Efficient energy-saving ammonia distillation system
By introducing preheating and distribution mechanisms into the ammonia vaporization system, the ammonia water and steam are preheated by wastewater and steam waste heat, and ensuring uniform contact of the steam and liquid through a specific distribution structure, the problems of low thermal energy utilization and low ammonia vaporization efficiency are solved, and the efficient and energy-saving ammonia vaporization effect is achieved.
Patent Information
- Application Number
- CN202422834221.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-11-20
AI Technical Summary
The current ammonia distillation system has low thermal energy utilization rate, low ammonia distillation efficiency, and uneven distribution of vapor and liquid leads to low ammonia distillation efficiency.
The preheating mechanism and distribution mechanism are adopted, including the first preheater, the second preheater, and the steam and ammonia water distributor. The wastewater discharged from the ammonia steam tower and the ammonia steam waste heat are used to preheat the remaining ammonia water and steam, and distributed through the "M" font ammonia water pipe and the upper and lower dislocation steam pipe to ensure uniform contact between the steam and liquid.
It improves the thermal energy utilization rate, enhances the ammonia vaporization efficiency, reduces heat energy waste, ensures full contact between vapor and liquid, and improves the evaporation effect of ammonia.
Smart Images
Figure CN223225833U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of ammonia distillation, and particularly relates to a high-efficiency and energy-saving ammonia distillation system. Background Art
[0002] During the coking process, coking plants produce excess ammonia. Directly discharging this excess ammonia would not only pollute the environment but also lead to ammonia waste. Currently, most coking enterprises use ammonia distillation systems to treat this excess ammonia. This not only reduces the pressure on wastewater biochemical treatment, but also allows the ammonia obtained from the distillation to be directly fed into the ammonium sulfate process, reducing production costs. The working principle of ammonia distillation is as follows: using water vapor as the heating agent, the equilibrium vapor pressure of ammonia on the circulating water surface is greater than the partial pressure of ammonia in the heat carrier. The vapor and liquid phases come into countercurrent contact, undergoing mass and heat transfer, thereby gradually releasing ammonia from the circulating water. A mixture of ammonia vapor and water vapor is obtained at the top of the tower. After the water vapor is condensed and discharged, the ammonia is directly fed into the ammonium sulfate process, resulting in relatively pure circulating water at the bottom of the tower. Existing ammonia distillation systems suffer from the following issues: ① Due to frequent heat conversion during the distillation process, some heat energy is not utilized effectively, resulting in heat waste; ② The countercurrent contact between the vapor and liquid phases within the distillation tower is unevenly distributed, preventing sufficient contact between the vapor and liquid phases, leading to low distillation efficiency. Therefore, the development of an ammonia distillation system with high heat energy utilization and high distillation efficiency is an objective need. Utility Model Content
[0003] The utility model aims to provide a high-efficiency and energy-saving ammonia distillation system with high thermal energy utilization rate and high ammonia distillation efficiency.
[0004] The purpose of the present invention is achieved in this way, including an ammonia still tower, a reboiler and a preheating mechanism, the preheating mechanism is used to preheat the residual ammonia water, the preheating mechanism includes a first preheater and a second preheater connected to the first preheater, the second preheater is connected to the ammonia still tower, the ammonia still wastewater discharged from the ammonia still tower flows through the first preheater, the ammonia steam produced by the ammonia still tower flows through the second preheater, the reboiler is connected to the ammonia still tower, and the ammonia still tower is provided with a residual ammonia water distribution mechanism and a steam distribution mechanism.
[0005] Furthermore, a residual ammonia water tank is provided at the front end of the residual ammonia water inlet of the first preheater, and a residual ammonia water pump is provided between the first preheater and the residual ammonia water tank.
[0006] Furthermore, an ammonia evaporation wastewater pump is provided between the ammonia evaporation tower and the first preheater.
