Flash desulfurization wastewater zero-discharge circulating treatment device based on glass fiber reinforced plastic pipeline

Abstract

The invention discloses a flash evaporation desulfurization wastewater zero-discharge circulating treatment device based on a glass fiber reinforced plastic pipeline. The flash evaporation desulfurization wastewater zero-discharge circulating treatment device comprises a flash evaporation tank and a heating evaporation tank, and a glass fiber reinforced plastic sleeve is fixedly sleeved with the flash evaporation tank; based on the operation principle of a conventional flash tank, the glass fiber reinforced plastic sleeve is additionally arranged in the upper end of the flash tank, an original single flash space is divided into double flash spaces including the inner flash chamber and the outer flash chamber, and the stirring diffusion assembly mounted in a rotary driving manner is additionally arranged in the inner flash space, so that the diffusion degree of sulfur wastewater at the top of the inner flash chamber is improved, and the sulfur wastewater can be recycled. Desulfurization waste water which is not evaporated in time from the inner flash chamber flows towards the outer flash chamber and moves downwards through the flow dividing groove and the heat exchange gap, in the process, hot air which is supplied and diffused upwards heats and evaporates the desulfurization waste water for the second time, and the heat exchange effect is improved. Moisture in the desulfurization wastewater is promoted to evaporate again in a narrow heat exchange space, and the crystallization rate is increased.

Description

Technical Field

[0001] The invention relates to the technical field of flash treatment of industrial wastewater, and more specifically to a zero-discharge circulation treatment device for flash desulfurization wastewater based on a glass fiber reinforced plastic pipeline. Background Art

[0002] Thermal power generation occupies an important position in my country's electricity production field. At present, more than 90% of my country's coal-fired power plants use limestone-gypsum wet flue gas desulfurization technology. In the wet flue gas desulfurization process, desulfurization wastewater will be generated.

[0003] The current flash evaporation system is one of the mainstream processes for treating desulfurized wastewater. For example, the desulfurized wastewater phase change flash evaporation crystallization zero-emission system and desulfurized wastewater treatment method disclosed in patent number CN108314119A use the waste heat of boiler flue gas as a heat source, subject the desulfurized wastewater to heat exchange treatment, and then pass it into a flash evaporator under negative pressure conditions for evaporation and concentration. However, in the traditional flash evaporation system, the wastewater enters the flash tank from the top, and the wastewater entering the flash tank is rapidly partially evaporated to form water vapor, which immediately overflows from the liquid phase, taking away a large amount of latent heat. This simple straight-through water distribution makes it difficult to achieve uniform distribution of wastewater at the top of the flash tank under high temperature. Some liquids that fail to form water vapor in time naturally flow downward under the action of gravity, and cool down after gradual heat exchange, resulting in a large amount of waste liquid discharged downward, because some soluble solids fail to fully crystallize, reducing the crystallization rate.

[0004] To this end, we proposed a flash desulfurization wastewater zero-discharge circulation treatment device based on FRP pipes to address practical problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the direct-through water distribution in the prior art cannot be evenly distributed and diffused under the high temperature state at the top of the flash tank, thereby reducing the flash evaporation effect, and to provide a zero-discharge circulation treatment device for flash desulfurization wastewater based on a glass fiber reinforced plastic pipeline.

[0006] The object of the present invention can be achieved by the following technical scheme: a zero-discharge circulation treatment device for flash desulfurization wastewater based on a glass fiber reinforced plastic pipeline, comprising a flash tank and a heating evaporation tank for heating desulfurization wastewater, a liquid inlet pipe is arranged on one side of the upper end of the flash tank, a steam discharge pipe is arranged on the top of the flash tank, a glass fiber reinforced plastic casing is fixedly sleeved inside the flash tank, an inner flash chamber is formed inside the glass fiber reinforced plastic casing, an outer flash chamber is formed between the outer wall of the glass fiber reinforced plastic casing and the inner wall of the flash tank, a dehumidifier connected to the outer flash chamber and the inner flash chamber is fixed on the top of the flash tank, and a plurality of discharge ports connected to the inner flash chamber and the outer flash chamber are arranged on the lower end wall of the glass fiber reinforced plastic casing; The inner end of the liquid inlet pipe passes through the top of the inner flash chamber and is fixed with a water distribution ring pipe. The lower end of the inner flash chamber is fixed with a water distribution cone located on the inner side of multiple discharge ports. A stirring and diffusion component is installed on the water distribution cone for rotation. The lower end of the outer flash chamber is distributed with a diverter table, an air distribution ring pipe and a solid-liquid separation tank from top to bottom. The diverter table is located below the multiple discharge ports.

