Flue gas SNCR denitration system for rotary kiln

Abstract

The utility model provides a flue gas SNCR denitration system for a rotary kiln. The flue gas SNCR denitration system comprises a liquid preparation unit, a liquid storage tank, a spraying unit and a gas compressor, wherein the liquid preparation unit, the liquid storage tank and the spraying unit are sequentially communicated through a first pipeline; the gas compressor is communicated with the first pipeline between the liquid storage tank and the spraying unit through a second pipeline; the liquid preparation unit is used for preparing a denitration solution; the liquid storage tank is used for storing a denitration solution; the gas compressor is used for compressing the denitration solution flowing out of the liquid storage tank into mist through compressed gas obtained after compression of the gas compressor; and the spraying unit is used for spraying the atomized denitration solution into the decomposing furnace between the preheater and the rotary kiln so as to realize SNCR denitration treatment on the flue gas in the decomposing furnace. According to the flue gas denitration device, the atomized denitration solution and nitric oxide in the flue gas react more sufficiently, so that the flue gas denitration efficiency is improved, the situation that the mist outlet of the spraying unit is damaged due to direct contact with the high-temperature flue gas is avoided, and the service life of the spraying unit is prolonged.

Description

Technical Field

[0001] The present application relates to the field of denitrification technology, and in particular to a flue gas SNCR denitrification system for a rotary kiln. Background Art

[0002] A rotary kiln refers to a rotary calcining kiln (commonly known as a rotary kiln), which belongs to the category of building materials equipment. It is mainly used for magnetization roasting of lean iron ore in steel plants in the metallurgical industry; silicon thermal method for magnesium smelting; oxidation roasting of chromium and nickel iron ores; and refractory plants (i.e. active lime kilns) for roasting active lime and dolomite for use in steel plants and ferroalloy plants. Among them, taking the calcination of dolomite in a rotary kiln as an example, specifically, after the fuel enters the rotary kiln and is fully burned, the heat energy generated by it is effectively transferred to the dolomite entering the rotary kiln, and the dolomite undergoes a series of physical and chemical changes after receiving the heat, and finally forms the finished clinker.

[0003] The dolomite in the rotary kiln enters the rotary kiln through the discharge port of the preheater and the decomposition furnace, and the flue gas in the rotary kiln is discharged through the kiln tail smoke chamber, decomposition furnace, preheater, waste heat boiler, raw material mill, kiln tail dust collector and kiln tail chimney at the tail of the rotary kiln. Usually, a denitrification device is arranged between the kiln tail dust collector and the kiln tail chimney to denitrify the flue gas discharged from the kiln tail dust collector before discharging it through the kiln tail chimney, so as to reduce the pollution of the flue gas generated by the rotary kiln calcining dolomite to the atmosphere after being discharged. In this place, all the flue gas generated by the rotary kiln calcining dolomite needs to be denitrified, resulting in a large amount of denitrified flue gas, so that the denitrification time is long, resulting in low denitrification efficiency. Since the flue gas temperature in the decomposition furnace between the preheater and the tail smoke chamber at the tail of the rotary kiln is between 900℃ and 1100℃, the flue gas within this temperature range is more suitable for denitrification treatment using SNCR denitrification. In order to improve the denitrification efficiency of the flue gas generated by calcining dolomite in the rotary kiln, there is an urgent need for a rotary kiln flue gas SNCR denitrification system for denitrifying the flue gas in the decomposition furnace. Utility Model Content

[0004] The present application provides a flue gas SNCR denitrification system for a rotary kiln, which is used to solve the technical problems described in the above background technology.

[0005] In order to solve the above technical problems, this application adopts the following technical solutions:

[0006] The present application provides a flue gas SNCR denitrification system for a rotary kiln, comprising: a liquid dispensing unit, a liquid storage tank and a spray unit connected in sequence through a first pipeline, and a gas compressor on the first pipeline connected between the liquid storage tank and the spray unit through a second pipeline;

[0007] The liquid preparation unit is used to prepare the denitration solution;

[0008] The liquid storage tank is used to store the denitration solution;

[0009] The gas compressor is used to compress the denitration solution flowing out of the liquid storage tank into a mist state by means of the compressed gas obtained after compression by the gas compressor;

[0010] The spray unit is used to spray the mist-like denitration solution into the decomposition furnace between the preheater and the rotary kiln, so as to achieve SNCR denitration treatment of the flue gas in the decomposition furnace.

