CN218795101U - A system for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization - Google Patents

Abstract

The utility model provides a system for recycling blast furnace gas fine desulfurization or dechlorinated waste water to flue gas desulfurization. pool and flue gas desulfurization system; the wastewater pool of the blast furnace gas fine desulfurization system or the blast furnace gas spray alkali dechlorination system is connected to the inlet of the filter through a pipe, the outlet of the filter is connected to the inlet of the oxidation box through a pipe, and the outlet of the oxidation box is passed through The pipeline is connected with the inlet of the conditioning tank, and the outlet of the conditioning tank is connected with the feeding port of the flue gas desulfurization system through the pipeline. The utility model creatively recycles the difficult-to-handle blast furnace gas fine desulfurization wastewater and alkali spraying chlorine washing wastewater and uses it in flue gas desulfurization, and realizes the treatment of blast furnace gas fine desulfurization wastewater and alkali spraying chlorine washing wastewater by means of waste treatment At the same time of recycling and reuse, SO ₂ in the flue gas of the internal process facilities of iron and steel enterprises is removed to achieve ultra-low emissions; and finally zero discharge of wastewater is realized.

Description

A system for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization

technical field

The utility model relates to a system for recycling blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization, which belongs to the technical field of waste water treatment and reuse in the iron and steel industry and flue gas desulfurization.

Background technique

Acidic media such as HCl in blast furnace gas can significantly reduce the pH value of blast furnace gas condensate, which can be as low as 2-3 ^. Unfavorable factors for the safe operation of its ancillary equipment. In order to improve the service life of pipelines and equipment and prevent serious safety accidents caused by poisoning caused by gas leakage, alkali spray chlorine tower/deacidification tower will be installed after blast furnace gas dust removal. The system uses NaOH or Na ₂ CO ₃ lye circulation spray The gas is washed, and the discharged wastewater is alkaline, with a pH value generally greater than 9.

The main components of blast furnace gas are N ₂ , CO and CO ₂ , of which the content of CO ₂ is 18%-22%, and contains a small amount of sulfur element. After the gas is burned, the SO ₂ in the flue gas produced will exceed the standard. Sulfur in blast furnace gas can be divided into organic sulfur and inorganic sulfur according to its form. The organic sulfur is mainly carbonyl sulfide (COS) with a content of 40-180mg/Nm ³ ; the inorganic sulfur is mainly H ₂ S with a content of 30- 60 mg/Nm ³ . At present, the blast furnace gas fine desulfurization market is rapidly opening up, in which the catalytic hydrolysis-alkali elution desulfurization process hydrolyzes COS into H ₂ S, and then uses NaOH spraying to remove H ₂ S; usually, the pH value of the waste liquid is maintained between 10-11 .

The above gas dechlorination and desulfurization technologies all discharge waste water, and the pH value of the waste water is high, which belongs to alkaline waste water. Due to the high CO ₂ content in the gas, NaOH absorbs CO ₂ and generates Na ₂ CO ₃ . The components of dechlorination wastewater are NaOH or NaHCO ₃ , Na ₂ CO ₃ and NaCl, etc.; the components of gas desulfurization wastewater are NaOH or NaHCO ₃ , NaHS, Na ₂ CO ₃ and NaCl, etc.

SO ₂ in the flue gas of multiple processes in iron and steel enterprises all exceeds the standard, such as sintering, pelletizing, coking, hot blast stove, heating furnace, self-provided power plant boiler, etc. Due to the improvement of environmental protection standards, the current hot blast stove, heating furnace and other processes are If the gas volume is not large, the SO ₂ concentration is not high, and the flue gas desulfurization facilities have not been installed, desulfurization is required.

Prior art one related to the utility model:

The technical scheme of prior art one:

Chinese patent CN204816202U discloses a spray tower hot blast stove flue gas desulfurization and denitrification device, which is a device that uses ammonia as a potion and completes the ceramic spray tower hot blast stove flue gas desulfurization and denitrification device in the spray tower.

The shortcoming of prior art one:

The spray tower hot blast furnace flue gas desulfurization and denitrification device disclosed in the first prior art is suitable for the desulfurization of the spray tower hot blast stove in the ceramic industry. Using ammonia water as a desulfurization agent has the risk of explosion and poisoning, and it is easy to cause ammonia escape to exceed the standard; and ammonia water is used as a desulfurization agent. agents, higher operating costs.

Related prior art two of the utility model:

The technical scheme of prior art 2:

Chinese patent CN215233228U discloses a hot blast stove flue gas automatic desulfurization device, which is a hot blast stove dry flue gas desulfurization device. The desulfurizer dry powder is sprayed into the desulfurizer, and a bag filter is arranged behind the desulfurizer, and the desulfurizer passes through The desulfurizer bin enters the grinding system for grinding, and then weighs and feeds.

