Boiler drainage utilization method and device for same

Abstract

The invention relates to the field of sewage recycling, in particular to a boiler drainage utilization method which comprises the following steps: S1, sewage mixing: discharging fixed-time drainage sewage and continuous drainage sewage into a flash tank for mixing; s2, sewage flash evaporation: carrying out flash evaporation on the mixed sewage in the flash tank, and sending flash evaporation steam generated by flash evaporation back to the boiler; and S3, mixing and pulping: introducing the sewage which is not subjected to flash evaporation in the flash tank into a pulping box of the absorption tower, and adding limestone and industrial softened water into the pulping box. The device has the effect of saving water resources.

Description

Technical Field

[0001] The present application relates to the field of sewage reuse, and in particular to a boiler wastewater utilization method and a device used in the method. Background Art

[0002] During the operation of industrial boilers, the water in the boilers is constantly evaporated and concentrated, and the salt content and various impurities gradually increase. In order to prevent scaling, various descaling agents are added to the boiler water, which will also cause some products to be deposited in the drum, thereby reducing the quality of boiler water and steam. In order to maintain the steam quality within a certain range, the boiler must be discharged. The water after the boiler discharge will enter the expansion tank for flash evaporation, and part of the water resources will be recovered through flash evaporation; the boiler discharges about 60 tons of water per day, and the continuous discharge is about 150 tons per day. Flash evaporation can only recover a small amount of water. The discharge of the high-temperature sewage that has not been flashed will increase the consumption of water resources, increase the amount of boiler water replenishment, and cause a large amount of heat loss, affecting the thermal economy of the boiler, and also causing thermal pollution to the environment. Summary of the invention

[0003] In order to save water resources, the present application provides a boiler drainage utilization method.

[0004] A boiler wastewater utilization method provided in this application adopts the following technical solution: A method for utilizing boiler wastewater, comprising the following steps: S1: Mixed sewage, discharge fixed sewage and continuous sewage into the expansion tank for mixing; S2: Sewage flash evaporation, the mixed sewage is flash-evaporated in the expansion tank, and the flash steam generated by the flash evaporation is sent back to the boiler; S3: Mixed pulping: the un-flashed sewage in the expansion vessel is passed into the pulping box of the absorption tower and limestone and industrial softened water are added into the pulping box.

[0005] By adopting the above technical solution, by mixing boiler sewage with industrial softened water, the sewage discharged by the boiler is reasonably utilized, water resources are saved, and at the same time, high-temperature sewage is treated, the impact of sewage and high temperature on the environment is reduced, and the environment is protected.

[0006] Optionally, the fixed wastewater and the continuous wastewater are desalinated before entering the expansion vessel.

[0007] By adopting the above technical solution, the suspended solids in the fixed-discharge sewage and the continuous-discharge sewage are removed by desalting water, thereby reducing the influence of the suspended solids in the fixed-discharge sewage and the continuous-discharge sewage on the subsequent pulping.

[0008] Optionally, the mixed sewage is flash evaporated and then enters a deaerator for heat exchange.

[0009] By adopting the above technical solution, the heat of sewage can be reasonably utilized through heat exchange, and the heat of sewage can also be reduced, thereby reducing the probability that the sewage temperature is too high and affects subsequent pulping.

[0010] A device for boiler drainage utilization method comprises a boiler furnace body, the boiler furnace body is connected with fixed row pipes and continuous row pipes, the fixed row pipes and continuous row pipes are both connected to an expansion vessel, the expansion vessel is connected to a pulping box, and the pulping box is connected with a water supply pipe.

[0011] By adopting the above technical scheme, by connecting the fixed-drain pipe and the continuous-drain pipe to the pulping box, the fixed-drain sewage and the continuous-drain sewage are sent into the pulping box after being discharged from the boiler, so as to reasonably utilize the sewage discharged from the boiler and save water resources.

[0012] Optionally, a flushing pipe is connected to the pulping box.

[0013] By adopting the above technical solution, the flushing pipe is used to connect to the water source to facilitate flushing of the pulping box.

[0014] Optionally, an emergency pool is provided between the expansion vessel and the pulping box.

