A desulfurization wastewater concentrate treatment system and method, and an oxidation separation device

Abstract

The application discloses a desulfurization wastewater concentrate oxidizing and separating device, which comprises an outer nozzle, an inner nozzle is embedded in the outer nozzle, an air suction hole is arranged at one end of the outer nozzle close to the inner nozzle, and a solid-liquid separator is arranged at the other end of the outer nozzle far from the inner nozzle. The application further discloses a desulfurization wastewater concentrate treatment system and a desulfurization wastewater concentrate treatment method. The desulfurization wastewater concentrate oxidizing and separating device utilizes the self-suction pressurization of the coupling nozzle and the centrifugal separation difference characteristics of the solid-liquid phase, realizes the conditioning oxidation and separation of the flue gas waste heat desulfurization wastewater concentrate, and through the solid-liquid-dissolved material balance calculation of the flue gas waste heat desulfurization wastewater concentrate treatment system in the desulfurization wastewater concentrate treatment method, the selection parameters of each equipment are obtained, and the investment operation cost of the desulfurization wastewater concentrate treatment system is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to a desulfurization wastewater concentrate treatment system and method, and an oxidation separation device. Background Technology

[0002] Limestone-gypsum wet desulfurization technology is a widely used flue gas treatment process in coal-fired power plants. It utilizes calcium carbonate to remove SO2 from flue gas. During the operation of the desulfurization system, a certain amount of desulfurization wastewater must be discharged, mainly containing Cl- from the system. - In order to maintain system balance, in addition to dissolved substances (mainly chlorides), desulfurization wastewater also contains a large amount of suspended solids.

[0003] Currently, zero-discharge wastewater technology using flue gas waste heat as a heat source is gaining attention. This technology concentrates and reduces wastewater volume through direct heat exchange between wastewater and flue gas, and then uses a flue gas bypass or main flue duct to evaporate and dry the concentrate, thereby achieving zero discharge. During the concentration process, the wastewater comes into direct contact with sulfur-containing flue gas, making the concentrate highly acidic and containing a large amount of dissolved salts (mainly chlorides) and suspended solids (calcium sulfite, calcium sulfate, etc.). Because calcium sulfite has poor crystallization properties, the viscosity of the concentrate increases and its fluidity decreases. To ensure the operation of the downstream flue gas evaporation and drying unit, the concentrate must be treated and separated.

[0004] Patent CN 106865667A discloses a waste heat concentration and reduction system for desulfurization wastewater flue gas and its process, specifically disclosing how an aeration device is installed in the concentration tower to reduce SO3. 2- Oxidized to SO4 2- Solid-liquid separation is achieved using plate and frame filter presses or belt filter presses. However, the process equipment in this patent is numerous and the system is complex, requiring a large amount of civil engineering work, resulting in high overall investment and operating costs. Summary of the Invention

[0005] The purpose of this invention is to provide a desulfurization wastewater concentrate treatment system and method, and an oxidation separation device, to solve the technical problem in the existing desulfurization wastewater zero-discharge technology that uses flue gas waste heat as a heat source, where the concentrate has high viscosity and poor fluidity, which in turn affects the normal operation of the downstream flue gas evaporation and drying device.

[0006] To achieve the above objectives, one embodiment of the present invention provides an oxidation separation device for desulfurization wastewater concentrate, including an outer nozzle, an inner nozzle embedded in the outer nozzle, an air intake hole at one end of the outer nozzle near the inner nozzle, and a solid-liquid separator at the other end away from the inner nozzle.

[0007] In one preferred embodiment of the present invention, a spiral guide vane is provided inside the solid-liquid separator, and the spiral angle of the spiral guide vane is 10°-30°.

[0008] In one preferred embodiment of the present invention, the solid-liquid separator includes an upper separator part and a lower separator part. A collection pipe is provided at the end of the upper separator part away from the lower separator part, and the lower separator part is of the contraction type with a spiral guide vane located in the lower separator part.

[0009] In one preferred embodiment of the present invention, the contraction starting point of the inner nozzle is on the side of the outer nozzle that is far away from the solid-liquid separator, and the outlet of the inner nozzle is on the side of the outer nozzle that is close to the solid-liquid separator, and does not exceed the outlet of the outer nozzle.

