Desulfurization and dust removal device and method for WSA acid-making tail gas

Abstract

The invention provides a desulfurization and dust removal device and method for WSA acid-making tail gas. The device comprises a fixed bed desulfurization tower and a tail gas washing tower, the fixed bed desulfurization tower is connected with a tail gas pipeline of a WSA condenser, and the tail gas pipeline is connected with a chimney; the tail gas washing tower is connected with the fixed bed desulfurization tower; the tail gas washing tower is connected with a tail gas induced draft fan through a third connecting pipeline; the tail gas induced draft fan is connected with a chimney; the tail gas washing tower comprises a filler layer, a demister, a second spraying assembly and a third spraying assembly, the second spraying assembly is arranged between the filler layer and the demister, the third spraying assembly is arranged above the demister, the second spraying assembly is connected with the desulfurization waste liquid pipeline and the NaOH solution pipeline through a fourth connecting pipeline, and the third spraying assembly is connected with a flushing water pipe. The desulfurization efficiency can be improved, and particulate matters in the tail gas can be effectively removed; surplus sodium carbonate in the desulfurization waste liquid can be fully utilized, cyclic utilization of waste resources is achieved, and the method has the advantages of being short in technological process, easy to operate, low in operation cost and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of WSA wet acid production, and in particular to a desulfurization and dust removal device and method for WSA acid production tail gas. Background Art

[0002] WSA acid production is a wet acid production technology developed by Denmark's Topsoe. It can process hydrogen sulfide concentrations ranging from a few tenths of a percent to more than 90 percent, and can also accept process gases with a relatively high moisture content. It does not require drying before processing, has great operational flexibility, can adapt to large fluctuations in raw gas flow and sulfide concentration, and has the advantages of simple process layout, economical operation, high thermal efficiency, high product value, and low energy consumption. It is widely used in oil refining, metallurgy, coal chemical industry, coking, viscose fiber and other industries. In the coking industry, it is often used in conjunction with the vacuum carbonate desulfurization process to produce sulfuric acid with a concentration of 98% from acidic gas containing H2S.

[0003] The main process of WSA acid production includes acid gas combustion, SCR denitrification, SO2 conversion, SO3 hydration, and gaseous H2SO4 condensation. The tail gas after gaseous H2SO4 condensation contains SO2, SO3, NO x In recent years, the national environmental protection requirements have become increasingly stringent, and the emission limit requirements have been continuously reduced. Following the release of the "Coking Chemical Industry Pollutant Emission Standard" (GB16171-2012) in 2012, the Ministry of Ecology and Environment issued the "Opinions on Promoting the Implementation of Ultra-low Emissions in the Coking Industry" in 2024, requiring that the particulate matter content of the exhaust gas of the heating furnace burning coal gas be ≤10mg / m 3 , sulfur dioxide ≤ 30mg / m 3 , the particulate matter and sulfur dioxide content of the untreated WSA acid-making tail gas cannot meet the ultra-low emission requirements, so the WSA acid-making tail gas must be desulfurized and dusted. The current WSA acid-making tail gas purification treatment mainly includes two processes: "alkaline washing + electrostatic demister" and "hydrogen peroxide washing":

[0004] The "alkaline washing + electric mist removal" process has problems such as high requirements for electric mist removal materials, large project investment and high operating costs; and the hydrogen peroxide used in the "hydrogen peroxide washing" process is an explosive chemical and is listed as one of the key hazardous chemicals, with great safety risks. In recent years, Topsoe has developed the "hydrogen peroxide quenching washing + acid mist filtration" and double condensation (WSA-DC) processes, and has made "hydrogen peroxide quenching washing + acid mist filtration" the main process. The safety management of hydrogen peroxide in this process cannot be ignored. The WSA-DC process must be heated before the secondary conversion, and the energy consumption required for heating is relatively large. Summary of the invention

[0005] According to the technical problems raised above, a desulfurization and dust removal device and method for WSA acid production tail gas is provided. The present invention adopts a process combining solid absorbent and liquid absorption method to remove SO2 and SO3 in WSA acid production tail gas in two stages, which can effectively remove particulate matter in the tail gas while improving the desulfurization efficiency; in the liquid absorption unit, the surplus sodium carbonate in the desulfurization waste liquid is fully utilized to realize the recycling of waste resources, which has the advantages of short process flow, simple operation, and low operating cost.

