Concentrated sulfuric acid drying device

Abstract

This utility model discloses a concentrated sulfuric acid drying device, including a sulfuric acid drying tower, an upper circulation loop, and a lower circulation loop. The sulfuric acid drying tower includes an upper tower section and a lower tower section. The middle section of the lower tower section is suitable for introducing tail gas to be treated, and the top of the upper tower section is suitable for introducing concentrated sulfuric acid in a spray pattern. The bottom of the upper tower section is provided with a sulfuric acid collection port, and the top of the upper tower section is also provided with a tail gas outlet. The middle section of the upper tower section is provided with an upper sulfuric acid reflux port, and the bottom of the lower tower section is provided with a sulfuric acid outlet. The top and / or middle of the lower tower section is provided with a lower sulfuric acid reflux port. The upper circulation loop is connected to the sulfuric acid collection port and the upper sulfuric acid reflux port; the lower circulation loop is connected to the sulfuric acid outlet and the lower sulfuric acid reflux port. The tail gas entering the lower tower section has some moisture absorbed by the sulfuric acid in the lower tower section before entering the upper tower section where it continues to have moisture absorbed by the sulfuric acid. This utility model improves the drying and absorption effect of moisture in the tail gas.

Description

Technical Field

[0001] This utility model relates to a concentrated sulfuric acid drying device, belonging to the field of tail gas treatment technology. Background Technology

[0002] Currently, the exhaust gas generated after the production of chemical products (such as methyl dichloride) needs to be treated before being discharged. During the exhaust gas treatment process, a drying tower is required to absorb and dry the moisture in the exhaust gas. Patent CN111170826B discloses a clean recovery system and process for chloromethane in glyphosate production exhaust gas, which discloses the use of a multi-stage series concentrated sulfuric acid drying tower to absorb and dry the moisture in the exhaust gas; however, the disclosed concentrated sulfuric acid drying tower is a single-stage drying tower, and the moisture drying effect of a single concentrated sulfuric acid drying tower may not be ideal. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a concentrated sulfuric acid drying device that improves the drying and absorption effect of moisture in the exhaust gas.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is: a concentrated sulfuric acid drying device, comprising:

[0005] A sulfuric acid drying tower includes an upper tower section and a lower tower section that are separated but connected. The middle section of the lower tower section is suitable for introducing tail gas to be treated. The top of the upper tower section is suitable for introducing concentrated sulfuric acid and spraying it. The bottom of the upper tower section is provided with a sulfuric acid collection port. The top of the upper tower section is also provided with a tail gas outlet for discharging the tail gas after absorbing moisture. The middle section of the upper tower section is provided with an upper sulfuric acid reflux port. The bottom of the lower tower section is provided with a sulfuric acid outlet. The top and / or middle of the lower tower section is provided with a lower sulfuric acid reflux port.

[0006] An upper circulation loop is connected to the sulfuric acid collection port and the upper sulfuric acid reflux port, and the upper circulation loop is used to circulate the sulfuric acid in the upper tower section;

[0007] A lower circulation loop is provided, connected to the sulfuric acid outlet and the lower sulfuric acid reflux port, and is used to signal the sulfuric acid within the lower tower section; wherein...

[0008] The exhaust gas entering the lower tower section has some moisture absorbed by sulfuric acid in the lower tower section, and then enters the upper tower section where it continues to have moisture absorbed by sulfuric acid.

[0009] Furthermore, in order to collect the sulfuric acid after the upper tower absorbs moisture from the tail gas, the sulfuric acid drying tower is provided with a collection tank connected to the sulfuric acid collection port, and the collection tank divides the sulfuric acid drying tower into the upper tower and the lower tower.

[0010] Furthermore, in order to allow the sulfuric acid from the upper tower to overflow into the lower tower for continued absorption of moisture in the tail gas, and in order to allow the tail gas rising from the lower tower to enter the upper tower, the collecting tank is provided with an overflow pipe. The upper part of the overflow pipe is connected to the upper tower, and the lower part of the overflow pipe is connected to the inner cavity of the lower tower.