[0010] In one preferred embodiment of the present invention, the contraction angle of the outer nozzle is not greater than the contraction angle of the inner nozzle, and the contraction angle of the inner nozzle is not less than 30°.

[0011] Based on the desulfurization wastewater concentrate oxidation separation device disclosed in this invention, this invention also discloses a desulfurization wastewater concentrate treatment system, including a concentration tower, a conditioning device connected to the concentration tower, an oxidation separation device connected to the end of the conditioning device away from the concentration tower, and an evaporation drying device connected to the end of the oxidation separation device away from the conditioning device.

[0012] This invention also discloses a method for treating desulfurization wastewater concentrate, comprising the following steps: The wastewater discharged from the desulfurization system is concentrated by exchanging heat with the flue gas in a thickening tower; The concentrated solution is then subjected to pH adjustment using a conditioning device. The concentrated liquid after pH adjustment is subjected to solid-liquid separation by an oxidation separation device; The separated clear liquid is then subjected to brine separation treatment using an evaporation and drying device.

[0013] In one preferred embodiment of the present invention, the relationship between the actual wastewater treatment capacity of the treatment system and the liquid flow rate of each device in the treatment system is as follows: (1) (2) In equations (1) and (2), This represents the actual wastewater treatment volume. To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow rate from the concentration tower, Add flow rate to the conditioning unit. The flow rate of the clear liquid at the top of the separator. This refers to the flow rate at the bottom of the separator.

[0014] One preferred embodiment of the present invention is that the actual Cl processing system- Processing capacity and the Cl of each device in the processing system - The concentration relationship is as follows: (3) (4) (5) In equations (3), (4), and (5), For processing the Cl of the system - Total amount For the wastewater Cl entering the concentration tower - concentration, To discharge the concentrated liquid Cl from the concentration tower - concentration, The clear liquid Cl at the top of the separator - concentration, For the concentrated liquid Cl at the bottom of the separator - concentration.

[0015] In one preferred embodiment of the present invention, the relationship between the concentrations of solid insoluble matter in each device within the processing system is as follows: (6) (7) In equations (6) and (7), To determine the concentration of insoluble solids in the wastewater entering the thickening tower, To reduce the concentration of insoluble solids in the concentrate from the concentration tower, To adjust the pH of the conditioning unit, the concentration of solid insoluble matter is increased by adding alkaline liquid. The concentration of insoluble solids in the clear liquid at the top of the separator. The concentration of insoluble solids in the concentrated liquid at the bottom of the separator. To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow from the concentration tower, Add flow rate to the conditioning unit. The flow rate of the clear liquid at the top of the separator. This refers to the flow rate at the bottom of the separator.

[0016] In summary, the beneficial effects of the present invention are as follows: 1. The desulfurization wastewater concentrate oxidation separation device of the present invention utilizes the self-priming and pressurizing effect of the coupled nozzle and the difference in centrifugal separation characteristics between the solid and liquid phases to achieve conditioning, oxidation and separation of the flue gas waste heat desulfurization wastewater concentrate; at the same time, in the desulfurization wastewater concentrate treatment method, by calculating the material balance of solids, liquids and dissolved substances in the flue gas waste heat desulfurization wastewater concentrate treatment system, the selection parameters of each device are obtained, which effectively reduces the investment and operating costs of the desulfurization wastewater concentrate treatment system.

[0017] 2. The desulfurization wastewater concentrate oxidation separation device of the present invention realizes the oxidation and solid-liquid separation of the desulfurization wastewater concentrate after flue gas waste heat concentration, and removes SO3 from the concentrate. 2- Oxidized to SO4 2- This improves the fluidity, corrosiveness, and atomization performance of the concentrate, thereby effectively preventing the concentrate from clogging and corroding downstream equipment.

[0018] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objects and other advantages of this disclosure may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a desulfurization wastewater concentrate oxidation separation device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a desulfurization wastewater concentrate treatment system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the equipment structure of the desulfurization wastewater treatment system in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the equipment structure of the desulfurization wastewater treatment system in Embodiment 2 of the present invention.

