CN109110846B - Desulfurization wastewater flue gas concentration reduction and cementing fixing system and process - Google Patents
Desulfurization wastewater flue gas concentration reduction and cementing fixing system and process Download PDFInfo
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- CN109110846B CN109110846B CN201810957696.5A CN201810957696A CN109110846B CN 109110846 B CN109110846 B CN 109110846B CN 201810957696 A CN201810957696 A CN 201810957696A CN 109110846 B CN109110846 B CN 109110846B
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/043—Details
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/16—Treatment of water, waste water, or sewage by heating by distillation or evaporation using waste heat from other processes
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/18—Nature of the water, waste water, sewage or sludge to be treated from the purification of gaseous effluents
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/06—Controlling or monitoring parameters in water treatment pH
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00767—Uses not provided for elsewhere in C04B2111/00 for waste stabilisation purposes
- C04B2111/00775—Uses not provided for elsewhere in C04B2111/00 for waste stabilisation purposes the composition being used as waste barriers or the like, e.g. compositions used for waste disposal purposes only, but not containing the waste itself
Abstract
The invention belongs to the field of industrial wastewater treatment, and particularly relates to a desulfurization wastewater flue gas concentration and decrement and cementing fixing system and a desulfurization wastewater flue gas concentration and decrement and cementing fixing process, wherein the system comprises an electric dust remover, a flue gas concentration tower, a desulfurization tower and a chimney are sequentially connected behind the electric dust remover, the electric dust remover and the desulfurization tower are communicated through a main flue, and a flue gas inlet and a flue gas outlet of the flue gas concentration tower are respectively communicated with the main flue through two branch pipelines; the bottom of the desulfurization tower is connected with a dehydration system, a liquid outlet of the dehydration system is connected to a desulfurization wastewater liquid storage tank, and the desulfurization wastewater liquid storage tank is connected to the concentrated solution of the flue gas concentration tower; the flue gas concentration tower is connected to the concentrated water tank, the concentrated water tank is connected to the feed inlet of the mixing stirrer, the slurry mixture of the mixing stirrer enters the forming equipment, and the forming equipment is connected with the curing chamber. The process is suitable for the system, the low-temperature flue gas is used for concentration and reduction, the performance of the solidified body is stable, pollutants in the desulfurization wastewater are solidified, the secondary pollution of the desulfurization wastewater is effectively reduced, and the zero emission of the desulfurization wastewater is really realized.
Description
Technical Field
The invention belongs to the field of industrial wastewater treatment, and particularly relates to a desulfurization wastewater flue gas concentration reduction and cementing fixing system and process, which are mainly suitable for a power plant adopting wet desulfurization.
Background
The limestone-gypsum wet flue gas desulfurization process is mature in technology, stable in operation, convenient to maintain and ultrahigh in desulfurization efficiency, and is the most widely applied desulfurization technology at present. In order to ensure the stable operation and desulfurization efficiency of the desulfurization system, the concentration of chloride ions in the circulating desulfurization slurry is controlled to be 12000-20000 mg/L, and the desulfurization system needs to discharge wastewater periodically. The desulfurization wastewater is used as power plant terminal wastewater, the water quality is complex, the wastewater has the characteristics of weak acidity, high content of suspended matters, excessive COD (chemical oxygen demand) and heavy metal element content, high salinity such as chloride sulfate and the like, the water quantity is large, and the water quality and the water quantity are affected to different degrees by burning coal, a pollutant removal system in front of a desulfurization tower, limestone quality, the operation condition of a desulfurization system and the like. Due to the complex water quality condition and the characteristic of multiple influence factors of the desulfurization wastewater, the treatment difficulty of the desulfurization wastewater is far higher than that of common industrial wastewater.