[0006] The technical means adopted by the present invention are as follows:

[0007] A desulfurization and dust removal device for WSA acid production tail gas, comprising: a fixed bed desulfurization tower and a tail gas washing tower, wherein the fixed bed desulfurization tower is filled with a desulfurizer, and the fixed bed desulfurization tower has a first inlet and a first outlet, wherein the first inlet is connected to the tail gas pipeline of the WSA condenser through a first connecting pipe, and the tail gas pipeline of the WSA condenser is connected to the chimney through a second connecting pipe;

[0008] The tail gas scrubber has a second inlet, which is connected to the first outlet of the fixed bed desulfurization tower; the top of the tail gas scrubber has a second outlet, which is connected to the inlet of the tail gas induced draft fan through a third connecting pipe, and the outlet of the tail gas induced draft fan is connected to the chimney;

[0009] The tail gas washing tower includes a packing layer, a demister, a second spray assembly and a third spray assembly arranged inside, the packing layer is located at the lower part of the tail gas washing tower, the demister is located at the upper part of the tail gas washing tower, at least one group of second spray assemblies is arranged between the packing layer and the demister, at least one group of third spray assemblies is arranged above the demister, the second spray assembly is connected to the desulfurization waste liquid pipeline and the NaOH solution pipeline through a fourth connecting pipe, and the third spray assembly is connected to the flushing water pipe.

[0010] Furthermore, the exhaust gas washing tower also includes at least one group of first spray components arranged inside, the first spray components are arranged between the packing layer and the demister and are located below the second spray components, and the bottom of the exhaust gas washing tower has a third outlet, the third outlet is connected to the inlet of the washing liquid circulation pump through an inlet pipe, and the outlet of the washing liquid circulation pump is connected to the first spray component through an outlet pipe.

[0011] Furthermore, the outlet pipeline is connected to a production pipe, the production pipe is connected to the residual ammonia water tank, a fourth regulating valve is installed on the production pipe, and the fourth regulating valve is interlocked with the liquid level meter of the tail gas washing tower.

[0012] Furthermore, a desulfurizer feeding port and a desulfurizer discharging port are provided at the top and bottom of the fixed bed desulfurization tower, and a gate valve and a star-shaped discharger are installed at the desulfurizer discharging port.

[0013] Furthermore, a pressure difference detection device is also included.

[0014] Furthermore, a first pressure detection device and a second regulating valve are installed on the first connecting pipeline, a first regulating valve is installed on the second connecting pipeline, and a second pressure detection device is installed on the third connecting pipeline. The first regulating valve and the second regulating valve are both interlocked and controlled with the pressure difference detection device, and the detection values ​​of the first pressure detection device and the second pressure detection device are both transmitted to the pressure difference detection device.

[0015] Furthermore, a liquid level meter is provided on the tail gas washing tower, a first flow meter is installed on the outlet pipe, and a pH value online detection device is installed between the outlet pipe and the inlet pipe.

[0016] Furthermore, the fourth connecting pipeline is provided with a second flow meter, the NaOH solution pipeline is provided with a third regulating valve, and the third regulating valve is interlocked with the pH value online detection device for control;

[0017] The desulfurization waste liquid in the desulfurization waste liquid pipeline is the waste liquid generated by the vacuum carbonate desulfurization device, or the desulfurization waste liquid generated in the PDS and ADA alkaline desulfurization processes;

[0018] The flushing water in the flushing water pipe is residual ammonia water at 60°C.

[0019] Furthermore, the tail gas washing tower is made of stainless steel, and the packing layer and the demister are made of polytetrafluoroethylene.