[0020] Among them, 1-inner nozzle, 2-flange, 3-air intake hole, 4-outer nozzle, 5-solid-liquid separator, 6-collection pipe, 7-upper part of separator, 8-lower part of separator, 9-spiral guide vane, 10-concentration tower, 11-flue gas inlet, 12-desulfurization wastewater inlet, 13-flue gas outlet, 14-concentrate outlet, 15-concentrate discharge pump, 16-conditioning device, 17-agitator, 18-pH meter, 19-oxidation separation device, 20-evaporation drying device, 21-coal-fired boiler, 22-air preheater, 23-dust collector, 24-desulfurization tower, 25-chimney, 26-dehydrator. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0022] This invention provides an oxidation separation device for desulfurization wastewater concentrate, such as... Figure 1As shown, it includes an outer nozzle 4, and an inner nozzle 1 is embedded in the outer nozzle 4. The outer nozzle 4 and the inner nozzle 1 are detachably connected. The detachable connection makes it easy to pull out the inner nozzle 1 for replacement and maintenance. Preferably, the detachable connection is a flange 2 connection.

[0023] An air intake hole 3 is provided at the end of the outer nozzle 4 closest to the inner nozzle 1, and a solid-liquid separator 5 is provided at the end furthest from the inner nozzle 1. During concentrated liquid injection, the pressure difference between the outer nozzle 4 and the inner nozzle 1 is 0.1 kPa-5 kPa. This invention provides an air intake hole 3 on the connecting pipe of the outer nozzle 4. The injection action of the inner nozzle 1 creates a negative pressure within the cavity between the outer nozzle 4 and the inner nozzle 1. Utilizing the pressure difference with the external atmosphere, air is drawn in through the air intake hole 3 and mixed with the injected concentrated liquid under pressure in the contraction section of the outer nozzle 4, thus removing SO3 from the concentrated liquid. 2- Oxidized to SO4 2- This improves the fluidity, corrosiveness, and atomization performance of the concentrate.

[0024] The solid-liquid separator 5 is equipped with a spiral guide vane 9, the spiral angle of which is 10°-30°. The spiral guide vane 9 enhances the solid-liquid separation effect of the solid-liquid separator 5. The solid-liquid separator 5 includes an upper separator 7 and a lower separator 8. A collection pipe 6 is located at the end of the upper separator 7 furthest from the lower separator 8. The lower separator 8 is a contraction type, with the spiral guide vane 9 located in the lower separator 8. After separation by the solid-liquid separator 5, the concentrate with high solid content is discharged from the bottom of the solid-liquid separator 5 and returned to the desulfurization system, while the clear liquid with low solid content is discharged from the top of the collection pipe 6 located in the center of the upper separator 7 and enters the subsequent evaporation and drying device 20. Throughout the separation process, the collection pipe 6 also plays an auxiliary separation role. The oxidation separation device 19 pressurizes the oxidized concentrate through the outer nozzle 4 to form a high-speed jet, which enters the solid-liquid separator 5 tangentially. The lower separator 8 is a contraction type, utilizing the different densities between solid and liquid, coupled with the change in centrifugal force caused by the change in rotation radius, to achieve solid-liquid separation.

[0025] The contraction point of the inner nozzle 1 is on the side of the outer nozzle 4 away from the solid-liquid separator 5, and the outlet of the inner nozzle 1 is on the side of the outer nozzle 4 closer to the solid-liquid separator 5, but does not exceed the outlet of the outer nozzle 4. The contraction angle of the outer nozzle 4 is not greater than the contraction angle of the inner nozzle 1, and the contraction angle of the inner nozzle 1 is not less than 30°.