[0011] Optionally, the spray unit includes an annular tube and a plurality of injectors;

[0012] The annular tube is arranged around the peripheral wall of the decomposition furnace body and is connected to the end of the first pipe between the liquid storage tank and the spray unit away from the liquid storage tank. A plurality of flue gas denitrification holes are opened on the peripheral wall of the decomposition furnace body. A plurality of injectors are connected to the annular tube and correspond one-to-one to the plurality of flue gas denitrification holes. The mist outlet of each injector extends into the decomposition furnace from the corresponding flue gas denitrification hole.

[0013] Optionally, the injector is made of high temperature resistant stainless steel.

[0014] Optionally, a connecting rod for fixing the annular tube to the outer peripheral wall of the decomposition furnace is provided on the peripheral wall of the decomposition furnace.

[0015] Optionally, the liquid preparation unit includes a preparation tank and a stirring member arranged on the preparation tank;

[0016] The preparation tank is connected with a raw material pipe and a solvent pipe, and the liquid outlet of the preparation tank is connected with the liquid inlet of the liquid storage tank through the first pipeline;

[0017] The bottom end of the stirring member passes through the top of the preparation tank and extends into the preparation tank, and is used to stir the raw materials and solvent entering the preparation tank to obtain the denitration solution.

[0018] Optionally, the stirring member includes a rotating shaft and a stirring blade;

[0019] The bottom end of the rotating shaft passes through the top of the preparation tank and extends into the preparation tank. The shaft body of the rotating shaft is rotatably connected to the preparation tank. A driving motor for driving the rotating shaft to rotate is arranged on the top of the rotating shaft. The stirring blade is arranged on the shaft body of the rotating shaft located in the preparation tank.

[0020] Optionally, a first filter and a first delivery pump are sequentially arranged on the first pipeline between the liquid dispensing unit and the liquid storage tank.

[0021] Optionally, a liquid level sensor is provided in the liquid storage tank.

[0022] Optionally, a second filter, a second delivery pump and a flow meter are sequentially arranged on the first pipeline between the liquid storage tank and the second pipeline, the second filter is arranged on the first pipeline close to the liquid outlet of the liquid storage tank, and the flow meter is arranged on the first pipeline close to the second pipeline.

[0023] Optionally, a ball valve is provided on the pipe body of the first pipe between the second pipe and the spray unit and on the second pipe.

[0024] The present application provides a flue gas SNCR denitrification system for a rotary kiln, which configures a denitrification solution through a liquid preparation unit and transports the denitrification solution to a liquid storage tank through a first pipeline for storage. The denitrification solution in the liquid storage tank meets the compressed gas compressed by the gas compressor and connected to the first pipeline during transportation along the first pipeline to the spray unit, so that the denitrification solution is compressed into a mist under the action of the compressed gas, and the misted denitrification solution is sprayed into a decomposition furnace between a preheater and a rotary kiln through the spray unit under the motive force of the compressed gas, and the flue gas between 900°C and 1100°C in the decomposition furnace is subjected to SNCR denitrification treatment. Compared with a liquid denitrification solution, the misted denitrification solution can contact the flue gas more fully, so that the misted denitrification solution reacts more fully with the nitrogen oxides in the flue gas, thereby improving the denitrification efficiency of the flue gas. In addition, the mist-like denitrification solution is sprayed out from the spray unit for a certain distance under the power provided by the compressed gas until it comes into contact with the flue gas, thereby avoiding direct contact between the mist outlet of the spray unit and the high-temperature flue gas, causing damage to it, thereby increasing the service life of the spray unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A flow chart of a SNCR denitration system for flue gas of a rotary kiln provided in one embodiment of the present application;

[0027] Figure 2 A schematic diagram of the structure of a flue gas SNCR denitration system for a rotary kiln provided in one embodiment of the present application;

[0028] Figure 3 A schematic diagram of the structure of a liquid dispensing unit provided in one embodiment of the present application;

[0029] Figure 4 A schematic diagram of the structure of an atomization unit and an injector provided in an embodiment of the present application, arranged in a flue gas denitrification hole of a decomposition furnace.

