A reactor for catalytic oxidation of sulfur dioxide

Abstract

The utility model provides a kind of reactor for sulfur dioxide catalytic oxidation, belong to waste acid regeneration process field.The existing sulfur dioxide catalytic oxidation reaction device cannot guarantee the air supply of oxidation reaction enough, and process gas temperature cannot be adjusted to the temperature interval of catalyst reaction activity, leading to the problem of low SO2 conversion rate.It includes lower box, upper box, air distributor, grating plate and heat exchanger, heat exchanger is installed between upper box and lower box, three layers of grating plate are horizontally installed in upper box, platinum catalyst assembly is equipped above first layer grating plate from top to bottom, vanadium-based catalyst assembly is equipped above other two layers, four air distributors are evenly distributed between first layer grating plate and second layer grating plate on vanadium-based catalyst assembly in upper box, grating plate with surface provided with bulk vanadium catalyst assembly is installed in the bottom of lower box.It is mainly used for SO2 conversion in process gas.

Description

Technical Field

[0001] This utility model belongs to the field of waste acid regeneration process, and in particular relates to a reactor for the catalytic oxidation of sulfur dioxide. Background Technology

[0002] In sulfur oxidation and waste acid regeneration processes, the combustion of waste acid gas or the cracking of waste sulfuric acid will generate high-temperature process gas containing SO2. According to the process requirements, SO2 is oxidized to SO3 in the oxidation unit. In the subsequent process unit, SO3 is converted into sulfuric acid, thereby realizing "acid regeneration". In the entire process, the SO2 oxidation to SO3 step is particularly important and is the core influencing factor that determines the sulfuric acid yield.

[0003] However, existing sulfur dioxide catalytic oxidation reactors cannot guarantee sufficient air supply for the oxidation reaction, and the process gas temperature cannot be adjusted to the temperature range where the catalyst is active, resulting in low SO2 conversion rate. Summary of the Invention

[0004] In view of this, the present invention aims to propose a reactor for the catalytic oxidation of sulfur dioxide, in order to solve the problems that existing sulfur dioxide catalytic oxidation reactors cannot guarantee sufficient air supply for the oxidation reaction and that the process gas temperature cannot be adjusted to the temperature range of catalyst activity, resulting in low SO2 conversion rate.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A reactor for the catalytic oxidation of sulfur dioxide includes a lower chamber, an upper chamber, air distributors, a platinum catalyst assembly, grating plates, a vanadium-based catalyst assembly, a heat exchanger, and a bulk vanadium catalyst assembly. The upper chamber has an air inlet at its top and is connected to the air inlet of the lower chamber at its bottom. The lower chamber has an air outlet at its bottom. The heat exchanger is installed between the upper and lower chambers. Three layers of grating plates are horizontally installed inside the upper chamber. From top to bottom, a platinum catalyst assembly is installed above the first layer of grating plates, and vanadium-based catalyst assemblies are installed above the other two layers. Four air distributors are provided, evenly distributed between the vanadium-based catalyst assemblies on the first and second layers of grating plates inside the upper chamber. A grating plate with a bulk vanadium catalyst assembly on its surface is installed at the bottom of the lower chamber.

[0006] Furthermore, the air distributor has several air outlets evenly distributed on it.

[0007] Furthermore, the heat exchanger is a finned tube heat exchanger, with a heat transfer salt inlet and a heat transfer salt outlet at each end of the heat exchange tube.

[0008] Furthermore, an inlet guide plate is provided below the air inlet of the upper housing, and guide plates are provided above the air outlet of the upper housing and below the air inlet of the lower housing.

[0009] Furthermore, the lower housing, upper housing, air distributor, and grille are all made of high-temperature and corrosion-resistant materials such as 904L.

[0010] Furthermore, a temperature compensator is provided between the lower housing and the heat exchanger.