The shortcoming of prior art two:

In prior art 2, the desulfurizer dry powder is ground and sprayed into a desulfurizer for desulfurization. The utilization rate of dry desulfurization and desulfurization agent is not high, resulting in impure desulfurization by-products and affecting the effective utilization of by-products; in order to ensure the desulfurization effect, it is necessary to use a desulfurization agent with high activity, which is costly; and it is also necessary to configure a bag filter, the system The resistance loss is greatly increased, which increases power consumption and operating costs.

The prior art three related to the utility model:

The technical scheme of prior art three:

Chinese patent CN211936312U discloses a blast furnace hot blast stove exhaust gas desulfurization and denitrification system, which uses a dry desulfurization tower and a dust removal and denitrification integrated reactor. The desulfurizer is ground and sprayed into the venturi tube. The system is equipped with a bag filter and a denitration catalyst.

Shortcoming of prior art three:

In prior art 3, the venturi tube is used in the desulfurization tower, and the resistance loss is large; at the same time, the bag filter is configured, and the system resistance loss is greatly increased, thereby further increasing power consumption and operating costs. The combination of the dust collector and the denitrification reactor, in order to replace the bag, the clear height of the reactor is very large, which significantly increases the investment cost.

Therefore, it has become an urgent technical problem in this field to provide a new type of system and process for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization.

Utility model content

In order to solve the above-mentioned shortcomings and deficiencies, the purpose of this utility model is to provide a system for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization. The utility model can realize the recycling and reuse of the waste water of the fine desulfurization of the blast furnace gas and the waste water of alkali spraying and chlorine washing, and can be used for the desulfurization of the flue gas, and realize zero discharge of the waste water while treating the waste with the waste.

In order to achieve the above objectives, the utility model provides a system for recycling blast furnace gas fine desulfurization or dechlorinated wastewater to flue gas desulfurization, wherein the system includes: blast furnace gas fine desulfurization system or blast furnace gas alkali spraying dechlorination system, Filters, oxidation tanks, conditioning tanks and flue gas desulfurization systems;

The wastewater pool of the blast furnace gas fine desulfurization system or the blast furnace gas spray alkali dechlorination system is connected to the inlet of the filter through a pipeline, and the outlet of the filter is connected to the inlet of the oxidation box through a pipeline, and the oxidation box The outlet of the conditioning tank is connected to the inlet of the conditioning tank through a pipeline, and the outlet of the conditioning tank is connected to the feed port of the flue gas desulfurization system through a pipeline.

As a specific embodiment of the system described above in the present invention, the flue gas desulfurization system includes a wet desulfurization tower, a semi-dry desulfurization tower or a semi-dry desulfurization flue reactor.

As a specific embodiment of the above-mentioned system of the utility model, wherein, when the flue gas desulfurization system is a wet desulfurization tower, the system includes a water flushing slag system, and the liquid outlet of the wet desulfurization tower passes through The pipeline is connected with the water flushing slag system through a liquid drainage pump.

As a specific embodiment of the system described above in the present invention, the water slag flushing system is a blast furnace ironmaking water slag flushing system or a steelmaking water slag flushing system.

As a specific embodiment of the system described above in the present invention, nozzles, spray guns or desulfurization liquid atomization devices are installed in the semi-dry desulfurization tower or the semi-dry desulfurization flue reactor.

As a specific embodiment of the system described above in the present utility model, wherein, the top of the oxidation box is provided with a top agitator or a side agitator; the top dosing port of the oxidation box is connected to the dosing system through a dosing pipeline, and /or an oxidation air pipeline is arranged at the bottom, and the oxidation air pipeline is connected to the oxidation air system;

The upper part of the box body of the oxidation box is provided with an inlet and the lower part of the box body is provided with an outlet, and a liquid level gauge is arranged on the box body.

As a specific implementation of the above-mentioned system of the utility model, wherein, the top of the conditioning tank is provided with a top mixer, and its conditioning water inlet is connected with the conditioning water system through a pipeline, and the upper part of the conditioning tank is Set the inlet and the outlet at the lower part of the pool body, and set the pH meter in the pool body.

As a specific implementation of the above-mentioned system of the utility model, wherein, the outlet of the filter is connected to the inlet of the oxidation tank through a pipeline through a waste water pump; the outlet of the conditioning tank is connected to the inlet through a pipeline through a feeding pump It is connected to the feeding port of the above-mentioned flue gas desulfurization system.

As a specific embodiment of the system described above in the present invention, the wet desulfurization tower can be a conventional wet desulfurization tower used in the field. As in some embodiments of the present utility model, the tower of the wet desulfurization tower is provided with multi-layer spray layers, and the multi-layer spray layers respectively pass through the pipeline and the slurry of the wet desulfurization tower through the circulating pump. The pools are connected; the upper part of the wet desulfurization tower is provided with a demister, the middle and lower part is provided with a raw flue gas inlet, the top of the tower is provided with a net flue gas outlet, and the bottom of the tower is provided with a liquid outlet.