[0011] Furthermore, a specific structure for an upper loop is provided, the upper loop comprising:

[0012] Sulfuric acid buffer tank;

[0013] An upper circulating cooler, wherein the cooling outlet of the upper circulating cooler is connected to the upper sulfuric acid reflux port;

[0014] The upper circulating pump unit has its inlet connected to the bottom of the sulfuric acid buffer tank, and its outlet connected to the cooling inlet of the upper circulating cooler.

[0015] Furthermore, a specific structure for a lower loop is provided, the lower loop comprising:

[0016] A lower circulating cooler, wherein the cooling outlet of the lower circulating cooler is connected to the lower sulfuric acid reflux port;

[0017] The lower circulation pump unit has its inlet connected to the sulfuric acid outlet and its outlet connected to the cooling inlet of the lower circulation cooler.

[0018] Furthermore, in order to discharge some sulfuric acid that does not meet the required concentration, the concentrated sulfuric acid drying device also includes a sulfuric acid discharge pipeline connected to the outlet of the lower circulating pump group. The sulfuric acid discharge pipeline is equipped with a discharge valve, and a concentration acquisition device is provided on the lower part of the lower tower for collecting the concentration of sulfuric acid in the lower tower. The opening or closing of the discharge valve is controlled according to the concentration collected by the concentration acquisition device.

[0019] Furthermore, in order to ensure that the sulfuric acid level at the bottom of the lower tower does not exceed the standard, the concentrated sulfuric acid drying device also includes a concentrated sulfuric acid feed pipeline connected to the top of the upper tower. The concentrated sulfuric acid feed pipeline is equipped with a feed control valve, and a level acquisition device is provided on the lower part of the lower tower for collecting the sulfuric acid level in the lower tower. The feed control valve is opened or closed according to the level collected by the level acquisition device.

[0020] Furthermore, the concentrated sulfuric acid drying device also includes a tail gas inlet pipe, which is connected to the middle part of the lower tower section to introduce the tail gas to be treated into the lower tower section.

[0021] Furthermore, in order to separate and remove some of the condensate from the tail gas entering the concentrated sulfuric acid drying tower, the concentrated sulfuric acid drying device also includes a gas-liquid separator, the bottom of which is adapted to allow tail gas to pass through, and the top of which is connected to the tail gas inlet pipe.

[0022] Furthermore, to prevent the tail gas from carrying away concentrated sulfuric acid after being treated by the concentrated sulfuric acid drying tower, the concentrated sulfuric acid drying device also includes a demister. The inlet of the demister is connected to the tail gas outlet, and the sulfuric acid recovery collection port of the demister is connected to the top of the upper tower.

[0023] By adopting the above technical solution, this utility model uses a staged absorption structure consisting of an upper tower and a lower tower arranged vertically. The exhaust gas first enters the middle of the lower tower and comes into countercurrent contact with the concentrated sulfuric acid sprayed by the lower circulation loop in the lower tower and / or the concentrated sulfuric acid overflowing from the upper tower to the lower tower, thus initially absorbing moisture. After being initially dried in the lower tower, the exhaust gas continues to rise to the upper tower, where it comes into countercurrent contact again with the concentrated sulfuric acid sprayed by the upper circulation loop in the upper tower and the incoming concentrated sulfuric acid, further removing moisture. Finally, the dried exhaust gas is discharged from the exhaust gas outlet at the top of the tower, thereby improving the effect of moisture absorption in the exhaust gas. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the concentrated sulfuric acid drying device of this utility model;

[0025] Figure 2 This is a schematic diagram of the concentrated sulfuric acid drying tower of this utility model; wherein,

[0026] 1. Sulfuric acid drying tower; 11. Upper tower section; 11a. Sulfuric acid collection port; 11b. Tail gas outlet; 11c. Upper sulfuric acid reflux port; 11d. Supplementary sulfuric acid inlet; 12. Lower tower section; 12a. Sulfuric acid outlet; 12b. Lower sulfuric acid reflux port; 12c. Tail gas inlet; 13. Collection tank; 13a. Overflow pipe;