[0007] Furthermore, an annular heat exchanger is installed inside the heating evaporator, and an air inlet pipe and an exhaust pipe connected to the annular heater are respectively installed at the upper and lower ends of the heating evaporator, the air inlet pipe is connected to the boiler flue exhaust pipe, the top of the heating evaporator is externally connected to an inlet pipe for introducing desulfurized waste water, and the bottom of the heating evaporator is provided with an outlet pipe connected to the liquid inlet pipe for heating the desulfurized waste water and discharging it. The desulfurized waste water is heat treated with the waste heat of the boiler flue gas as a heat source, and then introduced into a flash tank under negative pressure conditions for evaporation and concentration.

[0008] Furthermore, the stirring and diffusion assembly includes a stirring shaft rotatably mounted on a water distribution cone, a water distribution hood located below the water distribution ring pipe is fixed to the upper end of the stirring shaft, an overflow port is opened in the middle of the bottom end of the water distribution hood, and an upper drive motor for rotationally driving the stirring shaft is installed at the bottom of the fiberglass casing.

[0009] Furthermore, the water distribution hood is a hollow conical structure with an upward opening and is wide at the top and narrow at the bottom. The water distribution cone is a conical structure with a narrow top and a wide bottom and a bottom edge connected to the discharge port. A plurality of scraping strips that are movably fitted on the outer wall of the water distribution cone are fixed to the bottom end of the stirring shaft.

[0010] Furthermore, a plurality of downwardly disposed atomizing nozzles are installed on the water distribution ring pipe along a circular array with the center point of the flash tank, and a plurality of upwardly disposed air jets are installed on the air distribution ring pipe along a circular array with the center point of the tower flash tank.

[0011] Furthermore, a heating box connected to the air distribution ring pipe is provided outside the flash tank, the other end of the liquid inlet pipe is connected to the heating box, and a shunt pipe is externally connected to the steam exhaust pipe.

[0012] Furthermore, a plurality of diversion grooves which are staggered inside and outside and penetrate vertically are provided on the diversion platform, and an annular heat exchange gap is reserved between the outer edge of the diversion platform and the flash tank.

[0013] Furthermore, a salt collecting tank is provided inside the solid-liquid separation tank, and a discharge hopper connected to the bottom of the salt collecting tank and a discharge pipe connected to the bottom of the flash tank are provided on the bottom wall of the flash tank from top to bottom.

[0014] Furthermore, a discharge port connected to the discharge hopper is opened on one side of the bottom end of the salt collecting tank, a material-shifting piece is rotatably installed inside the salt collecting tank, and a lower drive motor for rotationally driving the material-shifting piece is installed in the middle of the solid-liquid separation tank.

[0015] Compared with the prior art, the advantages of the present invention are: (1) This scheme is based on the operating principle of a conventional flash tank. A glass fiber reinforced plastic casing is added to the upper end of the inner side of the flash tank to separate the original single flash space into a double flash space of an inner flash chamber and an outer flash chamber. A rotating driven stirring diffusion component is added to the inner flash space. On the one hand, it improves the diffusion degree of the desulfurized wastewater at the top of the inner flash chamber. On the other hand, it is conducive to slowing down the descending speed of the desulfurized wastewater and improving the flash evaporation effect. The desulfurized wastewater that has not evaporated in time in the inner flash chamber flows to the diversion table of the outer flash space. In this process, the hot gas diffused upward contacts the desulfurized wastewater, realizing secondary heating evaporation and improving the crystallization rate.