As a specific embodiment of the system described above in the present invention, a wet electrostatic precipitator may also be installed on the upper part of the wet desulfurization tower.

As a specific embodiment of the above-mentioned system of the present invention, wherein, the oxidation tank is a metal tank or a pool with a concrete structure; the tempering pool is a pool with a concrete structure.

The system for recycling blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization described in the utility model can be applied to a variety of different processes to return blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization, in order to further improve the utility model A new system for reusing blast furnace gas fine desulfurization or dechlorination waste water for flue gas desulfurization will be described. A process for recycling coal gas fine desulfurization or dechlorinated waste water to flue gas desulfurization, said process comprising the following steps:

(1) Use a filter to filter and remove slag from the wastewater discharged from the blast furnace gas fine desulfurization system or the blast furnace gas spray alkali dechlorination system to avoid wear or blockage of subsequent pipelines and equipment;

(2) Transporting the filtered waste water obtained in step (1) to an oxidation tank, in which the HS ^- and S ^{2 -} in the waste water are oxidized into SO ₄ ^2- ;

(3) The oxidized wastewater in step (2) flows into the conditioning tank by itself, and is mixed and tempered with the conditioning water in the conditioning tank to adjust the pH value or alkalinity to the required parameters of the flue gas desulfurization system;

(4) Transporting the wastewater conditioned and tempered in step (3) as a desulfurizer to a flue gas desulfurization system, where it contacts flue gas to realize flue gas desulfurization.

As a specific implementation of the process described above in the present utility model, wherein, in step (2), the oxidation includes: adding an oxidant to the oxidation tank through a dosing system, and/or adding an oxidant to the oxidation tank through an oxidation wind system. Oxidation wind is transported in the oxidation tank, and the HS ^- and S ^{2 -} in the waste water in the oxidation tank are oxidized to SO ₄ ^2- after contacting with the oxidant and/or the oxidation wind;

Wherein, the oxidizing agent includes one or a combination of strong oxidizing agents such as ozone, chlorine gas, sodium hypochlorite, permanganate and hydrogen peroxide;

Oxidizing air includes ambient air or factory compressed air.

As a specific embodiment of the process described above in the present invention, wherein, in step (2), ambient air is blown into the oxidation box by a fan.

Wherein, in step (2), the oxidation in the oxidation box can be realized by blowing oxidizing air into the oxidation box through the oxidation air system, or can be realized by adding a strong oxidant to the oxidation box through the dosing system, or Simultaneously, so as to prevent the HS- and ^S2- in the wastewater from being brought into the subsequent flue gas desulfurization system, and then gasified again and discharged into the atmosphere when entering the water flushing slag system.

As a specific embodiment of the process described above in the present utility model, wherein, in step (3), the tempered water includes alkaline blowdown wastewater and/or new water, wherein the alkaline blowdown wastewater includes ammonia zone wastewater , boiler blowdown water, boiler slag flushing water, blast furnace ironmaking slag flushing water, steelmaking slag flushing water, etc. or a combination of several.

Wherein, in step (3), the conditioning process is to supplement low-grade alkaline sewage wastewater or new water to the wastewater discharged from the blast furnace gas fine desulfurization system or the blast furnace gas spray alkali dechlorination system, and adjust the pH value or alkalinity , to achieve a homogeneous and stable supply of desulfurization agents, to avoid large fluctuations in the water balance in the flue gas desulfurization system, to achieve continuous and stable treatment of the flue gas desulfurization system, and to realize the rational use and disposal of low-quality alkaline sewage.

As a specific embodiment of the process described above in the present utility model, wherein, in step (4), the flue gas can be various types of low SO in iron and steel enterprises _{Concentration} or flue gas of small flue gas volume, including ironmaking blast furnace Flue gas from hot blast furnace, flue gas from coal-injection pulverizing heating furnace, flue gas from steel rolling heating furnace or annealing furnace, lime kiln flue gas, boiler flue gas (such as self-provided power plant boiler flue gas), and even sintered balls with high _SO2 concentration Puff of smoke etc.

As a specific embodiment of the process described above in the present utility model, wherein, in step (4), when the flue gas desulfurization reactor system adopts wet desulfurization, the process includes: The waste water used as desulfurization agent is lifted twice through the feed pump, pumped into the wet desulfurization tower, and the desulfurizer is lifted from the bottom of the tower to the multi-layer spray layer by the circulation pump for spraying, and mixed with the flue gas (temperature) entering the wet desulfurization tower It can be under 180°C) for countercurrent contact to achieve flue gas desulfurization, and the desulfurized flue gas is dehydrated by the demister and then discharged.

