping condensate are fed into the condensate tank and then into the desalination distillation tower to distill off ammonia and carbon dioxide. The residue is the waste desalination liquid, with a temperature of 95°C and a flow rate of 50 m³ / h. 3In winter, the waste distillate can be directly mixed with circulating water to make brine, but in summer, the utilization rate is only 30%. This is mainly because the waste distillate needs to be cooled to 40-50℃ before use; otherwise, the temperature of the refined brine will rise, reducing its effectiveness in the carbonization tail gas ammonia purification tower and the absorption tail gas ammonia purification tower. Complete cooling requires a large amount of circulating water, which is difficult to achieve in actual summer production. If discharged into a waste liquid pool or ditch, the Na2CO3 and NaHCO3 contained in the waste liquid easily form scale with calcium ions in the waste liquid, causing scale buildup in the waste liquid pipelines or ditches and affecting the transport volume. In short, the low utilization rate of waste distillate in summer has always been a troublesome problem that urgently needs to be solved. Therefore, this invention connects the waste distillate from the distillation tower to various equipment to achieve waste distillate reuse. During tower warming, waste desalinated liquid enters the mother liquor pipeline, then the ammonia condenser, and finally enters the ammonia stripping tower from the top. After passing through the preheating and decomposition section, it enters the pre-ash tank. Simultaneously, waste desalinated liquid also enters the pre-ash tank from the ash emulsion pipeline. Both enter the ash-adding distillation section of the ammonia stripping tower from the blending liquid pipeline. Once the blending liquid pipeline begins to overflow, the sand liquid pipeline is opened, and steam pressure is added before the mother liquor and ash emulsion to complete the entire tower warming process. To start up the tower, simply switch the waste desalinated liquid to mother liquor and ash emulsion. The initial mother liquor distillation rate is generally 30 m³ / h. 3 / h, at this time, due to the small evaporation rate, the tray efficiency is low, and the ammonia content of the waste liquid is high, resulting in a large ammonia loss. In this scheme, the feed rate of the waste distillate in the warming tower is maintained at 40~50m³. 3 Under the premise that the sand slurry pipeline valves are open and operating normally, the mother liquor can be introduced at a total evaporation rate of at least 70m³ / h. 3 The distillation rate is above [amount] / h, meeting the tray efficiency requirements for distillation volume, thus improving the ammonia distillation efficiency during the start-up process and preventing blockage of the sand liquid pipeline. When the ammonia distillation tower is shut down, after emptying the pre-ash liquid in the pre-ash tank, 50m [of water / liquid] is [discharged / removed / etc.]. 3 All wastewater is fed into the heating and distillation section of the ammonia stripping tower to replace circulating water for boiling. A small amount of steam is introduced to maintain the pressure of the ammonia stripping tower for wastewater discharge. This reduces circulating water usage, saves water resources, and improves the utilization rate of wastewater. Furthermore, in case of an emergency requiring significant load reduction, wastewater can be fed into the ammonia stripping tower to balance the distillation volume, preventing excessive load reduction and shortening the tower's operating cycle.

[0007] Furthermore, it also includes a steam ejector, a first flash evaporator, and a second flash evaporator; the steam outlet of the steam pipeline is connected to the steam inlet of the steam ejector, and the steam outlet of the steam ejector is connected to the steam inlet of the bottom ring of the ammonia stripping tower; the liquid outlet of the bottom ring of the ammonia stripping tower is connected to the liquid inlet of the first flash evaporator, and the steam outlet at the top of the first flash evaporator is connected to the steam inlet of the steam ejector; the liquid outlet at the bottom of the first flash evaporator is connected to the liquid inlet of the second flash evaporator, and the steam outlet at the top of the second flash evaporator is connected to the steam inlet of the distillation tower; the liquid outlet at the bottom of the second flash evaporator is connected to the inlet of the waste liquid pump.