[0027] 21. Sulfuric acid buffer tank; 22. Upper circulating cooler; 23. Upper circulating pump set;

[0028] 31. Lower circulating cooler; 32. Lower circulating pump set;

[0029] 4. Sulfuric acid discharge pipeline; 41. Drain valve;

[0030] 5. Concentrated sulfuric acid feed pipeline; 51. Feed control valve;

[0031] 6. Liquid level acquisition device;

[0032] 7. Exhaust gas intake pipe;

[0033] 8. Gas-liquid separator;

[0034] 9. Demister. Detailed Implementation

[0035] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0036] like Figure 1 , 2 As shown, a concentrated sulfuric acid drying apparatus includes:

[0037] Sulfuric acid drying tower 1 includes an upper tower section 11 and a lower tower section 12 that are separated but connected. The middle part of the lower tower section 12 is suitable for introducing tail gas to be treated. The top of the upper tower section 11 is suitable for introducing concentrated sulfuric acid and making it spray. The bottom of the upper tower section 11 is provided with a sulfuric acid collection port 11a. The top of the upper tower section 11 is also provided with a tail gas outlet 11b for discharging the tail gas after absorbing moisture. The middle part of the upper tower section 11 is provided with an upper sulfuric acid reflux port 11c. The bottom of the lower tower section 12 is provided with a sulfuric acid outlet 12a. The top and middle parts of the lower tower section 12 are provided with a lower sulfuric acid reflux port 12b.

[0038] The upper circulation loop is connected to the sulfuric acid collection port 11a and the upper sulfuric acid reflux port 11c. The upper circulation loop is used to circulate the sulfuric acid in the upper tower section 11.

[0039] The lower circulation loop is connected to the sulfuric acid outlet 12a and the lower sulfuric acid reflux port 12b. The lower circulation loop is used for the sulfuric acid within the lower tower section 12.

[0040] The exhaust gas entering the lower tower section 12 has some moisture absorbed by sulfuric acid in the lower tower section 12, and then enters the upper tower section 11 where it continues to have moisture absorbed by sulfuric acid.

[0041] Specifically, such as Figure 2 As shown, in order to collect the sulfuric acid after the upper tower section 11 absorbs the moisture in the tail gas, the sulfuric acid drying tower 1 is provided with a collection tank 13 connected to the sulfuric acid collection port 11a. The collection tank 13 divides the sulfuric acid drying tower 1 into an upper tower section 11 and a lower tower section 12.

[0042] Specifically, in order to allow the sulfuric acid in the upper tower 11 to overflow to the lower tower 12 to continue absorbing moisture in the tail gas, and in order to allow the tail gas rising in the lower tower 12 to enter the upper tower 11, an overflow pipe 13a is provided on the collecting tank 13. The upper part of the overflow pipe 13a is connected to the upper tower 11, and the lower part of the overflow pipe 13a is connected to the inner cavity of the lower tower 12.

[0043] In this embodiment, a staged absorption structure consisting of an upper tower section 11 and a lower tower section 12 arranged vertically is adopted. The tail gas first enters the middle of the lower tower section 12 and comes into countercurrent contact with the concentrated sulfuric acid sprayed by the lower circulation loop in the lower tower section 12 and the concentrated sulfuric acid overflowing from the upper tower section 11 to the lower tower section 12, thus initially absorbing moisture. After being initially dried in the lower tower section 12, the tail gas continues to rise to the upper tower section 11, where it comes into countercurrent contact again with the concentrated sulfuric acid sprayed by the upper circulation loop in the upper tower section 11 and the incoming concentrated sulfuric acid, thus further removing moisture. Finally, the dried tail gas is discharged from the tail gas outlet 11b at the top of the tower, thereby improving the effect of moisture absorption in the tail gas.

