An SO3 recycling system

Abstract

This utility model relates to the field of sulfuric acid preparation technology, specifically to an SO3 recovery system. The outlet of the acid mist collection device is connected to the inlet of the first SO3 absorption tower, the outlet of the first SO3 absorption tower is connected to the inlet of the drying tower, the outlet of the drying tower is connected to the input of the negative pressure fan, the output of the negative pressure fan is connected to the inlet of the conversion device, the outlet of the conversion device is connected to the inlet of the second SO3 absorption tower, the outlet of the second SO3 absorption tower is connected to the inlet of the tail gas desulfurization device, and the outlet of the tail gas desulfurization device is connected to the chimney. The liquid outlets of both the first and second SO3 absorption towers are connected to the circulation tank. This utility model, by setting up two SO3 absorption towers, combines the acid mist collection system and the SO2 conversion system, improving the acid mist recovery rate and effectively reducing the environmental pollution caused by acid mist emissions.

Description

Technical Field

[0001] This utility model relates to the field of sulfuric acid preparation technology, specifically to an SO3 recovery system. Background Technology

[0002] In chemical production, fuming acid is an important chemical raw material widely used in the production processes of dyes, pharmaceuticals, and explosives. However, during the loading of fuming acid, its high volatility easily generates acid mist containing SO3.

[0003] SO3 is a highly corrosive gas; direct release into the atmosphere causes severe environmental damage. It combines with moisture in the air to form sulfuric acid mist, which not only corrodes surrounding equipment and buildings but also contributes to acid rain, disrupting the ecological balance and posing a significant threat to plant and animal growth and human health. Furthermore, direct SO3 emissions waste resources and reduce the economic efficiency of production. To address the SO3 volatilization problem during the loading of fuming acid, some SO3 recovery devices have emerged in existing technologies. However, these devices often suffer from low recovery efficiency, with large amounts of SO3 remaining unrecovered and some acid mist still being released into the atmosphere. In addition, existing recovery systems have relatively simple structures and lack deep gas treatment; the exhaust gas after recovery may still contain a certain amount of SO3 and other harmful gases, making it difficult to meet increasingly stringent environmental standards. Moreover, some recovery systems exhibit poor stability and reliability. During long-term operation, problems such as equipment blockage and corrosion can easily occur, affecting normal system operation and increasing maintenance costs and downtime. Moreover, existing recovery systems typically cannot effectively recycle the absorbent, resulting in waste of the absorbent and increased operating costs. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides an SO3 recovery system.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] An SO3 recovery system includes an acid mist collection device, a first SO3 absorption tower, a drying tower, a negative pressure fan, a conversion device, a second SO3 absorption tower, a tail gas desulfurization device, a chimney, a circulation tank, and a solution pump. Both the first and second SO3 absorption towers have an outlet and a liquid inlet at their upper parts, and an inlet and an outlet at their lower parts. The acid mist collection device is located at the fuming acid loading point. The outlet of the acid mist collection device is connected to the inlet of the first SO3 absorption tower, and the outlet of the first SO3 absorption tower is connected to the inlet of the drying tower. The inlet of the drying tower is also connected to an SO2 flue gas pipeline, and the outlet of the drying tower is connected to the negative pressure fan. The input end of the air compressor and the output end of the negative pressure air compressor are connected to the air inlet of the conversion device. The air outlet of the conversion device is connected to the air inlet of the second SO3 absorption tower. The air outlet of the second SO3 absorption tower is connected to the air inlet of the tail gas desulfurization device. The air outlet of the tail gas desulfurization device is connected to the chimney. The input end of the solution pump is connected to the circulation tank. The output end of the solution pump is provided with a first branch and a second branch. The first branch is connected to the liquid inlet of the first SO3 absorption tower, and the second branch is connected to the liquid inlet of the second SO3 absorption tower. The liquid outlets of both the first SO3 absorption tower and the second SO3 absorption tower are connected to the circulation tank.