As a specific embodiment of the process described above in this utility model, wherein, in step (4), when the flue gas desulfurization reactor system adopts a wet desulfurization tower, the process also includes: when the desulfurizer fails, It is discharged to the water slag flushing system through the drainage pump for flushing slag, so as to realize zero discharge of waste water. Among them, the wet desulfurization is forced circulation desulfurization of slurry.

As a specific implementation of the process described above in the utility model, wherein, in step (4), when the flue gas desulfurization reactor system is a semi-dry desulfurization tower or a semi-dry desulfurization flue reactor, at this time The flue gas desulfurization reactor system does not have a circulating pump, and the process includes:

The conditioned wastewater in step (3) is used as a desulfurizer to be lifted twice by the feeding pump, and directly pumped into the semi-dry desulfurization tower or semi-dry desulfurization flue reactor, and sprayed through nozzles, spray guns or desulfurization liquid atomization devices. After desulfurization, the desulfurizer quickly absorbs _SO2 in the high-temperature flue gas (such as the temperature is 75-180°C) to achieve desulfurization, and at the same time the droplets evaporate, and the net flue gas after desulfurization is dry flue gas. At this time, the system also has no waste water discharge, and also realizes zero discharge of waste water and ultra-low discharge of flue gas.

As a specific embodiment of the process described above in the present utility model, wherein, in step (4), when the flue gas desulfurization system adopts a semi-dry desulfurization method, the process also includes: directly desulfurizing the flue gas after desulfurization of the waste water The system evaporates, and also realizes zero discharge of waste water, and adopts a dust removal system to collect dust.

Compared with the prior art, the beneficial technical effects that the utility model can achieve include:

The utility model creatively recycles the difficult-to-handle blast furnace gas fine desulfurization wastewater and alkali spray chlorine washing wastewater and uses them for flue gas desulfurization. Since the blast furnace gas fine desulfurization wastewater and alkali spray chlorine washing wastewater have strong alkalinity, direct discharge will cause Causes environmental pollution, and NaOH, NaHCO ₃ , Na ₂ CO ₃ contained in it are all effective components of desulfurization agent for deSO ₂ , so wastewater treatment and flue gas desulfurization are organically combined to realize blast furnace gas desulfurization through waste treatment. While fine desulfurization wastewater and alkali spraying chlorine washing wastewater are treated and reused, SO ₂ in the flue gas of the internal process facilities of iron and steel enterprises is removed, which completely solves the current ineffective utilization of blast furnace gas fine desulfurization wastewater and alkali spraying chlorine washing wastewater Ways to increase the load of sewage treatment in the factory area, and at the same time complete the purification of flue gas in iron and steel enterprises, meet the requirements of zero discharge of waste water and ultra-low discharge of waste gas, and make full use of unreacted effective desulfurizer components in waste water, save desulfurizers, and The desulfurization agent preparation system and the by-product and waste water treatment system can be omitted, thereby saving investment and significantly reducing the operating cost of the traditional flue gas desulfurization system.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are the For some embodiments of the present invention, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural diagram of a blast furnace gas fine desulfurization or dechlorination waste water reuse system for flue gas desulfurization provided by an embodiment of the utility model.

Explanation of main figures and symbols:

1. Blast furnace gas spray alkali dechlorination system or blast furnace gas fine desulfurization system;

2. Filter;

3. Waste water pump;

4. Oxidation box;

5. Stirrer;

6. Dosing system;

7. Oxidation wind system;

8. Conditioning pool;

9. Top mixer;

10. Conditioning water system;

11. Feeding pump;

12. Flue gas desulfurization system;

13. Circulation pump;

14. Drainage pump;

15. Water flushing slag system.

Detailed ways

It should be noted that the terms "comprising" and any variations thereof in the specification and claims of the present utility model and the above drawings are intended to cover non-exclusive inclusion, for example, processes and methods that include a series of steps or units A process, system, product or device is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to the process, method/process, product or device.

In the present invention, the orientations or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "middle", "top" and "bottom" are based on the orientations or positional relationships shown in the drawings. Positional relationship. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

Moreover, some of the above terms may be used to indicate other meanings besides orientation or positional relationship, for example, the term "upper" may also be used to indicate a certain attachment relationship or connection relationship in some cases. Those of ordinary skill in the art can understand the specific meanings of these terms in the present invention according to specific situations.

Furthermore, the terms "setting", "connecting" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediary, or two devices, components or Internal connectivity between components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

The "range" disclosed in the present application is given in the form of lower limit and upper limit. There can be one or more lower bounds, and one or more upper bounds, respectively. A given range is defined by selecting a lower limit and an upper limit. Selected lower and upper limits define the boundaries of a particular range. All ranges defined in this manner are combinable, ie, any lower limit can be combined with any upper limit to form a range. For example, ranges of 60-120 and 80-110 are listed for a particular parameter, with the understanding that ranges of 60-110 and 80-120 are also contemplated. Additionally, if the minimum range values listed are 1 and 2, and the maximum range values listed are 3, 4, and 5, the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.

