Sulfur trioxide absorption system

Abstract

The utility model provides a sulfur trioxide absorption system, which belongs to the technical field of sulfuric acid preparation and comprises an absorption tower, a middle through pipe and a return pipe. A sulfuric acid inlet and a tail gas outlet are respectively formed in the top of the absorption tower, the sulfuric acid inlet is communicated with a sulfuric acid inlet pipe, the tail gas outlet is communicated with a tail gas outlet pipe, and a sulfuric acid outlet is formed in the bottom of the absorption tower; the sulfuric acid inlet is communicated with the spraying gas guide assembly and provides sulfuric acid liquid required by spraying sulfur trioxide for the spraying gas guide assembly; the middle through pipe penetrates into the absorption tower from top to bottom and sequentially penetrates through the spraying gas guide assembly and the filtering assembly, and a sulfur trioxide inlet pipe is arranged on one side of the upper end of the middle through pipe; two ends of the return pipe are respectively communicated with the sulfuric acid outlet and the top of the middle through pipe, and a circulating pump is arranged on the return pipe. The sulfur trioxide absorption system provided by the utility model can absorb sulfur trioxide gas for three times and can effectively remove the sulfur trioxide gas.

Description

Technical Field

[0001] The utility model belongs to the technical field of sulfuric acid preparation, and more specifically, relates to a sulfur trioxide absorption system. Background Art

[0002] In the contact process of producing sulfuric acid with sulfur dioxide, sulfur dioxide gas will be converted into sulfur trioxide after passing through the catalyst layer. Compared with sulfur dioxide, sulfur trioxide is more harmful. Sulfur trioxide will not only cause air pollution and pose a serious threat to the environment and human health. Moreover, sulfur trioxide is extremely easy to absorb the moisture in the flue gas, forming an aerosol-like substance, reducing the opacity of the flue gas and causing the occurrence of the "blue plume" phenomenon. And with the increase of the sulfur trioxide content, the acid dew point of the flue gas will be greatly increased, causing corrosion to the boiler system. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a sulfur trioxide absorption system, which can effectively complete the absorption of sulfur trioxide.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is: to provide a sulfur trioxide absorption system, including:

[0005] An absorption tower, the top of the absorption tower is respectively provided with a sulfuric acid inlet and a tail gas discharge port. The sulfuric acid inlet is communicated with a sulfuric acid inlet pipe, the tail gas discharge port is communicated with a tail gas discharge pipe, the bottom of the absorption tower is provided with a sulfuric acid discharge port, and a spray gas guiding component and a filtering component are arranged in the inner cavity of the absorption tower from bottom to top. The sulfuric acid inlet is communicated with the spray gas guiding component and provides the sulfuric acid liquid required for spraying sulfur trioxide for the spray gas guiding component;

[0006] A middle through pipe, the middle through pipe penetrates into the absorption tower from top to bottom and sequentially penetrates through the spray gas guiding component and the filtering component. One side of the upper end of the middle through pipe is provided with a sulfur trioxide inlet pipe;

[0007] A reflux pipe, both ends of the reflux pipe are respectively communicated with the sulfuric acid discharge port and the top of the middle through pipe, and a circulation pump is arranged on the reflux pipe.

[0008] In a possible implementation manner, the spray gas guiding component includes:

[0009] A partition board, the partition board transversely seals the inner cavity of the absorption tower, the partition board divides the inner cavity of the absorption tower into an upper chamber and a lower chamber, the sulfuric acid inlet is communicated with the upper chamber, and the filtering component is located in the lower chamber and is arranged at an interval with the partition board;

[0010] A plurality of spray heads, the plurality of spray heads are uniformly arranged on the lower end surface of the partition board and are communicated with the upper chamber;

[0011] A plurality of gas guide pipes, and the plurality of gas guide pipes are uniformly arranged on the upper end surface of the partition plate and communicate with the lower chamber.

[0012] In a possible implementation manner, the filtering component includes:

[0013] An upper filter screen, which is arranged at intervals below the partition plate;

[0014] A lower filter screen, which is arranged at intervals below the upper filter screen;

[0015] A packing layer, which is located between the upper filter screen and the lower filter screen.

[0016] In a possible implementation manner, the middle through pipe includes:

[0017] An upper flared pipe section, the inner diameter of which decreases from top to bottom. The sulfur trioxide inlet pipe is horizontally connected to one side of the upper end of the upper flared pipe section, and the reflux pipe is connected to the upper end of the upper flared pipe section;

[0018] A middle straight pipe section, which is connected to the lower end of the upper flared pipe section and penetrates into the absorption tower from top to bottom;

[0019] A lower flared pipe section, which is connected to the lower end of the middle straight pipe section, the inner diameter of which increases from top to bottom, and the lower flared pipe section sequentially penetrates through the spray gas guide assembly and the filtering component from top to bottom.