[0008] 0.3MPa steam from the pipe gallery, used as working steam, enters the steam ejector and, together with the waste liquid flash vapor from the first flash evaporator, enters the bottom ring of the ammonia stripping tower. From bottom to top, it flows counter-currently with the mixing liquid on the tower plates, undergoing heat and mass exchange. The waste liquid discharged from the bottom ring of the ammonia stripping tower flashes through the first flash evaporator; the flash vapor returns to the steam ejector, while the liquid enters the second flash evaporator. The liquid after flashing in the second flash evaporator is then pumped to the waste liquid treatment area as waste liquid by the waste liquid pump. The flash vapor after flashing is used as makeup steam in the distillation tower for reuse, fully recovering the heat from the waste liquid at the bottom of the tower and reducing heat energy consumption.

[0009] Furthermore, it also includes a gas-liquid separator; the gas outlet at the top of the ammonia stripping tower is connected to the feed inlet of the gas-liquid separator, the gas outlet of the gas-liquid separator is connected to the heat medium inlet of the ammonia condenser, and the liquid outlet of the gas-liquid separator is connected to the liquid inlet at the top of the preheating decomposition section of the ammonia stripping tower.

[0010] After heat exchange with the mother liquor, ammonia gas exits from the top of the ammonia stripping tower. After passing through the gas-liquid separator to remove entrained liquid, it enters the ammonia condenser for further heat exchange. The stripped ammonia gas is cooled by the mother liquor and then enters the ammonia cooler, where it is indirectly cooled again by circulating water. The cooled gas, along with the ammonia and CO2 gas expelled from the ammonia condenser, enters the absorption tower. The liquid exiting the gas-liquid separator returns to the upper part of the preheating and decomposition section of the ammonia stripping tower for re-steaming. The gas-liquid separator reduces the workload of the ammonia condenser, further improving energy efficiency and reducing consumption.

[0011] Beneficial Effects: This utility model provides an energy-saving and consumption-reducing ammonia stripping system. Waste distillate from the distillation tower is fed into the ammonia condenser, pre-ash tank, and ammonia stripping tower for warming and shutdown operations. This meets the steam generation requirements of the ammonia stripping tower's tray efficiency, improves the efficiency of warming and shutdown, avoids blockage in the sand liquid pipeline, and enables the reuse of waste distillate, thus reducing energy consumption. Furthermore, the installation of a two-stage flash evaporator, with the flash vapor used as supplementary steam in the distillation tower for reuse, saves primary steam and further achieves energy saving and consumption reduction. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of an energy-saving and consumption-reducing ammonia stripping system.

[0014] The attached diagram is described below: 1. Mother liquor pipeline; 2. Ammonia condenser; 3. Ammonia stripping tower; 4. Pre-ash tank; 5. Blending liquid pipeline; 6. Sand liquid pipeline; 7. Ammonia cooler; 8. Condensate tank; 9. Absorption tower; 10. Condensate pump; 11. Distillation tower; 12. Steam pipeline; 13. Steam ejector; 14. First flash evaporator; 15. Second flash evaporator; 16. Waste liquid pump; 17. Gas-liquid separator. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. In the description of the present utility model, it should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0016] Example An energy-saving and consumption-reducing ammonia stripping system, such as Figure 1 As shown, it includes an ammonia condenser 2, an ammonia stripping tower 3, a pre-ash tank 4, an ammonia cooler 7, a condensate tank 8, an absorption tower 9, a distillation tower 11, a steam ejector 13, a first flash evaporator 14, a second flash evaporator 15, a waste liquid pump 16, and a gas-liquid separator 17.