[0015] By adopting the above technical solution, the setting of the accident pool can store drainage, and can also store sewage when the sewage discharge volume is greater than the sewage required for pulping.

[0016] Optionally, the accident pool is connected to a pit.

[0017] By adopting the above technical solution, the pit can store and treat sewage by discharging it into the pit when the sewage in the accident pool is full.

[0018] Optionally, the accident pool is connected to the process water tank of the desulfurization tower.

[0019] By adopting the above technical solution and connecting the process water tank of the desulfurization tower through the accident pool, part of the sewage can be used in the desulfurization tower body, further improving the reuse rate of sewage and thus saving water resources.

[0020] Optionally, a process water pipe is connected to the process water tank.

[0021] By adopting the above technical solution, the sewage is hardened water, which has already produced scale. The process water pipe can replenish industrial softened water into the process water tank, and the probability of scale generation is reduced by neutralizing the sewage.

[0022] Optionally, a flow meter is installed on the serial pipes.

[0023] By adopting the above technical solution, the setting of the flow meter can facilitate the calculation of the amount of sewage discharged from the continuous pipeline, thereby facilitating the planning of subsequent sewage treatment plans.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. Mixing boiler wastewater with industrial softened water makes reasonable use of boiler wastewater and saves water resources; 2. Remove suspended solids in fixed-discharge sewage and continuous-discharge sewage by desalting water, thereby reducing the impact of suspended solids in fixed-discharge sewage and continuous-discharge sewage on subsequent pulping; 3. Heat exchange can reasonably utilize the heat of sewage, and at the same time reduce the heat of sewage, thereby reducing the probability of excessive sewage temperature affecting subsequent pulping; 4. The setting of the accident pool can store the drainage, and can also store the sewage when the sewage discharge volume is greater than the sewage required for pulping; 5. When the sewage in the accident pool is full, the pit can be discharged into the pit for storage and treatment of sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flowchart of this embodiment.

[0026] Figure 2 It is a schematic diagram of the overall structure of this embodiment.

[0027] Figure 3 It is a structural schematic diagram of the three-way valve in this embodiment.

[0028] Figure 4 yes Figure 3 Magnified view of part A in the middle.

[0029] Description of reference numerals: 1. boiler body; 2. steam drum; 3. continuous pipe; 4. fixed pipe; 5. desalted water equipment; 6. expansion tank; 7. deaerator; 8. pulping box; 9. water supply pipe; 10. accident pool; 11. pit; 12. process water tank; 13. process water pipe; 14. flushing pipe; 15. drain valve; 16. process water valve; 17. pulping valve; 18. desulfurization tower; 19. reflux pipe; 20, flow meter; 21, three-way valve; 22, exhaust pipe; 23, exhaust valve; 24, impeller; 241, wheel body; 242, blades; 25, spikes; 26, disassembly and assembly mechanism; 261, T-slot; 262, T-block; 263, cover plate; 27, T-bump; 28, threaded rod; 29, nut; 30, positioning groove; 31, positioning block; 32, embedded groove; 33, rotating shaft. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-3 This application is described in further detail.