In the present invention, unless otherwise stated, the numerical range "a-b" represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" indicates that all the real numbers between "0-5" have been listed in the present invention, and "0-5" is only an abbreviated representation of these numerical combinations.

In the utility model, if there is no special description, all the implementation modes and preferred implementation modes mentioned in the utility model can be combined with each other to form a new technical solution.

In the utility model, if there is no special description, all the technical features and preferred features mentioned in the utility model can be combined with each other to form a new technical solution.

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described below are some embodiments of the present utility model, rather than all embodiments, and are only used to illustrate the present utility model, and should not be regarded as limiting the scope of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

Example 1

In order to prevent Cl ^- corrosion, a blast furnace gas spraying alkali dechlorination system is installed after the TRT system of a blast furnace; at the same time, the _SO2 of the hot blast stove system of the blast furnace exceeds the standard, and a flue gas desulfurization system, that is, a desulfurization reactor is required; therefore, this embodiment provides A kind of blast furnace gas dechlorination waste water is reused in the system of flue gas desulfurization, and its structure diagram is as shown in Figure 1, as can be seen from Figure 1, described system comprises: blast furnace gas spray alkali dechlorination system 1, filter 2. Oxidation box 4, conditioning tank 8, flue gas desulfurization system 12 and water slag flushing system 15;

Wherein, the agitator 5 is arranged on the top of the oxidation box 4, and the oxidation air pipeline is arranged at the bottom, and the oxidation air pipeline is connected with the oxidation air system 7, and the upper part of the oxidation box 4 is provided with an inlet and the lower part of the box is provided with At the outlet, a liquid level gauge is installed on the tank;

The top of the tempering pool 8 is provided with a top mixer 9, and its tempering water inlet is connected to the tempering water system 10 through a pipeline. pH meter, and the conditioning water system 10 adopts wastewater from the ammonia zone;

The flue gas desulfurization system 12 is a wet desulfurization tower, the tower of the wet desulfurization tower is provided with multi-layer spray layers, and the multi-layer spray layers pass through pipelines and circulate pumps 13 to communicate with the wet desulfurization towers respectively. The slurry tanks of the towers are connected; the upper part of the wet desulfurization tower is provided with a demister, the middle and lower part is provided with a raw flue gas inlet, the top of the tower is provided with a net flue gas outlet, and the bottom of the tower is provided with a liquid outlet;

The water slag flushing system 15 is a blast furnace ironmaking water slag flushing system;

The wastewater pool of the blast furnace gas spray alkali dechlorination system 1 is connected to the inlet of the filter 2 through a pipeline, and the outlet of the filter 2 is connected to the inlet of the oxidation tank 4 through a wastewater pump 3 through a pipeline. The outlet of the oxidation tank 4 is connected to the inlet of the conditioning tank 8 through a pipeline, and the outlet of the conditioning tank 8 is connected to the feeding port of the flue gas desulfurization system 12 through a pipeline through a feeding pump 11;

The liquid outlet of the wet desulfurization tower is connected to the water flushing slag system 15 through a pipe through a liquid discharge pump 14 .

In order to more clearly illustrate the system that the blast furnace gas dechlorination wastewater provided in Example 1 of the present invention is reused for flue gas desulfurization, the system for utilizing the blast furnace gas dechlorination wastewater for flue gas desulfurization is now introduced in detail. The dechlorination wastewater is reused in the process of flue gas desulfurization, wherein the process specifically includes the following steps:

(1) Utilize the filter to filter and remove the slag from the waste water (pH value is 9-10) discharged from the blast furnace gas spray alkali dechlorination system;

(2) The primary lifting pump, that is, the waste water pump pumps the waste water obtained after filtering and removing slag in step (1) to the oxidation tank, and in the oxidation tank, a small amount of HS ^- and S ^{2 -} in the waste water are blown by the oxidation wind system The incoming oxidizing air is oxidized to SO ₄ ^2- ;

(3) The oxidized wastewater in step (2) enters the conditioning tank by itself, that is, the effective desulfurizer components NaHCO ₃ and Na ₂ CO ₃ in the wastewater enter the conditioning tank by gravity, and in the conditioning tank, the wastewater and Ammonia zone wastewater mixed conditioning;

(4) Use the waste water after conditioning in step (3) as the desulfurizing agent for flue gas desulfurization, and send it to the wet desulfurization tower through the secondary lifting of the feeding pump. The wet desulfurization tower is equipped with a multi-stage desulfurizing agent circulation pump; The pump _pumps the desulfurizer from the slurry tank at the bottom of the tower to the spray layer inside the tower, and the spray liquid is in countercurrent contact with the flue gas sent into the wet desulfurization tower by the nearby hot blast stove. At the same time, the exhausted/absorbed saturated desulfurizer is discharged to the blast furnace ironmaking water slag flushing system for slag flushing, so as to achieve zero discharge of wastewater.