[0017] The outlet of the mother liquor pipeline 1 is connected to the cold medium inlet of the ammonia condenser 2. The cold medium outlet of the ammonia condenser 2 is connected to the liquid inlet at the top of the preheating decomposition section of the ammonia stripping tower 3. The ammonia stripping tower 3 is a cross-flow sieve plate ammonia stripping tower. The outlet of the preheating decomposition section of the ammonia stripping tower 3 is connected to the liquid inlet of the pre-ash tank 4. The gas outlet at the top of the pre-ash tank 4 is connected to the gas inlet of the preheating decomposition section of the ammonia stripping tower 3. The outlet at the bottom of the pre-ash tank 4 is connected to the liquid inlet of the ash-adding distillation section of the ammonia stripping tower 3 through the blending liquid pipeline 5. The gas outlet of the ash-adding distillation section of the ammonia stripping tower 3 is connected to the gas inlet at the top of the pre-ash tank 4. The sand liquid outlet at the bottom of the pre-ash tank 4 is connected to the ammonia stripping tower 3. The inlet of the ash distillation section is connected to the sand-liquid pipeline 6; the outlet of the top of the ammonia stripping tower 3 is connected to the inlet of the gas-liquid separator 17, the outlet of the gas-liquid separator 17 is connected to the inlet of the hot medium of the ammonia condenser 2, and the outlet of the gas-liquid separator 17 is connected to the inlet of the upper part of the preheating decomposition section of the ammonia stripping tower 3; the outlet of the hot medium of the ammonia condenser 2 is connected to the inlet of the hot medium of the ammonia cooler 7, the gas phase outlet of the hot medium of the ammonia cooler 7 is connected to the inlet of the absorption tower 9, the liquid phase outlet of the hot medium of the ammonia cooler 7 is connected to the inlet of the condensate tank 8, and the outlet of the top of the condensate tank 8 is connected to the inlet of the absorption tower 9.

[0018] The outlet of the condensate tank 8 is connected to the distillation tower 11 via the condensate pump 10; the outlet of the distillation tower 11 is connected to the mother liquor pipeline 1; the outlet of the distillation tower 11 is connected to the ash milk inlet of the pre-ash tank 4; and the outlet of the distillation tower 11 is connected to the inlet of the upper part of the preheating decomposition section of the ammonia stripping tower 3.

[0019] The steam outlet of steam pipeline 12 is connected to the steam inlet of steam ejector 13, and the steam outlet of steam ejector 13 is connected to the steam inlet of the bottom ring of ammonia stripping tower 3; the liquid outlet of the bottom ring of ammonia stripping tower 3 is connected to the liquid inlet of the first flash evaporator 14, and the steam outlet at the top of the first flash evaporator 14 is connected to the steam inlet of steam ejector 13; the liquid outlet at the bottom of the first flash evaporator 14 is connected to the liquid inlet of the second flash evaporator 15, and the steam outlet at the top of the second flash evaporator 15 is connected to the steam inlet of distillation tower 11; the liquid outlet at the bottom of the second flash evaporator 15 is connected to the inlet of waste liquid pump 16.

[0020] When using: The mother liquor enters the bottom of the ammonia condenser 2 through mother liquor pipeline 1, where it undergoes counter-current heat exchange with the ammonia stripping gas from the ammonia stripping tower 3. After being heated in the ammonia condenser 2, the mother liquor flashes some free ammonia and CO2 gas at the top. The heated mother liquor, after separation, flows by gravity into the 35# tray at the top of the ammonia stripping tower 3, where it is evenly distributed across the entire sieve plate surface from top to bottom. It then undergoes counter-current heat exchange with the rising steam, stripping away most of the free ammonia and CO2. The liquid flows out from the middle of the ammonia stripping tower 3 as preheated mother liquor and enters the middle of the pre-ash tank 4. In the pre-ash tank 4, it fully reacts with the lime slurry from the lime slurry pipeline (the reaction liquid is the mixing liquid), thereby removing most of the free ammonia and CO2. Some of the NH4Cl decomposes into free ammonia, and some of the free ammonia is released from the liquid phase and enters the 25# tray of the ammonia stripping tower 3 through the top outlet of the pre-ash tank 4. The decomposed blended liquid enters the 21# tray in the middle of the ammonia stripping tower 3 through the blended liquid pipeline 5. It comes into countercurrent contact with the steam from top to bottom, and almost all of the ammonia is stripped out. The waste liquid is discharged from the bottom of the tower and enters the first flash evaporator 14 to recover the steam. The waste liquid after flashing enters the second flash evaporator 15 and flashes again. The secondary steam generated is used as the gas source for the distillation tower 11. The waste liquid after flashing in the second flash evaporator 15 is sent to the waste liquid treatment plant by the waste liquid pump 16 for further treatment and reuse. 0.3MPa steam from the pipe gallery is used as working steam. It enters the steam ejector 13 through steam pipeline 12. The steam ejector 13 combines the steam with the flash vapor from the waste liquid in the first flash evaporator 14 and enters the bottom ring of the ammonia stripping tower 3. From bottom to top, it comes into countercurrent contact with the conditioning liquid on the tower plate for heat and mass exchange. After exchanging heat with the mother liquor, the ammonia gas comes out from the top of the tower and passes through the gas-liquid separator 17 for gas-liquid separation. The liquid from the gas-liquid separator 17 returns to the upper part of the preheating and decomposition section of the ammonia stripping tower 3 for re-steaming. The gas enters the ammonia condenser 2 and is cooled by the mother liquor. The cooled ammonia gas enters the ammonia cooler 7 and is indirectly cooled again by circulating water. The cooled condensate flows into the condensate tank 8. The cooled gas, together with the ammonia and CO2 gas expelled from the ammonia condenser 2, enters the absorption tower 9 for treatment.