4 months in 2015, the State institutes release a Water pollution action plan, emphasizing the enhancement of the water environment treatment; in 6 months 2017, the 'feasible technical guidelines for pollution control of thermal power plants' issued by ministry of environmental protection formally starts to be implemented, wherein the key for realizing near-zero emission of wastewater is to realize zero emission of desulfurization wastewater. With the promotion of national policies, the treatment of desulfurization waste water becomes an industrial hotspot. In view of the difficulty in treating desulfurization wastewater, researchers at home and abroad have developed various methods for treating desulfurization wastewater. The common desulfurization wastewater treatment method at present mainly comprises the traditional chemical treatment method, evaporation pond treatment, flue evaporation, evaporative crystallization, bypass evaporation and the like. Most heavy metal ions and suspended matters in the desulfurization wastewater can be removed by the traditional chemical treatment method through the triple box, but soluble salt which mainly contains chloride ions and has strong mobility cannot be removed; the evaporation pond has low treatment cost, but the treatment effect is greatly limited by the wind speed, the wastewater concentration and the water environment, and wind blowing loss exists, so that the influence on the surrounding environment is large; the flue evaporation technology has the condition that the flue cannot be completely evaporated to dryness, so that the flue is corroded, and the pressure of the dust remover is greatly increased; chinese patent No. CN201610522598 discloses a wet desulphurization wastewater zero discharge treatment method, wherein effluent of a triple box sequentially passes through membrane pretreatment, a secondary nanofiltration membrane, a high-pressure reverse osmosis membrane and evaporative crystallization equipment, chloride is separated out and crystallized independently, a sulfate recycling desulphurization system is discharged along with gypsum, and a large amount of softening and dosing cost is reduced. In order to realize efficient salt separation, the evaporative crystallization technology needs to elongate a crystallization pretreatment process, so that the operation cost is greatly increased no matter the membrane method or the medicine adding treatment is adopted, and the crystallized salt is difficult to treat; chinese patent No. CN201710942060 discloses a system and method for zero discharge of desulfurization wastewater from coal-fired power plants, wherein high-temperature flue gas in front of an air preheater and low-temperature flue gas in back of the air preheater are respectively extracted as heat sources, a small amount of fine mist droplets of desulfurization wastewater after ca (oh)2 is uniformly mixed in a specially-arranged spray drying tower by evaporation, a small-sized pre-dust collector is additionally arranged behind the spray drying tower, and substances such as salts in the dried flue gas are collected without affecting the comprehensive utilization of fly ash. The medium-low temperature flue gas behind this kind of bypass evaporation technology extraction air preheater is as supplementary heat source to remedy the influence of the high temperature flue gas before the single extraction air preheater to boiler efficiency, is more accepted by the power plant, but still can avoid influencing boiler efficiency, and the danger that produces is useless is difficult to handle, and there is the problem that the pressure drop is difficult to solve in small-size dust remover.
Aiming at the research of desulfurization waste water decrement, Chinese patent with the patent number of CN201710240967 discloses a desulfurization waste water flue gas waste heat concentration decrement system and a process thereof. Chinese patent No. 201710379789 discloses a wet desulfurization wastewater recycling treatment system and a treatment method thereof, wherein a pretreatment system is specially provided with a concentration tower, part of hot flue gas in front of the desulfurization tower is extracted, and evaporation concentration is carried out on the hot flue gas and desulfurization wastewater fog drops passing through a spray layer. The two methods utilize hot flue gas in front of the desulfurizing tower to evaporate and concentrate the desulfurization wastewater, and spray layers are adopted to atomize the desulfurization wastewater to improve the concentration effect. But the former is directly concentrated in the flue, most of the desulfurization waste water in the fixed flue can be directly blown into the desulfurization tower by the flue gas due to the large flow velocity of the flue gas, the gas-liquid contact time is extremely short, and the concentration effect is difficult to realize; the latter desulfurization waste water is not treated by the triplex box before concentration, and the demister is arranged above the spraying layer, so that the demister is easy to scale and block seriously due to high suspended matter content and high calcium and magnesium content in the desulfurization waste water.
In summary, the concentration and decrement effects of the desulfurization wastewater in the above technologies are limited, and only chloride ions with strong mobility are transferred to an electric dust remover or crystalline salt in the subsequent treatment method, so that the potential hazard of secondary pollution exists, and a new desulfurization wastewater treatment process needs to be developed.
Disclosure of Invention
Therefore, a new desulfurization wastewater flue gas concentration and reduction and cementing fixing system and process are needed, and the system and the process can efficiently utilize energy and material resources of a power plant, avoid secondary pollution and achieve the effects of energy conservation and water conservation.
In order to achieve the purpose, the invention provides a desulfurization wastewater flue gas concentration and reduction and cementing fixing system, which comprises a flue gas concentration tower and a communicating pipeline, wherein the flue gas concentration and reduction system is sequentially connected with the flue gas concentration tower, a desulfurization tower and a chimney behind an electric dust remover, the electric dust remover is communicated with the desulfurization tower through a main flue, the flue gas concentration tower is arranged in a bypass manner, and a flue gas inlet and a flue gas outlet of the flue gas concentration tower are respectively communicated with the main flue through two branch pipelines;
the bottom of the desulfurization tower is connected with a conventional dehydration system, a liquid outlet of the dehydration system is connected to a desulfurization wastewater liquid storage tank, and the desulfurization wastewater liquid storage tank is connected to the concentrated solution of the flue gas concentration tower;
the cementing fixing system comprises a concentrated water tank, a mixing stirrer, a forming device and a curing chamber, wherein the flue gas concentration tower is connected to the concentrated water tank, the concentrated water tank is connected to a feed inlet of the mixing stirrer, a slurry mixture of the mixing stirrer enters the forming device, and the curing chamber is connected behind the forming device.
Further, two lateral conduits are first lateral conduit and second lateral conduit respectively, and first lateral conduit is flue gas inlet pipe way, and first lateral conduit end-to-end connection is to the flue gas concentration tower, and the second lateral conduit is the exhanst gas outlet pipeline, and the second lateral conduit end is still connected in the main flue between electrostatic precipitator and the desulfurizing tower, and is close desulfurizing tower one end.
