Desulfurization wastewater zero discharge device adopting low-temperature triple-effect flash evaporation and bypass flue double-fluid spray drying tower combined process
By combining low-temperature triple-effect flash evaporation with a bypass flue dual-fluid spray drying tower, steam is prepared using the waste heat of flue gas after the boiler induced draft fan. Combined with concentration and solidification processes, the problem of zero discharge of desulfurization wastewater in existing technologies is solved, achieving zero wastewater discharge, energy saving and cost reduction, and improved evaporation efficiency.
Patent Information
- Application Number
- CN202422618195.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2034-10-29
AI Technical Summary
In existing technologies, standalone evaporation and concentration processes cannot achieve zero discharge of desulfurization wastewater, and when power plant auxiliary steam is used as the heat source for concentration, a desuperheating and pressure reduction system is required, which leads to reduced steam quality and energy waste.
The combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower is adopted. By combining the low-temperature triple-effect flash evaporation system and the bypass flue dual-fluid spray drying tower, steam is generated from the waste heat of flue gas after the boiler induced draft fan. Combined with concentration and solidification processes, zero wastewater discharge is achieved.
It achieves zero wastewater discharge, avoids the consumption of auxiliary steam, saves energy and reduces operating costs, improves evaporation efficiency, and avoids the risk of scaling in the evaporator and subsequent flue gas system.
Smart Images
Figure CN223547754U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of power plant desulfurization water equipment, and in particular to a desulfurization wastewater zero-discharge device using a combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower. Background Technology
[0002] Power plant desulfurization wastewater is characterized by high heavy metal content and strong corrosiveness, resulting in poor water quality and high treatment difficulty. Zero discharge is gradually becoming the trend for power plants in treating desulfurization wastewater.
[0003] Currently, commonly used zero-emission processes include evaporation concentration, solidification processes, or a combination of both.
[0004] In practical applications, the following two issues still arise when using existing emission control equipment:
[0005] 1. Evaporation and concentration processes alone cannot truly achieve zero wastewater discharge;
[0006] 2. When using auxiliary steam from a power plant as a heat source for concentration, a desuperheating and pressure reduction system is required, which reduces the quality of the steam and results in energy waste.
[0007] Therefore, this utility model provides a desulfurization wastewater zero-discharge device using a combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower. Utility Model Content
[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a desulfurization wastewater zero-discharge device using a combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower.
[0009] To achieve the above objectives, this utility model adopts the following technical solution: a desulfurization wastewater zero-discharge device combining a low-temperature triple-effect flash evaporation and a bypass flue dual-fluid spray drying tower process, including a low-temperature triple-effect flash evaporation system.
[0010] The low-temperature triple-effect flash evaporation system includes a flue gas heater, a preheater installed on one side of the flue gas heater, a first-effect separator installed on the side of the preheater away from the flue gas heater, a second-effect separator installed on the side of the first-effect separator away from the preheater, and a third-effect separator installed on the side of the second-effect separator away from the first-effect separator.
[0011] A first-effect forced circulation pump is installed at the bottom of the single-effect separator, a second-effect forced circulation pump is installed at the bottom of the double-effect separator, and a triple-effect forced circulation pump is installed at the bottom of the triple-effect separator.
[0012] A discharge pump is installed on the side of the triple-effect forced circulation pump away from the triple-effect separator. The discharge pump is located on the side of the double-effect forced circulation pump. The output end of the discharge pump is connected to a discharge pipe. A concentrate tank is installed on the outside of the discharge pipe. A plate and frame filter press is installed at the other end of the discharge pipe. A filtrate tank is installed at the bottom of the plate and frame filter press. A filtrate pump is installed on the outside of the filtrate tank. The output end of the filtrate pump is connected to an external pipe. The concentrate pump sends the concentrate to the plate and frame filter press. After the filter press is activated, the solid sludge is sent to the location designated by the owner. The filtrate is sent to the filtrate tank and then sent to the bypass flue dual-fluid spray drying system by the filtrate pump.