[0026] Working principle: The desulfurization wastewater concentrate oxidation separation device 19 uses the pressure difference between the inner nozzle 1 and the outer nozzle 4 to make the concentrate entering the inner nozzle 1 flow in the outer nozzle 4 in the form of a high-speed jet. At the same time, the pressure difference between the cavity between the inner nozzle 1 and the outer nozzle 4 and the external atmosphere draws in external air through the air intake hole 3, thereby realizing the oxidation of the concentrate sprayed from the inner nozzle 1. The oxidized concentrate enters the solid-liquid separator 5 tangentially. By utilizing the different densities between the solid and liquid, coupled with the change in centrifugal force caused by the change in the rotation radius, solid-liquid separation is achieved.

[0027] A desulfurization wastewater concentrate treatment system, such as Figure 2 As shown, it includes a concentration tower 10, a conditioning device 16 connected to the concentration tower 10, an oxidation separation device 19 connected to the end of the conditioning device 16 away from the concentration tower 10, and an evaporation drying device 20 connected to the end of the oxidation separation device 19 away from the conditioning device 16.

[0028] The concentration tower 10 uses the heat from the flue gas before the wet desulfurization absorption tower to evaporate, concentrate, and reduce the volume of desulfurization wastewater. It includes a flue gas inlet 11, a flue gas outlet 13, a desulfurization wastewater inlet 12, and a concentrate outlet 14.

[0029] The conditioning unit 16 adjusts the pH of the concentrated solution from acidic to 6-8 by adding reagents and stirring thoroughly. The conditioning unit 16 is equipped with a stirrer 17 and a pH meter 18 for adjusting the dosage. The preferred reagent is calcium carbonate, readily available in wet desulfurization systems, with a dry powder dosage of 10-20 kg / m³. 3 Using calcium carbonate as a reagent for wastewater treatment has the advantage of easy availability and reduces the cost of the desulfurization wastewater concentrate treatment system. It eliminates the need for additional equipment for reagent preparation, thus simplifying the system structure. Alkaline reagents such as calcium hydroxide and sodium hydroxide can also be used. When calcium hydroxide is used, the dosage is 5 kg / m³. 3 -8kg / m 3 Wastewater; furthermore, for ease of transport, the alkaline agents used for conditioning can be in a certain proportion of liquid or can be added as dry powder.

[0030] The evaporation drying device 20 is used to perform brine separation treatment on the clear liquid separated by the oxidation separation device 19. It can be selected by multiphase fluid atomization or mechanical high-speed rotation atomization according to the actual situation. The hot flue gas can be the flue gas from the denitrification outlet or the air preheater outlet.

[0031] Working process: The desulfurization wastewater concentrate treatment system first evaporates and concentrates the desulfurization wastewater and flue gas through the concentration tower 10 to reduce the volume. The concentrated liquid is then subjected to pH adjustment treatment by the conditioning device 16. After pH adjustment, the concentrated liquid undergoes solid-liquid separation by the oxidation separation device 19. The portion with high solid content is returned to the desulfurization system, while the clear liquid with low solid content enters the evaporation drying device 20 for brine separation.

[0032] A method for treating desulfurization wastewater concentrate includes the following steps: Step (1): The wastewater discharged from the desulfurization system is concentrated by heat exchange with the flue gas in the concentration tower 10; specifically, the wastewater discharged from the desulfurization system is concentrated by heat exchange with the flue gas in the concentration tower 10, and the wastewater will absorb a large amount of SO2 to form SO3. 2- This causes the liquid viscosity to increase, its fluidity to decrease, and it to contain a large amount of suspended solids and dissolved salts; Step (2): The concentrated solution is pH adjusted by the conditioning device 16; specifically, the concentrated solution is discharged to the conditioning device 16 through the concentrated solution discharge pump 15, and the pH is adjusted at the conditioning device 16 to adjust the pH of the concentrated solution to above 6. Step (3): The concentrated liquid after pH adjustment is subjected to solid-liquid separation by oxidation separation device 19; specifically, the concentrated liquid after pH adjustment is transported to oxidation separation device 19 by a transfer pump. After forced pressure oxidation separation, the clear liquid with low solid content in the upper part 7 of the separator enters the buffer tank, and the suspension with high solid content in the lower part 8 of the separator returns to the desulfurization tower 24. Step (4): The separated clear liquid is subjected to brine separation treatment by the evaporation drying device 20; specifically, the separated clear liquid enters the evaporation drying device 20, which adopts a high-temperature air preheater bypass evaporation tower, and uses SCR (selective catalytic reduction technology) to completely evaporate the wastewater after denitrification of the flue gas, thereby achieving brine separation and zero discharge.

