Flue gas desulfurization system

Abstract

The invention relates to a flue gas desulfurization system which comprises an absorption tower provided with a desulfurization pool, a flue gas inlet and a flue gas outlet higher than the flue gas inlet, and the desulfurization pool is used for containing limestone slurry; the spraying assembly is mounted in the absorption tower, is arranged between the smoke inlet and the smoke outlet in the height direction, and is used for spraying limestone slurry to the raw smoke entering from the smoke inlet, the raw smoke leaves the absorption tower through the smoke outlet after being desulfurized by the limestone slurry, and the spraying assembly is in liquid communication with the desulfurization pool; the liquid inlet pipe is used for supplying liquid into the desulfurization pool, a liquid outlet of the liquid inlet pipe extends below the lowest liquid level of the desulfurization pool, a liquid inlet of the liquid inlet pipe is higher than the liquid outlet, and an included angle between a section, inserted into the liquid level of the desulfurization pool, of the liquid inlet pipe and the liquid level is not smaller than 45 degrees, so that liquid in the liquid inlet pipe can quickly flow into the desulfurization pool. Meanwhile, the slurry can form water seal for the end, so that the original flue gas is prevented from directly leaving the absorption tower through the liquid inlet pipe when water is cut off, and the pollution to external air is avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of flue gas desulfurization, and in particular, to a flue gas desulfurization system. Background Art

[0002] Thermal power plants can use limestone-gypsum wet desulfurization to desulfurize raw flue gas. The basic principle is that the raw flue gas enters the desulfurization absorption tower and flows from bottom to top. The limestone slurry is pumped into the spray layer in the upper part of the desulfurization absorption tower by the slurry circulation pump and flows downward. The flue gas and the slurry are in countercurrent contact to remove sulfur dioxide. The desulfurization process consumes the water in the limestone slurry. In order to ensure the sustainability of the desulfurization process, technicians will add water to the limestone slurry through pipelines. In related technologies, when the water in the pipeline is cut off, the raw flue gas will leave the absorption tower through the pipeline, causing air pollution. Summary of the invention

[0003] An object of the present disclosure is to provide a flue gas desulfurization system to at least partially solve the problems existing in the related art.

[0004] In order to achieve the above object, the present disclosure provides a flue gas desulfurization system, comprising: An absorption tower, provided with a desulfurization tank, a smoke inlet and a smoke exhaust port arranged above the smoke inlet, wherein the desulfurization tank is used to accommodate limestone slurry; A spray assembly is installed in the absorption tower and is disposed between the smoke inlet and the smoke outlet in the height direction, so as to spray limestone slurry to the raw flue gas entering the smoke inlet. The raw flue gas leaves the absorption tower through the smoke outlet after being desulfurized by the limestone slurry. The spray assembly is in liquid communication with the desulfurization tank; and A liquid inlet pipe is used to supply liquid into the desulfurization tank, wherein the liquid outlet of the liquid inlet pipe extends below the lowest liquid level of the desulfurization tank, and the liquid inlet of the liquid inlet pipe is arranged higher than the liquid outlet, wherein the angle between the section of the liquid inlet pipe inserted into the liquid surface of the desulfurization tank and the liquid surface is not less than 45 degrees.

[0005] Optionally, the angle between the section of the liquid inlet pipe inserted into the liquid surface of the desulfurization tank and the liquid surface is 90 degrees.

[0006] Optionally, the distance from the liquid outlet of the liquid inlet pipe to the lowest liquid level is 500 mm to 1000 mm.

[0007] Optionally, the absorption tower is further provided with a through hole, which is provided above the highest liquid level of the desulfurization tank. The liquid inlet pipe enters the absorption tower through the through hole and extends downward to below the lowest liquid level.

[0008] Optionally, the liquid inlet pipe includes a first straight pipe portion, a first oblique pipe portion and a second straight pipe portion connected in sequence, the first straight pipe portion is located outside the absorption tower, the first oblique pipe portion is arranged above the highest liquid level and passes through the through hole, and at least a portion of the second straight pipe portion is arranged below the lowest liquid level, wherein an angle between the first oblique pipe portion and the liquid surface is not less than 45 degrees.

[0009] Optionally, the angle between the first inclined tube portion and the liquid surface is 60 degrees.