[0013] One end of the filtrate pump is connected to a bypass flue dual-fluid spray drying system via an external pipeline. Wastewater enters the preheater, where it is first preheated by the steam condensate, then enters the first-effect separator. From the lower end of the first-effect separator, it is drawn out by a first-effect forced circulation pump and sent to the tube side of the first-effect heater, where it exchanges heat with 0.14 MPa saturated steam before returning to the first-effect separator. Under vacuum, the wastewater rapidly evaporates. The second-effect steam in the upper part of the first-effect separator enters the second-effect heater, while the concentrated water in the lower part of the first-effect separator enters... The concentrated water enters the double-effect separator. The concentrated water in the double-effect separator is pumped out by the double-effect forced circulation pump and sent to the double-effect heater. After exchanging heat with the double-effect steam in the double-effect heater, it re-enters the double-effect separator, where gas-liquid separation is achieved. The triple-effect steam at the top of the double-effect separator enters the triple-effect heater, while the concentrated water at the bottom of the double-effect separator enters the triple-effect separator. Under the action of the triple-effect forced circulation pump, it re-enters the triple-effect heater until the density of the concentrated water at the bottom of the triple-effect separator reaches the set value. Then, it is pumped to the concentrated water tank by the discharge pump.
[0014] In a preferred embodiment, the bypass flue dual-fluid spray drying system includes an A-side inlet flue electric damper and a B-side inlet flue electric damper. An A-side inlet flue electric damper is installed on one side of the filtrate pump, and a B-side inlet flue electric damper is installed on one side of the A-side inlet flue electric damper. A main flue is installed at one end of both the A-side and B-side inlet flue electric dampers. A dual-fluid evaporator is installed at one end of the main flue. In the bypass flue dual-fluid spray drying system, high-temperature flue gas from the A / B side inlets of the air preheater passes through the A-side inlet flue electric damper and the side inlet flue, respectively. The flue gas flows into the main flue after the electric damper. An electric regulating damper for the inlet of the two-fluid evaporator is installed on the main flue. This damper adjusts the inlet flue gas volume in real time according to operating conditions. The flue gas ultimately enters the two-fluid evaporator. An electric regulating damper for the inlet of the two-fluid evaporator is installed on the outer side of the main flue, near the end of the two-fluid evaporator. Gas-liquid two-phase flow nozzles are installed on both sides of the two-fluid evaporator. Another main flue is installed on the outer side of one of the two-fluid evaporators where the gas-liquid two-phase flow nozzles are located. An electric damper for the A-side outlet flue is installed on the outer side of the other main flue. An electric damper for the B-side outlet flue is installed on one side of the A-side outlet flue electric damper.
[0015] The technical effect of adopting the above-mentioned further solution is as follows: gas-liquid two-phase flow nozzles are arranged in the dual-fluid evaporation tower. After the wastewater from the filtrate pump enters the nozzle, it is atomized into droplets by compressed air and completely evaporated by high-temperature flue gas, achieving zero wastewater discharge. The flue gas is discharged from the bottom of the drying tower, passes through the main flue, and then passes through the electric damper gate of the A-side outlet flue and the electric damper gate of the side outlet flue respectively, and merges with the main system flue into the subsequent equipment.
[0016] In a preferred embodiment, a first-effect heater is installed between the first-effect separator and the preheater; a first reflux pipe is installed between the first-effect heater and the first-effect separator; a first installation pipe is installed between the first-effect heater and the first-effect forced circulation pump; a second-effect heater is installed between the first-effect separator and the second-effect separator; a second reflux pipe is installed between the second-effect heater and the second-effect forced circulation pump; a first fixed pipe is installed between the second-effect heater and the first-effect separator; and the third-effect separator is connected to the second-effect separator. A triple-effect heater is installed between the triple-effect heater and the triple-effect separator. A third return pipe is installed between the triple-effect heater and the triple-effect forced circulation pump. A second fixed pipe is installed between the triple-effect heater and the triple-effect separator. A tail-end condenser is installed on the side of the triple-effect separator away from the triple-effect heater. A connecting pipe is installed on the outside of the tail-end condenser. The other end of the connecting pipe is connected to the top of the triple-effect separator. The tail-end condenser is used to cool the non-condensable vapors generated in the system and recover them to the location designated by the owner. The vapors are then transported back to the top of the triple-effect separator through the connecting pipe.