[0007] Furthermore, the residual ammonia water distribution mechanism includes a residual ammonia water pipe and a liquid outlet hole. The longitudinal section of the residual ammonia water pipe is in the shape of a "M". The residual ammonia water pipe is fixedly installed on the upper inner wall of the ammonia evaporation tower. Several liquid outlet holes are opened on the lower pipe wall of the residual ammonia water pipe.
[0008] Furthermore, the steam distribution mechanism includes a steam outlet pipe, an air outlet hole and a steam inlet pipe. The steam inlet pipe is fixedly installed in the center of the bottom of the ammonia still. The steam outlet pipe is arranged in two layers, upper and lower. Each layer of steam outlet pipes has 6 steam outlet pipes evenly distributed outward with the steam inlet pipe as the center. The 6 steam outlet pipes are on the same horizontal plane. The 6 steam outlet pipes in the upper and lower layers are staggered. A number of air outlet holes are opened on the upper pipe wall of the steam outlet pipe.
[0009] Furthermore, the reboiler is used to heat the circulating water in the ammonia distillation tower, and the heat source of the reboiler is high-temperature steam.
[0010] The first preheater and the second preheater of the present technical solution are used to preheat the residual ammonia water to ensure a constant temperature in the ammonia still tower. The heat source of the first preheater comes from the ammonia still wastewater discharged from the ammonia still tower. The first preheater can absorb the heat in the ammonia still wastewater to reduce the pressure of the biochemical treatment of the ammonia still wastewater; the heat source of the second preheater comes from the ammonia steam produced by the ammonia still tower. The second preheater can absorb the heat in the ammonia steam, condense the water vapor in the ammonia steam into condensed water and discharge it, thereby reducing the water vapor content in the ammonia gas entering the ammonium sulfate section; the residual ammonia water distribution mechanism and the steam distribution mechanism arranged in the ammonia still tower make the residual ammonia water and steam entering the ammonia still tower evenly distributed and fully mixed, so that the residual ammonia water and steam are fully in contact, thereby making the ammonia evaporation effect better and improving the ammonia still efficiency; a reboiler is used to heat the circulating water, and high-temperature steam is used as the heat source of the reboiler. The high-temperature steam is converted into steam condensate for recycling after heat exchange, thereby avoiding the increase of moisture in the ammonia still wastewater. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is a schematic diagram of the overall structure of the utility model;
[0012] Figure 2 for Figure 1 A schematic structural diagram of the residual ammonia distribution mechanism 6;
[0013] Figure 3 It is a structural diagram of a steam outlet pipe 81 on one floor.
[0014] In the figure: 1-residual ammonia water tank, 2-residual ammonia water pump, 3-evaporation ammonia wastewater pump, 4-first preheater, 5-second preheater, 6-residual ammonia water distribution mechanism, 61-residual ammonia water pipe, 62-liquid outlet, 7-evaporation ammonia tower, 8-steam distribution mechanism, 81-steam outlet pipe, 82-gas outlet, 83-steam inlet pipe, 9-reboiler. DETAILED DESCRIPTION
[0015] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the scope of protection of the present invention.