[0010] Optionally, the absorption tower is provided with an installation port, the installation port is located below the lowest liquid level, and the liquid inlet pipe is passed through the installation port.

[0011] Optionally, the liquid inlet pipe includes a third straight pipe portion and a second oblique pipe portion connected in sequence, the third straight pipe portion is located outside the absorption tower, the second oblique pipe portion is passed through the installation port, and the angle between the second oblique pipe portion and the liquid surface is not less than 45 degrees, and at least a portion of the second oblique pipe portion is arranged below the lowest liquid level.

[0012] Optionally, the flue gas desulfurization system also includes a gypsum processing mechanism disposed outside the absorption tower, the gypsum processing mechanism is located above the minimum liquid level, the gypsum processing mechanism is connected to the desulfurization tank through a recovery pipe, and is used to receive the slurry in the desulfurization tank and centrifugally dehydrate the slurry, and the liquid inlet of the liquid inlet pipe is connected to the gypsum processing mechanism, so that the liquid separated by the gypsum processing mechanism flows back to below the minimum liquid level under the action of gravity.

[0013] Optionally, the gypsum processing mechanism is located 20 meters to 30 meters above the lowest liquid level.

[0014] Optionally, the gypsum processing mechanism comprises: a gypsum cyclone station, used for centrifugally dehydrating the gypsum slurry from the desulfurization tank; and The filtrate component is connected to the gypsum cyclone station and the liquid inlet pipe respectively, and is used for filtering impurities in the separated water.

[0015] Optionally, the spray assembly includes a plurality of spray layers spaced apart from each other.

[0016] Optionally, a demisting assembly is installed above the spray assembly, and the demisting assembly is used to remove moisture in the gas after desulfurization by limestone slurry.

[0017] Optionally, a slurry pipe is installed between the spray assembly and the desulfurization tank, and a pump body is installed on the slurry pipe for pumping the limestone slurry in the desulfurization tank from bottom to top.

[0018] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects: The original flue gas enters the absorption tower through the smoke inlet and reacts with the limestone slurry for desulfurization. The desulfurized gas can leave the absorption tower through the smoke outlet to avoid air pollution caused by the direct discharge of the original flue gas. The angle between the section of the liquid inlet pipe inserted into the liquid surface of the desulfurization tank and the liquid surface is not less than 45 degrees, ensuring that the liquid in the liquid inlet pipe can quickly flow into the desulfurization tank and ensure the replenishment of water in the desulfurization tank.

[0019] Furthermore, one end of the liquid inlet pipe extends below the lowest liquid level of the limestone slurry, and the limestone slurry can form a water seal on this end to prevent the original flue gas from directly leaving the absorption tower through the liquid inlet pipe when the water flow is cut off, thereby avoiding polluting the external air.

[0020] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 A schematic diagram of a flue gas desulfurization system according to an exemplary embodiment of the present disclosure is shown in FIG. Figure 1 .

[0022] Figure 2 A schematic diagram of a flue gas desulfurization system according to an exemplary embodiment of the present disclosure is shown in FIG. Figure 2 .

[0023] Description of Reference Numerals 100. Absorption tower; 110. Desulfurization tank; 111. Minimum liquid level; 120. Smoke inlet; 130. Smoke exhaust outlet; 140. Through hole; 150. Mounting port; 200. Spray assembly; 210. Spray layer; 300. Liquid inlet pipe; 310. First straight pipe portion; 320. First inclined pipe portion; 330. Second straight pipe portion; 340. Third straight pipe portion; 350. Second inclined pipe portion; 400. Gypsum processing mechanism; 410. Recovery pipe; 500. Demisting assembly. DETAILED DESCRIPTION

[0024] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0025] In the present disclosure, unless otherwise stated, directional words such as "up, down, left, right" are used for the convenience of description and are defined according to the drawing direction of the corresponding drawings, and "inside and outside" are defined according to the contours of the corresponding parts themselves. The terms used in the present disclosure such as "first, second, third" etc. are used to distinguish one element from another and have no order or importance. The direction indicated by the straight arrow is the flow direction of the flue gas in the desulfurization system. In addition, when the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0026] Thermal power plants can use limestone-gypsum wet desulfurization to desulfurize raw flue gas. In order to ensure the sustainability of the desulfurization process, technicians will add water to the limestone slurry through pipelines. In related technologies, when the water in the pipeline is cut off, the raw flue gas will leave the absorption tower through the pipeline, causing air pollution.