[0017] The technical effect of adopting the above-mentioned further scheme is as follows: Wastewater enters the preheater, is first preheated by the steam condensate, and then enters the first-effect separator. From the lower end of the first-effect separator, it is drawn out by the first-effect forced circulation pump and sent to the tube side of the first-effect heater. After heat exchange with saturated steam at 0.14MPa, it returns to the first-effect separator. Under vacuum, the wastewater evaporates rapidly. The second-effect steam at the upper part of the first-effect separator enters the second-effect heater, while the concentrated water at the lower part of the first-effect separator enters the second-effect separator. The concentrated water in the second-effect separator is drawn out by the second-effect forced circulation pump and sent to the second-effect heater. After heat exchange with the second-effect steam in the second-effect heater, it re-enters the second-effect separator, where gas-liquid separation is achieved. The third-effect steam at the upper part of the second-effect separator enters the third-effect heater, while the concentrated water at the lower end of the second-effect separator enters the third-effect separator. Under the action of the third-effect forced circulation pump, it re-enters the third-effect heater until the density of the concentrated water at the lower end of the third-effect separator reaches the set value, and then it is pumped to the concentrated water tank by the discharge pump.
[0018] In a preferred embodiment, a flue gas humidification tank is installed on the side of the preheater adjacent to the first-effect heater. A flue gas humidification water pump is installed on one side of the flue gas humidification tank. The output end of the flue gas humidification water pump is connected to a conveying pipe. One end of the conveying pipe is connected to the flue gas humidification water pump, and the other end of the conveying pipe is connected to the flue gas heater. When the flue gas humidification water pump operates, it heats the water inside the flue gas humidification tank through the conveying pipe. Two concentrate pumps are installed on the outside of the discharge pipe, between the concentrate tank and the filtrate tank.
[0019] The technical effect of adopting the above-mentioned further solution is as follows: the concentrate pump is used to control the opening and closing of the discharge pipeline. The concentrate pump sends the concentrate to the plate and frame filter press. After the action of the filter press, the solid sludge is sent to the location designated by the owner, the filtrate is sent to the filtrate tank, and then sent to the bypass flue dual-fluid spray drying system by the filtrate pump. The low-temperature flue gas after the boiler induced draft fan is used as a hot fluid to heat the water from the flue gas humidification tank in the flue gas heater, so that the liquid water becomes saturated steam at about 0.14MPa. The steam enters the shell side of the first-effect heater, releases latent heat, and becomes steam condensate at the same temperature.
[0020] In a preferred embodiment, a control panel is externally mounted on the flue gas heater. The flue gas heater, preheater, first-effect heater, first-effect separator, second-effect heater, second-effect separator, third-effect heater, third-effect separator, tail-end condenser, first-effect forced circulation pump, second-effect forced circulation pump, third-effect forced circulation pump, discharge pump, flue gas humidification water pump, concentrate pump, filtrate water pump, and plate and frame filter press are all electrically connected to the control panel.
[0021] The technical effect of adopting the above-mentioned further solution is that the control panel is used to control the operation of the flue gas heater, preheater, first-effect heater, first-effect separator, second-effect heater, second-effect separator, third-effect heater, third-effect separator, tail-end condenser, first-effect forced circulation pump, second-effect forced circulation pump, third-effect forced circulation pump, discharge pump, flue gas humidification water pump, concentrate pump, filtrate water pump and plate and frame filter press, realizing unified management of electrical equipment.
[0022] Compared with the prior art, the advantages and positive effects of this utility model are as follows:
[0023] By setting up flue gas heaters, preheaters, and single-effect heaters, and using a combination of concentration and solidification processes during operation, zero wastewater discharge is truly achieved. Steam is generated by utilizing the waste heat from the flue gas after the induced draft fan of the power plant boiler, avoiding the consumption of auxiliary steam, saving energy and reducing operating costs. The configuration of the gas-liquid two-phase flow nozzles in the dual-fluid evaporator tower greatly improves the evaporation efficiency and avoids the risk of scaling in the evaporator and subsequent flue gas system due to incomplete evaporation. Attached Figure Description
[0024] Figure 1 A schematic diagram of the low-temperature triple-effect flash evaporation system of the desulfurization wastewater zero-discharge device for the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower provided by this utility model;
[0025] Figure 2 A schematic diagram of the bypass flue dual-fluid spray drying system of the desulfurization wastewater zero-discharge device for the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower provided by this utility model.