[0021] After the furnace gas condensate and ammonia stripping condensate are sent to the condensate tank 8, the condensate pump 10 sends them to the distillation tower 11 to distill off the ammonia and carbon dioxide in the condensate. The remaining liquid is the waste distillate, with a temperature of 95℃ and a service life of 50m. 3 / h. During tower warming, the waste desalinated liquid enters the mother liquor pipeline 1, then enters the ammonia condenser 2. After heat exchange, it enters the ammonia stripping tower 3 from the top, passes through the preheating and decomposition section, and enters the pre-ash tank 4. At the same time, the waste desalinated liquid also enters the pre-ash tank 4 from the ash emulsion pipeline. Both enter the ash-adding distillation section of the ammonia stripping tower 3 from the blending liquid pipeline 5. When the blending liquid pipeline 5 begins to overflow, the sand liquid pipeline 6 is opened. Steam pressure is added before the mother liquor and ash emulsion to complete the entire tower warming process. If start-up is required, simply switch the waste desalinated liquid to mother liquor and ash emulsion. The initial mother liquor steaming rate is generally 30m³. 3 / h, at this time, due to the small evaporation rate, the tray efficiency is low, and the ammonia content of the waste liquid is high, resulting in a large ammonia loss. In this scheme, the feed rate of the waste distillate in the warming tower is maintained at 40~50m³. 3 Under the premise that the sand slurry pipeline valves are open and operating normally, the mother liquor can be introduced at a total evaporation rate of at least 70m³ / h. 3 The distillation rate exceeded 100 m³ / h, meeting the tray efficiency requirements for distillation volume and thus improving the ammonia distillation efficiency during the start-up process of ammonia stripping tower 3, while also preventing blockage of the sand liquid pipeline. When ammonia stripping tower 3 is shut down, after emptying the pre-ash liquid in pre-ash tank 4, 50 m³ of... 3 All wastewater is fed into the preheating and decomposition section of ammonia stripping tower 3 to replace circulating water for boiling. A small amount of steam is introduced when necessary to maintain the pressure of the ammonia stripping tower for wastewater discharge. This reduces circulating water usage, saves water resources, and improves the utilization rate of wastewater. Furthermore, in case of an emergency requiring significant load reduction, wastewater can be fed into ammonia stripping tower 3 to balance the steaming volume, preventing excessive load reduction and a shortened operating cycle of the ammonia stripping tower 3. In addition, the wastewater can be reused in other workshops.