[0016] (2) This scheme opens a plurality of diversion slots on the diversion table that are staggered inside and outside, and a ring-shaped heat exchange gap is reserved between the outer edge of the diversion table and the flash tank. The desulfurization wastewater that has not evaporated in time from the inner flash chamber flows along the inclined end surface of the water distribution cone and the discharge port toward the diversion table, and moves downward through the plurality of diversion slots and the heat exchange gap. At this time, the hot air diffused upward at a high speed from the plurality of air nozzles contacts the desulfurization wastewater, thereby achieving rapid evaporation of the water in the desulfurization wastewater again in the narrow heat exchange space. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is a cross-sectional view of a flash tank of the present invention; Figure 3 It is a partial cross-sectional view of the junction of the glass fiber reinforced plastic casing and the dehumidifier of the present invention; Figure 4 It is an internal cross-sectional view of the glass fiber reinforced plastic casing of the present invention; Figure 5 It is a bottom view of the joint between the glass fiber reinforced plastic casing, the manifold and the air distribution ring pipe of the present invention; Figure 6 It is a structural schematic diagram of the solid-liquid separation tank of the present invention; Figure 7 It is a structural schematic diagram of the solid-liquid separation tank of the present invention when discharging materials using the material-discharging sheet; Figure 8 It is a cross-sectional view of the present invention when it is working.

[0018] Description of the numbers in the figure: 1. Flash tank; 101. Liquid inlet pipe; 102. Steam outlet pipe; 2. Heating evaporator; 201. Water inlet pipe; 202. Water outlet pipe; 203. Air inlet pipe; 204. Exhaust pipe; 3. FRP casing; 301. Discharge port; 4. Water distribution ring pipe; 401. Atomizing nozzle; 5. Water distribution cone; 6. Stirring shaft; 601. Scraper; 7. Water distribution cover; 8. Dehumidifier; 9. Diverter table; 901. Diverter trough; 10. Protective cover; 11. Air distribution ring pipe; 111. Air nozzle; 12. Heating box; 13. Diverter pipe; 14. Solid-liquid separation tank; 141. Salt collecting tank; 142. Discharge port; 15. Diverter sheet; 16. Discharge pipe; 17. Discharge hopper. DETAILED DESCRIPTION

[0019] The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0020] Example 1: The present invention discloses a zero-discharge circulation treatment device for flash desulfurization wastewater based on a glass fiber reinforced plastic pipeline. Figure 1 , including a flash tank 1 and a heating evaporation tank 2 for heating desulfurization wastewater, a liquid inlet pipe 101 for heating desulfurization wastewater is provided on one side of the upper end of the flash tank 1, and a steam exhaust pipe 102 is provided on the top of the flash tank 1; An annular heat exchanger is installed inside the heating evaporator 2. An air inlet pipe 203 and an exhaust pipe 204 connected to the annular heater are respectively installed at the upper and lower ends of the heating evaporator 2. The air inlet pipe 203 is connected to the boiler flue exhaust pipe. The top of the heating evaporator 2 is externally connected to an inlet pipe 201 for introducing desulfurized waste water. The bottom of the heating evaporator 2 is provided with an outlet pipe 202 connected to the liquid inlet pipe 101 for heating and discharging the desulfurized waste water. The desulfurized waste water is heat treated with the waste heat of the boiler flue gas as a heat source, and then introduced into the flash tank 1 under negative pressure conditions for evaporation and concentration. The evaporated water vapor is discharged from the steam exhaust pipe 102.

[0021] See also Figure 2 A glass fiber reinforced plastic casing 3 is fixedly sleeved inside the flash tank 1, an inner flash chamber is formed inside the glass fiber reinforced plastic casing 3, an outer flash chamber is formed between the outer wall of the glass fiber reinforced plastic casing 3 and the inner wall of the flash tank 1, a dehumidifier 8 connected with the outer flash chamber and the inner flash chamber is fixed on the top of the flash tank 1, and a plurality of discharge ports 301 connected with the inner flash chamber and the outer flash chamber are opened on the lower end wall of the glass fiber reinforced plastic casing 3.