Furthermore, a first flue gas baffle and a second flue gas baffle are respectively arranged at inlets of the first branch pipeline and the second branch pipeline to control the flue gas to enter and exit, a high-pressure fan is arranged in the first branch pipeline, the flue gas enters a flue gas concentration tower after the high-pressure fan extracts the electric dust remover, and the air extraction proportion is 10% -15%.
Furthermore, a draught fan is arranged in the main flue between the electric dust collector and the desulfurizing tower.
Furthermore, the desulfurization waste water liquid storage tank is connected to the concentrated solution of the flue gas concentration tower through a water pump and a raw water inlet pipeline.
Further, the flue gas concentration tower is connected to the concentrated water tank through a bottom concentration water pump 14, a mass flow control device is arranged at the water outlet end of the concentrated water tank, and the mass flow control device controls the quality of concentrated water entering the mixing stirrer according to a fixed ratio.
Further, a spray pipe system is arranged above the concentrated liquid level in the flue gas concentration tower, the tail end of the first branch pipeline is arranged between the concentrated liquid level and the spray pipe system, a stirring device is arranged in the concentrated liquid on the side surface of the flue gas concentration tower, the concentrated liquid is connected to the spray pipe system through a circulating water pump, and heat is exchanged in the flue gas concentration tower in a circulating mode.
Further, the concentrated water tank is provided with a pH detection instrument and a slaked lime water dosing system, the pH detection instrument is used for detecting the pH value of the concentrated water, and when the pH value of the concentrated water is less than 4, slaked lime water is added to adjust the pH value of the concentrated water to 4.0-7.0.
Furthermore, the curing room keeps constant temperature and humidity, the temperature is controlled at 20 +/-3 ℃, the relative humidity is controlled at 60-80%, and if standard curing conditions cannot be provided, at least watering equipment and drying equipment are required to be arranged in the curing room.
The invention also provides a desulfurization wastewater flue gas concentration reduction and cementing fixing process, which is suitable for the system and comprises the following steps:
the method comprises the following steps: the clean flue gas dedusted by the electric precipitator enters a main flue through an induced draft fan, 85% -90% of the flue gas directly enters a desulfurizing tower, and after the wet flue gas desulfurization process, when the concentration of chloride ions in the slurry is accumulated to reach the maximum limit value, the desulfurized slurry needs to be quantitatively discharged, the desulfurized slurry is dehydrated by a dehydration system to obtain gypsum and desulfurized wastewater, and the desulfurized wastewater is stored in a desulfurized wastewater storage tank;
step two: raw water in the desulfurization wastewater storage tank enters concentrated solution of the flue gas concentration tower through a water pump and a raw water inlet pipeline; 10-15% of flue gas in the main flue is extracted by a high-pressure fan and enters a first branch pipeline, the flue gas enters a flue gas concentration tower through the first branch pipeline, the flue gas exchanges heat with a liquid column of a concentrated solution, part of water in the desulfurization wastewater is evaporated into water vapor after the heat exchange, and the flue gas enters the main flue along with the heat exchange through a second branch pipeline on the top of the flue gas concentration tower and then enters the desulfurization tower;
step three: conveying the concentrated solution in the flue gas concentration tower to a spray pipe system through a circulating water pump, performing circulating heat exchange in the flue gas concentration tower, discharging the concentrated solution into a concentrated water tank through the concentrated water pump when the concentrated solution reaches a designed concentration ratio, detecting the pH value of concentrated water through a pH detection instrument in the concentrated water tank, adding a proper amount of slaked lime water into a slaked lime water dosing system to adjust the pH value of the concentrated water to 4.0-7.0 if the pH value of the concentrated water is less than 4, quantitatively outputting the concentrated water into a mixing stirrer according to the required water amount in the mixing ratio of a solidified body through a mass flow control device at the outlet of the concentrated water tank after the pH value is normal, adding cementing materials such as cement, fly ash and the like into the mixing stirrer through a feeding machine, starting the mixing stirrer, and mixing and stirring all raw materials;
step four: and transferring the slurry mixture formed after the mixing of the mixing stirrer into a forming device in time, transferring the solidified body into a curing room after the slurry is formed for 24 hours, and continuously curing at a certain temperature and humidity.
Furthermore, the concentration ratio of the desulfurization wastewater in the third step is controlled to be 5-10 times.
Further, the mass mixing ratio of the solidified body in the third step is cement, coal ash, concentrated wastewater and river sand = 3-6: 1: 2-4: 3-6.5.
Different from the prior art, the technical scheme has the following beneficial effects:
(1) the invention provides a desulfurization waste water flue gas concentration and reduction and cementing fixing system and process, which are characterized in that a special flue gas concentration tower is arranged, and flue gas waste heat and desulfurization waste water are subjected to mass transfer and heat transfer after an electric dust collector is utilized in the flue gas concentration tower, so that the effect of concentration and reduction of desulfurization waste water is achieved, and the flue gas concentration and reduction and cementing fixing system and process are capable of fully utilizing waste heat resources of a power plant.
(2) Set up the spray tube system among the flue gas concentration tower, utilize the liquid column and the heat transfer of hot flue gas that form, improve heat exchange efficiency greatly, reduce the spray nozzle that the layer set up and cause and block up the problem, desulfurization waste water liquid column whereabouts in-process can also form the washing effect to the spray tube system.
