SO2 converter

Abstract

The utility model discloses an SO2 converter which comprises a reaction tower, a catalyst bed layer and a heat exchanger are arranged in the reaction tower, the heat exchanger is of an up-down hollow structure defined by heat exchange fins, and an interception plate is laid at the bottom of the heat exchanger. The heat exchanger is reasonable in structural design and has the advantages that the heat exchanger is of an up-down hollow structure defined by the heat exchange fins, process gas enters the heat exchanger from the middle, and the process gas is discharged from inside to outside in the peripheral direction; meanwhile, an interception plate is laid at the bottom of the heat exchanger, when process gas enters the middle air inlet of the heat exchanger through a flow guide plate at the top of the heat exchanger, most catalyst chippings and scrap iron fall onto the interception plate at the bottom of the heat exchanger due to flow direction deflection due to flow direction change, and therefore the situation that fins of the heat exchanger are blocked is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical equipment, in particular to a SO 2 Converter. Background Art

[0002] In the production of sulfuric acid, the core process step is SO 2 The main function of this process step is to convert SO 2 The process flue gas is converted into SO3 by the catalytic converter. The converter is filled with vanadium pentoxide catalyst. In order to achieve a higher conversion effect, in addition to the catalyst being filled flat and without accumulation, SO 2 The operating pressure difference resistance drop is very important. If the pressure difference resistance drop is too large, it will not only increase energy consumption and fail to meet the load capacity increase, but also cause the process gas flow rate to slow down, fail to achieve the optimal reaction rate and optimal reaction time, and cause SO 2 The conversion rate is reduced. In addition, the operating resistance is too large, and there is a risk of process gas leakage, so the SO 2 The converter pressure difference and resistance drop problem is particularly important, which can improve the conversion effect, reduce operating energy consumption and avoid leakage risks.

[0003] Currently, all sulfuric acid plants SO 2 The converter generally lacks consideration for reducing the resistance drop in design, which causes the resistance drop to increase with the extension of operation time, especially SO 2 During the stage when the converter produces more powder, the resistance drop and pressure difference increase phenomenon is particularly serious, which seriously affects SO 2 The conversion effect and operating energy consumption result in the inability to increase the production capacity of the device. In response to the problem of increased resistance drop, the current common practice is to stop the device to screen the converter catalyst when the resistance drop is found to be increased, reduce the amount of catalyst debris, and blow away the catalyst debris and metal rust debris remaining between the heat exchanger fins. Because the catalyst debris and rust debris mixed in the heat exchanger fins will be tightly blocked in the heat exchanger fins after a long period of operation, especially in the middle and lower fin layers of the heat exchanger, which cannot be blown away by compressed air. After the catalyst debris and rust debris are blocked in the fins, it will cause an increase in energy consumption during operation, which cannot meet the increase in load capacity and the heat cannot be taken away in time, affecting the heat exchange effect and further affecting the conversion efficiency. Utility Model Content

[0004] The purpose of the utility model is to provide a SO 2 Converter, solve the SO 2 During the operation of the converter, the problem of increased pressure difference resistance drop caused by blockage of the heat exchanger fins is solved, so that the process gas flow can pass smoothly and react evenly during operation, achieving the optimal operating energy consumption and conversion rate and reducing the risk of process gas leakage.

[0005] To achieve the above object, the technical solution of the present utility model provides a SO 2 converter, including a reaction tower, wherein a catalyst bed and a heat exchanger are arranged in the reaction tower. The heat exchanger is a vertically hollow structure surrounded by heat exchange fins, and a retaining plate is laid at the bottom of the heat exchanger.

[0006] Further, the heat exchanger is a cubic structure composed of four vertical heat exchange fins, and the heat exchange fins are connected to each other in pairs.

[0007] Further, the angle at which the heat exchange fins are connected is 90°, and the heat exchanger is a cuboid structure.

[0008] Further, a dust baffle is arranged at the top of the heat exchanger, and the dust baffle is vertically arranged at the outer extension of the top of the heat exchanger.

[0009] Further, the height of the dust baffle is 150 - 200 mm.

[0010] Further, a deflector is arranged at the top of the heat exchanger. One side of the deflector is connected to the outer extension of the top of the heat exchanger, and the other side is connected to the inner side of the outer skin of the reaction tower. The height of the deflector connected to the inner side of the outer skin of the reaction tower is higher than that of the deflector connected to the outer extension of the top of the heat exchanger.

[0011] Further, a process gas distribution plate is arranged below the heat exchanger. A number of round holes of the same size are arranged on the process gas distribution plate, and the structure of the process gas distribution plate is a conical structure.

[0012] Further, a maintenance hole is arranged at the bottom of the heat exchanger.

[0013] Further, the retaining plate is a steel plate, and a number of manholes are arranged on the reaction tower.

[0014] Further, two catalyst beds and a heat exchanger are arranged in the reaction tower. A process gas inlet, a catalyst bed, a heat exchanger, a catalyst bed, a heat exchanger, and a process gas outlet are arranged in the reaction tower from top to bottom; the distance between two adjacent heat exchangers is ≥ 800 mm.