[0022] See also Figure 3 , Figure 4, the inner end of the liquid inlet pipe 101 passes through the top of the inner flash chamber and is fixed with a water distribution ring pipe 4, on which a plurality of downwardly arranged atomizing nozzles 401 are installed in a circular array along the center point of the flash tank 1, and a water distribution cone 5 located inside a plurality of discharge ports 301 is fixed at the lower end of the inner flash chamber, and a stirring and diffusion component extending to the bottom of the water distribution ring pipe 4 is rotatably installed on the water distribution cone 5, and a water distribution cover 7 located below the water distribution ring pipe 4 is fixed at the upper end of the stirring shaft 6, and an overflow port is opened in the middle of the bottom end of the water distribution cover 7, and an upper drive motor for rotating the stirring shaft 6 is installed at the bottom of the glass fiber reinforced plastic casing 3; The water distribution hood 7 is a hollow conical structure with an upward opening and a wide top and a narrow bottom. The water distribution cone 5 is a conical structure with a narrow top and a wide bottom, and the bottom edge is connected and communicated with the discharge port 301. A plurality of scraper strips 601 movably fitted on the outer wall of the water distribution cone 5 are fixed at the bottom end of the stirring shaft 6. The heated desulfurized wastewater is introduced into the internal flash chamber through the liquid inlet pipe 101. The desulfurized wastewater is sprayed downward by a plurality of atomizing nozzles 401 and efficiently diffused through the rotation of the water distribution hood 7. On the one hand, it improves the diffusion degree of the desulfurized wastewater at the top of the inner flash chamber, and on the other hand, it is beneficial to slow down the descending speed of the desulfurized wastewater and improve the flash evaporation effect. The evaporated water vapor is dehumidified by the dehumidifier 8 and discharged from the steam discharge pipe 102. The addition of a synchronously rotating scraper 601 is beneficial to discharge the aqueous solution attached to the water distribution cone 5 toward the discharge port 301 to prevent the residual aqueous solution from crystallizing at the low-temperature water distribution cone 5.

[0023] See also Figure 2 and Figure 5-Figure 8 The lower end of the outer flash chamber is provided with a diverter table 9, an air distribution ring pipe 11 and a solid-liquid separation tank 14 from top to bottom. The diverter table 9 is located below the multiple discharge ports 301. The air distribution ring pipe 11 is provided with multiple upwardly disposed air nozzles 111 in a circular array at the center point of the tower flash tank 1. The desulfurized wastewater that has not been evaporated in time in the inner flash chamber flows toward the diverter table 9 in the outer flash space. In this process, the hot air diffused upward contacts the desulfurized wastewater to realize secondary heating and evaporation. The secondary evaporated water vapor is also dehumidified by the dehumidifier 8 and discharged from the steam exhaust pipe 102.

[0024] A salt collecting tank 141 is provided inside the solid-liquid separation tank 14, and a discharge hopper 17 connected to the bottom of the salt collecting tank 141 and a discharge pipe 16 connected to the bottom of the flash tank 1 are provided on the bottom wall of the flash tank 1 from top to bottom. Finally, the condensed water enters the salt collecting tank 141, and the solid-liquid separation tank 14 performs solid-liquid separation. The clean condensed water after separation is discharged from the discharge pipe 16, and the crystals remain in the salt collecting tank 141 and are finally discharged from the discharge hopper 17.