(3) Partial water in raw water of the desulfurization wastewater is evaporated into steam in the process of mass and heat transfer with hot flue gas, and the steam enters the desulfurization system along with the cooled flue gas, so that the moisture content is increased, the process supplementing water of the desulfurization system can be greatly reduced, and the effect of saving water is achieved.
(4) The salt and heavy metal ions in the cement solidification desulfurization wastewater are utilized to convert the flowing desulfurization wastewater into a solidified body which is stable in physical and chemical properties and not easy to disperse, after 28d of curing age, the compressive strength of the solidified body is over 32 MPa, the leaching rate is lower than 20%, and chloride ions with strong mobility are fixed in the solidified body, so that secondary pollution is effectively avoided.
(5) The fly ash in the power plant is used for replacing part of cement to fix the high-salinity wastewater, so that the solidification effect can be improved, the fixing capacity for chloride ions is enhanced, the fly ash can be reasonably treated by the power plant, and byproducts of the power plant are fully utilized.
(6) The invention has simple structure and low investment and operation cost, can bring remarkable economic benefit for enterprises and has good environmental and social benefits.
Drawings
Fig. 1 is a schematic structural diagram of a system according to an embodiment of the present invention.
Description of reference numerals:
1. the system comprises a dust remover, a draught fan 2, a flue gas baffle 3, a high-pressure fan 4, a flue gas baffle 5, a desulfurizing tower 6, a chimney 7, a dehydration system 8, gypsum 9, a desulfurized wastewater storage tank 10, a water pump 11, a flue gas concentration tower 12, a flue gas concentration tower 13, a concentrated water pump 14, a concentrated water tank 15, a mixing stirrer 16, a forming device 17, a curing chamber 18, a main flue 19, a first branch pipeline 20, a second branch pipeline 21, a pipeline 22 and a raw water inlet pipeline 23.
Detailed Description
To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
Referring to fig. 1, the desulfurization waste water flue gas concentration, decrement and cementing fixing system of the present embodiment includes an electric dust collector 1, a flue gas concentration tower 13, a desulfurization tower 6, a mixing stirrer 16 and a curing chamber 18;
the flue gas concentration tower 13, the desulfurizing tower 6 and the chimney 7 are sequentially connected behind the electric dust collector 1; an induced draft fan 2 is arranged in a main flue 19 between the electric dust collector 1 and the desulfurizing tower 6, the main flue 19 is connected with two branch pipelines behind the induced draft fan 2, wherein a first branch pipeline 20 is a flue gas inlet pipeline, the tail end of the first branch pipeline 20 is connected to the flue gas concentrating tower 13, a second branch pipeline 21 is a flue gas outlet pipeline, and the tail end of the second branch pipeline 21 is still connected into the main flue 19 between the electric dust collector 1 and the desulfurizing tower 6 and is close to one end of the desulfurizing tower 6; the inlets of the first branch pipeline 20 and the second branch pipeline 21 are respectively provided with a flue gas baffle 3 and a flue gas baffle 5 for controlling the flue gas to enter and exit, the high-pressure fan 4 is arranged in the first branch pipeline 20, the flue gas enters the flue gas concentration tower 13 after the electric dust remover 1 is extracted, and the air extraction proportion is 10-15%.
The bottom of the desulfurizing tower 6 is connected with a dehydration system 8, the liquid outlet of the dehydrating tower is connected to a desulfurizing waste water liquid storage tank 10, and the desulfurizing waste water liquid storage tank 10 is connected to the concentrated solution of the flue gas concentration tower 13 through a water pump 11 and a raw water inlet pipeline 23;
the flue gas concentration tower 13 is connected to a concentrated water tank 15 through a bottom concentrated water pump 14, a spray pipe system is arranged above the concentrated liquid level in the flue gas concentration tower 13, and the tail end of the first branch pipeline 20 is arranged between the concentrated liquid level and the spray pipe system; a stirring device is arranged in the concentrated solution on the side surface of the flue gas concentration tower 13, the concentrated solution is connected to a spray pipe system through a circulating water pump 12, and heat exchange is carried out in the flue gas concentration tower 12 in a circulating mode.