[0044] In this embodiment, the structure of the collecting tank 13 is specifically as follows: Figure 2 As shown, the edge of the collecting tank 13 is provided with a recessed collecting trough, which is connected to the sulfuric acid collecting port 11a. The rest of the collecting tank 13 is equipped with multiple overflow pipes 13a, from which sulfuric acid can overflow into the lower tower section 12. Of course, the tail gas in the lower tower section 12 can also enter the upper tower section 11 through the overflow pipe 13a.

[0045] Specifically, such as Figure 1 As shown, a specific structure of an upper loop is provided, which specifically includes:

[0046] Sulfuric acid buffer tank 21;

[0047] The upper circulating cooler 22 has its cooling outlet connected to the upper sulfuric acid reflux port 11c.

[0048] The upper circulating pump group 23 has its inlet connected to the bottom of the sulfuric acid buffer tank 21, and its outlet connected to the cooling inlet of the upper circulating cooler 22.

[0049] After absorbing moisture from the tail gas in the upper tower section 11, the sulfuric acid is collected in the collecting tank 13. Part of it is discharged from the sulfuric acid collecting port 11a to the sulfuric acid buffer tank 21, and the other part flows into the lower tower section 12 through the overflow pipe 13a to participate in the lower absorption. The sulfuric acid at the bottom of the sulfuric acid buffer tank 21 is transported to the upper circulating cooler 22 by the upper circulating pump group 23. The heat released by the sulfuric acid in absorbing moisture is removed by cooling (lowering the sulfuric acid temperature and maintaining the absorption efficiency). The cooled sulfuric acid is returned to the upper sulfuric acid return port 11c and sprayed to absorb moisture from the tail gas again.

[0050] Specifically, such as Figure 1 As shown, a specific structure of a lower loop is provided, which specifically includes:

[0051] The lower circulating cooler 31 has its cooling outlet connected to the lower sulfuric acid reflux port 12b.

[0052] The lower circulating pump group 32 has its inlet connected to the sulfuric acid outlet 12a, and its outlet connected to the cooling inlet of the lower circulating cooler 31.

[0053] The sulfuric acid in the lower tower section 12 is transported to the lower circulating cooler 31 by the lower circulating pump group 32 for cooling, and then returned to the lower tower section 12 from the lower sulfuric acid return port 12b for spraying again to absorb the remaining moisture in the tail gas, thus completing the lower section circulation.

[0054] In this embodiment, as Figure 1 As shown, both the upper circulation pump group 23 and the lower circulation pump group 32 can be equipped with two circulation pumps connected in parallel. The two circulation pumps can be used simultaneously or individually as needed.

[0055] Specifically, in this embodiment, the concentrated sulfuric acid entering the concentrated sulfuric acid drying tower 1 is 98% concentrated sulfuric acid. When the concentration of sulfuric acid after circulating and absorbing the tail gas in the concentrated sulfuric acid drying tower 1 is <80% dilute sulfuric acid, it does not meet the usage requirements and needs to be partially discharged to the dilute sulfuric acid storage tank. In order to discharge some sulfuric acid with a concentration that does not meet the requirements, the concentrated sulfuric acid drying device also includes a sulfuric acid discharge pipeline 4 connected to the outlet of the lower circulating pump group 32. The sulfuric acid discharge pipeline 4 is equipped with a drain valve 41. A concentration acquisition device is provided on the lower part of the lower tower 12 for collecting the concentration of sulfuric acid in the lower tower 12. The opening or closing of the drain valve 41 is controlled according to the concentration collected by the concentration acquisition device. Specifically, when the concentration of sulfuric acid in the lower part of the lower tower 12 collected by the concentration acquisition device is <80%, the PLC will open the drain valve 41 to discharge part of the sulfuric acid to the dilute sulfuric acid storage tank. The concentration acquisition device can be a concentration meter or concentration detector, etc.