[0030] In the figure: 101, first pipeline; 1011, gas compressor; 1012, first filter; 1013, first delivery pump; 1014, second filter; 1015, second delivery pump; 1016, flow meter; 102, second pipeline; 200, liquid preparation unit; 201, preparation tank; 2011, raw material pipe; 2012, solvent pipe; 202, stirring element; 2021, rotating shaft; 2022, stirring blade; 300, liquid storage tank; 400, spray unit; 401, annular pipe; 402, ejector; 500, preheater; 600, rotary kiln; 700, decomposition furnace; 701, flue gas denitrification hole; 702, connecting rod; 900, driving motor. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0032] refer to Figures 1 to 4 The present application provides a flue gas SNCR denitrification system for a rotary kiln, comprising: a liquid dispensing unit 200, a liquid storage tank 300 and a spray unit 400 connected in sequence through a first pipeline 101, and a gas compressor 1011 on the first pipeline 101 connected between the liquid storage tank 300 and the spray unit 400 through a second pipeline 102; wherein, the gas (which may be air) enters the gas compressor 1011 through the air inlet of the gas compressor 1011, is compressed by the gas compressor 1011, and then enters the second pipeline 102 from the compressed gas outlet on the gas compressor 1011. The specifications and models of the gas compressor 1011 in the present application can be selected and purchased according to actual needs, and the present application does not specifically limit them here.

[0033] The liquid preparation unit 200 is used to prepare a denitrification solution; wherein the denitrification solution is a urea solution of a certain concentration obtained by mixing urea and water in a certain proportion, and the urea solution contacts with nitrogen oxides in the flue gas and reacts to generate N2 and H2O, thereby achieving the purpose of denitrification.

[0034] The liquid storage tank 300 is used to store the denitrification solution; wherein, the volume of the liquid storage tank 300 can be set according to actual needs, and its purpose is to ensure that it can store a certain amount of denitrification solution, so that the denitrification solution therein can ensure the continuity of the flue gas denitrification treatment process.

[0035] The gas compressor 1011 is used to compress the denitration solution flowing out of the liquid storage tank 300 into mist by means of the compressed gas obtained after compression thereof; wherein the compressed gas provides the power for compressing the denitration solution and the power for conveying the mist-like denitration solution.

[0036] The spray unit 400 is used to spray the mist-like denitration solution into the decomposition furnace 700 between the preheater 500 and the rotary kiln 600, so as to achieve SNCR denitration treatment of the flue gas in the decomposition furnace 700. Taking the calcination of dolomite in the rotary kiln 600 as an example, the dolomite enters the rotary kiln 600 through the discharge port of the preheater 500 and the decomposition furnace 700, and the flue gas in the rotary kiln 600 is discharged through the kiln tail smoke chamber at the tail of the rotary kiln 600, the decomposition furnace 700, the preheater 500, the waste heat boiler, the raw material mill, the kiln tail dust collector and the kiln tail chimney. After the mist-like denitration solution fully contacts the flue gas in the decomposition furnace 700, it reacts with the nitrogen oxides therein to generate N2 and H2O, thereby achieving the purpose of denitration of the flue gas in the decomposition furnace 700.

[0037] The flue gas SNCR denitrification system for a rotary kiln provided in the present application configures a denitrification solution through a liquid preparation unit 200 and transports the denitrification solution to a liquid storage tank 300 through a first pipe 101 for storage. The denitrification solution in the liquid storage tank 300 meets the compressed gas compressed by a gas compressor 1011 and connected to the first pipe 101 during transportation to the spray unit 400 along the first pipe 101, so that the denitrification solution is compressed into a mist under the action of the compressed gas. The misted denitrification solution is sprayed into a decomposition furnace 700 between a preheater 500 and a rotary kiln 600 through the spray unit 400 under the motive force of the compressed gas, and the flue gas between 900°C and 1100°C in the decomposition furnace 700 is subjected to SNCR denitrification treatment. Compared with a liquid denitrification solution, the misted denitrification solution can contact the flue gas more fully, so that the misted denitrification solution reacts more fully with the nitrogen oxides in the flue gas, thereby improving the denitrification efficiency of the flue gas. In addition, the mist-like denitrification solution is sprayed out from the spray unit 400 for a certain distance under the power provided by the compressed gas until it comes into contact with the flue gas, thereby avoiding direct contact between the mist outlet of the spray unit 400 and the high-temperature flue gas, causing damage to it, thereby increasing the service life of the spray unit 400.