[0020] In a possible implementation manner, a conical inner pipe is arranged at the upper end of the upper flared pipe section, the outer diameter of which decreases from top to bottom. The lower end of the conical inner pipe penetrates into the interior of the upper flared pipe section, and the upper end of the conical inner pipe is connected to the reflux pipe.

[0021] In a possible implementation manner, an extension pipe section is connected to the lower end of the lower flared pipe section, and a baffle groove is arranged below the extension pipe section.

[0022] In a possible implementation manner, the sulfuric acid inlet and the tail gas discharge port are symmetrically arranged on both sides of the top of the absorption tower.

[0023] In a possible implementation manner, the bottom of the absorption tower has a downwardly convex arc bottom, and the sulfuric acid discharge port is arranged in the middle of the arc bottom.

[0024] In a possible implementation manner, a sulfuric acid finished product discharge pipe is arranged on the reflux pipe through a three-way valve.

[0025] In a possible implementation, the sulfuric acid inlet pipe includes an acid replenishment pipe and an acid return pipe arranged in parallel. The acid return pipe is connected to one end of the reflux pipe close to the middle through pipe. Switching valves are provided on both the acid replenishment pipe and the acid return pipe.

[0026] The beneficial effects of a sulfur trioxide absorption system provided by the present utility model are as follows: Compared with the prior art, the sulfuric acid liquid circulates in the absorption tower through the reflux pipe. The sulfuric acid liquid enters from the upper end of the middle through pipe. At the same time, the sulfur trioxide inlet pipe introduces sulfur trioxide gas into the upper end of the middle through pipe. The sulfuric acid liquid performs the first absorption on the sulfur trioxide that enters the inner cavity of the absorption tower together. Then the sulfuric acid liquid enters the reflux pipe again for circulation, and the circulation pump provides the power for the reflux of the sulfuric acid liquid in the reflux pipe. The sulfur trioxide gas entering the inner cavity of the absorption tower moves upward. The sulfur trioxide gas first passes through the filtering component to complete the second absorption. The sulfur trioxide gas then passes through the spraying gas guiding component. The sulfuric acid inlet pipe provides the sulfuric acid liquid for spraying the sulfur trioxide gas to the spraying gas guiding component. The sulfur trioxide gas completes the third absorption through the spraying of the sulfuric acid liquid and is finally discharged through the tail gas discharge pipe. A sulfur trioxide absorption system provided by the present utility model can absorb sulfur trioxide gas three times and can effectively remove sulfur trioxide gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a schematic structural diagram of a sulfur trioxide absorption system provided by an embodiment of the present utility model.

[0029] In the figure: 1, absorption tower; 2, acid replenishment pipe; 3, acid return pipe; 4, tail gas discharge pipe; 5, reflux pipe; 6, sulfuric acid finished product discharge pipe; 7, circulation pump; 8, sulfur trioxide inlet pipe; 9, partition board; 10, spray head; 11, upper filter screen; 12, packing layer; 13, lower filter screen; 14, upper flared pipe section; 15, middle straight pipe section; 16, lower flared pipe section; 17, conical inner pipe; 18, extension pipe section; 19, baffle groove; 20, arc bottom; 21, switching valve; 22, opening and closing valve; 23, three-way valve; 24, gas guide pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0031] In the claims, the description and the above-mentioned drawings of the present utility model, unless otherwise clearly defined, when using terms such as "first", "second" or "third", etc., are used to distinguish different objects and not to describe a specific order.

[0032] In the claims, the description and the above-mentioned drawings of the present utility model, unless otherwise clearly defined, for orientation terms, when using terms such as "center", "horizontal", "vertical", "level", "vertical", "top", "bottom", "inner", "outer", "upper", "lower", "front", "rear", "left", "right", "clockwise", "counterclockwise", "high", "low", etc. to indicate the orientation or position relationship, it is based on the orientation and position relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, so it cannot be understood as limiting the specific protection scope of the present utility model.

[0033] Please refer to Figure 1 , and now a sulfur trioxide absorption system provided by the present utility model will be described. A sulfur trioxide absorption system includes an absorption tower 1, a middle-through pipe and a reflux pipe 5.