[0056] In this embodiment, to ensure that the sulfuric acid level at the bottom of the lower tower 12 does not exceed the limit and to avoid excessive feeding, such as... Figure 1 As shown, the concentrated sulfuric acid drying device also includes a concentrated sulfuric acid feed pipeline 5 connected to the top of the upper tower 11. The concentrated sulfuric acid feed pipeline 5 is equipped with a feed control valve 51. The lower part of the lower tower 12 is equipped with a liquid level acquisition device 6 for collecting the sulfuric acid liquid level in the lower tower 12. The feed control valve 51 is opened or closed according to the liquid level collected by the liquid level acquisition device 6. When the liquid level acquisition device 6 collects that the sulfuric acid liquid level in the lower part of the lower tower 12 reaches 80% (this value can be set, not limited to 80%), the feed control valve 51 is closed by controlling the PLC to stop the replenishment of concentrated sulfuric acid. The liquid level acquisition device 6 can be a differential pressure transmitter. Of course, in the concentrated sulfuric acid drying tower 1, the upper tower 11 is equipped with a supplementary sulfuric acid inlet 11d above the upper sulfuric acid reflux port 11c, and the concentrated sulfuric acid feed pipeline 5 is connected to the supplementary sulfuric acid inlet 11d.

[0057] Specifically, such as Figure 1As shown, the concentrated sulfuric acid drying device also includes a tail gas inlet pipe 7, which is connected to the middle of the lower tower section 12 so that the tail gas to be treated can be introduced into the lower tower section 12 through the tail gas inlet pipe 7; of course, the concentrated sulfuric acid drying tower 1 is provided with a tail gas inlet 12c at this position, and the tail gas inlet pipe 7 is connected to the tail gas inlet 12c.

[0058] Specifically, in order to separate and remove some of the condensate from the tail gas entering concentrated sulfuric acid drying tower 1, such as... Figure 1 As shown, the concentrated sulfuric acid drying device also includes a gas-liquid separator 8, the bottom of which is adapted to allow tail gas to pass through, and the top of which is connected to the tail gas inlet pipe 7.

[0059] Specifically, to prevent the concentrated sulfuric acid from being carried away by the tail gas after treatment in concentrated sulfuric acid drying tower 1, such as Figure 1 As shown, the concentrated sulfuric acid drying unit also includes a demister 9. The inlet of the demister 9 is connected to the tail gas outlet 11b, and the sulfuric acid recovery collection port of the demister 9 is connected to the top of the upper tower 11. In this embodiment, the drying tail gas discharged from the top of the concentrated sulfuric acid drying tower 1 can pass through the demister 9, and the sulfuric acid mist carried in the tail gas can be separated and recovered by the demister 9 (the recovered sulfuric acid is returned to the concentrated sulfuric acid drying tower 1 for recycling), ensuring the cleanliness of the tail gas.

[0060] Specifically, in this embodiment, the supplementary sulfuric acid inlet 11d, the upper sulfuric acid reflux port 11c, the sulfuric acid collection port 11a, the lower sulfuric acid reflux port 12b, and the tail gas inlet 12c are all located on the side of the concentrated sulfuric acid drying tower 1. Furthermore, the concentrated sulfuric acid drying tower 1 may be equipped with a first spray nozzle group connected to the supplementary sulfuric acid inlet 11d, a second spray nozzle group connected to the upper sulfuric acid reflux port 11c, and a third spray nozzle group connected to the lower sulfuric acid reflux port 12b. An air distributor connected to the tail gas inlet 12c may also be installed within the concentrated sulfuric acid drying tower 1. Of course, the concentrated sulfuric acid drying tower 1 is also equipped with a packing layer. The specific arrangement of the packing layer can be as follows: a packing layer may be installed between the first and second spray nozzle groups, between the second spray nozzle group and the collection tank 13, and between the third spray nozzle group and the air distributor corresponding to the tail gas inlet 12c.