[0033] The relationship between the actual wastewater treatment capacity of the treatment system and the liquid flow rate of each device in the system is as follows: ; ; In the formula, This represents the actual wastewater treatment volume. To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow from the concentration tower, Add flow rate to the conditioning unit. The flow rate of the clear liquid at the top of the separator. This refers to the flow rate at the bottom of the separator.

[0034] According to Cl - Concentration meter, actual Cl in the treatment system- Processing capacity and the Cl of each device in the processing system - The concentration relationship is as follows: ; ; ; In the formula, For processing the Cl of the system - Total amount For the wastewater Cl entering the concentration tower - concentration, To discharge the concentrated liquid Cl from the concentration tower - concentration, The clear liquid Cl at the top of the separator - concentration, For the concentrated liquid Cl at the bottom of the separator - concentration.

[0035] The relationship between the concentrations of solid insolubles in each device in the treatment system, based on solid content concentration, is as follows: ; ; In the formula, To determine the concentration of insoluble solids in the wastewater entering the thickening tower, To reduce the concentration of insoluble solids in the concentrate from the concentration tower, To adjust the pH of the conditioning unit, the concentration of solid insoluble matter is increased by adding alkaline liquid. The concentration of insoluble solids in the clear liquid at the top of the separator. The concentration of insoluble solids in the concentrated liquid at the bottom of the separator. To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow from the concentration tower, Add flow rate to the conditioning unit. The flow rate of the clear liquid at the top of the separator. This refers to the flow rate at the bottom of the separator.

[0036] Liquid flow rate and Cl in each device of the treatment system - The relationship between concentration and concentration of insoluble solids is as follows:

[0037] In the formula, To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow from the concentration tower, For the wastewater Cl entering the concentration tower - concentration, To discharge the concentrated liquid Cl from the concentration tower - concentration, To determine the concentration of insoluble solids in the wastewater entering the thickening tower, To determine the concentration of insoluble solids in the concentrate from the concentration tower.

[0038] Example 1 like Figure 3 As shown, the heat source flue gas received by the waste heat concentration tower 10 of the flue gas desulfurization wastewater of a 600MW coal-fired unit is raw flue gas that has not undergone desulfurization. The flue gas is rich in SO2. The wastewater discharged from the desulfurization system (including coal-fired boiler 21, air preheater 22, dust collector 23, desulfurization tower 24 and chimney 25) has a flow rate of 8m³ / h. 3 / h,Cl - During the heat exchange and concentration process of wastewater (concentration 15000 mg / L, solid content 1%, pH: 5.5-6.5) with flue gas in concentration tower 10, the wastewater absorbs a large amount of SO2, forming SO3. 2- This causes the pH of the concentrate to drop to around 2, while simultaneously increasing the liquid viscosity, reducing its fluidity, and increasing the content of suspended solids and dissolved salts. The concentrate (flow rate 2m³ / h) is discharged from the concentrate discharge pump 15. 3 / h,Cl - A solution with a concentration of 60,000 mg / L, a solid content of 4%, and a pH of 2 is discharged into a conditioning unit 16. The conditioning unit 16 is equipped with a stirrer 17, and a calcium carbonate solution (flow rate 0.1 m³ / L) prepared by the desulfurization system is added. 3 (20% solids content), adjust the pH of the concentrated solution to above 6; then use a transfer pump to transfer the conditioned concentrated solution (flow rate 2.1 m³ / h) to the solution. 3 A solution with a concentration of 57143 mg / L Cl-, a solid content of 4.76%, and a pH of 6 (per hour) is fed into an oxidation separation unit 19. The separation spiral angle is 20°. After forced pressure oxidation separation, the clear liquid with low solid content (flow rate 1.5 m³ / h) at the top of the separator is discharged. 3 / h,Cl - The wastewater (concentration 57143 mg / L, solids content 0.5%, pH: 6) enters the buffer tank. The terminal evaporation drying unit 20 uses a high-temperature air preheater bypass evaporation tower, utilizing the flue gas after SCR denitrification to completely evaporate the wastewater, achieving brine separation and zero discharge. The lower part of the separator contains a high-solids suspension (flow rate 0.6 m³ / L). 3 / h,Cl - (Concentration 57143 mg / L, solid content 15%, pH: 6) The slurry was returned to desulfurization tower 24, with a slurry volume of approximately 1000 m³. 3 The returned liquid causes slurry Cl - The concentration increased by approximately 34 mg / L, which is about 34 mg / L of the original slurry Cl. -A concentration of 15000 mg / L and a concentration of 0.23% will cause a 0.09% increase in the solids content of the slurry in desulfurization tower 24. This will not have a negative impact on the desulfurization system, therefore no additional treatment is required. The actual water volume treated by the zero-discharge system is: 8 - 2 + (1.5 - 0.1) = 7.4 m³. 3 / h, actual Cl processed - The total amount is: 8 15000-0.6 57143 = 857142 g / h.