[0020] The present invention also provides a dust removal method for a desulfurization and dust removal device for WSA acid production tail gas, comprising the following steps:

[0021] The outlet tail gas of S1 and WSA condenser enters the fixed bed desulfurization tower through the tail gas pipeline and the first connecting pipeline. The fixed bed desulfurization tower is filled with a desulfurizer that can absorb and adsorb SO2 and SO3. SO2 and SO3 in the tail gas are initially removed and then enter the tail gas washing tower;

[0022] S2. The tail gas washing tower is continuously supplemented with the desulfurization waste liquid generated during the vacuum carbonate desulfurization, PDS, and ADA alkaline desulfurization processes. In the packing layer of the tail gas washing tower, the tail gas is sprayed and washed by the washing liquid circulation pump. The SO2 and SO3 in the tail gas react chemically with the surplus Na2CO3 in the desulfurization waste liquid, and SO2 and SO3 are deeply removed. At the same time, the dust contained in the tail gas itself and the desulfurizer dust entrained by the tail gas through the fixed bed desulfurization tower are intercepted and removed by the washing liquid in the tail gas washing tower. After that, the washing liquid entrained by the tail gas is captured by the demister and finally sent to the chimney through the tail gas induced draft fan to meet the emission standards; the washing liquid is controlled by the fourth regulating valve on the production pipe at the outlet of the washing liquid circulation pump, and the liquid level of the tail gas washing tower is maintained stable; in order to maintain good washing liquid quality and the efficiency of removing SO2 and SO3, the pH value of the washing liquid is guaranteed to be 13. When the pH value of the washing liquid is low, NaOH solution is added to the tail gas washing tower to improve it;

[0023] S3. When the overall pressure difference of the device is too large, measures are taken to improve it by replacing the desulfurizer in the fixed-bed desulfurization tower and flushing the demister of the tail gas washing tower. When the pressure difference exceeds the process control limit, the first regulating valve of the tail gas direct exhaust chimney is interlocked to open and the second regulating valve is closed synchronously to ensure the overall safe and stable operation of the WSA acid production unit.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The desulfurization and dust removal device and method for WSA acid production tail gas provided by the present invention uses a fixed bed desulfurization tower and a tail gas washing tower, and adopts a process combining a solid absorbent and a liquid absorption method to remove SO2 and SO3 in the WSA acid production tail gas in two stages. While improving the desulfurization efficiency, the particulate matter in the tail gas can be effectively removed; in the liquid absorption unit, the surplus sodium carbonate in the desulfurization waste liquid is fully utilized to realize the recycling of waste resources, which has the advantages of short process flow, simple operation, and low operating cost.

[0026] 2. The desulfurization and dust removal device and method for WSA acid production tail gas provided by the present invention is that a desulfurizer that can absorb and adsorb SO2 and SO3 is filled in the fixed bed desulfurization tower, which can achieve the preliminary removal of SO2 and SO3 in the tail gas.

[0027] 3. The desulfurization and dust removal device and method for WSA acid production tail gas provided by the present invention continuously replenishes the desulfurization waste liquid generated in the alkaline desulfurization process such as vacuum carbonate desulfurization, PDS, ADA, etc. in the tail gas washing tower, and the tail gas is sprayed and washed by the washing liquid circulation pump. The SO2 and SO3 in the tail gas react chemically with the surplus Na2CO3 in the desulfurization waste liquid, which can achieve deep removal of SO2 and SO3. At the same time, the dust contained in the tail gas itself and the desulfurization agent dust entrained by the tail gas through the fixed bed desulfurization tower can also be intercepted and removed by the washing liquid in the tail gas washing tower. The washing liquid entrained by the tail gas is captured by the demister and can also be sent to the chimney through the tail gas induced draft fan to meet the emission standards.

[0028] 4. In the desulfurization and dust removal device and method for WSA acid production tail gas provided by the present invention, the washing liquid is produced by controlling the fourth regulating valve on the outlet production pipe of the washing liquid circulation pump, which can maintain the liquid level of the tail gas washing tower stable.