[0016] like Figure 1 As shown, the utility model includes an ammonia still 7, a reboiler 9 and a preheating mechanism, the preheating mechanism is used to preheat the residual ammonia water, the preheating mechanism includes a first preheater 4 and a second preheater 5 connected to the first preheater 4, the second preheater 5 is connected to the ammonia still 7, the residual ammonia water is first preheated by the first preheater 4 and then passed into the second preheater 5 for preheating again, the ammonia still wastewater discharged from the ammonia still 7 flows through the first preheater 4, the heat source of the first preheater 4 comes from the waste heat in the ammonia still wastewater, the ammonia vapor produced by the ammonia still 7 flows through the second preheater 5, the heat source of the second preheater 5 comes from the waste heat of the ammonia vapor, the reboiler 9 is connected to the ammonia still 7, the reboiler 9 is used to heat the circulating water at the bottom of the ammonia still 7, the heat source of the reboiler 9 is high-temperature steam, and the high-temperature steam is converted into steam condensed water for recycling after heat exchange with the circulating water, thereby avoiding the increase of moisture in the ammonia still wastewater. A residual ammonia water tank 1 is provided at the front end of the residual ammonia water inlet of the first preheater 4, and the residual ammonia water tank 1 is used to store residual ammonia water. A residual ammonia water pump 2 is provided between the first preheater 4 and the residual ammonia water tank 1, and the residual ammonia water pump 2 is used to pump the residual ammonia water in the residual ammonia water tank 1 into the first preheater 4. An ammonia evaporation wastewater pump 3 is provided between the ammonia evaporation tower 7 and the first preheater 4, and the ammonia evaporation wastewater pump 3 is used to pump the ammonia evaporation wastewater discharged from the ammonia evaporation tower 7 into the first preheater 4. The arrangement of the first preheater 4 and the second preheater 5 ensures the rational utilization of heat energy and reduces the waste of heat energy.
[0017] like Figures 1 to 3As shown, the ammonia still 7 is provided with a residual ammonia distribution mechanism 6 and a steam distribution mechanism 8. The residual ammonia distribution mechanism 6 includes a residual ammonia pipe 61 and a liquid outlet 62. The longitudinal section of the residual ammonia pipe 61 is in the shape of a "M". The residual ammonia pipe 61 is fixedly mounted on the upper inner wall of the ammonia still 7. A plurality of liquid outlets 62 are provided on the lower pipe wall of the residual ammonia pipe 61. The residual ammonia enters the residual ammonia pipe 61 and is sprinkled to the lower part of the ammonia still 7 from the plurality of liquid outlets 62 provided on the lower pipe wall of the residual ammonia pipe 61. Since the longitudinal section of the residual ammonia pipe 61 is in the shape of a "M", the residual ammonia can be dispersed. The steam distribution mechanism 8 includes a steam outlet pipe 81, an air outlet 82 and a steam inlet pipe 83. The steam inlet pipe 83 is fixedly mounted on the bottom center of the ammonia still 7. 1 is arranged in two layers, and each layer of steam outlet pipes 81 has six steam outlet pipes 81 evenly distributed outward with the steam inlet pipe 83 as the center. The six steam outlet pipes 81 are on the same horizontal plane, and the six steam outlet pipes 81 of the upper and lower layers are staggered. The six steam outlet pipes 81 of the upper layer and the six steam outlet pipes 81 of the lower layer are not on the same longitudinal section. A plurality of air outlet holes 82 are opened on the upper tube wall of the steam outlet pipe 81. Steam enters from the steam inlet pipe 83 and fills the upper and lower layers of steam outlet pipes 81. It is sprayed toward the upper part of the ammonia distillation tower 7 from the plurality of air outlet holes 82 opened on the upper tube wall of the steam outlet pipe 81. Since the steam outlet pipes 81 are arranged in two layers, and there are six on each layer, the steam can be evenly distributed. The arrangement of the residual ammonia water distribution mechanism 6 and the steam distribution mechanism 8 allows the residual ammonia water to fully contact with the steam, thereby improving the ammonia distillation efficiency.