[0027] To solve the above problems, see Figure 1 and Figure 2 , the embodiment of the present disclosure provides a flue gas desulfurization system, which may include an absorption tower 100, a spray assembly 200 and a liquid inlet pipe 300. Among them, the absorption tower 100 may be provided with a desulfurization pool 110, a smoke inlet 120 and a smoke exhaust port 130 arranged higher than the smoke inlet 120. The smoke inlet 120 may be equipped with a fan (not shown in the figure) to ensure that the raw flue gas can quickly enter the absorption tower 100. The desulfurization pool 110 can be used to accommodate limestone slurry (desulfurizer). The spray assembly 200 can be installed in the absorption tower 100 and is arranged between the smoke inlet 120 and the smoke exhaust port 130 in the height direction, so as to spray limestone slurry to the raw flue gas entering the smoke inlet 120, and the raw flue gas can leave the absorption tower 100 through the smoke exhaust port 130 after being desulfurized by the limestone slurry. The spray assembly 200 can be in liquid communication with the desulfurization tank 110, so that the desulfurization tank 110 can provide limestone slurry to the spray assembly 200, and the limestone slurry discharged from the spray assembly 200 can enter the desulfurization tank 110. The liquid inlet pipe 300 can be used to supply liquid to the desulfurization tank 110, and the liquid outlet of the liquid inlet pipe 300 can extend below the lowest liquid level 111 of the desulfurization tank 110. The liquid inlet of the liquid inlet pipe 300 can be set higher than the liquid outlet, wherein the angle between the section of the liquid inlet pipe 300 inserted into the liquid surface of the desulfurization tank 110 and the liquid surface is not less than 45 degrees. For example, the angle between the section of the liquid inlet pipe 300 inserted into the liquid surface of the desulfurization tank 110 and the liquid surface can be 45 degrees, 60 degrees or 90 degrees, etc., which is not specifically limited here.

[0028] It is understandable that the raw flue gas enters the absorption tower 100 through the smoke inlet 120, and it can flow from bottom to top and react with the limestone slurry discharged from the spray assembly 200 for desulfurization. The desulfurized gas (clean flue gas) can leave the absorption tower 100 through the smoke outlet 130, avoiding air pollution caused by the direct discharge of the raw flue gas. The angle between the section of the liquid inlet pipe 300 inserted into the liquid surface of the desulfurization tank 110 and the liquid surface is not less than 45 degrees, avoiding the accumulation of liquid in the liquid inlet pipe 300, ensuring that the liquid can quickly flow into the desulfurization tank 110, and ensuring the rapid replenishment of water in the desulfurization tank 110. One end of the liquid inlet pipe 300 extends below the lowest liquid level 111 of the limestone slurry, so that the limestone slurry can form a water seal on this end, avoiding the raw flue gas from directly leaving the absorption tower 100 through the liquid inlet pipe 300 when the water is cut off, thereby avoiding polluting the external air and ensuring the safety and reliability of the operation of the desulfurization tower.

[0029] In one embodiment, see Figure 1 The angle between the section of the liquid inlet pipe 300 inserted into the liquid surface of the desulfurization tank 110 and the liquid surface can be 90 degrees, ensuring that the liquid in the liquid inlet pipe 300 can quickly enter the desulfurization tank 110.

[0030] In one embodiment, see Figure 1 and Figure 2 , the distance from the liquid outlet of the liquid inlet pipe 300 to the lowest liquid level 111 (as shown by H in the figure) can be 500 mm to 1000 mm, so as to ensure that the pipeline is not wasted and the liquid sealing effect on the flue gas is ensured. For example, the distance from the liquid outlet of the liquid inlet pipe 300 to the lowest liquid level 111 can be 500 mm, 600 mm, 750 mm, 900 mm or 1000 mm, etc. If the distance from the liquid outlet of the liquid inlet pipe 300 to the lowest liquid level 111 is less than 500 mm, when the liquid level fluctuates, the limestone slurry cannot continuously form a liquid seal on the liquid outlet of the liquid inlet pipe 300, resulting in the liquid in the liquid inlet pipe 300 being pushed out from the liquid inlet of the liquid inlet pipe 300 under the pressure of the original flue gas; if the distance from the liquid outlet of the liquid inlet pipe 300 to the lowest liquid level 111 is greater than 1000 mm, the distance of the liquid inlet pipe 300 in the desulfurization tank 110 is too long, which is easy to cause waste of pipelines.