In this embodiment, according to the grade of the desulfurizer and the concentration of SO in the flue gas of _the hot blast stove, the number of multi-stage desulfurizer circulation pumps can be matched and adjusted in _real time to realize the dynamic control of SO removal, which has good adaptability; The high-efficiency mist eliminator installed in the wet desulfurization tower can remove the free mist droplets in the flue gas and also has the function of dust removal.

Example 2

An iron and steel enterprise is equipped with a blast furnace gas fine desulfurization system, which adopts the catalytic hydrolysis-alkali washing desulfurization process, and the pH value of the wastewater discharged from the system is between 10-12. Therefore, this embodiment provides a blast furnace gas fine desulfurization wastewater reuse The system for flue gas desulfurization is shown in Figure 1. It can be seen from Figure 1 that the system includes: blast furnace gas fine desulfurization system 1, filter 2, oxidation box 4, conditioning tank 8, flue gas Gas desulfurization system 12 and water slag flushing system 15;

Wherein, the top of the oxidation box 4 is provided with a stirrer 5, the top dosing port is connected with the dosing system 6 through the dosing pipeline, and the oxidation air pipeline is arranged at the bottom, and the oxidation air pipeline is connected with the oxidation air system 7, so The upper part of the box body of the oxidation box 4 is provided with an inlet and the lower part of the box body is provided with an outlet, and a liquid level gauge is arranged on the box body;

The top of the tempering pool 8 is provided with a top mixer 9, and its tempering water inlet is connected to the tempering water system 10 through a pipeline. pH meter, and the tempered water system 10 adopts boiler blowdown water and boiler slag flushing waste water;

The flue gas desulfurization system 12 is a wet desulfurization tower, the tower of the wet desulfurization tower is provided with multi-layer spray layers, and the multi-layer spray layers pass through pipelines and circulate pumps 13 to communicate with the wet desulfurization towers respectively. The slurry tanks of the towers are connected; the upper part of the wet desulfurization tower is provided with a mist eliminator and a wet electrostatic precipitator, the middle and lower part is provided with a raw flue gas inlet, the top of the tower is provided with a clean flue gas outlet, and the bottom of the tower is provided with a liquid outlet;

The water slag flushing system 15 is a blast furnace ironmaking water slag flushing system;

The wastewater pool of the blast furnace gas fine desulfurization system 1 is connected to the inlet of the filter 2 through a pipeline, and the outlet of the filter 2 is connected to the inlet of the oxidation tank 4 through a pipeline through a waste water pump 3, and the oxidation tank The outlet of 4 is connected to the inlet of the conditioning tank 8 through a pipeline, and the outlet of the conditioning tank 8 is connected to the feeding port of the flue gas desulfurization system 12 through a pipeline through a feeding pump 11;

The liquid outlet of the wet desulfurization tower is connected to the water flushing slag system 15 through a pipe through a liquid discharge pump 14 .

In order to more clearly illustrate the system for recycling blast furnace gas dechlorination wastewater to flue gas desulfurization provided by Embodiment 2 of the utility model, the system for blast furnace gas dechlorination wastewater recycling for flue gas desulfurization is introduced in detail. The dechlorination wastewater is reused in the process of flue gas desulfurization, wherein the process specifically includes the following steps:

(1) filter and remove slag from waste water (pH value is 10-12) discharged from blast furnace gas fine desulfurization system by filter;

(2) The waste water obtained after filtering and removing slag in step (1) is pumped to the oxidation tank by the primary lifting pump, that is, the waste water pump, and in the oxidation tank, a small amount of HS ^- and S ^{2 -} in the waste water are oxidized by the wind system The oxidizing air blown by the Roots blower, that is, the ambient air and the strong oxidant sodium hypochlorite added by the dosing system are oxidized to SO ₄ ^2- ;

(3) The oxidized wastewater in step (2) enters the conditioning pool by itself, that is, the effective desulfurizer components NaOH and Na ₂ CO ₃ in the wastewater enter the conditioning pool along with the wastewater, and in the conditioning pool, the wastewater and the boiler Mixing and tempering of sewage and boiler slag flushing wastewater;

(4) Use the waste water after conditioning in step (3) as the desulfurizing agent for flue gas desulfurization, and send it to the wet desulfurization tower through the secondary lifting of the feeding pump. The wet desulfurization tower is equipped with a multi-stage desulfurizing agent circulation pump; The pump pumps the desulfurizing agent from the slurry tank at the bottom of the tower to the spray layer inside the tower, and the spray liquid is in countercurrent contact with the flue gas sent into the wet desulfurization tower by the heating furnace of the nearby coal injection pulverizing system, and the desulfurizing agent absorbs the flue gas SO ₂ , to achieve ultra-low emission of flue gas; at the same time, the exhausted/absorbed desulfurizer is discharged to the blast furnace ironmaking water slag flushing system by the liquid discharge pump for slag flushing, so as to realize zero discharge of waste water.