[0007] Furthermore, it also includes an acid mixer, which is installed inside the circulation tank. The output end of the solution pump is also provided with a third branch, which is connected to the inlet of the acid mixer. The inlet of the acid mixer is also connected to a water pipe, and the outlet of the acid mixer is connected to the inside of the circulation tank.

[0008] Furthermore, the drying tower is filled with 3% concentrated sulfuric acid, an acid concentration sensor is installed at the bottom of the drying tower, and the outlet of the drying tower is connected to the circulation tank.

[0009] Furthermore, both the first SO3 absorption tower and the second SO3 absorption tower are equipped with a spray layer and a packing layer, with the spray layer located above the packing layer.

[0010] Furthermore, the circulation tank is filled with 98% concentrated sulfuric acid, and a stirring device is provided in the circulation tank.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0012] This invention provides an SO3 recovery system that combines an acid mist collection system and an SO2 conversion system by setting up two SO3 absorption towers. Acid mist enters the acid mist collection device and the first SO3 absorption tower through the negative pressure in the SO2 conversion system, improving the acid mist recovery rate. Simultaneously, the absorbed SO3 acid mist, along with SO2 flue gas, passes through a drying tower and conversion device before entering the second SO3 absorption tower for further SO3 absorption, increasing the SO3 recovery rate and effectively reducing the environmental pollution caused by acid mist emissions. The system also includes an acid mixer that adds water to the circulation tank to dilute the sulfuric acid, maintaining the sulfuric acid concentration in the circulation tank at 98%, ensuring stable system operation. The drying tower is filled with 93% concentrated sulfuric acid. An acid concentration sensor at its bottom is linked to a replenishment device; when the acid concentration falls below 90%, concentrated sulfuric acid is automatically added, while dilute acid is discharged into the circulation tank for sulfuric acid dilution. This achieves stable control of the sulfuric acid concentration in the drying tower and rationally utilizes dilute acid, further optimizing the system's treatment and utilization of sulfuric acid, and improving overall resource utilization and system reliability. Attached Figure Description

[0013] The embodiments of this utility model will be further described below with reference to the accompanying drawings, wherein:

[0014] Figure 1 A schematic diagram of an embodiment of the SO3 recovery system is shown;

[0015] Attached diagram labels: 1-Acid mist collection device, 2-First SO3 absorption tower, 3-Drying tower, 4-Negative pressure fan, 5-Conversion device, 6-Second SO3 absorption tower, 7-Tail gas desulfurization device, 8-Chimney, 9-Circulation tank, 10-Solution pump, 11-Acid mixer. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0017] Reference Appendix Figure 1An SO3 recovery system includes an acid mist collection device 1, a first SO3 absorption tower 2, a drying tower 3, a negative pressure fan 4, a conversion device 5, a second SO3 absorption tower 6, a tail gas desulfurization device 7, a chimney 8, a circulation tank 9, and a solution pump 10. Both the first SO3 absorption tower 2 and the second SO3 absorption tower 6 have an outlet and a liquid inlet at their upper parts, and an inlet and an outlet at their lower parts. The acid mist collection device 1 is located at the fuming acid loading point. The outlet of the acid mist collection device 1 is connected to the inlet of the first SO3 absorption tower 2, and the outlet of the first SO3 absorption tower 2 is connected to the inlet of the drying tower 3. The inlet of the drying tower 3 is also connected to an SO2 flue gas pipeline. The outlet of tower 3 is connected to the input of negative pressure fan 4. The output of negative pressure fan 4 is connected to the inlet of conversion device 5. The outlet of conversion device 5 is connected to the inlet of second SO3 absorption tower 6. The outlet of second SO3 absorption tower 6 is connected to the inlet of tail gas desulfurization device 7. The outlet of tail gas desulfurization device 7 is connected to chimney 8. The input of solution pump 10 is connected to circulation tank 9. The output of solution pump 10 is provided with a first branch and a second branch. The first branch is connected to the liquid inlet of first SO3 absorption tower 2. The second branch is connected to the liquid inlet of second SO3 absorption tower 6. The liquid outlets of first SO3 absorption tower 2 and second SO3 absorption tower 6 are both connected to circulation tank 9.