The water outlet end of the concentrated water tank 15 is provided with a mass flow control device which controls the quality of concentrated water entering the mixing stirrer 16 according to a fixed proportion; the concentrated water tank 15 is provided with a pH detection instrument and a slaked lime water dosing system, the pH detection instrument is used for detecting the pH value of the concentrated water, and when the pH value of the concentrated water is less than 4, slaked lime water is added to adjust the pH value of the concentrated water to 4.0-7.0; the concentrated water tank 15 is connected to a feeding hole of a mixing stirrer 16, a valve is arranged at the bottom of the mixing stirrer 16, slurry mixture in the mixing stirrer 16 is controlled to enter a forming device 17, and a curing chamber 18 is connected behind the forming device 17; the curing room 18 needs to maintain constant temperature and humidity, the temperature is controlled at 20 +/-3 ℃, the relative humidity is controlled at 60-80%, and if standard curing conditions cannot be provided, at least watering equipment and drying equipment are required to be arranged in the curing room 18;
the embodiment also discloses a desulfurization waste water flue gas concentration decrement and cementization fixing process, and the process is suitable for the system, and comprises the following processes:
the method comprises the following steps: the clean flue gas after being dedusted by the electric precipitator 1 enters the main flue 19 through the induced draft fan 2, 85% -90% of the flue gas directly enters the desulfurizing tower 6, and after the wet flue gas desulfurization process, when the concentration of chloride ions in the slurry is accumulated to reach the maximum limit value, the desulfurized slurry needs to be quantitatively discharged, the desulfurized slurry is dehydrated by the dehydration system 8 to obtain gypsum 9 and desulfurized wastewater, and the desulfurized wastewater is stored in the desulfurized wastewater storage tank 10;
step two: raw water in the desulfurization wastewater storage tank 10 enters a concentrated solution of a flue gas concentration tower 13 through a water pump 11 and a raw water inlet pipeline 23; 10-15% of flue gas in the main flue 19 is extracted by the high-pressure fan 4, enters a first branch pipeline 20, enters the flue gas concentration tower 13 through the first branch pipeline 20, exchanges heat with a liquid column of a concentrated solution, partial water in the desulfurization wastewater is evaporated into water vapor after heat exchange, and the flue gas after heat exchange enters the main flue through a second branch pipeline 21 at the top of the flue gas concentration tower 13 and then enters the desulfurization tower 6;
step three: the concentrated solution in the flue gas concentration tower 13 is conveyed to a spray pipe system through a circulating water pump 12, heat exchange is carried out in the flue gas concentration tower 13 in a circulating mode, when the concentrated solution reaches a designed concentration ratio, the concentrated solution is discharged into a concentrated water tank 15 through a concentrated water pump 14, a pH detector in the concentrated water tank 15 detects the pH value of concentrated water, if the pH value of the concentrated water is smaller than 4, a proper amount of slaked lime water needs to be added through a slaked lime water dosing system to adjust the pH value of the concentrated water to 4.0-7.0, after the pH value is normal, mass flow control equipment at the outlet of the concentrated water tank 15 quantitatively outputs concentrated water into a mixing stirrer 16 according to the required water amount in the mixing ratio of a solidified body, cement, fly ash and other raw materials are added into the mixing stirrer 16 through a feeding machine, the mixing stirrer 16 is started, and all the raw materials are mixed and stirred; the concentration ratio of the desulfurization wastewater in the third step needs to be controlled to be 5-10 times; the mass mixing ratio of the solidified body in the third step is cement, coal ash, concentrated wastewater and river sand = 3-6: 1: 2-4: 3-6.5;
step four: and (3) timely transferring the slurry mixture formed after the mixing of the mixing stirrer 16 into a forming device 17, transferring the solidified body into a curing chamber 18 after the slurry is formed for 24 hours, and continuing curing at a certain temperature and humidity.
The desulfurization waste water flue gas concentration decrement and cementition fixed system and technology that this embodiment provided, the main theory of operation utilizes low-grade heat energy behind the dust remover to carry out evaporative concentration to desulfurization waste water, utilizes cementitious material such as cement to fix the high salt waste water after the concentration, uses as building materials such as curb stone. In order to improve the concentration effect, the system is particularly provided with a flue gas concentration tower, concentrated liquid is injected into the flue gas concentration tower by utilizing a spray pipe and a concentrated water pump to form a water column, the water column of the water column is contacted with hot flue gas twice in an ascending stage and a falling stage, the average temperature difference and the partial pressure difference in the heat exchange process are large, the contact time of the gas phase and the liquid phase is longer, the heat transfer and the mass transfer of the hot flue gas and the desulfurization wastewater are conveniently carried out, the heat energy utilization rate is higher, and the falling water column can play a good washing effect on the spray pipe system.
The cement is the curing agent which is most widely applied at present, and has the advantages of good treatment effect, low cost and the like, so the cement is selected as the curing agent for the desulfurization wastewater. The cement and the water in the desulfurization wastewater generate hydration reaction to generate gel which can wrap the heavy metal ions in the desulfurization wastewater to a certain degree. Meanwhile, chloride ions with strong mobility in the desulfurization wastewater can be fixed in the cement. In fact, chloride ions are mainly present in cement systems in three ways:
(1) chemically combined chlorine ions, the hydration product of cement tricalcium aluminate phase reacts with chlorine ions to generate low-solubility calcium monochloroaluminate 3 CaO. Al2O3·CaCl2·10H2O, also known as fischer-tropsch salt (Friedel salt);
(2) the chloride ions are absorbed in the hydrated calcium silicate gel of the cement cementing material in a physical adsorption state, and the free chloride ions are fixed in the physical adsorption mode. The physical adsorption mode is mainly based on the theory of electric double layers, and can not only prevent further diffusion of chloride ions, but also stabilize free chloride ions. However, the physical adsorption capacity is limited, and the space structure needs to be refined, so that the physical adsorption can be more durable and effective;
(3) the free chloride ions present in the pore liquid are the chloride ions that most affect the curing effect. When the total amount of the chloride ions is constant, the smaller the amount of the free chloride ions is, the stronger the curing ability of the cement system is.