[0022] Before the improvement, during the start-up and shutdown of ammonia stripping tower 3, the steam consumption for heating the tower was 66.68 t and the steam consumption for shutting down the tower was 115.1 t, totaling 181.78 t. Assuming 37 tower shutdowns throughout the year, the steam consumption for the start-up and shutdown of ammonia stripping tower 3 alone could reach 6725.86 t, increasing steam consumption by 18.68 kg / t of alkali.

[0023] After the improvement, waste desalination liquid is used to replace low-pressure steam to complete the warming and cleaning work of ammonia stripping tower 3 during shutdown, and the flash steam is used as supplementary steam to enter the desalination distillation tower 11 for reuse. This can reduce steam consumption, improve ammonia distillation efficiency, avoid blockage of sand liquid pipeline 6, and realize the reuse of waste desalination liquid heat, which has significant energy saving, consumption reduction and economic benefits.

[0024] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An energy-saving and consumption-reducing ammonia stripping system, comprising an ammonia condenser, an ammonia stripping tower, a pre-ash tank, an ammonia cooler, a condensate tank, and an absorption tower; the outlet of the mother liquor pipeline is connected to the cold medium inlet of the ammonia condenser, and the cold medium outlet of the ammonia condenser is connected to the liquid inlet at the upper part of the preheating decomposition section of the ammonia stripping tower; the outlet of the preheating decomposition section of the ammonia stripping tower is connected to the liquid inlet of the pre-ash tank, the gas outlet at the top of the pre-ash tank is connected to the gas inlet of the preheating decomposition section of the ammonia stripping tower, and the outlet at the lower part of the pre-ash tank is connected to the liquid inlet of the ash-adding distillation section of the ammonia stripping tower; the ammonia stripping tower's ash-adding distillation section... The outlet of the ash distillation section is connected to the inlet of the pre-ash tank at the top; the sand liquid outlet at the bottom of the pre-ash tank is connected to the liquid inlet of the ash distillation section of the ammonia stripping tower; the outlet of the top of the ammonia stripping tower is connected to the heat medium inlet of the ammonia condenser; the heat medium outlet of the ammonia condenser is connected to the heat medium inlet of the ammonia cooler; the gas phase outlet of the heat medium of the ammonia cooler is connected to the inlet of the absorption tower; the liquid phase outlet of the heat medium of the ammonia cooler is connected to the liquid inlet of the condensate tank; and the outlet of the top of the condensate tank is connected to the inlet of the absorption tower. Its characteristic is that: The outlet of the condensate tank is connected to a distillation tower via a condensate pump; the outlet of the distillation tower is connected to the mother liquor pipeline; the outlet of the distillation tower is connected to the ash slurry inlet of the pre-ash tank; and the outlet of the distillation tower is connected to the inlet at the top of the preheating and decomposition section of the ammonia stripping tower.

2. The energy-saving and consumption-reducing ammonia stripping system according to claim 1, characterized in that, It also includes a steam ejector, a first flash evaporator, and a second flash evaporator; the steam outlet of the steam pipeline is connected to the steam inlet of the steam ejector, and the steam outlet of the steam ejector is connected to the steam inlet of the bottom ring of the ammonia stripping tower; the liquid outlet of the bottom ring of the ammonia stripping tower is connected to the liquid inlet of the first flash evaporator, and the steam outlet at the top of the first flash evaporator is connected to the steam inlet of the steam ejector; the liquid outlet at the bottom of the first flash evaporator is connected to the liquid inlet of the second flash evaporator, and the steam outlet at the top of the second flash evaporator is connected to the steam inlet of the distillation tower; the liquid outlet at the bottom of the second flash evaporator is connected to the inlet of the waste liquid pump.

3. The energy-saving and consumption-reducing ammonia stripping system according to claim 1, characterized in that, It also includes a gas-liquid separator; the gas outlet at the top of the ammonia stripping tower is connected to the feed inlet of the gas-liquid separator, the gas outlet of the gas-liquid separator is connected to the heat medium inlet of the ammonia condenser, and the liquid outlet of the gas-liquid separator is connected to the liquid inlet at the top of the preheating and decomposition section of the ammonia stripping tower.

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