[0029] 5. In the desulfurization and dust removal device and method for WSA acid production tail gas provided by the present invention, the pH value of the scrubbing liquid is set at about 13, which can maintain good scrubbing liquid quality and efficiency of removing SO2 and SO3. When the pH value of the scrubbing liquid is low, it can be improved by adding NaOH solution to the tail gas scrubber.

[0030] 6. The desulfurization and dust removal device and method for WSA acid-making tail gas provided by the present invention can improve the overall pressure difference of the device by replacing the desulfurizer in the fixed-bed desulfurization tower and flushing the demister of the tail gas washing tower. When the pressure difference exceeds the process control limit, the first regulating valve of the tail gas direct discharge chimney is interlocked to open and the second regulating valve 9 of the tail gas entering the device is synchronously closed, which can ensure the overall safe and stable operation of the WSA acid-making device.

[0031] Based on the above reasons, the present invention can be widely promoted in the fields of WSA wet acid production or other wet acid production tail gas treatment process equipment and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 It is a schematic structural diagram of the desulfurization and dust removal device for WSA acid production tail gas of the present invention.

[0034] In the figure: 1. fixed bed desulfurization tower; 1-1. desulfurizer feeding port; 1-2. desulfurizer discharge port; 1-3. first pressure detection device; 2. tail gas washing tower; 2-1. packing layer; 2-2. demister; 2-3. first spray assembly; 2-4. second spray assembly; 2-5. third spray assembly; 2-6. liquid level gauge; 2-7. second pressure detection device; 3. tail gas induced draft fan; 4. washing liquid circulation pump; 5. PH value online detection device; 6. first flow meter; 7. second flow meter; 8. first regulating valve; 9. second regulating valve; 10. pressure difference detection device; 11. third regulating valve; 12. fourth regulating valve; 13. WSA condenser; 14. chimney. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0039] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0040] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0041] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0042] like Figure 1As shown, the present invention provides a desulfurization and dust removal device for WSA acid production tail gas, including a fixed bed desulfurization tower 1, a tail gas washing tower 2 and a pressure difference detection device 10.

[0043] The fixed bed desulfurization tower 1 includes a desulfurizer feeding port 1-1 and a desulfurizer unloading port 1-2. The inlet of the fixed bed desulfurization tower 1 is connected to the tail gas pipeline of the WSA condenser 13 through a first connecting pipe, and a first pressure detection device 1-3 and a switch valve (second regulating valve 9) are installed on the first connecting pipe. The tail gas pipeline of the WSA condenser 13 can also directly lead to the chimney 14 through a second connecting pipe, and a switch valve (first regulating valve 8) is installed on the second connecting pipe.

[0044] Preferably, the fixed bed desulfurization tower 1 can be filled with a solid desulfurizer that has an absorption and adsorption effect on SO2 and SO3, and an operation mode of regularly and quantitatively updating the desulfurizer can be adopted.

[0045] Preferably, the desulfurizing agent discharge port 1-2 is equipped with a gate valve and a star-shaped discharger.

[0046] The inlet of the tail gas washing tower 2 is connected to the outlet of the fixed bed desulfurization tower 1 , and the outlet at the top of the tail gas washing tower 2 is connected to the inlet of the tail gas induced draft fan 3 through a third connecting pipe, and the outlet of the tail gas induced draft fan 3 is connected to the chimney 14 .

[0047] Preferably, the tail gas scrubber 2 is made of stainless steel.

[0048] The tail gas washing tower 2 includes a packing layer 2-1, a demister 2-2, a first spray assembly 2-3, a second spray assembly 2-4, a third spray assembly 2-5 and a liquid level meter 2-6.

[0049] Preferably, the packing layer 2-1 and the demister 2-2 are made of polytetrafluoroethylene.