[0031] The embodiment of the present application discloses a method for utilizing boiler drainage water, comprising the following steps: S1: mixing sewage, discharging fixed-discharge sewage and continuous-discharge sewage into the expansion tank 6 for mixing, and desalting the fixed-discharge sewage and continuous-discharge sewage before entering the expansion tank 6; continuous drainage is also called surface drainage, which is to continuously discharge boiler water from the part with a higher concentration of dissolved salts in the drum 2 at the top of the boiler (the surface of boiler water), the purpose of which is to prevent the boiler water from having too high salt and silicon content and to remove fine suspended matter in the boiler water; fixed-discharge drainage is also called bottom drainage, which is to discharge part of the boiler water from the lowest point of the boiler water circulation (the lower header of the water-cooled wall), the purpose of which is to remove the slag and iron oxide sediments settled at the bottom, a large amount of suspended matter and sediments will exist in the fixed-discharge sewage and continuous-discharge sewage, and the presence of suspended matter and sediments will affect the reuse of sewage; the suspended matter and sediments in the fixed-discharge sewage and continuous-discharge sewage are removed by desalting water, thereby reducing the influence of the suspended matter and sediments in the fixed-discharge sewage and continuous-discharge sewage on subsequent pulping; S2: sewage Flash evaporation, in the expansion tank 6, the mixed sewage is depressurized for flash evaporation, so that part of the sewage is vaporized into flash steam, and the flash steam generated by the flash evaporation is sent back to the boiler to reuse water resources. After the mixed sewage is flashed, the sewage that has not been flashed enters the deaerator 7 for heat exchange; the heat exchange can reasonably utilize the heat of the sewage, and at the same time, it can also reduce the heat of the sewage, and reduce the probability that the sewage temperature is too high and affects the subsequent pulping; S3: mixed pulping, the sewage in the expansion tank 6 that has not been flashed and has passed through the deaerator 7 after heat exchange is passed into the pulping box 8 of the absorption tower and limestone and industrial softened water are added to the pulping box 8; the boiler sewage is mixed with industrial softened water and limestone is used to make limestone slurry. The boiler sewage is alkaline and has a high temperature. The high temperature and alkaline water can improve the activity of the limestone during pulping, and can improve the efficiency and effect of pulping. The treated boiler sewage is used for pulping, which reasonably utilizes the sewage discharged from the boiler, saves water resources, and improves the efficiency and effect of limestone pulping.

[0032] A device for boiler wastewater utilization method, referring to Figure 2, including a boiler furnace body 1, a drum 2 connected to the boiler furnace body 1 is installed on the top of the boiler furnace body 1, the drum 2 is a cylindrical pressure vessel used for steam-water separation and steam purification in the boiler, forming a water circulation loop and storing boiler water, and its main function is to receive water from the economizer, separate steam and water and supply water to the circulation loop, and transport saturated steam to the superheater. Most of the suspended matter in the boiler exists in the drum 2 and needs to be discharged through the row. The drum 2 is connected and connected with a row of pipes 3, and the row of pipes 3 is easy to scale. In this embodiment, the row of pipes 3 adopts a fluoroplastic inner tube and a stainless steel shell. The fluoroplastic inner tube can reduce the scale in the sewage. The probability of suspended matter scaling on the inner wall of the pipe is reduced. The bottom of the boiler body 1 is connected and communicated with a fixed discharge pipe 4. The fixed discharge pipe 4 and the continuous discharge pipe 3 are both connected to, and the fixed discharge pipe 4 and the continuous discharge pipe 3 are both connected and communicated with a desalted water device 5. In this embodiment, the desalted water device 5 is a conventional device in the prior art. This embodiment will not be elaborated in detail. The desalted water device 5 is used to desalinate the fixed discharge sewage and the continuous discharge sewage, thereby reducing the sediment in the fixed discharge sewage and the suspended matter in the continuous discharge sewage. The desalted water device 5 is connected and communicated with the expansion tank 6 through a pipe, and the fixed discharge sewage and the continuous discharge sewage after desalting are discharged into the expansion tank 6 for reduction. Flash evaporation, the expansion tank 6 is connected and communicated with a reflux pipe, the reflux pipe is connected and communicated with the boiler furnace body 1 at one end away from the expansion tank 6, the expansion tank 6 is connected and communicated with a deaerator 7 through a pipeline, the sewage is heat exchanged in the deaerator 7, and the heat generated by the exchange is used in areas where heat is required, such as for preheating boiler water, the deaerator 7 is connected and communicated with a pulping box 8 through a pipeline, the pulping box 8 in this embodiment is a pulping box 8 for making limestone slurry in the desulfurization tower 18, and the pulping box 8 is connected and communicated with a water supply pipe 9, and the sewage in the boiler furnace body 1 enters the desalted water device 5 through the fixed discharge pipe 4 and the continuous discharge pipe 3 for desalting water , then the sewage enters the expansion tank 6 for flash evaporation, and the flash steam generated by the flash evaporation returns to the boiler furnace body 1 through the reflux pipe, and the un-flashed part is sent to the deaerator 7 through the pipeline for heat exchange. After the heat exchange, the sewage is sent to the pulping box 8 filled with limestone and supplemented with industrial softened water through the water supply pipe 9 to make limestone slurry in the pulping box 8. The pulping box 8 sprays the inside of the desulfurization tower 18 through the spray pipe; by connecting the fixed discharge pipe 4 and the continuous discharge pipe 3 to the pulping box 8, the fixed discharge sewage and the continuous discharge sewage are sent to the pulping box 8 after being discharged from the boiler, so that the sewage discharged from the boiler is reasonably utilized and water resources are saved.