[0026] Legend:
[0027] 1. Flue gas heater; 2. Preheater; 3. First-effect heater; 4. First-effect separator; 5. Second-effect heater; 6. Second-effect separator; 7. Third-effect heater; 8. Third-effect separator; 9. Tail-end condenser; 10. First-effect forced circulation pump; 11. Second-effect forced circulation pump; 12. Third-effect forced circulation pump; 13. Discharge pump; 14. Flue gas humidification pump; 15. Flue gas humidification tank; 16. Concentrate tank; 17. Concentrate pump; 18. Filtrate tank; 19. Filtrate pump; 20. Plate and frame filter press; 21. Electric damper for A-side inlet flue; 22. Electric damper for B-side inlet flue; 23. Electric regulating valve for inlet of two-fluid evaporator; 24. Two-fluid evaporator; 25. Electric damper for A-side outlet flue; 26. Electric damper for B-side outlet flue. Detailed Implementation
[0028] 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. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0029] like Figures 1-2As shown, this embodiment provides a technical solution: a desulfurization wastewater zero-discharge device using a combined low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower process, including a low-temperature triple-effect flash evaporation system. The low-temperature triple-effect flash evaporation system includes a flue gas heater 1. A preheater 2 is installed on one side of the flue gas heater 1. A first-effect separator 4 is installed on the side of the preheater 2 away from the flue gas heater 1. A second-effect separator 6 is installed on the side of the first-effect separator 4 away from the preheater 2. A triple-effect separator 8 is installed on the side of the second-effect separator 6 away from the first-effect separator 4. A first-effect forced circulation pump 10 is installed at the bottom of the first-effect separator 4, and a second-effect forced circulation pump 10 is installed at the bottom of the second-effect separator 6. A forced circulation pump 11 is installed at the bottom of the triple-effect separator 8, and a triple-effect forced circulation pump 12 is installed at the bottom of the triple-effect forced circulation pump 12. A discharge pump 13 is installed on the side of the triple-effect forced circulation pump 12 away from the triple-effect separator 8. The discharge pump 13 is located on the side of the forced circulation pump 11. The output end of the discharge pump 13 is connected to a discharge pipe. A concentrate tank 16 is installed on the outside of the discharge pipe. A plate and frame filter press 20 is installed at the other end of the discharge pipe. A filtrate tank 18 is installed at the bottom of the plate and frame filter press 20. A filtrate pump 19 is installed on the outside of the filtrate tank 18. The output end of the filtrate pump 19 is connected to an external pipe. The concentrate pump 17 sends the concentrate to the plate and frame filter press 20. After passing through the filter press... After processing, the solid sludge is sent to the location designated by the owner, and the filtrate is sent to the filtrate tank 18, and then to the bypass flue dual-fluid spray drying system via the filtrate pump 19. One end of the filtrate pump 19 is connected to the bypass flue dual-fluid spray drying system via an external pipeline. The wastewater enters the preheater 2, is first preheated by the steam condensate, and then enters the first-effect separator 4. From the lower end of the first-effect separator 4, it is drawn out by the first-effect forced circulation pump 10 and sent to the tube side of the first-effect heater 3. After heat exchange with saturated steam at 0.14 MPa, it returns to the first-effect separator 4. Under vacuum, the wastewater evaporates rapidly, and the second-effect steam at the upper part of the first-effect separator 4 evaporates. Steam enters the second-effect heater 5, while the concentrated water at the bottom of the first-effect separator 4 enters the second-effect separator 6. The concentrated water in the second-effect separator 6 is pumped out by the second-effect forced circulation pump 11 and sent to the second-effect heater 5. After exchanging heat with the second-effect steam in the second-effect heater 5, it re-enters the second-effect separator 6, where gas-liquid separation is achieved. The third-effect steam at the top of the second-effect separator 6 enters the third-effect heater 7, while the concentrated water at the bottom of the second-effect separator 6 enters the third-effect separator 8. Under the action of the third-effect forced circulation pump 12, it re-enters the third-effect heater 7 until the density of the concentrated water at the bottom of the third-effect separator 8 reaches the set value, at which point it is pumped to the concentrated water tank 16 by the discharge pump 13.