[0039] Example 2 like Figure 4 As shown, a 1000MW coal-fired power unit discharges wastewater (flow rate 10m³) from its desulfurization system (including coal-fired boiler 21, air preheater 22, dust collector 23, desulfurization tower 24, and chimney 25). 3 / h,Cl - During the heat exchange and concentration process of the wastewater (concentration 20000 mg / L, solid content 3%, pH: 5.5-6.5) in the concentration tower 10, the pH of the wastewater decreases to around 2. The concentrated liquid (flow rate 3 m³ / L) is then discharged from the concentrate discharge pump 15. 3 / h,Cl - A solution with a concentration of 66667 mg / L, a solid content of 10%, and a pH of 2 is discharged into a conditioning unit 16. The conditioning unit 16 is equipped with a stirrer 17. 20 kg of dry calcium hydroxide powder is added, and the pH of the concentrated solution is adjusted to above 6. Then, the conditioned concentrate (flow rate 3 m³ / L) is pumped through a transfer pump. 3 / h,Cl - A solution with a concentration of 66,667 mg / L, a solid content of 10.67%, and a pH of 6 is fed into an oxidation separation unit 19. The separation spiral angle is 12°. After forced pressure oxidation separation, the clear liquid with low solid content (flow rate 2 m³ / L) at the top of the separator is separated. 3 / h,Cl - The wastewater (concentration 66667 mg / L, solids content 0.75%, pH: 6) enters the buffer tank. The terminal evaporation and drying device 20 uses direct injection into the flue gas, utilizing the heat from the flue gas before the dust collector 23 to completely evaporate the wastewater, achieving brine separation. Water vapor enters the flue gas, while the salt enters the fly ash and is captured by the dust collector 23, achieving zero emissions. The lower part of the separator contains a high-solids suspension (flow rate 1 m³ / L). 3 / h,Cl - The solid (66667 mg / L, solid content 30%, pH: 6) is returned to the dewatering machine 26 in the desulfurization system. Dewatering machine 26 is a vacuum belt dewatering machine, which achieves complete separation. The solid (333 kg, water content 10%, main component calcium sulfate) is mixed with gypsum for comprehensive utilization. The filtrate (flow rate 0.97 m³ / L) is then processed. 3 / h,Cl -Concentration 66667 mg / L), returned to the slurry tank 24 of the desulfurization tower (volume 1500 m³). 3 Cl - (Concentration 20000 mg / L), causing 24 Cl in the desulfurization tower - The concentration increase of 43 mg / L, representing an increase of approximately 2.15%, will not negatively impact the desulfurization system; therefore, no additional treatment is required. The actual water volume treated by the zero-emission system is: 10 - 3 + 2 = 9 m³. 3 / h, actual Cl processed - Total: 10 20000-1 66667 = 1933333 g / h.