Free chloride ions in a cement system are reduced as much as possible, and the fixing efficiency of the process can be improved.
In the embodiment, the mass ratio of the solidified body is determined as cement, fly ash, concentrated wastewater, river sand =5.5:1:3.5:5.6, sodium chloride solutions with different chloride ion concentrations are used as concentrated water samples, mixed with other materials uniformly and then placed in a mold for molding, after 24 hours, the mold is transferred into a stable curing environment for curing, and after 28 days, the compressive strength and the leaching rate of the solidified body are measured, and the results are shown in the following table:
| numbering | L0 | L3 | L4 | L5 | L6 | L7 | L8 | L9 | L10 |
| Chloride ion concentration (mg/L) | 0 | 30000 | 40000 | 50000 | 60000 | 70000 | 80000 | 90000 | 100000 |
| Pressure-resistantStrength (MPa) | 32.94 | 36.97 | 40.36 | 40.86 | 40.5 | 44.62 | 42.05 | 42.84 | 42.17 |
| Chloride ion leaching rate (%) | — | 15.60 | 12.41 | 12.53 | 12.02 | 11.18 | 11.35 | 11.54 | 10.78 |
Wherein the leaching rate is the ratio of the total amount of chloride ions leached out after the cured body maintained for 28 days is soaked in 300 mL of deionized water for 7 days to the total amount of chloride ions in the cured body.
From the general trend, the compressive strength of the cured body did not generally show a continuous increasing trend as the chloride ion concentration increased, and the compressive strength of the cured body increased with increasing chloride ion concentration at a chloride ion concentration of less than 70000mg/L, reached a maximum of 44.62M Pa at 70000mg/L, and then decreased with increasing concentration. The leaching rates of the solidified bodies after curing for 28 days are all less than 16 percent, and the minimum leaching rate is 10.78 percent. Because the chloride ion concentration in the concentrated high-salinity wastewater is high, the reinforcement corrosion is easily caused, and the durability of the reinforced concrete is influenced, so that the solidified body produced by the process is suitable for non-reinforced concrete or curbstone, the compressive strength and the leaching performance of the solidified body can meet the construction requirement, and the secondary pollution is not easily formed.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.
Although the embodiments have been described, once the basic inventive concept is obtained, other variations and modifications of these embodiments can be made by those skilled in the art, so that the above embodiments are only examples of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures or equivalent processes using the contents of the present specification and drawings, or any other related technical fields, which are directly or indirectly applied thereto, are included in the scope of the present invention.
Claims (6)
1. The utility model provides a desulfurization waste water flue gas concentration decrement and cementite fixing system which characterized in that: the flue gas concentration and reduction system comprises a flue gas concentration tower and a communicating pipeline, the flue gas concentration tower, a desulfurizing tower and a chimney are sequentially connected behind an electric dust remover, the electric dust remover and the desulfurizing tower are communicated through a main flue, a flue gas concentration tower is arranged in a bypass mode, and a flue gas inlet and a flue gas outlet of the flue gas concentration tower are respectively communicated with the main flue through two branch pipelines;
the bottom of the desulfurization tower is connected with a conventional dehydration system, a liquid outlet of the dehydration system is connected to a desulfurization wastewater liquid storage tank, and the desulfurization wastewater liquid storage tank is connected to the concentrated solution of the flue gas concentration tower;
the cementing fixing system comprises a concentrated water tank, a mixing stirrer, a forming device and a curing chamber, wherein the flue gas concentration tower is connected to the concentrated water tank, the concentrated water tank is connected to a feed inlet of the mixing stirrer, a slurry mixture of the mixing stirrer enters the forming device, and the rear part of the forming device is connected with the curing chamber;
the two branch pipelines are respectively a first branch pipeline and a second branch pipeline, the first branch pipeline is a flue gas inlet pipeline, the tail end of the first branch pipeline is connected to a flue gas concentration tower, the second branch pipeline is a flue gas outlet pipeline, and the tail end of the second branch pipeline is still connected to a main flue between an electric dust remover and a desulfurizing tower and is close to one end of the desulfurizing tower;
the inlets of the first branch pipeline and the second branch pipeline are respectively provided with a first smoke baffle and a second smoke baffle for controlling the smoke to enter and exit, the first branch pipeline is internally provided with a high-pressure fan, the high-pressure fan extracts partial smoke at the rear part of the electric dust remover and enters a smoke concentration tower, and the air extraction proportion is 10-15%;
arrange the spray tube system in the flue gas concentration tower above the concentrated liquid level, first branch pipeline end is arranged in between concentrated liquid level and the spray tube system arrange agitating unit in the concentrated liquid of flue gas concentration tower side, and the concentrate is connected to the spray tube system through circulating water pump, the heat transfer that circulates in the flue gas concentration tower, the spray tube system jets into the flue gas concentration tower with the concentrate, forms the water column, and the rising process of water column and whereabouts process all contact with the flue gas.