[0030] Going further, such as Figures 1-2As shown: The bypass flue dual-fluid spray drying system includes an A-side inlet flue electric damper 21 and a B-side inlet flue electric damper 22. The A-side inlet flue electric damper 21 is installed on one side of the filtrate pump 19, and the B-side inlet flue electric damper 22 is installed on one side of the A-side inlet flue electric damper 21. A main flue is installed at one end of both the A-side and B-side inlet flue electric dampers 21 and 22, respectively. A dual-fluid evaporator 24 is installed at one end of the main flue. In the bypass flue dual-fluid spray drying system, high-temperature flue gas from the A / B side inlets of the air preheater flows into the main flue after passing through the A-side inlet flue electric damper 21 and the B-side inlet flue electric damper 22, respectively. A dual-fluid evaporator inlet electric regulating damper 23 is installed on the main flue. The function of this regulating damper is to adjust the inlet flue gas volume in real time according to the operating conditions. The flue gas finally enters the dual-fluid evaporator... The evaporator 24 has an electric regulating damper 23 at the inlet of the two-fluid evaporator 24, located on the outer side of the main flue and near the end of the two-fluid evaporator 24. Gas-liquid two-phase flow nozzles are provided on both sides of the two-fluid evaporator 24. Another main flue is installed on the outer side of one of the two-fluid evaporator 24 where the gas-liquid two-phase flow nozzles are located. An electric damper 25 for the A-side outlet flue is installed on the outer side of the other main flue. An electric damper 26 for the B-side outlet flue is installed on one side of the electric damper 25 for the A-side outlet flue. Gas-liquid two-phase flow nozzles are arranged inside the two-fluid evaporator 24. Wastewater from the filtrate pump 19 enters the nozzles and is atomized into droplets by compressed air, then completely evaporated by the high-temperature flue gas, achieving zero wastewater discharge. The flue gas is discharged from the bottom of the drying tower, passes through the main flue, and then merges with the main system flue through the electric damper 25 for the A-side outlet flue and the electric damper 26 for the side outlet flue, before entering subsequent equipment.
[0031] Going further, such as Figure 1As shown: In this scheme, a first-effect heater 3 is installed between the first-effect separator 4 and the preheater 2; a first return pipe is installed between the first-effect heater 3 and the first-effect separator 4; a first installation pipe is installed between the first-effect heater 3 and the first-effect forced circulation pump 10; a second-effect heater 5 is installed between the first-effect separator 4 and the second-effect separator 6; a second return pipe is installed between the second-effect heater 5 and the second-effect separator 6; a second installation pipe is installed between the second-effect heater 5 and the second-effect forced circulation pump 11; and a first solid pipe is installed between the second-effect heater 5 and the first-effect separator 4. A triple-effect heater 7 is installed between the triple-effect separator 8 and the double-effect separator 6. A third return pipe is installed between the triple-effect heater 7 and the triple-effect separator 8. A third installation pipe is installed between the triple-effect heater 7 and the triple-effect forced circulation pump 12. A second fixed pipe is installed between the triple-effect heater 7 and the double-effect separator 6. A tail-end condenser 9 is installed on the side of the triple-effect separator 8 away from the triple-effect heater 7. A connecting pipe is installed on the outside of the tail-end condenser 9, and the other end of the connecting pipe is connected to the top of the triple-effect separator 8. The tail-end condenser 9 is used for system... The non-condensable steam generated is cooled and recovered to the location designated by the owner, then transported back to the top of the triple-effect separator 8 via connecting pipelines. Wastewater enters the preheater 2, where it is first preheated by the steam condensate, then enters the first-effect separator 4. From the lower end of the first-effect separator 4, it is drawn out by the first-effect forced circulation pump 10 and sent to the tube side of the first-effect heater 3, where it exchanges heat with saturated steam at 0.14 MPa before returning to the first-effect separator 4. Under vacuum, the wastewater rapidly evaporates. The second-effect steam at the top of the first-effect separator 4 enters the second-effect heater 5, while the concentrated water at the bottom of the first-effect separator 4 enters the second-effect heater 5. The concentrated water in the second-effect separator 6 is pumped out by the second-effect forced circulation pump 11 and sent to the second-effect heater 5. After exchanging heat with the second-effect steam in the second-effect heater 5, it re-enters the second-effect separator 6, where gas-liquid separation is achieved. The third-effect steam at the top of the second-effect separator 6 enters the third-effect heater 7, while the concentrated water at the bottom of the second-effect separator 6 enters the third-effect separator 8. Under the action of the third-effect forced circulation pump 12, it re-enters the third-effect heater 7 until the density of the concentrated water at the bottom of the third-effect separator 8 reaches the set value, at which point it is pumped to the concentrated water tank 16 by the discharge pump 13.