[0031] In one embodiment, see Figure 1 The absorption tower 100 may also be provided with a through hole 140, which may be provided above the highest liquid level of the desulfurization tank 110. The liquid inlet pipe 300 may enter the absorption tower 100 through the through hole 140 and may extend downward to below the lowest liquid level 111 to prevent the liquid in the desulfurization tank 110 from overflowing from the through hole 140.

[0032] For further information, see Figure 1, the liquid inlet pipe 300 may include a first straight pipe portion 310, a first oblique pipe portion 320 and a second straight pipe portion 330 connected in sequence, the first straight pipe portion 310 may be located outside the absorption tower 100, the first oblique pipe portion 320 may be arranged above the highest liquid level and penetrated through the through hole 140, and at least part of the second straight pipe portion 330 may be arranged below the lowest liquid level 111, wherein the angle between the first oblique pipe portion 320 and the liquid surface is not less than 45 degrees. For example, the angle between the first oblique pipe portion 320 and the liquid surface may be 45 degrees, 50 degrees, 60 degrees or 75 degrees, etc., to avoid the liquid in the first straight pipe portion 310 from causing liquid accumulation in the oblique pipe portion, and to ensure that the liquid can flow smoothly into the desulfurization tank 110.

[0033] It should be noted that the straight tube portion and the oblique tube portion are two relative concepts. The straight tube portion refers to the portion parallel to the vertical direction. The oblique tube portion refers to the portion arranged at an angle to the vertical direction. The first straight tube portion 310, the first oblique tube portion 320 and the second straight tube portion 330 can be three pipelines respectively, which is convenient for the segmented assembly of the liquid inlet pipe 300 on the absorption tower 100; or, the first straight tube portion 310, the first oblique tube portion 320 and the second straight tube portion 330 can also be an integrated structure, which is convenient for the processing and manufacturing of the liquid inlet pipe 300.

[0034] In this implementation, see Figure 1 , the angle between the first oblique tube portion 320 and the liquid surface can be 60 degrees. If the angle between the first oblique tube portion 320 and the liquid surface is much smaller than 60 degrees, the liquid is easily accumulated in the oblique tube, affecting the speed of the liquid outflow; if the angle between the first oblique tube portion 320 and the liquid surface is much larger than 60 degrees, it is difficult for the two ends of the first oblique tube portion 320 to dock with the first straight tube portion 310 and the second straight tube portion 330 respectively.

[0035] In one embodiment, see Figure 2 The absorption tower 100 may be provided with an installation opening 150, and the installation opening 150 may be located below the lowest liquid level 111, so that the length of the liquid inlet pipe 300 outside the installation opening 150 is greater than its length inside the installation opening 150, which is convenient for workers to inspect most structures of the liquid inlet pipe 300 outside the absorption tower 100. The liquid inlet pipe 300 may be inserted into the installation opening 150, and the circumference of the liquid inlet pipe 300 may be connected to the installation opening 150 through a sealing ring to prevent the limestone slurry from overflowing through the installation opening 150.

[0036] In one embodiment, reference Figure 2The liquid inlet pipe 300 may include a third straight pipe portion 340 and a second oblique pipe portion 350 connected in sequence. The third straight pipe portion 340 may be located outside the absorption tower 100. The second oblique pipe portion 350 may be inserted into the installation port 150, and the angle between the second oblique pipe portion 350 and the liquid surface is not less than 45 degrees, so as to avoid the formation of liquid accumulation in the oblique pipe portion and ensure that the liquid can smoothly enter the desulfurization tank 110. At least part of the second oblique pipe portion 350 may be arranged below the lowest liquid level 111, and the limestone slurry may form a water seal on this end, so as to avoid the original flue gas from directly leaving the absorption tower 100 through the liquid inlet pipe 300 when the water is cut off, thereby avoiding polluting the external air.