[0011] Furthermore, two temperature sensors are installed below each layer of grating in the upper chamber, and two temperature sensors are installed below the grating in the lower chamber and above the bulk vanadium catalyst assembly. The temperature sensors in the upper chamber feed back the temperature of the process gas to the control system, and the temperature sensors in the lower chamber monitor the temperature of the catalytic oxidation reaction window of the bulk vanadium catalyst and feed it back to the control system. The control system controls the flow rate of the heat-conducting salt in the heat exchanger.

[0012] Furthermore, both the lower and upper housings are supported and fixed by four equipment supports.

[0013] Furthermore, the upper housing is equipped with an inspection door.

[0014] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model has four air distributors, each with several air outlets, which makes the air distribution in the space more uniform, which is conducive to the full mixing of air and process gas, ensuring that the oxidation reaction can continue. It solves the problem that existing sulfur dioxide catalytic oxidation reaction devices cannot guarantee sufficient air supply for the oxidation reaction, and improves the conversion rate of SO2 in the process gas.

[0015] 2. This utility model provides a heat exchanger between the upper and lower housings. In the heat exchanger, the process gas passes through the gaps between the heat exchanger tubes from top to bottom. The heat exchanger tubes are filled with thermally conductive salt, and a temperature sensor feeds back the temperature of the process gas to the control system. The control system adjusts the flow rate of the thermally conductive salt to change the heat exchanger's heat exchange capacity, thereby adjusting the temperature of the process gas to the catalytic oxidation reaction window temperature of the bulk vanadium catalyst assembly, thus improving the conversion efficiency.

[0016] 3. The lower housing, upper housing, air distributor, and grating plate of this utility model are all made of high-temperature and corrosion-resistant materials such as 904L, which increases the service life of the device. Attached Figure Description

[0017] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings: Figure 1 This is a front view of a reactor for the catalytic oxidation of sulfur dioxide according to the present invention. Figure 2 This is a side view of a reactor for the catalytic oxidation of sulfur dioxide according to the present invention. Figure 3 This is a schematic diagram of the grating plate structure; Figure 4 This is a schematic diagram of the air distributor. Figure 5 This is a schematic diagram of the guide vane structure; Figure 6 This is a structural schematic diagram of the equipment support; Figure 7 This is a schematic diagram of the temperature compensator. Figure 8 This is a structural diagram of an inspection door.

[0018] In the picture: 1-Lower housing, 2-Heat transfer salt outlet, 3-Heat transfer salt inlet, 4-Upper housing, 5-Equipment support, 6-Air distributor, 7-Temperature sensor, 8-Maintenance door, 9-Inlet baffle, 10-Platinum catalyst assembly, 11-Grate plate, 12-Vanadium-based catalyst assembly, 13-Baffle, 14-Heat exchanger, 15-Temperature compensator, 16-Bulk vanadium catalyst assembly, 17-Air inlet, 18-Air outlet. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present utility model can be combined with each other, and the described embodiments are only some embodiments of the present utility model, not all embodiments.

[0020] Detailed Implementation Method 1: See Figure 1-8This embodiment describes a reactor for the catalytic oxidation of sulfur dioxide, comprising a lower chamber 1, an upper chamber 4, an air distributor 6, a platinum catalyst assembly 10, a grid plate 11, a vanadium-based catalyst assembly 12, a heat exchanger 14, and a bulk vanadium catalyst assembly 16. The upper chamber 4 has an air inlet 17 at its top and is connected to the air inlet of the lower chamber 1 at its bottom. The lower chamber 1 has an air outlet 18 at its bottom. The heat exchanger 14 is installed between the upper chamber 4 and the lower chamber 1. Three layers of grid plates 11 are horizontally installed inside the upper chamber 4. From top to bottom, the first layer of grid plates 11 has a platinum catalyst assembly 10 on top, and the other two layers have vanadium-based catalyst assemblies 12 on top. Four air distributors 6 are provided, evenly distributed between the vanadium-based catalyst assemblies 12 on the first and second layers of grid plates 11 inside the upper chamber 4. A grid plate 11 with a bulk vanadium catalyst assembly 16 on its surface is installed at the bottom of the lower chamber 1.