[0033] Reference Figure 2An accident pool 10 is provided between the expansion tank 6 and the pulping box 8. The accident pool 10 is connected and communicated with the pulping box 8 and the deaerator 7. The accident pool 10 can store drainage, and can also store sewage when the sewage drainage volume is greater than the sewage required for pulping; the accident pool 10 is connected to the pit 11, and the pit 11 can store and treat sewage by discharging it into the pit 11 when the sewage in the accident pool 10 is full; the accident pool 10 is connected to the process water tank 12 of the desulfurization tower 18, and the process water tank 12 sprays and demists the inside of the desulfurization tower 18 through the demister pipe, and The accident pool 10 is connected to the process water tank 12 of the desulfurization tower 18, so that part of the sewage can be used for demisting inside the tower body of the desulfurization tower 18, further improving the reuse rate of sewage and thus saving water resources; the process water tank 12 is connected and communicated with a process water pipe 13, and the process water pipe 13 replenishes the process water tank 12 with industrial softened water. The pulping box 8 is also connected and communicated with a flushing pipe 14, and the flushing pipe 14 connects the process water tank 12 and the pulping box 8. The process water tank 12 can also be used as a sewage storage area, and the pulping box 8 is subsequently flushed or replenished with water through the flushing pipe 14.

[0034] Reference Figure 2 A drain valve 15 is installed on the pipe connecting the accident pool 10 and the pit 11. Opening the drain valve 15 can discharge excess sewage in the accident pool 10 to the pit 11 through the pipe, which is convenient for subsequent sewage treatment. A process water valve 16 is installed on the pipe connecting the accident pool 10 and the process water tank 12. Opening the process water valve 16 can replenish sewage into the process water tank 12 for reasonable use of sewage. A pulping valve 17 is installed on the pipe connecting the accident pool 10 and the pulping box 8. Opening the pulping valve 17 can replenish sewage into the process water tank 12 for reasonable use of sewage. The drain valve 15, the process water valve 16 and the pulping valve 17 are all solenoid valves, which are remotely controlled through the control terminal without manual opening and closing, which is efficient and convenient.

[0035] Reference Figure 2 and Figure 3, a flow meter 20 is installed on the continuous pipe 3. The setting of the flow meter 20 can conveniently calculate the amount of sewage discharged from the continuous pipe 3, so as to facilitate the planning of subsequent sewage treatment plans; a three-way valve 21 is installed on the continuous pipe 3 on the side of the flow meter 20 facing the boiler, and two horizontal interfaces of the three-way valve 21 are connected to the continuous pipe 3. The three-way valve 21 is connected to an exhaust pipe 22 installed on the interface perpendicular to the continuous pipe 3, and an exhaust valve 23 is installed on the exhaust pipe 22. The exhaust valve 23 allows gas to be discharged quickly and limits the discharge of liquid. The exhaust pipe 22 cooperates with the exhaust valve 23 to discharge gas in the continuous sewage, thereby ensuring the accuracy of the flow meter 20 calculation; a rotating shaft 33 is rotatably provided on the three-way valve 21, one end of the rotating shaft 33 is inserted into the three-way valve 21 and the other end extends out of the three-way valve 21, and the rotating shaft 33 is inserted into the three-way valve 21. One end is fixed with an impeller 24, and the impeller 24 includes The impeller 241 and the blades 242 are provided, wherein the wheel 241 is fixed to one end of the rotating shaft 33 inserted into the three-way valve 21, and the blades 242 have a plurality of blades evenly distributed around the wheel 241, and a plurality of spikes 25 are evenly distributed on the surface of the blades 242 facing the boiler furnace body 1. The impeller 24 can rotate and stir the continuous discharge sewage when the continuous discharge sewage is discharged, so that the bubbles in the continuous discharge sewage are discharged from the exhaust pipe 22, and the spikes 25 on the blades 242 can penetrate into the bubbles and burst the bubbles when the impeller 24 rotates, so that the gas in the bubbles is discharged from the exhaust pipe, and the rotating shaft 33 passes through the three-way valve 21 for sealing. The rotating shaft 33 extends out of one end of the three-way valve 21 for connecting other equipment requiring power, such as being connected to the structure for stirring in the pulping box 8 after connecting the coupling, and can also be used to connect a generator set to convert kinetic energy into electrical energy for storage, thereby saving energy.