[0034] The top of the absorption tower 1 is respectively provided with a sulfuric acid inlet and a tail gas discharge port. A sulfuric acid inlet pipe is connected to the sulfuric acid inlet, and a tail gas discharge pipe 4 is connected to the tail gas discharge port. The bottom of the absorption tower 1 is provided with a sulfuric acid discharge port. The inner cavity of the absorption tower 1 is provided with a spray gas guiding component and a filtering component from bottom to top. The sulfuric acid inlet is connected to the spray gas guiding component and provides the sulfuric acid liquid required for spraying sulfur trioxide for the spray gas guiding component; the middle-through pipe penetrates into the absorption tower 1 from top to bottom and sequentially penetrates through the spray gas guiding component and the filtering component. A sulfur trioxide inlet pipe 8 is opened on one side of the upper end of the middle-through pipe; both ends of the reflux pipe 5 are respectively connected to the sulfuric acid discharge port and the top of the middle-through pipe, and a circulation pump 7 is arranged on the reflux pipe 5.

[0035] A sulfur trioxide absorption system provided by the present utility model, compared with the prior art, the sulfuric acid solution circulates in the absorption tower 1 through the reflux pipe 5. The sulfuric acid solution enters from the upper end of the middle through pipe. At the same time, the sulfur trioxide inlet pipe 8 introduces sulfur trioxide gas into the upper end of the middle through pipe. The sulfuric acid solution conducts the first absorption of the sulfur trioxide that enters the inner cavity of the absorption tower 1 together. After that, the sulfuric acid solution enters the reflux pipe 5 again for circulation, and the circulation pump 7 provides the power for the reflux of the sulfuric acid solution in the reflux pipe 5. The sulfur trioxide gas that enters the inner cavity of the absorption tower 1 moves upward. The sulfur trioxide gas first passes through the filtration component to complete the second absorption. The sulfur trioxide gas then passes through the spray gas guiding component. The sulfuric acid inlet pipe provides the sulfuric acid solution for spraying the sulfur trioxide gas to the spray gas guiding component. The sulfur trioxide gas completes the third absorption after being sprayed by the sulfuric acid solution, and finally is discharged through the tail gas discharge pipe 4. The sulfur trioxide absorption system provided by the present utility model can absorb sulfur trioxide gas three times and can effectively remove sulfur trioxide gas.

[0036] Specifically, the spray gas guiding component includes a partition plate 9 and a plurality of spray heads 10. The partition plate 9 transversely seals the inner cavity of the absorption tower 1. The partition plate 9 divides the inner cavity of the absorption tower 1 into an upper chamber and a lower chamber. The sulfuric acid inlet is communicated with the upper chamber. The filtration component is located in the lower chamber and is arranged at an interval with the partition plate 9. A plurality of spray heads 10 are evenly arranged on the lower end surface of the partition plate 9 and are communicated with the upper chamber. A plurality of gas guide pipes 24 are evenly arranged on the upper end surface of the partition plate 9 and are communicated with the lower chamber. The sulfuric acid solution that enters the upper chamber through the sulfuric acid inlet pipe is evenly sprayed downward after passing through the plurality of spray heads 10 on the partition plate 9, which can effectively spray the sulfur trioxide gas moving upward from bottom to top. As the sulfuric acid solution is consumed, it is continuously supplemented through the sulfuric acid inlet pipe to ensure the continuous absorption of sulfur trioxide gas. After the sulfur trioxide gas passes through the filtration component, it is transmitted upward to the upper chamber through the plurality of gas guide pipes 24 and is finally discharged through the tail gas discharge pipe 4.

[0037] Specifically, the filtration component includes an upper filter net 11, a lower filter net 13 and a packing layer 12. The upper filter net 11 is arranged at an interval below the partition plate 9. The lower filter net 13 is arranged at an interval below the upper filter net 11. The packing layer 12 is located between the upper filter net 11 and the lower filter net 13. The outer peripheries of the upper filter net 11 and the lower filter net 13 are both fixed to the circumferential wall of the inner wall of the absorption tower 1. The packing layer 12 is installed between the upper filter net 11 and the lower filter net 13. Generally, graphite or polytetrafluoroethylene is selected for the packing layer 12. The sulfur trioxide gas can smoothly pass through the lower filter net 13 and the upper filter net 11 and be effectively absorbed by the packing layer 12.