2. The desulfurization waste water flue gas concentration, reduction and cementing fixing system according to claim 1, characterized in that: the flue gas concentration tower is connected to the concentrated water tank through a bottom concentrated water pump, the water outlet end of the concentrated water tank is provided with a mass flow control device, and the mass flow control device controls the quality of concentrated water entering the mixing stirrer according to a fixed ratio.
3. The desulfurization waste water flue gas concentration, reduction and cementing fixing system according to claim 1, characterized in that: the concentrated water tank is provided with a pH detection instrument and a slaked lime water dosing system, the pH detection instrument is used for detecting the pH value of the concentrated water, and when the pH value of the concentrated water is less than 4, slaked lime water is added to adjust the pH value of the concentrated water to 4.0-7.0.
4. The desulfurization waste water flue gas concentration, reduction and cementing fixing system according to claim 1, characterized in that: the curing room keeps constant temperature and humidity, the temperature is controlled to be 20 +/-3 ℃, and the relative humidity is controlled to be 60-80%.
5. A desulfurization waste water flue gas concentration, reduction and cementing fixing process which is applicable to any one of the desulfurization waste water flue gas concentration, reduction and cementing fixing systems of claims 1-4, and is characterized in that: the method comprises the following steps:
the method comprises the following steps: the clean flue gas dedusted by the electric precipitator enters a main flue through an induced draft fan, 85% -90% of the flue gas directly enters a desulfurizing tower, and after the wet flue gas desulfurization process, when the concentration of chloride ions in the slurry is accumulated to reach the maximum limit value, the desulfurized slurry needs to be quantitatively discharged, the desulfurized slurry is dehydrated by a conventional dehydration system to obtain gypsum and desulfurized wastewater, and the desulfurized wastewater is stored in a desulfurized wastewater storage tank;
step two: raw water in the desulfurization wastewater storage tank enters concentrated solution of the flue gas concentration tower through a water pump and a raw water inlet pipeline; 10-15% of flue gas in the main flue is extracted by a high-pressure fan and enters a first branch pipeline, the flue gas enters a flue gas concentration tower through the first branch pipeline, the flue gas exchanges heat with a liquid column of a concentrated solution, part of water in the desulfurization wastewater is evaporated into water vapor after the heat exchange, and the flue gas enters the main flue along with the heat exchange through a second branch pipeline on the top of the flue gas concentration tower and then enters the desulfurization tower;
step three: the concentrated solution in the flue gas concentration tower is conveyed to a spray pipe system through a circulating water pump, and is subjected to circulating heat exchange in the flue gas concentration tower, when the concentration reaches the designed concentration ratio, the concentration of chloride ions is 70000mg/L-100000mg/L, discharging into concentrated water tank by concentrated water pump, detecting pH of concentrated water by pH detector in concentrated water tank, if pH is less than 4, adding appropriate amount of slaked lime water to adjust pH to 4.0-7.0 by slaked lime water dosing system, after pH is normal, the mass flow control equipment at the outlet of the concentrated water tank quantitatively outputs concentrated water to the mixing stirrer according to the required water quantity in the mixing proportion of the solidified bodies, adding cementing materials such as cement, fly ash and the like into the mixing stirrer through a feeding machine, starting the mixing stirrer, all the raw materials are mixed and stirred, and the mass mixing ratio of a solidified body is as follows: fly ash: concentrating wastewater: river sand =5.5:1:3.5: 5.6;
step four: and transferring the slurry mixture formed after the mixing of the mixing stirrer into a forming device in time, transferring the solidified body into a curing room after the slurry is formed for 24 hours, and continuously curing at a certain temperature and humidity.
6. The desulfurization wastewater flue gas concentration reduction and cementing fixation process according to claim 5, characterized in that: and the concentration ratio of the desulfurization wastewater in the third step is controlled to be 5-10 times.