[0037] In one embodiment, see Figure 2 The second inclined tube portion 350 may include an inner tube extending into the absorption tower 100 and an outer tube connected to the inner tube and located outside the absorption tower 100. The inner tube and the outer tube may be connected at the mounting hole by a flange. Dividing the second inclined tube portion 350 into two sections may facilitate the installation of the second inclined tube portion 350 on the absorption tower 100. When the height of the gypsum cyclone station described below from the lowest liquid level 111 is determined, the total length of the outer tube and the third straight tube portion 340 is greater than the length of the inner tube, thereby avoiding inconvenience in maintenance of the liquid inlet pipe 300 due to the longer inner tube.

[0038] In one embodiment, see Figure 1 and Figure 2 The flue gas desulfurization system may further include a gypsum processing mechanism 400 disposed outside the absorption tower 100. The gypsum processing mechanism 400 may be located above the lowest liquid level 111. The gypsum processing mechanism 400 may be connected to the desulfurization tank 110 through a recovery pipe 410, and is used to receive the slurry in the desulfurization tank 110 and centrifugally dehydrate the slurry. The liquid inlet of the liquid inlet pipe 300 may be connected to the gypsum processing mechanism 400, so that the liquid separated by the gypsum processing mechanism 400 flows back to below the lowest liquid level 111 under the action of gravity.

[0039] It is understandable that the limestone slurry sprayed from the spray assembly 200 reacts with the original flue gas to generate gypsum slurry (solid content 10-15%), which can fall into the desulfurization tank 110 under the action of gravity, and can enter the gypsum treatment mechanism 400 through the recovery pipe 410. After the gypsum slurry is centrifuged in the gypsum treatment mechanism 400, its dense phase part (solid content 50-60%) can be discarded or processed into finished gypsum, and its dilute phase part (filtrate water) can be returned to the absorption tower 100 through the liquid inlet pipe 300 to provide water supplement for the desulfurization tank 110. Workers can put limestone into the desulfurization tank 110, and the limestone is mixed with water to generate limestone slurry.

[0040] In one embodiment, see Figure 1 and Figure 2The gypsum processing mechanism 400 can be located 20 to 30 meters above the lowest liquid level 111, ensuring that the dilute phase of the gypsum slurry can flow into the desulfurization tank 110 under the action of gravity after centrifugal separation, without the need to use a pump to transport the filtrate water. For example, the gypsum processing mechanism 400 is located 20 meters, 25 meters, or 30 meters above the lowest liquid level 111, which is not specifically limited here.

[0041] In one embodiment, the gypsum processing mechanism 400 may include a gypsum cyclone station and a filtrate assembly. The gypsum cyclone station may be used to centrifugally dehydrate the gypsum slurry from the desulfurization tank 110. The filtrate assembly may be connected to the gypsum cyclone station and the liquid inlet pipe 300, respectively, and may be used to filter impurities in the separated water to ensure that the water entering the desulfurization tank 110 is relatively clean, thereby avoiding poor desulfurization effect of the original flue gas due to impurities.

[0042] In one embodiment, see Figure 1 and Figure 2 The spray assembly 200 may include a plurality of spray layers 210 spaced apart from each other. For example, the spray assembly 200 may include 3 to 5 spray layers 210 to ensure the desulfurization effect of the original flue gas.

[0043] In one embodiment, see Figure 1 and Figure 2 A demisting assembly 500 can be installed above the spray assembly 200. The demisting assembly 500 is used to remove moisture from the gas after desulfurization with limestone slurry to prevent the original flue gas after desulfurization from carrying too much moisture. The demisting assembly 500 can transport the collected moisture to the desulfurization pool 110 to ensure the water supply of the desulfurization pool 110.

[0044] In one embodiment, a slurry pipe is installed between the spray assembly 200 and the desulfurization tank 110 , and a pump body is installed on the slurry pipe for pumping the limestone slurry in the desulfurization tank 110 from bottom to top to ensure the supply of limestone slurry to the spray assembly 200 .