[0036] Reference Figure 3 and Figure 4A disassembly and assembly mechanism 26 is provided between the wheel body 241 and the blades 242. The disassembly and assembly mechanism 26 includes a plurality of T-shaped slots 261 provided in the circumference of the wheel body 241, T-shaped plugs 262 fixed on the blades 242, and a cover plate 263 installed on the wheel body 241. In this embodiment, there are twelve T-shaped slots 261 evenly distributed in the circumference of the wheel body 241. The T-shaped slots 261 penetrate the side of the wheel body 241 away from the rotating shaft 33. In this embodiment, six blades 242 are provided. The T-shaped plugs 262 of the six blades 242 are respectively inserted into the six T-shaped slots 261 of the wheel body 241. The T-shaped slots 261 cooperate with the T-shaped plugs 262 to adjust the density of the blades 242, and also to When blade 242 is damaged, normal use of impeller 24 is ensured by replacing blade 242 without replacing the entire impeller 24, thus saving resources. Cover plate 263 and T-slot 261 penetrate one side of wheel body 241 and are covered on wheel body 241. A plurality of T-shaped protrusions 27 are fixedly arranged on cover plate 263 corresponding to T-slot 261. In this embodiment, the width of T-shaped plug 262 is less than the depth of T-slot 261. The depth of T-slot 261 is equal to the sum of the width of T-shaped plug 262 and the width of T-shaped protrusion 27. When the end cover is covered on wheel body 241, T-shaped protrusion 27 is inserted into T-slot 261. A threaded rod 28 is fixedly arranged on rotating shaft 33 toward one side of wheel body 241. The threaded rod 28 is fixedly arranged on the rotating shaft 33 toward one side of wheel body 241. The rod 28 passes through the wheel body 241 and the cover plate 263, and the threaded rod 28 and the cover plate 263 are threadedly connected with a nut 29 on the side facing away from the wheel body 241; the cover plate 263 is fixed on the wheel body 241 while the impeller 24 is fixed to the rotating shaft 33 by the threaded rod 28 and the nut 29; the wheel body 241 is provided with a positioning groove 30 at the center of one side facing the cover plate 263, and a positioning block 31 is fixed on the cover plate 263. The positioning groove 30 and the positioning block 31 are both adapted to be polygonal, and the number of sides of the polygon is the same as the number of T-slots 261. In this embodiment, the polygon is a dodecagon, and each side of the polygon corresponds to a T-slot 261. The polygonal positioning groove 30 and the positioning block 31 can be located on the cover When the plate 263 is covered, it is positioned so that each T-shaped protrusion 27 can be inserted into the T-shaped slot 261. A groove 32 is provided in the center of the side of the cover plate 263 facing away from the wheel body 241. The groove 32 is used for countersunk placement of the nut 29. The positioning block 31 is arranged in the center to increase the thickness of the central area of ​​the cover plate 263 and facilitate the opening of the groove 32. In this embodiment, the thread rotation direction of the threaded rod 28 is opposite to the rotation direction of the impeller 24, that is, the tightening direction of the nut 29 is opposite to the rotation direction of the impeller 24. If the nut 29 is driven when the impeller 24 rotates, the nut 29 can be driven to be tightened, thereby reducing the probability that the impeller 24 drives the nut 29 to rotate when the impeller 24 rotates, causing the impeller 24 to separate from the rotating shaft 33.