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| CN112551627B (en) * | 2020-11-26 | 2022-01-18 | 武汉天空蓝环保科技有限公司 | Desulfurization waste water enrichment facility and zero discharge system |
| CN113582281A (en) * | 2021-08-11 | 2021-11-02 | 成都市蜀科科技有限责任公司 | Energy-saving low-temperature flue gas concentration process and device for desulfurization wastewater |
| CN114702094B (en) * | 2021-12-22 | 2023-11-28 | 国电电力邯郸东郊热电有限责任公司 | Comprehensive treatment system for tail end wastewater and tail end wastewater of coal-fired power plant |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1238233A (en) * | 1998-06-05 | 1999-12-15 | 清华大学 | Process for integrating dust removal with desulfurization by water film and system thereof |
| CN1262236A (en) * | 1999-01-26 | 2000-08-09 | 三菱重工业株式会社 | Desulfurization waste water treating method |
| CN1286135A (en) * | 2000-08-18 | 2001-03-07 | 清华大学 | Liquid column spray process and system with pH value regulator for desulfurizing flue gas |
| CN107739119A (en) * | 2017-11-28 | 2018-02-27 | 华电郑州机械设计研究院有限公司 | - kind of cascade utilization power-plant flue gas waste heat realizes the device of desulfurization wastewater zero-emission |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2540379B1 (en) * | 2010-02-25 | 2019-10-09 | Mitsubishi Heavy Industries, Ltd. | Exhaust gas treatment system, and exhaust gas treatment method |
| CN102151475B (en) * | 2011-03-23 | 2013-11-13 | 北京国电龙源环保工程有限公司 | Two-tower ammonia method desulfurization device and method |
| CN103342521B (en) * | 2013-07-03 | 2014-11-19 | 河北省电力勘测设计研究院 | Concrete capable of resisting concentrated seawater and desulfurization flue gas corrosion |
| CN103521052B (en) * | 2013-09-18 | 2016-06-08 | 广东电网公司电力科学研究院 | A kind of desulfurization wastewater utilizing coal-burning power plant carries out the method and system of flue gas demercuration |
| CN105152254B (en) * | 2015-10-08 | 2018-03-13 | 中国电建集团河北省电力勘测设计研究院有限公司 | Coal fired power plant flue gas desulfurization waste water evaporating column processing system |
| CN105417604B (en) * | 2016-01-18 | 2018-11-20 | 重庆远达水务有限公司 | Utilize the method and device of fume afterheat processing desulfurization wastewater |
| CN105879542A (en) * | 2016-03-07 | 2016-08-24 | 上海龙净环保科技工程有限公司 | Power plant desulfurization wastewater bypass treatment system and method and flue gas treatment system and method |
| CN105692734A (en) * | 2016-03-30 | 2016-06-22 | 梁刚 | System and method for treating desulfurization wastewater concentrated solution |
| JP7005166B2 (en) * | 2016-04-29 | 2022-01-21 | ゼネラル エレクトリック テクノロジー ゲゼルシャフト ミット ベシュレンクテル ハフツング | Equipment and methods for evaporating wastewater and reducing acid gas emissions |
| CN106007144A (en) * | 2016-07-06 | 2016-10-12 | 杭州天创环境科技股份有限公司 | Wet desulphurization waste water zero-discharge treatment method |
| CN106167283B (en) * | 2016-08-17 | 2018-11-09 | 西安交通大学 | Desulphurization for Coal-fired Power Plant waste water flue spray evaporation zero discharge treatment device and method |
| CN106587239A (en) * | 2017-01-24 | 2017-04-26 | 山东神华山大能源环境有限公司 | Wastewater concentrating system and method utilizing flue gas waste heat and based on liquid column evaporation |
| CN106865667A (en) * | 2017-04-13 | 2017-06-20 | 盛发环保科技（厦门）有限公司 | A kind of desulfurization wastewater fume afterheat concentrates abatement system and its technique |
| CN107082523B (en) * | 2017-05-25 | 2023-08-08 | 国能龙源环保有限公司 | Wet desulfurization wastewater recycling treatment system and treatment method thereof |
| CN107697967A (en) * | 2017-10-11 | 2018-02-16 | 江苏中建材环保研究院有限公司 | A kind of Desulphurization for Coal-fired Power Plant wastewater zero discharge system and method |
| CN108006683A (en) * | 2017-12-28 | 2018-05-08 | 华电郑州机械设计研究院有限公司 | A kind of method and apparatus that desulfurization wastewater zero-emission is realized using full flue gas |
-
2018
- 2018-08-22 CN CN201810957696.5A patent/CN109110846B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1238233A (en) * | 1998-06-05 | 1999-12-15 | 清华大学 | Process for integrating dust removal with desulfurization by water film and system thereof |
| CN1262236A (en) * | 1999-01-26 | 2000-08-09 | 三菱重工业株式会社 | Desulfurization waste water treating method |
| CN1286135A (en) * | 2000-08-18 | 2001-03-07 | 清华大学 | Liquid column spray process and system with pH value regulator for desulfurizing flue gas |
| CN107739119A (en) * | 2017-11-28 | 2018-02-27 | 华电郑州机械设计研究院有限公司 | - kind of cascade utilization power-plant flue gas waste heat realizes the device of desulfurization wastewater zero-emission |
Non-Patent Citations (5)
| Title |
|---|
| Research on desulfurization wastewater evaporation: Present and future perspectives;Ma Shuangchen et al.;《Renewable and Sustainable Energy Reviews》;20151227;第1143-1151页 * |
| 旁路蒸发系统对燃煤电厂脱硫系统水平衡和氯平衡的影响;马双忱等;《动力工程学报》;20180415;第298-307页 * |
| 燃煤电厂高盐脱硫废水固化基础实验;马双忱等;《煤炭学报》;20190326;第2596-2602页 * |
| 高盐脱硫废水水泥化固定基础实验研究;马双忱等;《动力工程学报》;20190915;第740-746页 * |
| 高盐脱硫废水水泥化固定技术的研究现状与发展;马双忱等;《化工进展》;20190515;第4275-4283页 * |
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