[0025] Example 2: Based on Example 1, this example optimizes the secondary flash evaporation process as follows: See also Figure 5 The diverter platform 9 is provided with a plurality of diverter grooves 901 which are staggered inside and outside and penetrate up and down, and an annular heat exchange gap is reserved between the outer edge of the diverter platform 9 and the flash tank 1. A protective cover 10 located between the diverter platform 9 and the air distribution ring pipe 11 is also fixed on the lower end wall of the glass fiber reinforced plastic casing 3. The protective cover 10 is a conical sleeve structure which is wide at the top and narrow at the bottom. A gas rising gap is reserved between the bottom edge of the protective cover 10 and the flash tank 1. The desulfurized wastewater that is not evaporated in time from the inner flash chamber flows along the inclined end surface of the water distribution cone 5 and the discharge port 301 toward the diverter table 9, and moves downward through multiple diverter slots 901 and the heat exchange gap. At this time, the hot gas moving upward from the multiple air nozzles 111 diffuses to the lower part of the diverter table 9 through the gas rising gap, fully contacts with the desulfurized wastewater, and heats the desulfurized wastewater again. The protective cover 10 plays an anti-corrosion protection role for the air distribution ring pipe 11 and the multiple air nozzles 111. This process enables the water in the desulfurized wastewater to evaporate rapidly again in the narrow heat exchange space, generates steam to move upward, and the condensed water is concentrated in the solid-liquid separation tank 14; See also Figure 6-Figure 8 A discharge port 142 connected to the discharge hopper 17 is provided at one side of the bottom end of the salt collecting tank 141, a material-pickup sheet 15 is rotatably installed inside the salt collecting tank 141, and a lower driving motor for rotating the material-pickup sheet 15 is installed at the middle position of the solid-liquid separation tank 14. The material-pickup sheet 15 is a trapezoidal structure with a narrow upper part and a wide lower part, and the width of the bottom end of the material-pickup sheet 15 is greater than the width of the discharge port 142; During normal flash evaporation operation, the shifting piece 15 is located above the discharge port 142. When the amount of crystals in the salt collecting tank 141 is large, the shifting piece 15 can be driven by the lower driving motor to rotate, and the crystals in the salt collecting tank 141 can be discharged from the discharge port 142, thereby reducing the deposition and scaling of wastewater in the tank and improving the subsequent solid-liquid separation effect.

[0026] A heating box 12 connected to the air distribution ring pipe 11 is also provided on the outside of the flash tank 1. The other end of the liquid inlet pipe 101 is connected to the heating box 12. A shunt pipe 13 is also externally connected to the steam discharge pipe 102. The steam discharge pipe 102 is directly connected to the heating box 12, and the heated gas is passed into the air distribution ring pipe 11, so that the water vapor is effectively recycled. A flow meter for monitoring the gas flow is added at the connection point between the steam exhaust pipe 102 and the heating box 12 and the air distribution ring pipe 11, and a bypass pipe 13 is connected to the end of the steam exhaust pipe 102. When the amount of desulfurization wastewater introduced is constant, the amount of heating gas discharged from the heating box 12 into the air distribution ring pipe 11 is constant, which is conducive to determining the amount of gas discharged from the bypass pipe 13 according to the actual amount of gas discharged from the steam exhaust pipe 102, so as to ensure that the amount of heating gas discharged from the heating box 12 into the air distribution ring pipe 11 is a constant value. The hot gas discharged from the bypass pipe 13 can be used for preheating of desulfurization wastewater or other heat energy recovery.

[0027] In summary: this scheme is based on the operating principle of a conventional flash tank, and a glass fiber reinforced plastic casing 3 is added inside the upper end thereof to realize the separation of the original single flash space into a double flash space of an inner flash chamber and an outer flash chamber, and a stirring diffusion component installed with a rotary drive is added in the inner flash space, which, on the one hand, improves the diffusion degree of the sulfur wastewater at the top of the inner flash chamber, and on the other hand, is conducive to slowing down the falling speed of the desulfurized wastewater and improving the flash effect; The desulfurized wastewater that has not been evaporated in time in the inner flash chamber moves toward the outer flash chamber and downward through multiple diversion troughs and heat exchange gaps. In this process, the hot air diffused upward contacts the desulfurized wastewater for secondary heating and evaporation, so that the water in the desulfurized wastewater can be evaporated again in a narrow heat exchange space, thereby improving the crystallization rate. It should be added that in order to improve the anti-corrosion performance of the flash tank 3, the inner sleeve of the flash tank 3, the fiberglass sleeve 3 and other tubular structures inside the flash tank 3 can be made of fiberglass according to actual needs. Fiberglass has excellent chemical corrosion resistance and low thermal conductivity. It can resist the erosion of various acids, alkalis, salts and organic solvents, extend the service life of the equipment, and help maintain temperature stability during the flash process, improve evaporation efficiency, and perform well in treating corrosive wastewater.