[0038] Specifically, the through pipe includes an upper flared pipe section 14, a middle straight pipe section 15, and a lower flared pipe section 16. The inner diameter of the upper flared pipe section 14 decreases from top to bottom. The sulfur trioxide inlet pipe 8 is horizontally connected to one side of the upper end of the upper flared pipe section 14, and the reflux pipe 5 is connected to the upper end of the upper flared pipe section 14. The middle straight pipe section 15 is connected to the lower end of the upper flared pipe section 14, and the middle straight pipe section 15 penetrates into the absorption tower 1 from top to bottom. The lower flared pipe section 16 is connected to the lower end of the middle straight pipe section 15, and the inner diameter of the lower flared pipe section 16 increases from top to bottom. The lower flared pipe section 16 sequentially penetrates through the spray gas guiding assembly and the filtering assembly from top to bottom. The sulfuric acid liquid sequentially passes through the upper flared pipe section 14, the middle straight pipe section 15, and the lower flared pipe section 16, forming acceleration and dispersion of the sulfuric acid liquid, and can more effectively complete the absorption of the simultaneously introduced sulfur trioxide gas. Among them, the sulfuric acid liquid forms acceleration in the upper flared pipe section 14, corresponding to forming a negative pressure section for effectively inhaling the sulfur trioxide gas, and the sulfur trioxide gas smoothly enters the through pipe. The sulfuric acid liquid forms dispersion in the lower flared pipe section 16, enabling the sulfuric acid liquid to more fully contact the sulfur trioxide gas and improving the absorption efficiency.

[0039] Specifically, a conical inner pipe 17 is provided at the upper end of the upper flared pipe section 14. The outer diameter of the conical inner pipe 17 decreases from top to bottom. The lower end of the conical inner pipe 17 penetrates into the interior of the upper flared pipe section 14. The conical inner pipe 17 and the upper flared pipe section 14 form a Venturi structure, which can form an effective negative pressure effect for the entry of the sulfur trioxide gas. Among them, the upper end of the conical inner pipe 17 is connected to the reflux pipe 5 to enable the sulfuric acid liquid to flow back to the absorption tower 1 again.

[0040] Specifically, an extension pipe section 18 is connected to the lower end of the lower flared pipe section 16, and a baffle trough 19 is provided below the extension pipe section 18. The extension pipe section 18 is a straight section or a flared section. When the extension pipe section 18 is a flared section, its inner diameter increases from top to bottom, which can effectively guide the sulfuric acid liquid to disperse and flow into the baffle trough 19. The baffle trough 19 can hold the sulfuric acid liquid and make the sulfuric acid liquid stay in the baffle trough 19 for a period of time, enabling the sulfuric acid liquid to fully absorb the sulfur trioxide gas inside it, and then flow out of the baffle trough 19. The baffle trough 19 can prevent the sulfuric acid liquid mixed with the sulfur trioxide gas from entering the circulation pump 7 and affecting the normal operation of the circulation pump 7.

[0041] Preferably, the sulfuric acid inlet and the tail gas discharge port are symmetrically arranged on both sides of the top of the absorption tower 1, which can disperse the liquid inlet port and the exhaust port, and the liquid inlet and the exhaust do not affect each other.

[0042] The bottom of the absorption tower 1 has a downwardly convex arc bottom 20, and the sulfuric acid discharge port is arranged in the middle of the arc bottom 20, which can enable the sulfuric acid liquid at the bottom of the absorption tower 1 to be more smoothly discharged into the reflux pipe 5.

[0043] A sulfuric acid finished product discharge pipe 6 is provided on the reflux pipe 5 through a three-way valve 23. As the circulating sulfuric acid liquid continuously absorbs sulfur trioxide gas, the concentration of the sulfuric acid liquid itself will also increase accordingly. When the concentration of the sulfuric acid liquid reaches the required concentration, the three-way valve 23 is switched to discharge the sulfuric acid liquid from the reflux pipe 5 into the sulfuric acid finished product discharge pipe 6, and then new sulfuric acid liquid is replenished through the sulfuric acid inlet pipe.

[0044] The sulfuric acid inlet pipe includes an acid replenishing pipe 2 and an acid return pipe 3 arranged in parallel. The acid return pipe 3 is connected to one end of the reflux pipe 5 close to the middle pipe. Switching valves 21 are provided on both the acid replenishing pipe 2 and the acid return pipe 3. After the sulfuric acid liquid in the reflux pipe 5 is discharged through the sulfuric acid finished product discharge pipe 6, the acid replenishing pipe 2 is first used for acid replenishment. The sulfuric acid liquid enters the bottom of the absorption tower 1 through the multiple spray heads 10 of the partition plate 9, and the opening and closing valve 22 on the reflux pipe 5 is opened. The sulfuric acid liquid then flows back to the top through the reflux pipe 5. When the above cycle is stable, acid replenishment can be carried out separately through the acid return pipe 3.