[0050] The packing layer 2-1 is located at the lower part of the tail gas washing tower 2, and the demister 2-2 is located at the upper part of the tail gas washing tower 2. A first spray assembly 2-3 and a second spray assembly 2-4 are arranged between the packing layer 2-1 and the demister 2-2. The first spray assembly 2-3 is located below the second spray assembly 2-4, and a third spray assembly 2-5 is arranged above the demister 2-2. The second spray assembly 2-4 is connected to the desulfurization waste liquid pipeline and the NaOH solution pipeline through a fourth connecting pipeline, and the third spray assembly 2-5 is connected to the flushing water pipe. The bottom outlet of the tail gas washing tower 2 is connected to the inlet of the washing liquid circulation pump 4 through an inlet pipeline, and the outlet of the washing liquid circulation pump 4 is connected to the first spray assembly 2-3 through an outlet pipeline, and a first flowmeter 6 is installed on the outlet pipeline. A pH value online detection device 5 is installed between the inlet and outlet pipelines of the washing liquid circulation pump 4, and a production pipe is arranged on the outlet pipeline of the washing liquid circulation pump 4.

[0051] Preferably, a fourth regulating valve 12 is installed on the production pipe, and the fourth regulating valve 12 is interlocked with the liquid level meter 2 - 6 of the tail gas washing tower 2 for control.

[0052] The second spray assembly 2 - 4 is connected to the desulfurization waste liquid pipeline and the NaOH solution pipeline, and a second flow meter 7 is provided on the fourth connecting pipeline, and a third regulating valve 11 is provided on the NaOH solution pipeline.

[0053] Preferably, the desulfurization waste liquid is the waste liquid generated by a vacuum carbonate desulfurization device, and may also be the desulfurization waste liquid generated during alkaline desulfurization processes such as PDS and ADA.

[0054] Preferably, the third regulating valve 11 is interlocked with the pH value online detection device 5 for control.

[0055] The third spray assembly 2-5 is connected to the flushing water pipe, and residual ammonia water at about 60°C is preferably used as flushing water.

[0056] A second pressure detection device 2 - 7 is installed on the third connecting pipeline, and the detection values ​​of the first pressure detection device 1 - 3 and the second pressure detection device 2 - 7 are transmitted to the pressure difference detection device 10 .

[0057] Preferably, both the first regulating valve 8 and the second regulating valve 9 are interlocked and controlled with the pressure difference detection device 10 .

[0058] The present invention does not include the WSA condenser 13 and the chimney 14, but the illustration is made for ease of understanding.

[0059] The present invention also provides a method for desulfurization and dust removal of WSA acid production tail gas, using the above device, comprising the following steps:

[0060] The outlet exhaust gas of S1 and WSA condenser 13 first enters the fixed bed desulfurization tower 1 through the exhaust gas pipeline and the first connecting pipeline. The fixed bed desulfurization tower 1 is filled with a desulfurizer that can absorb and adsorb SO2 and SO3. SO2 and SO3 in the exhaust gas are preliminarily removed, and then enters the exhaust gas washing tower 2.

[0061] S2, the tail gas washing tower 2 is continuously supplemented with the desulfurization waste liquid generated during the vacuum carbonate desulfurization, PDS, ADA and other alkaline desulfurization processes. In the packing layer 2-1 of the tail gas washing tower 2, the tail gas is sprayed and washed by the washing liquid circulation pump 4, and the SO2 and SO3 in the tail gas react chemically with the surplus Na2CO3 in the desulfurization waste liquid, and SO2 and SO3 are deeply removed. At the same time, the dust contained in the tail gas itself and the desulfurization agent dust entrained by the tail gas through the fixed bed desulfurization tower 1 are also intercepted and removed by the washing liquid in the tail gas washing tower 2, and then the washing liquid entrained by the tail gas is captured by the demister 2-2, and finally sent to the chimney 14 through the tail gas induced draft fan 3 to meet the emission standards. The washing liquid is controlled by the regulating valve (the fourth regulating valve 12) on the outlet extraction pipe of the washing liquid circulation pump 4, and the liquid level of the tail gas washing tower 2 is maintained stable. In order to maintain good scrubbing liquid quality and the efficiency of removing SO2 and SO3, the pH value of the scrubbing liquid should be kept at around 13. When the pH value of the scrubbing liquid is low, NaOH solution should be added to the tail gas scrubbing tower 2 to improve it.