[0028] The above are only preferred specific implementation modes of the present invention; however, the protection scope of the present invention is not limited thereto; any technician familiar with the technical field within the technical scope disclosed by the present invention; any equivalent replacement or change based on the technical solution and improved concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A zero-discharge circulation treatment device for flash desulfurization wastewater based on a glass fiber reinforced plastic pipeline, comprising a flash tank (1) and a heating evaporation tank (2) for heating desulfurization wastewater, wherein the flash tank (1) is provided with a liquid inlet pipe (101) and a steam outlet pipe (102), and is characterized in that: A glass fiber reinforced plastic casing (3) is fixedly sleeved inside the flash tank (1), an inner flash chamber is formed inside the glass fiber reinforced plastic casing (3), an outer flash chamber is formed between the outer wall of the glass fiber reinforced plastic casing (3) and the inner wall of the flash tank (1), a dehumidifier (8) connected to both the outer flash chamber and the inner flash chamber is fixed at the top of the flash tank (1), and a plurality of discharge ports (301) connected to the inner flash chamber and the outer flash chamber are provided on the lower end wall of the glass fiber reinforced plastic casing (3); The inner end of the liquid inlet pipe (101) passes through the top of the inner flash chamber and is fixed with a water distribution ring pipe (4); the lower end of the inner flash chamber is fixed with a water distribution cone (5) located inside the plurality of discharge ports (301); a stirring and diffusion component is rotatably mounted on the water distribution cone (5); and the lower end of the outer flash chamber is provided with a diverter table (9), an air distribution ring pipe (11) and a solid-liquid separation tank (14) in sequence from top to bottom; the diverter table (9) is located below the plurality of discharge ports (301).

2. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 1 is characterized in that: An annular heat exchanger is installed inside the heating evaporator (2); an air inlet pipe (203) and an exhaust pipe (204) connected to the annular heater are installed at the upper and lower ends of the heating evaporator (2), respectively; the air inlet pipe (203) is connected to the flue gas exhaust pipe of the boiler; the top end of the heating evaporator (2) is externally connected to an inlet pipe (201) for introducing desulfurized waste water; the bottom end of the heating evaporator (2) is provided with an outlet pipe (202) for discharging heated desulfurized waste water and connected to the liquid inlet pipe (101).

3. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 1 is characterized in that: The stirring and diffusion assembly comprises a stirring shaft (6) rotatably mounted on a water distribution cone (5); a water distribution cover (7) located below the water distribution ring pipe (4) is fixed to the upper end of the stirring shaft (6); an overflow port is provided at the middle of the bottom end of the water distribution cover (7).

4. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 3 is characterized in that: The water distribution cover (7) is a hollow conical structure with an opening facing upward and being wide at the top and narrow at the bottom. The water distribution cone (5) is a conical structure with a narrow top and a wide bottom and a bottom edge connected to and communicated with the discharge port (301). A plurality of scraping strips (601) movably fitted on the outer wall of the water distribution cone (5) are fixed to the bottom end of the stirring shaft (6).

5. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 1 is characterized in that: The water distribution ring pipe (4) is provided with a plurality of downwardly disposed atomizing nozzles (401) in a circular array at the center point of the flash tank (1), and the air distribution ring pipe (11) is provided with a plurality of upwardly disposed air jet nozzles (111) in a circular array at the center point of the tower flash tank (1).

6. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 5 is characterized in that: A heating box (12) connected to the air distribution ring pipe (11) is also provided outside the flash tank (1), the other end of the liquid inlet pipe (101) is connected to the heating box (12), and a shunt pipe (13) is also externally connected to the steam outlet pipe (102).

7. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 1 is characterized in that: The diverter platform (9) is provided with a plurality of diverter grooves (901) which are staggered inside and outside and penetrate vertically, and an annular heat exchange gap is reserved between the outer edge of the diverter platform (9) and the flash tank (1).

8. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 1 is characterized in that: A salt collecting tank (141) is provided inside the solid-liquid separation tank (14), and a discharge hopper (17) connected to the bottom of the salt collecting tank (141) and a discharge pipe (16) connected to the bottom of the flash tank (1) are provided on the bottom wall of the flash tank (1) from top to bottom.

9. The zero-discharge circulation treatment device for flash desulfurization wastewater based on FRP pipeline according to claim 8 is characterized in that: A discharge port (142) connected to the discharge hopper (17) is provided on one side of the bottom end of the salt collecting tank (141), and a material shifting piece (15) is rotatably installed inside the salt collecting tank (141).

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