[0032] Going further, such as Figure 1As shown, in this scheme, a flue gas humidification tank 15 is installed on the side of the preheater 2 adjacent to the first-effect heater 3. A flue gas humidification water pump 14 is installed on one side of the flue gas humidification tank 15. The output end of the flue gas humidification water pump 14 is connected to a conveying pipe. One end of the conveying pipe is connected to the flue gas humidification water pump 14, and the other end of the conveying pipe is connected to the flue gas heater 1. When the flue gas humidification water pump 14 operates, it heats the water inside the flue gas humidification tank 15 through the conveying pipe. Two concentrate pumps 17 are installed outside the discharge pipe, between the concentrate tank 16 and the filtrate tank 18. Pump 17 is used to control the opening and closing of the discharge pipe. Concentrate pump 17 sends the concentrate to plate and frame filter press 20. After the action of the filter press, the solid sludge is sent to the location designated by the owner, and the filtrate is sent to filtrate tank 18. Then, the filtrate is sent to the bypass flue dual-fluid spray drying system by filtrate pump 19. The low-temperature flue gas after the boiler induced draft fan is used as a hot fluid to heat the water from the flue gas humidification tank 15 in the flue gas heater 1, so that the liquid water becomes saturated steam at about 0.14 MPa. The steam enters the shell side of the first-effect heater 3, and after releasing the latent heat, it becomes steam condensate at the same temperature.
[0033] Going further, such as Figures 1-2 As shown in the diagram, in this scheme, a control panel is installed externally on the flue gas heater 1. The flue gas heater 1, preheater 2, first-effect heater 3, first-effect separator 4, second-effect heater 5, second-effect separator 6, third-effect heater 7, third-effect separator 8, tail-end condenser 9, first-effect forced circulation pump 10, second-effect forced circulation pump 11, third-effect forced circulation pump 12, discharge pump 13, flue gas humidification pump 14, concentrate pump 17, filtrate pump 19, and plate and frame filter press 20 are all connected to the control panel. The plate and frame filter press are electrically connected. The control panel is used to control the operation of the flue gas heater 1, preheater 2, first-effect heater 3, first-effect separator 4, second-effect heater 5, second-effect separator 6, third-effect heater 7, third-effect separator 8, tail-end condenser 9, first-effect forced circulation pump 10, second-effect forced circulation pump 11, third-effect forced circulation pump 12, discharge pump 13, flue gas humidification pump 14, concentrate pump 17, filtrate pump 19 and plate and frame filter press 20, realizing unified management of electrical equipment.
[0034] Working principle:
[0035] like Figures 1-2 As shown:
[0036] When in use, the external control panel is opened. The low-temperature flue gas after the boiler induced draft fan is used as a hot fluid to heat the water from the flue gas humidification tank 15 in the flue gas heater 1, so that the liquid water becomes saturated steam at about 0.14MPa. The steam enters the shell side of the first-effect heater 3, and after releasing the latent heat, it becomes steam condensate at the same temperature.