[0062] S3. When the overall pressure difference of the device is too large, it can be improved by replacing the desulfurizer in the fixed bed desulfurization tower 1 and flushing the demister 2-2 of the tail gas washing tower 2. When the pressure difference exceeds the process control limit, the valve of the tail gas direct discharge chimney 14 (the first regulating valve 8) is interlocked to open and the tail gas valve (the second regulating valve 9) entering the device is closed synchronously to ensure the overall safe and stable operation of the WSA acid production device.

[0063] The desulfurization and dust removal device and method for WSA acid production tail gas of the present invention can be extended to WSA wet acid production or other wet acid production tail gas treatment process devices.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described 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 invention.

Claims

1. A desulfurization and dust removal device for WSA acid production tail gas, characterized in that: include: A fixed bed desulfurization tower (1) and an exhaust gas scrubber (2), wherein the interior of the fixed bed desulfurization tower (1) is filled with a desulfurizer, and the fixed bed desulfurization tower (1) has a first inlet and a first outlet, wherein the first inlet is connected to the exhaust gas pipeline of the WSA condenser (13) through a first connecting pipeline, and the exhaust gas pipeline of the WSA condenser (13) is connected to the chimney (14) through a second connecting pipeline; The tail gas washing tower (2) has a second inlet, which is connected to the first outlet of the fixed bed desulfurization tower (1); the top of the tail gas washing tower (2) has a second outlet, which is connected to the inlet of the tail gas induced draft fan (3) through a third connecting pipe, and the outlet of the tail gas induced draft fan (3) is connected to the chimney (14); The tail gas washing tower (2) comprises a packing layer (2-1), a demister (2-2), a second spray assembly (2-4) and a third spray assembly (2-5) arranged therein, wherein the packing layer (2-1) is located at the lower part of the tail gas washing tower (2), the demister (2-2) is located at the upper part of the tail gas washing tower (2), at least one group of second spray assemblies (2-4) is arranged between the packing layer (2-1) and the demister (2-2), at least one group of third spray assemblies (2-5) is arranged above the demister (2-2), the second spray assembly (2-4) is connected to a desulfurization waste liquid pipeline and a NaOH solution pipeline via a fourth connecting pipeline, and the third spray assembly (2-5) is connected to a flushing water pipe.

2. The desulfurization and dust removal device for WSA acid production tail gas according to claim 1, characterized in that: The tail gas washing tower (2) further comprises at least one group of first spray components (2-3) arranged inside, wherein the first spray components (2-3) are arranged between the packing layer (2-1) and the demister (2-2) and below the second spray components (2-4), and the bottom of the tail gas washing tower (2) has a third outlet, wherein the third outlet is connected to the inlet of a washing liquid circulation pump (4) via an inlet pipe, and the outlet of the washing liquid circulation pump (4) is connected to the first spray component (2-3) via an outlet pipe.

3. The desulfurization and dust removal device for WSA acid production tail gas according to claim 2, characterized in that: The outlet pipeline is connected to a production pipe, the production pipe is connected to a residual ammonia water tank, a fourth regulating valve (12) is installed on the production pipe, and the fourth regulating valve (12) is interlocked with the liquid level meter (2-6) of the tail gas washing tower (2) for control.

4. The desulfurization and dust removal device for WSA acid production tail gas according to claim 1, characterized in that: The top and bottom of the fixed bed desulfurization tower (1) are provided with a desulfurization agent feeding port (1-1) and a desulfurization agent discharging port (1-2), and the desulfurization agent discharging port (1-2) is equipped with a gate valve and a star-shaped discharger.

5. The desulfurization and dust removal device for WSA acid production tail gas according to claim 1, characterized in that: It also includes a pressure difference detection device (10).