[0061] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A concentrated sulfuric acid drying apparatus, characterized in that... ,include: A sulfuric acid drying tower includes an upper tower section and a lower tower section that are separated but connected. The middle section of the lower tower section is suitable for introducing tail gas to be treated. The top of the upper tower section is suitable for introducing concentrated sulfuric acid and spraying it. The bottom of the upper tower section is provided with a sulfuric acid collection port. The top of the upper tower section is also provided with a tail gas outlet for discharging the tail gas after absorbing moisture. The middle section of the upper tower section is provided with an upper sulfuric acid reflux port. The bottom of the lower tower section is provided with a sulfuric acid outlet. The top and / or middle of the lower tower section is provided with a lower sulfuric acid reflux port. An upper circulation loop is connected to the sulfuric acid collection port and the upper sulfuric acid reflux port, and the upper circulation loop is used to circulate the sulfuric acid in the upper tower section; A lower circulation loop is provided, connected to the sulfuric acid outlet and the lower sulfuric acid reflux port, and is used to signal the sulfuric acid within the lower tower section; wherein... The exhaust gas entering the lower tower section has some moisture absorbed by sulfuric acid in the lower tower section, and then enters the upper tower section where it continues to have moisture absorbed by sulfuric acid.

2. The concentrated sulfuric acid drying apparatus according to claim 1, characterized in that, The sulfuric acid drying tower is equipped with a collection tank that connects to the sulfuric acid collection port, and the collection tank divides the sulfuric acid drying tower into the upper tower section and the lower tower section.

3. The concentrated sulfuric acid drying apparatus according to claim 2, characterized in that, The collecting tank is equipped with an overflow pipe, the upper part of which is connected to the upper tower section, and the lower part of which is connected to the inner cavity of the lower tower section.

4. The concentrated sulfuric acid drying apparatus according to claim 1, characterized in that, The upper loop includes: Sulfuric acid buffer tank; An upper circulating cooler, wherein the cooling outlet of the upper circulating cooler is connected to the upper sulfuric acid reflux port; The upper circulating pump unit has its inlet connected to the bottom of the sulfuric acid buffer tank, and its outlet connected to the cooling inlet of the upper circulating cooler.

5. The concentrated sulfuric acid drying apparatus according to claim 1, characterized in that, The lower loop includes: A lower circulating cooler, wherein the cooling outlet of the lower circulating cooler is connected to the lower sulfuric acid reflux port; The lower circulation pump unit has its inlet connected to the sulfuric acid outlet and its outlet connected to the cooling inlet of the lower circulation cooler.

6. The concentrated sulfuric acid drying apparatus according to claim 5, characterized in that, It also includes a sulfuric acid discharge pipeline connected to the outlet of the lower circulating pump group, the sulfuric acid discharge pipeline is equipped with a discharge valve, and a concentration acquisition device is provided on the lower part of the lower tower for collecting the concentration of sulfuric acid in the lower tower. The discharge valve is opened or closed according to the concentration collected by the concentration acquisition device.

7. The concentrated sulfuric acid drying apparatus according to claim 1, characterized in that, It also includes a concentrated sulfuric acid feed pipeline connected to the top of the upper tower section, a feed control valve is provided on the concentrated sulfuric acid feed pipeline, and a liquid level acquisition device is provided on the lower part of the lower tower section for collecting the liquid level of sulfuric acid in the lower tower section, and the feed control valve is opened or closed according to the liquid level collected by the liquid level acquisition device.

8. The concentrated sulfuric acid drying apparatus according to claim 1, characterized in that, It also includes an exhaust gas inlet pipe, which is connected to the middle of the lower tower section to introduce the exhaust gas to be treated into the lower tower section.

9. The concentrated sulfuric acid drying apparatus according to claim 8, characterized in that, It also includes a gas-liquid separator, the bottom of which is adapted to allow exhaust gas to pass through, and the top of which is connected to the exhaust gas inlet pipe.

10. The concentrated sulfuric acid drying apparatus according to claim 1, characterized in that, It also includes a demister, the inlet of which is connected to the tail gas outlet, and the sulfuric acid recovery collection port of the demister is connected to the top of the upper tower.

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