[0040] In summary, the desulfurization wastewater concentrate treatment system of the present invention realizes the zero-discharge technology of wastewater using flue gas waste heat as a heat source. Furthermore, the desulfurization wastewater concentrate oxidation separation device of the present invention utilizes the self-priming and pressurizing effect of the coupled nozzle and the difference in centrifugal separation characteristics between the solid and liquid phases to achieve conditioning, oxidation and separation of flue gas waste heat desulfurization wastewater concentrate.

[0041] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An oxidation separation device for desulfurization wastewater concentrate, characterized in that: It includes an outer nozzle, an inner nozzle is embedded in the outer nozzle, an air intake hole is provided at the end of the outer nozzle near the inner nozzle, and a solid-liquid separator is provided at the end away from the inner nozzle. The inner nozzle's contraction point is on the side of the outer nozzle's contraction point that is far from the solid-liquid separator, and the inner nozzle's outlet is on the side of the outer nozzle's contraction point that is close to the solid-liquid separator, but does not exceed the outer nozzle's outlet. The contraction angle of the outer nozzle is not greater than that of the inner nozzle, and the contraction angle of the inner nozzle is not less than 30°.

2. The desulfurization wastewater concentrate oxidation separation device as described in claim 1, characterized in that: The solid-liquid separator is equipped with a spiral guide vane, and the spiral angle of the spiral guide vane is 10°-30°.

3. The desulfurization wastewater concentrate oxidation separation device as described in claim 2, characterized in that: The solid-liquid separator includes an upper separator part and a lower separator part. A collection pipe is provided at the end of the upper separator part away from the lower separator part. The lower separator part is a converging type, and the spiral guide vane is located in the lower separator part.

4. A desulfurization wastewater concentrate treatment system, characterized in that: The device includes a concentration tower connected to a conditioning device, an end of the conditioning device away from the concentration tower connected to an oxidation separation device according to any one of claims 1-3, and an evaporation drying device connected to the end of the oxidation separation device away from the conditioning device.

5. A treatment method for the desulfurization wastewater concentrate treatment system according to claim 4, characterized in that, Includes the following steps: The wastewater discharged from the desulfurization system is concentrated by exchanging heat with the flue gas in a thickening tower; The concentrated solution is then subjected to pH adjustment using a conditioning device. The concentrated liquid after pH adjustment is subjected to solid-liquid separation by an oxidation separation device; The separated clear liquid is then subjected to brine separation treatment using an evaporation and drying device.

6. A method for treating desulfurization wastewater concentrate as described in claim 5, characterized in that, The relationship between the actual wastewater treatment capacity of the treatment system and the liquid flow rate of each device in the system is as follows: （1） （2） In equations (1) and (2), This represents the actual wastewater treatment volume. To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow from the concentration tower, Add flow rate to the conditioning unit. The flow rate of the clear liquid at the top of the separator. This refers to the flow rate at the bottom of the separator.

7. A method for treating desulfurization wastewater concentrate as described in claim 5, characterized in that, Processing system actual Cl - Processing capacity and the Cl of each device in the processing system - The concentration relationship is as follows: （3） （4） （5） In equations (3), (4), and (5), For processing the Cl of the system - Total amount For the wastewater Cl entering the concentration tower - concentration, To discharge the concentrated liquid Cl from the concentration tower - concentration, The clear liquid Cl at the top of the separator - concentration, For the concentrated liquid Cl at the bottom of the separator - concentration.

8. A method for treating desulfurization wastewater concentrate as described in claim 5, characterized in that: The relationship between the concentrations of solid insoluble matter in each device in the treatment system is as follows: （6） （7） In equations (6) and (7), To determine the concentration of insoluble solids in the wastewater entering the thickening tower, To reduce the concentration of insoluble solids in the concentrate from the concentration tower, To adjust the pH of the conditioning unit, the concentration of solid insoluble matter is increased by adding alkaline liquid. The concentration of insoluble solids in the clear liquid at the top of the separator. The concentration of insoluble solids in the concentrated liquid at the bottom of the separator. To determine the wastewater flow rate entering the concentration tower, To discharge the concentrated liquid flow from the concentration tower, Add flow rate to the conditioning unit. The flow rate of the clear liquid at the top of the separator. This refers to the flow rate at the bottom of the separator.

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