[0021] Furthermore, an inlet guide plate 9 is provided below the air inlet 17 of the upper box 4, and guide plates 13 are provided above the air outlet of the upper box 4 and below the air inlet of the lower box 1.

[0022] Furthermore, two temperature sensors 7 are provided below each layer of grid plate 11 in the upper box 4, and two temperature sensors 7 are provided below the grid plate 11 and above the bulk vanadium catalyst assembly 16 in the lower box 1. The temperature sensors 7 in the upper box 4 feed back the temperature of the process gas to the control system, and the temperature sensors 7 in the lower box 1 are used to monitor the temperature of the catalytic oxidation reaction window of the bulk vanadium catalyst and feed it back to the control system. The control system controls the flow rate of the heat-conducting salt in the heat exchanger 14.

[0023] During operation, the process gas enters the device from top to bottom through inlet 17. Under the action of inlet guide plate 9, it enters the space region of the platinum catalyst assembly 10 evenly. The SO2 in the process gas undergoes a catalytic oxidation reaction with the existing oxygen under the action of the platinum catalyst. After the reaction, the SO2 conversion rate reaches approximately 95%. At this point, the SO2 and oxygen content in the process gas becomes significantly low. Therefore, to ensure the oxidation reaction continues, air is supplied above the vanadium-based catalyst through air distributor 6. After mixing with the process gas air, the air enters the vanadium-based catalyst region, where SO2 continues to undergo a catalytic oxidation reaction under the action of the vanadium-based catalyst. After the above reaction, the temperature of the process gas changes. The reacted process gas enters the heat exchanger 14 area for heat exchange. The temperature sensor 7 feeds back the temperature of the process gas to the control system. The control system adjusts the flow rate of the heat transfer salt to change the heat exchanger's heat exchange capacity, adjusting the temperature of the process gas to the catalytic oxidation reaction window temperature of the bulk vanadium catalyst assembly. The adjusted process gas is evenly distributed by the guide plate 13 and enters the bulk vanadium catalyst 16 assembly area. SO2 in the process gas undergoes catalytic oxidation under the action of the bulk vanadium catalyst. Afterward, the process gas is discharged from the outlet 18. After the above reaction, the SO2 conversion rate can reach 98%.

[0024] By equipping four air distributors 6, each with several air outlets, the air is more evenly distributed in the space, which is conducive to the full mixing of air and process gas, ensuring the continuous progress of the oxidation reaction. This solves the problem that existing sulfur dioxide catalytic oxidation reaction devices cannot guarantee sufficient air supply for the oxidation reaction, and improves the conversion rate of SO2 in the process gas. A heat exchanger 14 is installed between the upper chamber 4 and the lower chamber 1. In the heat exchanger 14, the process gas passes through the gaps between the tubes from top to bottom. The heat exchanger tubes are filled with thermally conductive salt, and the temperature sensor 7 feeds back the temperature of the process gas to the control system. The control system adjusts the flow rate of the thermally conductive salt to change the heat exchange capacity of the heat exchanger 14, thereby adjusting the temperature of the process gas to the catalytic oxidation reaction window temperature of the bulk vanadium catalyst assembly 16, and thus improving the conversion efficiency.

[0025] In this embodiment, the air distributor 6 is provided with several air outlets, which makes the air distribution in the space more uniform, which is conducive to the full mixing of air and process gas and can ensure the continuous progress of the oxidation reaction.

[0026] In this embodiment, the heat exchanger 14 is a finned tube heat exchanger. The two ends of the heat exchange tube are respectively provided with a thermally conductive salt inlet 3 and a thermally conductive salt outlet 2. The shell-side medium of the heat exchanger 14 is process gas, and the tube-side medium is thermally conductive salt. By adjusting the rate of thermally conductive salt, the temperature of the process gas is adjusted to ensure that the catalytic oxidation reaction matches the optimal temperature window of the catalyst and improve the conversion efficiency.