[0038] In some embodiments, reference Figure 4The spray unit 400 in the present application includes an annular tube 401 and a plurality of injectors 402; specifically, the annular tube 401 is arranged around the peripheral wall of the decomposition furnace 700 body and is connected to the end of the first pipe 101 between the liquid storage tank 300 and the spray unit 400 away from the liquid storage tank 300, and a plurality of flue gas denitrification holes 701 are opened on the peripheral wall of the decomposition furnace 700 body. The plurality of injectors 402 are connected to the annular tube 401 and correspond one-to-one to the plurality of flue gas denitrification holes 701, and the mist outlet of each injector 402 extends into the decomposition furnace 700 from the corresponding flue gas denitrification hole 701. Among them, multiple flue gas denitrification holes 701 are evenly spaced on the peripheral wall of the decomposition furnace 700 and are located at the same height, so that the misty denitrification solution sprayed into the decomposition furnace 700 through the multiple flue gas denitrification holes 701 forms a denitrification layer, and the flue gas is fully in contact with the misty denitrification solution when passing through the denitrification layer from bottom to top, thereby achieving the purpose of denitrifying the flue gas.

[0039] In the above embodiment, the denitrification solution in the liquid dispensing unit 200 sequentially passes through the first pipeline 101, the liquid storage tank 300 and the first pipeline 101 to meet the compressed gas compressed by the gas compressor 1011 and connected to the first pipeline 101, so that the denitrification solution is compressed into a mist under the action of the compressed gas, and the mist denitrification solution enters the annular pipe 401 through the first pipeline 101 between the liquid storage tank 300 and the spray unit 400 under the power of the compressed gas, and is sprayed into the decomposition furnace 700 from the multiple injectors 402 connected to the annular pipe 401 and the flue gas denitrification holes 701 corresponding to each injector 402 to contact with the flue gas in the decomposition furnace 700, thereby achieving the purpose of denitrification of the flue gas.

[0040] In some embodiments, the injector 402 in the present application is made of high-temperature resistant stainless steel. Among them, the injector 402 can be a spray gun, and the injector 402 is made of stainless steel to increase its service life. Stainless steel can be divided into 304 stainless steel, whose upper limit of heat resistance temperature is about 800°C, and its performance is relatively stable between 750 and 860°C. 316 stainless steel, whose upper limit of heat resistance temperature is about 1300°C, and its performance is relatively stable between 1200 and 1300°C. 310S stainless steel, whose upper limit of heat resistance temperature is between 1150 and 1260°C. Therefore, the stainless steel material used by the injector 402 in the present application can be set according to actual conditions, and it is not specifically limited here.

[0041] In some embodiments, reference Figure 4 The peripheral wall of the decomposition furnace 700 in the present application is provided with a connecting rod 702 for fixing the annular tube 401 on the outer peripheral wall of the decomposition furnace 700, thereby ensuring the stability of the annular tube 401 during the denitration process.

[0042] In some embodiments, reference Figure 3 The liquid preparation unit 200 in the present application includes a preparation tank 201 and a stirring member 202 arranged on the preparation tank 201; specifically, the preparation tank 201 is connected with a raw material pipe 2011 and a solvent pipe 2012, and the liquid outlet of the preparation tank 201 is connected with the liquid inlet of the liquid storage tank 300 through the first pipe 101; wherein, the raw material (urea) and solvent (water) required for preparing the denitrification solution are respectively added to the preparation tank 201 through the raw material pipe 2011 and the solvent pipe 2012, and the amount of the raw material and the amount of the solvent added are set according to actual needs, and the present application does not make specific limitations on them.

[0043] The bottom end of the stirring member 202 passes through the top of the preparation tank 201 and extends into the preparation tank 201, and is used to stir the raw material (urea) and solvent (water) entering the preparation tank 201 to obtain a denitrification solution (urea solution). The prepared denitrification solution (urea solution) with a certain concentration enters the liquid storage tank 300 through the liquid outlet on the preparation tank 201, the first pipeline 101 and the liquid inlet of the liquid storage tank 300. The denitrification solution is stored in the liquid storage tank 300 to ensure the progress of the denitrification process.