6. The desulfurization and dust removal device for WSA acid production tail gas according to claim 5, characterized in that: A first pressure detection device (1-3) and a second regulating valve (9) are installed on the first connecting pipeline, a first regulating valve (8) is installed on the second connecting pipeline, and a second pressure detection device (2-7) is installed on the third connecting pipeline. The first regulating valve (8) and the second regulating valve (9) are both interlocked and controlled with a pressure difference detection device (10), and the detection values ​​of the first pressure detection device (1-3) and the second pressure detection device (2-7) are both transmitted to the pressure difference detection device (10).

7. The desulfurization and dust removal device for WSA acid production tail gas according to claim 1, characterized in that: The tail gas washing tower (2) is provided with a liquid level meter (2-6), the outlet pipe is provided with a first flow meter (6), and a pH value online detection device (5) is provided between the outlet pipe and the inlet pipe.

8. The desulfurization and dust removal device for WSA acid production tail gas according to claim 1, characterized in that: The fourth connecting pipeline is provided with a second flow meter (7), the NaOH solution pipeline is provided with a third regulating valve (11), and the third regulating valve (11) is interlocked with the pH value online detection device (5) for control; The desulfurization waste liquid in the desulfurization waste liquid pipeline is the waste liquid generated by the vacuum carbonate desulfurization device, or the desulfurization waste liquid generated in the PDS and ADA alkaline desulfurization processes; The flushing water in the flushing water pipe is residual ammonia water at 60°C.

9. The desulfurization and dust removal device for WSA acid production tail gas according to claim 1, characterized in that: The tail gas washing tower (2) is made of stainless steel, and the packing layer (2-1) and the demister (2-2) are made of polytetrafluoroethylene.

10. A dust removal method for a WSA acid production tail gas desulfurization and dust removal device according to any one of claims 1 to 9, characterized in that: The steps include: The outlet tail gas of S1 and WSA condenser (13) enters the fixed bed desulfurization tower (1) through the tail gas pipeline and the first connecting pipeline. The fixed bed desulfurization tower (1) is filled with a desulfurizer capable of absorbing and adsorbing SO2 and SO3. SO2 and SO3 in the tail gas are initially removed, and then enters the tail gas washing tower (2); S2, the tail gas washing tower (2) is continuously supplemented with the desulfurization waste liquid generated during the vacuum carbonate desulfurization, PDS, and ADA alkaline desulfurization processes. In the packing layer (2-1) of the tail gas washing tower (2), the tail gas is sprayed and washed by the washing liquid circulation pump (4), and the SO2 and SO3 in the tail gas react chemically with the surplus Na2CO3 in the desulfurization waste liquid, so that SO2 and SO3 are deeply removed. At the same time, the dust contained in the tail gas itself and the desulfurization agent dust entrained by the tail gas through the fixed bed desulfurization tower (1) are intercepted by the washing liquid in the tail gas washing tower (2). The washing liquid is removed by the mist eliminator (2-2), and then the washing liquid carried by the tail gas is captured and sent to the chimney (14) through the tail gas induced draft fan (3) to meet the discharge standards; the washing liquid is controlled by the fourth regulating valve (12) on the extraction pipe at the outlet of the washing liquid circulation pump (4), and the liquid level of the tail gas washing tower (2) is maintained stable; in order to maintain good washing liquid quality and the efficiency of removing SO2 and SO3, the pH value of the washing liquid is guaranteed to be 13. When the pH value of the washing liquid is low, NaOH solution is added to the tail gas washing tower (2) to improve it; S3. When the overall pressure difference of the device is too large, the desulfurizer in the fixed bed desulfurization tower (1) is replaced and the demister (2-2) of the tail gas washing tower (2) is flushed to improve the situation. When the pressure difference exceeds the process control limit, the first regulating valve (8) of the tail gas direct exhaust chimney (14) is interlocked to open and the second regulating valve (9) is closed synchronously to ensure the overall safe and stable operation of the WSA acid production device.

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