[0027] In this embodiment, an inlet guide plate 9 is provided below the air inlet 17 of the upper box 4, and guide plates 13 are provided above the air outlet of the upper box 4 and below the air inlet of the lower box 1. This ensures that the process gas is evenly distributed in the box, so that the process gas can fully carry out the catalytic oxidation reaction and further improve the SO2 conversion rate.

[0028] In this embodiment, the lower housing 1, upper housing 4, air distributor 6, and grille 11 are all made of 904L high-temperature acid corrosion resistant material, which increases the service life of the device. In this embodiment, a temperature compensator 15 is provided between the lower housing 1 and the heat exchanger 14 to compensate for the equipment expansion caused by the temperature difference.

[0029] In this embodiment, both the lower housing 1 and the upper housing 4 are supported and fixed by four equipment supports 5, which respectively bear the weight of the upper housing 4 and the lower housing 1. There is no force transmission between the housings, which is conducive to the uniform distribution of equipment load.

[0030] In this embodiment, the upper housing 4 is provided with an inspection door 8 to facilitate the inspection and repair of damaged parts inside the upper housing 4.

[0031] The specific embodiments of this utility model disclosed above are merely illustrative of the present utility model. These specific embodiments do not exhaustively describe all details, nor do they limit the invention to the described embodiments. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it.

Claims

1. A reactor for the catalytic oxidation of sulfur dioxide, characterized in that: The system includes a lower housing (1), an upper housing (4), an air distributor (6), a platinum catalyst assembly (10), a grid plate (11), a vanadium-based catalyst assembly (12), a heat exchanger (14), and a bulk vanadium catalyst assembly (16). The upper housing (4) has an air inlet (17) at the top and is connected to the air inlet of the lower housing (1) at the bottom. The lower housing (1) has an air outlet (18) at the bottom. The heat exchanger (14) is installed between the upper housing (4) and the lower housing (1). The upper housing (4) is horizontal. The upper box (4) is equipped with a three-layer grid plate (11). A platinum catalyst assembly (10) is provided above the first layer grid plate (11) from top to bottom, and a vanadium-based catalyst assembly (12) is provided above the other two layers. There are four air distributors (6), which are evenly distributed between the vanadium-based catalyst assembly (12) on the first layer grid plate (11) and the second layer grid plate (11) in the upper box (4). A grid plate (11) with a loose vanadium catalyst assembly (16) is installed at the bottom of the lower box (1).

2. The reactor for catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: The air distributor (6) has several air outlets evenly distributed on it.

3. The reactor for catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: The heat exchanger (14) is a finned tube heat exchanger, with a thermally conductive salt inlet (3) and a thermally conductive salt outlet (2) at both ends of the heat exchange tube.

4. The reactor for catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: An inlet guide plate (9) is provided below the air inlet (17) of the upper box (4).

5. The reactor for catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: A guide plate (13) is provided above the air outlet of the upper box (4) and below the air inlet of the lower box (1).

6. The reactor for catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: The lower housing (1), upper housing (4), air distributor (6), and grille (11) are all made of 904L material.

7. A reactor for the catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: A temperature compensator (15) is provided between the lower casing (1) and the heat exchanger (14).

8. A reactor for the catalytic oxidation of sulfur dioxide according to claim 3, characterized in that: Two temperature sensors (7) are provided below each layer of grid plate (11) in the upper box (4). Two temperature sensors (7) are provided below the grid plate (11) and above the bulk vanadium catalyst assembly (16) in the lower box (1). The temperature sensors (7) in the upper box (4) feed back the temperature of the process gas to the control system. The temperature sensors (7) in the lower box (1) are used to monitor the temperature of the catalytic oxidation reaction window of the bulk vanadium catalyst and feed it back to the control system. The control system controls the flow rate of the heat-conducting salt in the heat exchanger (14).

9. A reactor for the catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: Both the lower housing (1) and the upper housing (4) are supported and fixed by four equipment supports (5).

10. A reactor for the catalytic oxidation of sulfur dioxide according to claim 1, characterized in that: The upper housing (4) is equipped with an inspection door (8).

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