[0037] The implementation principle of the embodiment of the present application is as follows: the sewage in the bubbles at the top of the boiler furnace body 1 is discharged from the continuous discharge pipe 3, and the sewage at the bottom of the boiler furnace body 1 is discharged from the fixed discharge pipe 4, and the discharged continuous discharge sewage and fixed discharge sewage are sent to the desalted water equipment 5 for desalting, and the suspended matter and sediment in the sewage are filtered out, and then the sewage enters the expansion tank 6 for pressure reduction and flash evaporation, and part of the flash steam is generated by flash evaporation, and the flash steam is sent back to the boiler furnace body 1 through the pipeline, and the un-flashed sewage is sent to the deaerator 7 through the pipeline for heat exchange, and the heat in part of the sewage is recovered for use in other equipment that requires heat. The sewage after heat exchange is discharged into the accident pool 10 for unified collection, and the process water valve 16 is opened to replenish the process water tank 12 with sewage, and the process water pipe 13 is opened to replenish the process water tank 12 with industrial softened water. When demisting is required, the sewage is sent to the desulfurization tower 18 through the demisting pipe. Internal spraying for demisting. When the process water tank 12 is insufficient in water, the process water valve 16 and the process water pipe 13 are opened at the same time to replenish sewage and industrial softened water for the process water tank 12. When limestone slurry is needed, limestone is placed in the pulping box 8, and then the pulping valve 17 is opened to pass sewage into the pulping box 8, and at the same time, the water supply pipe 9 is opened to pass softened industrial water into the pulping box 8. Limestone slurry is made by mixing sewage and softened industrial water with limestone, and then the limestone slurry is sent to the desulfurization tower 18 through the spray pipe for spraying during desulfurization. When the pulping box 8 needs to be flushed or the accident pool 10 is insufficient in sewage, the pulping box 8 is flushed or replenished with water by opening the flushing pipe 14. When there is too much sewage in the accident pool 10, the sewage is discharged into the pit 11 by opening the drain valve 15 for sewage treatment. The treated sewage in the pit 11 can be sent back to the accident pool 10 by a water pump for reuse.

[0038] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for utilizing boiler wastewater, comprising the following steps: S1: Mixed sewage, discharge fixed sewage and continuous sewage into the expansion tank (6) for mixing; S2: Sewage flash evaporation, flash evaporation of the mixed sewage in the expansion vessel (6), and sending the flash steam generated by the flash evaporation back to the boiler; S3: Mixing and pulping, the un-flashed sewage in the expansion vessel (6) is introduced into the pulping box (8) of the absorption tower and limestone and industrial softened water are added into the pulping box (8).

2. A boiler wastewater utilization method according to claim 1, characterized in that: The fixed wastewater and the continuous wastewater are desalinated before entering the expansion vessel (6).

3. A boiler wastewater utilization method according to claim 2, characterized in that: After flash evaporation, the mixed sewage enters the deaerator (7) for heat exchange.

4. An apparatus for the boiler wastewater utilization method according to claim 3, characterized in that: The invention comprises a boiler furnace body (1), the boiler furnace body (1) being connected to fixed row pipes (4) and continuous row pipes (3), the fixed row pipes (4) and continuous row pipes (3) being connected to an expansion vessel (6), the expansion vessel (6) being connected to a pulping box (8), and the pulping box (8) being connected to a water supply pipe (9).

5. The device for boiler wastewater utilization method according to claim 4, characterized in that: The pulping box (8) is connected to a flushing pipe (14).

6. The device for boiler wastewater utilization method according to claim 5, characterized in that: An accident pool (10) is provided between the expansion vessel (6) and the pulping box (8).

7. The device for boiler wastewater utilization method according to claim 6, characterized in that: The accident pool (10) is connected to the pit (11).

8. The device for boiler wastewater utilization method according to claim 7, characterized in that: The accident pool (10) is connected to the process water tank (12) of the desulfurization tower (18).

9. The device for boiler wastewater utilization method according to claim 8, characterized in that: The process water tank (12) is connected to a process water pipe (13).

10. The device for boiler wastewater utilization method according to claim 9, characterized in that: A flow meter is installed on the serial pipes (3).

Images