[0045] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0046] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0047] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A flue gas desulfurization system, characterized in that: include: An absorption tower, provided with a desulfurization tank, a smoke inlet and a smoke exhaust port arranged above the smoke inlet, wherein the desulfurization tank is used to accommodate limestone slurry; A spray assembly is installed in the absorption tower and is disposed between the smoke inlet and the smoke outlet in the height direction, so as to spray limestone slurry to the raw flue gas entering the smoke inlet. The raw flue gas leaves the absorption tower through the smoke outlet after being desulfurized by the limestone slurry. The spray assembly is in liquid communication with the desulfurization tank; and A liquid inlet pipe is used to supply liquid into the desulfurization tank, wherein the liquid outlet of the liquid inlet pipe extends below the lowest liquid level of the desulfurization tank, and the liquid inlet of the liquid inlet pipe is arranged higher than the liquid outlet, wherein the angle between the section of the liquid inlet pipe inserted into the liquid surface of the desulfurization tank and the liquid surface is not less than 45 degrees.

2. The flue gas desulfurization system according to claim 1, characterized in that: The included angle between the section of the liquid inlet pipe inserted into the liquid surface of the desulfurization tank and the liquid surface is 90 degrees.

3. The flue gas desulfurization system according to claim 1, characterized in that: The distance from the liquid outlet of the liquid inlet pipe to the minimum liquid level is 500 mm to 1000 mm.

4. The flue gas desulfurization system according to claim 1, characterized in that: The absorption tower is also provided with a through hole, which is arranged above the highest liquid level of the desulfurization tank. The liquid inlet pipe enters the absorption tower through the through hole and extends downward to below the lowest liquid level.

5. The flue gas desulfurization system according to claim 4, characterized in that: The liquid inlet pipe includes a first straight pipe portion, a first oblique pipe portion and a second straight pipe portion which are connected in sequence, the first straight pipe portion is located outside the absorption tower, the first oblique pipe portion is arranged above the highest liquid level and passes through the through hole, and at least a portion of the second straight pipe portion is arranged below the lowest liquid level, wherein the angle between the first oblique pipe portion and the liquid surface is not less than 45 degrees.

6. The flue gas desulfurization system according to claim 5, characterized in that: The included angle between the first inclined tube portion and the liquid surface is 60 degrees.

7. The flue gas desulfurization system according to claim 1, characterized in that: The absorption tower is provided with an installation opening, the installation opening is located below the lowest liquid level, and the liquid inlet pipe is passed through the installation opening.

8. The flue gas desulfurization system according to claim 7, characterized in that: The liquid inlet pipe includes a third straight pipe portion and a second oblique pipe portion connected in sequence, the third straight pipe portion is located outside the absorption tower, the second oblique pipe portion is passed through the installation port, and the angle between the second oblique pipe portion and the liquid surface is not less than 45 degrees, and at least a part of the second oblique pipe portion is arranged below the lowest liquid level.

9. The flue gas desulfurization system according to claim 1, characterized in that: The flue gas desulfurization system also includes a gypsum processing mechanism arranged outside the absorption tower, the gypsum processing mechanism is located above the minimum liquid level, the gypsum processing mechanism is connected to the desulfurization tank through a recovery pipe, and is used to receive the slurry in the desulfurization tank and centrifugally dehydrate the slurry. The liquid inlet of the liquid inlet pipe is connected to the gypsum processing mechanism, so that the liquid separated by the gypsum processing mechanism flows back to below the minimum liquid level under the action of gravity.

10. The flue gas desulfurization system according to claim 9, characterized in that: The gypsum processing mechanism is located 20 meters to 30 meters above the lowest liquid level.

11. The flue gas desulfurization system according to claim 10, characterized in that: The gypsum processing mechanism comprises: a gypsum cyclone station, used for centrifugally dehydrating the gypsum slurry from the desulfurization tank; and The filtrate component is connected to the gypsum cyclone station and the liquid inlet pipe respectively, and is used for filtering impurities in the separated water.

12. The flue gas desulfurization system according to claim 1, characterized in that: The spray assembly includes a plurality of spray layers spaced apart from each other.

13. The flue gas desulfurization system according to claim 12, characterized in that: A demisting assembly is installed above the spray assembly, and the demisting assembly is used to remove moisture in the gas after desulfurization by limestone slurry.

14. The flue gas desulfurization system according to claim 1, characterized in that: A slurry pipe is installed between the spray assembly and the desulfurization tank, and a pump body is installed on the slurry pipe for pumping the limestone slurry in the desulfurization tank from bottom to top.

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