[0018] The residual ammonia water is stored in the residual ammonia water tank 1. When ammonia distillation starts, the residual ammonia water is pumped into the first preheater 4 by the residual ammonia water pump 2. After being preheated by the first preheater 4, it flows through the second preheater 5. After being preheated by the second preheater 5, it is sprinkled into the ammonia distillation tower 7 through the residual ammonia water distribution mechanism 6. At the same time, the circulating water in the ammonia distillation tower 7 is passed into the reboiler 9. The heat source of the reboiler 9 is high-temperature steam. The high-temperature steam heats the circulating water to generate steam. The steam is sprayed into the ammonia distillation tower 7 through the steam distribution mechanism 8. The residual ammonia water flowing downward is fully in contact with the steam flowing upward, and the ammonia gas in the residual ammonia water is gradually released. The ammonia vapor is released and rises to the top of the ammonia distillation tower together with the water vapor, and then discharged. The discharged ammonia vapor still has a certain amount of waste heat. The ammonia vapor is passed into the second preheater 5 to preheat the remaining ammonia water. The ammonia vapor is condensed into ammonia gas and condensed water. The condensed water is discharged for reuse, and the ammonia gas is passed into the ammonium sulfate section. During the ammonia distillation process, the ammonia distillation tower 7 produces ammonia distillation wastewater, which is discharged from the bottom of the ammonia distillation tower 7. The discharged ammonia distillation wastewater still has a certain amount of waste heat. The ammonia distillation wastewater is pumped into the first preheater 4 by the ammonia distillation wastewater pump 3 to preheat the remaining ammonia water. The ammonia distillation wastewater that has absorbed heat is discharged into the biochemical treatment pool for biochemical treatment.
Claims
1. A high-efficiency and energy-saving ammonia distillation system, characterized by: The invention comprises an ammonia evaporation tower (7), a reboiler (9) and a preheating mechanism, wherein the preheating mechanism is used to preheat the residual ammonia water, the preheating mechanism comprises a first preheater (4) and a second preheater (5) connected to the first preheater (4), the second preheater (5) is connected to the ammonia evaporation tower (7), the ammonia evaporation wastewater discharged from the ammonia evaporation tower (7) flows through the first preheater (4), the ammonia steam produced by the ammonia evaporation tower (7) flows through the second preheater (5), the reboiler (9) is connected to the ammonia evaporation tower (7), and the ammonia evaporation tower (7) is provided with a residual ammonia water distribution mechanism (6) and a steam distribution mechanism (8).
2. The high-efficiency and energy-saving ammonia distillation system according to claim 1, characterized in that: A residual ammonia water tank (1) is provided at the front end of the residual ammonia water inlet of the first preheater (4), and a residual ammonia water pump (2) is provided between the first preheater (4) and the residual ammonia water tank (1).
3. The high-efficiency and energy-saving ammonia distillation system according to claim 1, characterized in that: An ammonia evaporation wastewater pump (3) is provided between the ammonia evaporation tower (7) and the first preheater (4).
4. The high-efficiency and energy-saving ammonia distillation system according to claim 1, characterized in that: The residual ammonia water distribution mechanism (6) comprises a residual ammonia water pipe (61) and liquid outlet holes (62). The longitudinal section of the residual ammonia water pipe (61) is in the shape of a "M". The residual ammonia water pipe (61) is fixedly mounted on the upper inner wall of the ammonia distillation tower (7). A plurality of liquid outlet holes (62) are formed on the lower pipe wall of the residual ammonia water pipe (61).
5. The high-efficiency and energy-saving ammonia distillation system according to claim 1, characterized in that: The steam distribution mechanism (8) comprises a steam outlet pipe (81), an air outlet hole (82) and a steam inlet pipe (83). The steam inlet pipe (83) is fixedly installed at the center of the bottom of the ammonia distillation tower (7). The steam outlet pipe (81) is arranged in two layers, upper and lower. Each layer of steam outlet pipes (81) has six steam outlet pipes (81) uniformly distributed outward with the steam inlet pipe (83) as the center. The six steam outlet pipes (81) are on the same horizontal plane. The six steam outlet pipes (81) on the upper and lower layers are staggered. A plurality of air outlet holes (82) are opened on the upper pipe wall of the steam outlet pipe (81).
6. The high-efficiency and energy-saving ammonia distillation system according to claim 1, characterized in that: The reboiler (9) is used to heat the circulating water in the ammonia distillation tower (7), and the heat source of the reboiler (9) is high-temperature steam.