In this embodiment, according to the grade of the desulfurizer and the concentration of _SO2 in the flue gas, the number of multi-stage desulfurizer circulation pumps can be matched and adjusted in real time to realize the dynamic control of _SO2 removal, which has good adaptability; The high-efficiency mist eliminator and wet electrostatic precipitator installed in the desulfurization tower can not only remove free mist droplets in the flue gas, but also have the function of dust removal.

Example 3

An iron and steel enterprise is equipped with a blast furnace gas fine desulfurization system, which adopts the catalytic hydrolysis-alkali washing desulfurization process, and the pH value of the wastewater discharged from the system is between 10-12. Therefore, this embodiment provides a blast furnace gas fine desulfurization wastewater reuse For flue gas desulfurization system, said system includes: blast furnace gas fine desulfurization system, filter, oxidation box, conditioning tank and flue gas desulfurization system;

Wherein, the top of the oxidation tank is equipped with a stirrer, the top dosing port is connected with the dosing system through the dosing pipeline, and the oxidation air pipeline is arranged at the bottom, and the oxidation air pipeline is connected with the oxidation wind system. The upper part of the tank is equipped with an inlet and the lower part of the tank is equipped with an outlet, and a liquid level gauge is set on the tank;

The top of the conditioning pool is equipped with a top mixer, and its conditioning water inlet is connected to the conditioning water system through a pipeline. The upper part of the pool body of the conditioning pool is provided with an inlet and the lower part of the pool body is provided with an outlet, and a pH meter is provided in the pool body, and The tempering water system adopts industrial water, blast furnace ironmaking slag washing water or steelmaking slag washing water;

The flue gas desulfurization system is a semi-dry desulfurization tower, and the semi-dry desulfurization tower is equipped with multiple dual-fluid spray guns;

The wastewater tank of the blast furnace gas fine desulfurization system is connected to the inlet of the filter through a pipeline, the outlet of the filter is connected to the inlet of the oxidation tank through a wastewater pump through a pipeline, and the outlet of the oxidation tank is connected to the inlet of the oxidation tank through a pipeline. The inlet of the conditioning tank is connected, and the outlet of the conditioning tank is connected to the feeding port of the flue gas desulfurization system through a pipeline through a feeding pump.

In order to more clearly illustrate the system that the blast furnace gas dechlorination wastewater provided in Example 3 of the present invention is reused for flue gas desulfurization, the system for utilizing the blast furnace gas dechlorination wastewater for flue gas desulfurization is now introduced in detail. The dechlorination wastewater is reused in the process of flue gas desulfurization, wherein the process specifically includes the following steps:

(1) filter and remove slag from waste water (pH value is 10-12) discharged from blast furnace gas fine desulfurization system by filter;

(2) The waste water obtained after filtering and removing slag in step (1) is pumped by the primary lifting pump, that is, the waste water pump, into the oxidation tank, and in the oxidation tank, the HS ^- and S ^{2 -} in the waste water are input by the oxidation wind system Ozone is oxidized into SO ₄ ^2- by the compressed air in the factory area and the strong oxidizing agent added by the dosing system;

(3) The oxidized wastewater in step (2) enters the conditioning pool by itself, that is, the effective desulfurizer components NaOH and Na ₂ CO ₃ in the wastewater enter the conditioning pool by gravity, and in the conditioning pool, the wastewater and industrial Water, blast furnace ironmaking slag washing water or steelmaking slag washing water are mixed and tempered;

(4) The waste water after conditioning in step (3) is used as the desulfurizing agent for flue gas desulfurization, and is directly sent to the semi-dry desulfurization tower through the second lift of the feeding pump. After being atomized by multiple two-fluid spray guns, the desulfurizing agent Rapidly absorb _SO2 in the flue gas to achieve desulfurization, and at the same time the droplets evaporate, and the net flue gas after desulfurization is dry flue gas. At this time, there is no waste water discharge in the system, and the system also realizes zero discharge of waste water and ultra-low discharge of flue gas.