[0044] In some embodiments, reference Figure 3 , the stirring member 202 in the present application includes a rotating shaft 2021 and a stirring blade 2022; specifically, the bottom end of the rotating shaft 2021 penetrates from the top of the preparation tank 201 and extends into the preparation tank 201, the shaft body of the rotating shaft 2021 is rotatably connected with the preparation tank 201, and the top of the rotating shaft 2021 is provided with a driving motor 800 for driving it to rotate, and the stirring blade 2022 is arranged on the shaft body of the rotating shaft 2021 located in the preparation tank 201. Among them, in order to achieve a better stirring effect, there can be multiple stirring blades 2022, and multiple stirring blades 2022 are arranged on the shaft body of the rotating shaft 2021 located in the preparation tank 201 at equal intervals from top to bottom, and the specific number of stirring blades 2022 can be set according to the length of the rotating shaft 2021 located in the preparation tank 201, and this application does not specifically limit it here. In addition, the output shaft of the driving motor 800 is connected to the top of the rotating shaft 2021.

[0045] In the above embodiment, the driving motor 800 is turned on, and the rotating shaft 2021 is driven to rotate by the driving motor 800. During the rotation process, the rotating shaft 2021 drives the stirring blades 2022 thereon to make circular motion in the preparation tank 201, so that the stirring blades 2022 stir the mixture (raw materials and solvent) in the preparation tank 201. Specifically, after stirring for a certain period of time at a certain stirring rate (the stirring time, stirring rate, etc. can be set according to actual needs, and the present application does not make specific limitations on them), a configured denitrification solution is obtained.

[0046] In some embodiments, reference Figure 2 In the present application, the first pipe 101 between the liquid dispensing unit 200 and the liquid storage tank 300 is provided with a first filter 1012 and a first delivery pump 1013 in sequence. The specifications and models of the first filter 1012 and the first delivery pump 1013 can be set according to actual needs, and therefore, the present application does not specifically limit them.

[0047] In the above embodiment, the impurities in the denitration solution prepared by the liquid preparation unit 200 are filtered once by the first filter 1012, thereby ensuring the purity of the denitration solution and preventing the impurities contained therein from clogging the pipeline and other components. The denitration solution after the first filtration is transported from the first pipeline 101 to the liquid storage tank 300 under the delivery power provided by the first delivery pump 1013, and the denitration solution after the first filtration is stored in the liquid storage tank 300.

[0048] In some embodiments, a liquid level sensor is provided in the liquid storage tank 300 in the present application. The liquid level sensor detects the liquid level of the denitration solution stored in the liquid storage tank 300 in real time, so that a sufficient amount of denitration solution is always stored in the liquid storage tank 300, thereby ensuring the continuity of the denitration process. The specifications and models of the liquid level sensor can be set according to actual needs, so the present application does not specifically limit it.

[0049] In some embodiments, reference Figure 2 In the present application, the first pipe 101 between the liquid storage tank 300 and the second pipe 102 is provided with a second filter 1014, a second delivery pump 1015 and a flow meter 1016 in sequence, the second filter 1014 is provided on the first pipe 101 near the liquid outlet of the liquid storage tank 300, and the flow meter 1016 is provided on the first pipe 101 near the second pipe 102. The specifications and models of the second filter 1014, the second delivery pump 1015 and the flow meter 1016 can be set according to actual needs, and therefore, the present application does not specifically limit them.

[0050] In the above embodiment, the second filter 1014 performs secondary filtration on impurities in the denitrification solution flowing out of the liquid storage tank 300, thereby ensuring the purity of the denitrification solution and preventing impurities therein from clogging pipes and other components, while the second delivery pump 1015 provides delivery power for the denitrification solution after secondary filtration, and the flow meter 1016 facilitates the control of the amount of denitrification solution required in the flue gas SNCR denitrification treatment process.

[0051] In some embodiments, reference Figure 2In the present application, a ball valve 900 is disposed on the pipe body of the first pipe 101 between the second pipe 102 and the spray unit 400 and on the second pipe 102. The ball valve 900 is a valve whose opening and closing member (ball) is driven by a valve stem and rotates around the axis of the ball valve 900. It is divided into pneumatic ball valves, electric ball valves, and manual ball valves according to the driving mode. The specific type can be selected according to the actual situation. Therefore, the present application does not further limit the specific type of the ball valve 900.