[0018] In one embodiment of this utility model, an acid mixer 11 is also included. The acid mixer is disposed inside the circulation tank 9. The output end of the solution pump 10 is also provided with a third branch. The third branch is connected to the inlet of the acid mixer 11. The inlet of the acid mixer 11 is also connected to a water pipe. The outlet of the acid mixer 11 is connected to the inside of the circulation tank 9. Water is added to the circulation tank 9 through the acid mixer to dilute the sulfuric acid in the circulation tank 9 and maintain the sulfuric acid concentration in the circulation tank 9 at 98%.

[0019] In one embodiment of this utility model, the drying tower 3 is filled with 93% concentrated sulfuric acid, and an acid concentration sensor is provided at the bottom of the drying tower 3. The outlet of the drying tower 3 is connected to the circulation tank 9. The acid concentration sensor is linked with the replenishment device. When the acid concentration is lower than 90%, concentrated sulfuric acid is automatically replenished. At the same time, dilute acid is discharged into the circulation tank 9 through the outlet of the drying tower 3 to dilute the sulfuric acid in the circulation tank 9, so that the sulfuric acid concentration in the circulation tank 9 is maintained at 98%.

[0020] In one embodiment of this utility model, both the first SO3 absorption tower 2 and the second SO3 absorption tower 6 are provided with a spray layer and a packing layer, with the spray layer located above the packing layer.

[0021] In one embodiment of this utility model, the circulation tank 9 is filled with 98% concentrated sulfuric acid, and the circulation tank 9 is equipped with a stirring device.

[0022] The above-mentioned SO3 recovery system is used in the following steps:

[0023] S1. Start the negative pressure fan 4 and solution pump 10. The acid mist generated by the fuming acid enters the acid mist collection device 1 and the first SO3 absorption tower 2 in sequence under the action of the negative pressure fan 4. The acid mist flows from bottom to top in the first SO3 absorption tower 2. The 98% concentrated sulfuric acid in the circulation tank 9 enters the first SO3 absorption tower and the second SO3 absorption tower from top to bottom under the action of the solution pump 10. The SO3 in the acid mist is absorbed by the 98% concentrated sulfuric acid in the first SO3 absorption tower. The first absorbent liquid generated is discharged into the circulation tank 9 through the outlet of the first SO3 absorption tower.

[0024] S2. The acid mist after passing through the first SO3 absorption tower enters the drying tower 3, where it is dehydrated together with the SO2 flue gas, and then enters the conversion unit 5 to produce SO3.

[0025] S3. The SO3 produced by the conversion unit 5 enters the second SO3 absorption tower from bottom to top under the action of the negative pressure fan 4. It is absorbed by the 98% concentrated sulfuric acid flowing from top to bottom in the second SO3 absorption tower. The resulting second absorption liquid is discharged into the circulation tank 9 through the outlet of the second SO3 absorption tower. The waste gas generated by the second SO3 absorption tower is desulfurized by the tail gas desulfurization unit 7 and then discharged through the chimney 8.