[0037] Wastewater enters preheater 2, where it is first preheated by the steam condensate, and then enters the first-effect separator 4. From the lower end of the first-effect separator 4, it is drawn out by the first-effect forced circulation pump 10 and sent to the tube side of the first-effect heater 3. After heat exchange with saturated steam at 0.14 MPa, it returns to the first-effect separator 4. Under vacuum, the wastewater rapidly evaporates. The second-effect steam in the upper part of the first-effect separator 4 enters the second-effect heater 5, while the concentrated water in the lower part of the first-effect separator 4 enters the second-effect separator 6. The concentrated water in the second-effect separator 6 is drawn out by the second-effect forced circulation pump 11 and sent to the second-effect heater. In the second-effect heater 5, the steam exchanged heat with the second-effect steam in the second-effect heater 5 and then entered the second-effect separator 6, where gas-liquid separation was achieved. The third-effect steam at the top of the second-effect separator 6 entered the third-effect heater 7, while the concentrated water at the bottom of the second-effect separator 6 entered the third-effect separator 8. Under the action of the third-effect forced circulation pump 12, it entered the third-effect heater 7 again until the density of the concentrated water at the bottom of the third-effect separator 8 reached the set value. Then, it was pumped to the concentrated water tank 16 by the discharge pump 13. The non-condensable steam generated in the system was cooled by the tail-end condenser 9 and recovered to the location designated by the owner.
[0038] Concentrate pump 17 delivers concentrate to plate and frame filter press 20. After being processed by the filter press, solid sludge is delivered to the location designated by the owner, and filtrate is delivered to filtrate tank 18. Then, filtrate pump 19 delivers it to the bypass flue dual-fluid spray drying system.
[0039] In the bypass flue dual-fluid spray drying system, high-temperature flue gas from the A / B side inlet of the air preheater flows into the main flue after passing through the A-side inlet flue electric damper 21 and the side inlet flue electric damper 22 respectively. The main flue is equipped with a dual-fluid evaporator inlet electric regulating damper 23, which adjusts the inlet flue gas volume in real time according to the operating conditions. The flue gas finally enters the dual-fluid evaporator 24. Gas-liquid two-phase flow nozzles are arranged inside the dual-fluid evaporator 24. Wastewater from the filtrate pump 19 enters the nozzle and is atomized into droplets by compressed air. It is completely evaporated by the high-temperature flue gas, achieving zero wastewater discharge. The flue gas is discharged from the bottom of the drying tower, passes through the main flue, and then passes through the A-side outlet flue electric damper 25 and the side outlet flue electric damper 26 respectively, and merges with the main system flue before entering the subsequent equipment.
[0040] By setting up flue gas heater 1, preheater 2 and single-effect heater 3, the combined process of concentration and solidification during operation truly achieves zero wastewater discharge. Steam is generated by using the waste heat of flue gas after the induced draft fan of the power plant boiler, avoiding the consumption of auxiliary steam, saving energy and reducing operating costs. The configuration of the gas-liquid two-phase flow nozzles in the dual-fluid evaporator tower greatly improves the evaporation efficiency and avoids the risk of scaling in the evaporator and subsequent flue gas system due to incomplete evaporation.
[0041] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.
Claims
1. A desulfurization wastewater zero-discharge device using a combined low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower process, comprising a low-temperature triple-effect flash evaporation system, characterized in that, The low-temperature triple-effect flash evaporation system includes a flue gas heater (1), a preheater (2) is installed on one side of the flue gas heater (1), a first-effect separator (4) is installed on the side of the preheater (2) away from the flue gas heater (1), a second-effect separator (6) is installed on the side of the first-effect separator (4) away from the preheater (2), and a triple-effect separator (8) is installed on the side of the second-effect separator (6) away from the first-effect separator (4). A first-effect forced circulation pump (10) is installed at the bottom of the first-effect separator (4), a second-effect forced circulation pump (11) is installed at the bottom of the second-effect separator (6), and a third-effect forced circulation pump (12) is installed at the bottom of the third-effect separator (8). A discharge pump (13) is installed on the side of the triple-effect forced circulation pump (12) away from the triple-effect separator (8). The discharge pump (13) is located on the side of the double-effect forced circulation pump (11). The output end of the discharge pump (13) is connected to a discharge pipe. A concentrate tank (16) is installed on the outside of the discharge pipe. A plate and frame filter press (20) is installed on the other end of the discharge pipe. A filtrate tank (18) is installed at the bottom of the plate and frame filter press (20). A filtrate pump (19) is installed on the outside of the filtrate tank (18). The output end of the filtrate pump (19) is connected to an external pipe. One end of the filtrate pump (19) is connected to a bypass flue dual-fluid spray drying system via an external pipe.
2. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 1, characterized in that: The bypass flue dual-fluid spray drying system includes an A-side inlet flue electric damper (21) and a B-side inlet flue electric damper (22). The A-side inlet flue electric damper (21) is installed on one side of the filtrate pump (19), and the B-side inlet flue electric damper (22) is installed on one side of the A-side inlet flue electric damper (21). A main flue is installed at one end of both the A-side inlet flue electric damper (21) and the B-side inlet flue electric damper (22), and a dual-fluid evaporation tower (24) is installed at one end of the main flue.
3. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 2, characterized in that: An electric regulating door (23) for the inlet of a two-fluid evaporator is installed on the outer side of the main flue and near the end of the two-fluid evaporator (24). Gas-liquid two-phase flow nozzles are provided on both sides of the two-fluid evaporator (24). Another main flue is installed on the outer side of one of the two-fluid evaporators (24) where the gas-liquid two-phase flow nozzles are arranged. An electric damper (25) for the outlet flue on side A is installed on the outer side of the other main flue. An electric damper (26) for the outlet flue on side B is installed on one side of the electric damper (25) for the outlet flue on side A.
4. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 3, characterized in that: A first-effect heater (3) is installed between the first-effect separator (4) and the preheater (2). A first return pipe is installed between the first-effect heater (3) and the first-effect separator (4). A first installation pipe is installed between the first-effect heater (3) and the first-effect forced circulation pump (10). A second-effect heater (5) is installed between the first-effect separator (4) and the second-effect separator (6). A second return pipe is installed between the second-effect heater (5) and the second-effect separator (6).
5. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 4, characterized in that: A second installation pipe is installed between the double-effect heater (5) and the double-effect forced circulation pump (11), a first fixed pipe is installed between the double-effect heater (5) and the first-effect separator (4), and a triple-effect heater (7) is installed between the triple-effect separator (8) and the double-effect separator (6).
6. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 5, characterized in that: A third return pipe is installed between the triple-effect heater (7) and the triple-effect separator (8), a third installation pipe is installed between the triple-effect heater (7) and the triple-effect forced circulation pump (12), and a second fixed pipe is installed between the triple-effect heater (7) and the double-effect separator (6).
7. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 6, characterized in that: The preheater (2) is located on the side adjacent to the first-effect heater (3) and a flue gas humidification tank (15) is installed thereon. A flue gas humidification water pump (14) is installed on one side of the flue gas humidification tank (15) and the output end of the flue gas humidification water pump (14) is connected to a conveying pipe.
8. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 7, characterized in that: One end of the conveying pipe is connected to the flue gas humidification pump (14), and the other end of the conveying pipe is connected to the flue gas heater (1). Two concentrate pumps (17) are installed on the outside of the discharge pipe and between the concentrate tank (16) and the filtrate tank (18).
9. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 8, characterized in that: The triple-effect separator (8) has a tail-end condenser (9) installed on the side away from the triple-effect heater (7). A connecting pipe is installed on the outside of the tail-end condenser (9), and the other end of the connecting pipe is connected to the top of the triple-effect separator (8).
10. The desulfurization wastewater zero-discharge device of the combined process of low-temperature triple-effect flash evaporation and bypass flue dual-fluid spray drying tower according to claim 9, characterized in that: The flue gas heater (1) is externally equipped with a control panel. The flue gas heater (1), preheater (2), first-effect heater (3), first-effect separator (4), second-effect heater (5), second-effect separator (6), third-effect heater (7), third-effect separator (8), tail-end condenser (9), first-effect forced circulation pump (10), second-effect forced circulation pump (11), third-effect forced circulation pump (12), discharge pump (13), flue gas humidification pump (14), concentrate pump (17), filtrate pump (19), and plate and frame filter press (20) are all electrically connected to the control panel.