[0052] In the above embodiment, the ball valve 900 on the pipe body of the first pipe 101 between the second pipe 102 and the spray unit 400 controls the flow of the denitration solution flowing from the liquid storage tank 300 into the first pipe 101 between the first pipe 101 and the second pipe 102, while the ball valve 900 on the second pipe 102 controls the flow of the compressed gas compressed by the gas compressor 1011, thereby realizing the regulation of the supply process of the denitration solution and the compressed gas.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A flue gas SNCR denitrification system for a rotary kiln, characterized in that: include: A liquid dispensing unit (200), a liquid storage tank (300) and a spray unit (400) connected in sequence via a first pipeline (101), and a gas compressor (1011) on the first pipeline (101) connected between the liquid storage tank (300) and the spray unit (400) via a second pipeline (102); The liquid preparation unit (200) is used to prepare a denitration solution; The liquid storage tank (300) is used to store the denitration solution; The gas compressor (1011) is used to compress the denitration solution flowing out of the liquid storage tank (300) into a mist state by using the compressed gas obtained after compression; The spray unit (400) is used to spray the mist-like denitration solution into the decomposition furnace (700) between the preheater (500) and the rotary kiln (600), so as to implement SNCR denitration treatment on the flue gas in the decomposition furnace (700).

2. The SNCR denitration system for flue gas of a rotary kiln according to claim 1, characterized in that: The spray unit (400) comprises an annular tube (401) and a plurality of injectors (402); The annular tube (401) is arranged around the peripheral wall of the decomposition furnace (700) body and is connected to the end of the first pipe (101) between the liquid storage tank (300) and the spray unit (400) away from the liquid storage tank (300). A plurality of flue gas denitrification holes (701) are opened on the peripheral wall of the decomposition furnace (700) body. A plurality of injectors (402) are connected to the annular tube (401) and correspond one-to-one to the plurality of flue gas denitrification holes (701). The mist outlet of each injector (402) extends from the corresponding flue gas denitrification hole (701) into the decomposition furnace (700).

3. The SNCR denitration system for flue gas of a rotary kiln according to claim 2, characterized in that: The ejector (402) is made of high temperature resistant stainless steel.

4. The SNCR denitration system for flue gas of a rotary kiln according to claim 2, characterized in that: A connecting rod (702) for fixing the annular tube (401) to the outer peripheral wall of the decomposition furnace (700) is provided on the peripheral wall of the decomposition furnace (700).

5. The SNCR denitration system for flue gas of a rotary kiln according to claim 1, characterized in that: The liquid preparation unit (200) comprises a preparation tank (201) and a stirring member (202) arranged on the preparation tank (201); The preparation tank (201) is connected to a raw material pipe (2011) and a solvent pipe (2012); the liquid outlet of the preparation tank (201) is connected to the liquid inlet of the liquid storage tank (300) through the first pipeline (101); The bottom end of the stirring member (202) passes through the top of the preparation tank (201) and extends into the preparation tank (201), and is used to stir the raw materials and solvent entering the preparation tank (201) to obtain the denitration solution.

6. The SNCR denitration system for flue gas of a rotary kiln according to claim 5, characterized in that: The stirring member (202) comprises a rotating shaft (2021) and a stirring blade (2022); The bottom end of the rotating shaft (2021) passes through the top of the preparation tank (201) and extends into the preparation tank (201); the shaft body of the rotating shaft (2021) is rotatably connected to the preparation tank (201); a driving motor (800) for driving the rotating shaft (2021) to rotate is disposed at the top of the rotating shaft (2021); and the stirring blade (2022) is disposed on the shaft body of the rotating shaft (2021) located inside the preparation tank (201).

7. The SNCR denitration system for flue gas of a rotary kiln according to claim 1, characterized in that: A first filter (1012) and a first delivery pump (1013) are sequentially arranged on the first pipeline (101) between the liquid dispensing unit (200) and the liquid storage tank (300).

8. The SNCR denitration system for flue gas of a rotary kiln according to claim 1, characterized in that: A liquid level sensor is arranged in the liquid storage tank (300).

9. The SNCR denitration system for flue gas of a rotary kiln according to claim 1, characterized in that: A second filter (1014), a second delivery pump (1015) and a flow meter (1016) are sequentially arranged on the first pipeline (101) between the liquid storage tank (300) and the second pipeline (102); the second filter (1014) is arranged on the first pipeline (101) close to the liquid outlet of the liquid storage tank (300); and the flow meter (1016) is arranged on the first pipeline (101) close to the second pipeline (102).

10. The SNCR denitration system for flue gas of a rotary kiln according to any one of claims 1 to 9, characterized in that: The first pipeline (101) is provided with a ball valve (900) on the pipe body between the second pipeline (102) and the spray unit (400) and on the second pipeline (102).

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