[0026] This invention provides an SO3 recovery system that combines an acid mist collection system and an SO2 conversion system by setting up two SO3 absorption towers. Acid mist enters the acid mist collection device and the first SO3 absorption tower through the negative pressure in the SO2 conversion system, improving the acid mist recovery rate. Simultaneously, the absorbed SO3 acid mist, along with SO2 flue gas, passes through a drying tower and conversion device before entering the second SO3 absorption tower for further SO3 absorption, increasing the SO3 recovery rate and effectively reducing the environmental pollution caused by acid mist emissions. The system also includes an acid mixer that adds water to the circulation tank to dilute the sulfuric acid, maintaining the sulfuric acid concentration in the circulation tank at 98%, ensuring stable system operation. The drying tower is filled with 93% concentrated sulfuric acid. An acid concentration sensor at its bottom is linked to a replenishment device; when the acid concentration falls below 90%, concentrated sulfuric acid is automatically added, while dilute acid is discharged into the circulation tank for sulfuric acid dilution. This achieves stable control of the sulfuric acid concentration in the drying tower and rationally utilizes dilute acid, further optimizing the system's treatment and utilization of sulfuric acid, and improving overall resource utilization and system reliability.

[0027] The foregoing description describes some exemplary embodiments of this utility model. It is understood that the above embodiments are only used to explain this utility model and do not constitute a limitation on the scope of protection of this utility model. The features in these embodiments can be recombine in a suitable manner, and the resulting solutions are still within the scope of protection claimed by this utility model. Based on the above embodiments, all other embodiments obtained by those skilled in the art without inventive effort, that is, all modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, fall within the scope of protection claimed by this utility model.

Claims

1. An SO3 recovery system, characterized in that, The system includes an acid mist collection device (1), a first SO3 absorption tower (2), a drying tower (3), a negative pressure fan (4), a conversion device (5), a second SO3 absorption tower (6), a tail gas desulfurization device (7), a chimney (8), a circulation tank (9), and a solution pump (10). Both the first SO3 absorption tower (2) and the second SO3 absorption tower (6) have an outlet and a liquid inlet at their upper parts, and an inlet and an outlet at their lower parts. The acid mist collection device (1) is located at the fuming acid loading point. The outlet of the acid mist collection device (1) is connected to the inlet of the first SO3 absorption tower (2), and the outlet of the first SO3 absorption tower (2) is connected to the inlet of the drying tower (3). The inlet of the drying tower (3) is also connected to the SO2 flue gas pipeline, and the outlet of the drying tower (3) is connected to the negative pressure fan. The input end of the machine (4) is connected to the output end of the negative pressure fan (4), which is connected to the air inlet of the conversion device (5). The air outlet of the conversion device (5) is connected to the air inlet of the second SO3 absorption tower (6). The air outlet of the second SO3 absorption tower (6) is connected to the air inlet of the tail gas desulfurization device (7). The air outlet of the tail gas desulfurization device (7) is connected to the chimney (8). The input end of the solution pump (10) is connected to the circulation tank (9). The output end of the solution pump (10) is provided with a first branch and a second branch. The first branch is connected to the liquid inlet of the first SO3 absorption tower (2), and the second branch is connected to the liquid inlet of the second SO3 absorption tower (6). The liquid outlets of the first SO3 absorption tower (2) and the second SO3 absorption tower (6) are both connected to the circulation tank (9).

2. The SO3 recovery system according to claim 1, characterized in that, It also includes an acid mixer (11), which is located inside the circulation tank (9). The output end of the solution pump (10) is also provided with a third branch, which is connected to the inlet of the acid mixer (11). The inlet of the acid mixer (11) is also connected to a water pipe. The outlet of the acid mixer (11) is connected to the inside of the circulation tank (9).

3. The SO3 recovery system according to claim 1, characterized in that, The drying tower (3) is filled with 93% concentrated sulfuric acid. An acid concentration sensor is provided at the bottom of the drying tower (3). The outlet of the drying tower (3) is connected to the circulation tank (9).

4. The SO3 recovery system according to claim 1, characterized in that, Both the first SO3 absorption tower (2) and the second SO3 absorption tower (6) are equipped with a spray layer and a packing layer, with the spray layer located above the packing layer.

5. The SO3 recovery system according to claim 1, characterized in that, The circulation tank (9) is filled with 98% concentrated sulfuric acid and is equipped with a stirring device.

Images