In summary, the embodiment of the utility model creatively recycles the difficult-to-treat waste water of blast furnace gas fine desulfurization and alkali spraying and chlorine washing wastewater for flue gas desulfurization. Strong, direct discharge will cause environmental pollution, and NaOH, NaHCO ₃ , Na ₂ CO ₃ contained in it are all effective desulfurization agent components for SO ₂ , so the organic combination of wastewater treatment and flue gas desulfurization, through waste treatment way, realize the treatment and reuse of wastewater from blast furnace gas fine desulfurization and alkali spraying chlorine washing, and at the same time remove SO ₂ in the flue gas of the internal process facilities of iron and steel enterprises, and completely solve the current wastewater from blast furnace gas fine desulfurization and alkali spraying washing Chlorine wastewater has no effective utilization method, which increases the load of sewage treatment in the factory area. At the same time, it completes the purification of flue gas in iron and steel enterprises, meets the requirements of zero discharge of waste water and ultra-low discharge of waste gas, and makes full use of unreacted effective desulfurizer components in waste water, saving The desulfurization agent is used, and the desulfurization agent preparation system and by-product and wastewater treatment system can be omitted, which can save investment and significantly reduce the operating cost of the traditional flue gas desulfurization system.

The above is only a specific embodiment of the utility model, and it cannot limit the scope of utility model implementation, so the replacement of its equivalent components, or the equivalent changes and modifications made according to the patent protection scope of the utility model should still belong to areas covered by this patent.

Claims (10)

1. A system for reusing blast furnace gas fine desulfurization or dechlorinated waste water for flue gas desulfurization, characterized in that the system includes: blast furnace gas fine desulfurization system or blast furnace gas alkali spray dechlorination system, filter, oxidation box, Conditioning pool and flue gas desulfurization system; The wastewater pool of the blast furnace gas fine desulfurization system or the blast furnace gas spray alkali dechlorination system is connected to the inlet of the filter through a pipeline, and the outlet of the filter is connected to the inlet of the oxidation box through a pipeline, and the oxidation box The outlet of the conditioning tank is connected to the inlet of the conditioning tank through a pipeline, and the outlet of the conditioning tank is connected to the feed port of the flue gas desulfurization system through a pipeline. 2. The system for recycling blast furnace gas fine desulfurization or dechlorinated waste water to flue gas desulfurization according to claim 1, wherein the flue gas desulfurization system includes a wet desulfurization tower, a semi-dry desulfurization tower or a semi-dry desulfurization tower. desulfurization flue reactor. 3. The system for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization according to claim 1 or 2, characterized in that, when the flue gas desulfurization system is a wet desulfurization tower, the system includes A water flushing slag system, the liquid outlet of the wet desulfurization tower is connected to the water flushing slag system through a pipeline through a liquid drainage pump. 4. The system for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization according to claim 3, characterized in that the water slag flushing system is a blast furnace ironmaking water flushing slag system or a steelmaking water flushing slag system system. 5. The system for reusing blast furnace gas fine desulfurization or dechlorination waste water for flue gas desulfurization according to claim 2, characterized in that, the semi-dry desulfurization tower or the semi-dry desulfurization flue reactor is provided with nozzles, spray guns or Desulfurization liquid atomization device. 6. The system for recycling blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization according to claim 1 or 2, characterized in that a top agitator or a side agitator is arranged on the top of the oxidation tank; The dosing port on the top of the oxidation box is connected to the dosing system through the dosing pipeline, and/or the oxidation air pipeline is arranged at the bottom, and the oxidation air pipeline is connected to the oxidation air system; The upper part of the box body of the oxidation box is provided with an inlet and the lower part of the box body is provided with an outlet, and a liquid level gauge is arranged on the box body. 7. The system for recycling blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization according to claim 1 or 2, characterized in that, the top of the conditioning tank is equipped with a top mixer, and the conditioning water inlet passes through the pipeline Connected with the tempering water system, the upper part of the tempering pool is provided with an inlet and the lower part of the pool is provided with an outlet, and a pH meter is provided in the pool. 8. The system for recycling blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization according to claim 1 or 2, characterized in that the outlet of the filter is connected to the inlet of the oxidation tank through a pipeline through a waste water pump connected; the outlet of the conditioning tank is connected to the feed port of the flue gas desulfurization system through a pipe through a feed pump. 9. The system for recycling blast furnace gas fine desulfurization or dechlorination waste water to flue gas desulfurization according to claim 2, characterized in that, the wet desulfurization tower is provided with a multi-layer spray layer, and the multi-layer The spray layer is respectively connected to the slurry pool of the wet desulfurization tower through pipelines and circulating pumps; the upper part of the wet desulfurization tower is provided with a demister, the middle and lower part is provided with a raw flue gas inlet, and the top of the tower is provided with a clean flue gas outlet , the bottom of the tower is provided with a drain port. 10. The system for recycling blast furnace gas fine desulfurization or dechlorination wastewater to flue gas desulfurization according to claim 1 or 2, characterized in that, the oxidation tank is a pool of metal tank or concrete structure; The pool is a pool of concrete structure.

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