[0045] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sulfur trioxide absorption system, characterized in that, Comprising: An absorption tower (1), the top of the absorption tower (1) is respectively provided with a sulfuric acid inlet and a tail gas discharge port. A sulfuric acid inlet pipe is connected to the sulfuric acid inlet, and a tail gas discharge pipe (4) is connected to the tail gas discharge port. The bottom of the absorption tower (1) is provided with a sulfuric acid discharge port. A spray gas guiding assembly and a filtering assembly are arranged in the inner cavity of the absorption tower (1) from bottom to top. The sulfuric acid inlet is connected to the spray gas guiding assembly and provides the sulfuric acid liquid required for spraying sulfur trioxide for the spray gas guiding assembly; A middle-through pipe, the middle-through pipe penetrates into the absorption tower (1) from top to bottom and sequentially penetrates through the spray gas guiding assembly and the filtering assembly. A sulfur trioxide inlet pipe (8) is opened on one side of the upper end of the middle-through pipe; A reflux pipe (5), the two ends of the reflux pipe (5) are respectively connected to the sulfuric acid discharge port and the top of the middle-through pipe, and a circulation pump (7) is arranged on the reflux pipe (5).

2. The sulfur trioxide absorption system according to claim 1, characterized in that, The spray gas guiding assembly includes: A partition plate (9), the partition plate (9) transversely seals the inner cavity of the absorption tower (1). The partition plate (9) divides the inner cavity of the absorption tower (1) into an upper chamber and a lower chamber. The sulfuric acid inlet is connected to the upper chamber, and the filtering assembly is located in the lower chamber and is arranged at an interval from the partition plate (9); A plurality of spray heads (10), the plurality of spray heads (10) are uniformly arranged on the lower end surface of the partition plate (9) and are connected to the upper chamber; A plurality of gas guide pipes (24), the plurality of gas guide pipes (24) are uniformly arranged on the upper end surface of the partition plate (9) and are connected to the lower chamber.

3. The sulfur trioxide absorption system according to claim 2, characterized in that, The filtering assembly includes: An upper filter screen (11), the upper filter screen (11) is arranged at an interval below the partition plate (9); A lower filter screen (13), the lower filter screen (13) is arranged at an interval below the upper filter screen (11); A packing layer (12), the packing layer (12) is located between the upper filter screen (11) and the lower filter screen (13).

4. A sulfur trioxide absorption system as described in claim 1, characterized in that, The middle-through pipe includes: An upper flared pipe section (14), the inner diameter of the upper flared pipe section (14) decreases from top to bottom. The sulfur trioxide inlet pipe (8) is horizontally connected to one side of the upper end of the upper flared pipe section (14), and the reflux pipe (5) is connected to the upper end of the upper flared pipe section (14); A middle straight pipe section (15), the middle straight pipe section (15) is connected to the lower end of the upper flared pipe section (14), and the middle straight pipe section (15) penetrates into the absorption tower (1) from top to bottom; A lower flared pipe section (16), the lower flared pipe section (16) is connected to the lower end of the middle straight pipe section (15), the inner diameter of the lower flared pipe section (16) increases from top to bottom, and the lower flared pipe section (16) sequentially penetrates through the spray gas guiding assembly and the filtering assembly from top to bottom.

5. The sulfur trioxide absorption system according to claim 4, wherein A conical inner pipe (17) is arranged at the upper end of the upper flared pipe section (14), the outer diameter of the conical inner pipe (17) decreases from top to bottom, the lower end of the conical inner pipe (17) penetrates into the inside of the upper flared pipe section (14), and the upper end of the conical inner pipe (17) is connected to the reflux pipe (5).

6. The sulfur trioxide absorption system according to claim 4, wherein The lower end of the lower flared pipe section (16) is connected to an extension pipe section (18), and a baffle groove (19) is arranged below the extension pipe section (18).

7. The sulfur trioxide absorption system according to claim 1, wherein, The sulfuric acid inlet and the tail gas discharge port are symmetrically arranged on both sides of the top of the absorption tower (1).

8. The sulfur trioxide absorption system according to claim 1, characterized in that The bottom of the absorption tower (1) has a downwardly convex arc bottom (20), and the sulfuric acid discharge port is arranged in the middle of the arc bottom (20).

9. A sulfur trioxide absorption system according to any one of claims 1-8, characterized in that, A sulfuric acid finished product discharge pipe (6) is arranged on the reflux pipe (5) through a three-way valve (23).

10. A sulfur trioxide absorption system according to any one of claims 1-8, characterized in that, The sulfuric acid inlet pipe includes a make-up acid pipe (2) and a return acid pipe (3) arranged in parallel. The return acid pipe (3) is connected to one end of the reflux pipe (5) close to the middle through pipe. Switching valves (21) are arranged on both the make-up acid pipe (2) and the return acid pipe (3).

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