[0015] In summary, the device structure of the present utility model is reasonably designed. By using the technical solution of the present utility model, the following beneficial effects are achieved: the heat exchanger is set as a vertically hollow structure surrounded by heat exchange fins, with process gas entering in the middle and flowing out in the circumferential direction from the inside to the outside; at the same time, a retaining plate is laid at the bottom of the heat exchanger. When the process gas enters the middle air inlet of the heat exchanger through the deflector at the top of the heat exchanger, due to the change in flow direction, most of the catalyst debris and iron filings fall onto the retaining plate at the bottom of the heat exchanger due to the flow deflection, thereby reducing the occurrence of blockage of the heat exchange fins of the heat exchanger. Description of the Drawings

[0016] Figure 1 is the SO 2 structural schematic diagram of the converter of the present utility model;

[0017] Figure 2 is the structural schematic diagram of the heat exchanger of the present utility model;

[0018] Figure 3 is the sectional structural schematic diagram of the process gas distribution plate of the present utility model;

[0019] Explanation of reference numerals in the drawings: 1 - process gas inlet; 2 - catalyst bed; 3 - heat exchanger; 4 - process gas outlet; 5 - dust baffle; 6 - deflector; 7 - process gas distribution plate; 8 - inspection hole; 9 - manhole; 10 - intercepting plate. Specific embodiments

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model, but it does not constitute a limitation to the protection scope of the present utility model.

[0021] In the present utility model, for clearer description, the following is stated: The observer observes facing the attached Figure 1 drawing. The front left side of the observer is set as the front, the rear right side of the observer is set as the rear, the rear left side of the observer is set as the left, the front right side of the observer is set as the right, the upper side of the observer is set as the upper, and the lower side of the observer is set as the lower. It should be noted that the terms "front end", "rear end", "left side", "right side", "middle part", "upper side", "lower side", etc. in the text indicate the orientation or position relationship based on the orientation or position relationship set by the drawing, and are only for the purpose of clearly describing the present utility model, rather than indicating or implying that the structures or components referred to must have a specific orientation and be constructed in a specific orientation. Therefore, it cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", "third", "fourth" are only used for the purpose of clear or simplified description, and cannot be understood as indicating or implying relative importance or quantity.

[0022] Currently, for the SO 2 conventional installation method of the steam heat exchanger in the converter is to horizontally place the heat exchanger transversely and weld it to the steel structure below the catalyst. For the SO 2 After the process gas undergoes an exothermic catalytic reaction through the catalyst, the process gas all enters the heat exchange fins through the deflector for heat exchange reaction with steam. Through the heat exchanger, the heat is carried away by the steam, the process gas is cooled, and the reaction proceeds smoothly.

[0023] For the SO 2 conversion catalyst is in the form of diatomaceous earth particles, and under the condition of long-term high-temperature gas flow scouring, it is easy to break and form catalyst debris.

[0024] The process gas flow direction is to first pass through the catalyst bed for reaction and then through the heat exchanger for heat exchange. During operation, a large amount of catalyst debris and converter iron filings are carried by the process gas and fall into the fins of the cross-flow heat exchanger together. When passing through the heat exchanger, the catalyst debris and iron rust filings get stuck in the heat exchanger fins and are intercepted, blocking the heat exchanger for a long time and causing poor air flow.

[0025] SO 2 The common preventive measures for blocking the fins of the converter heat exchanger are as follows:

[0026] 1. Regularly stop the device to screen the catalyst to reduce the amount of catalyst debris. Due to screening the catalyst, the device shutdown will cause: reduction of the device production operation time, increase of safety and environmental protection risks, increase of equipment corrosion risks, and increase of start-up and shutdown economic costs.

[0027] 2. Use compressed air to blow and clean the upper fins of the heat exchanger. Although the upper and lower fins of the heat exchanger can be cleaned, the fins of the middle heat exchange tubes of the heat exchanger cannot be cleaned because they are blocked by the upper and lower fin tubes, and the blockage still exists.

[0028] Therefore, after many research, analysis and calculations, a device for reducing the resistance in the SO 2 converter is made. By changing the installation layout of the heat exchanger inside the SO 2 converter, it is ensured that the catalyst debris and iron rust filings entrained in the process gas during operation are not blown into and blocked in the heat exchanger fins, ultimately affecting the effect of the operating pressure difference.

[0029] See Figure 1 、 Figure 2 This utility model provides a SO 2 converter, which includes a reaction tower. Inside the reaction tower, a catalyst bed 2 and a heat exchanger 3 are arranged. The heat exchanger 3 is a hollow structure with upper and lower parts surrounded by heat exchange fins, and a retaining plate 10 is laid at the bottom of the heat exchanger 3.

[0030] By setting the heat exchanger 3 as a hollow structure with upper and lower parts surrounded by heat exchange fins, the process gas enters the middle of the heat exchanger 3 and exits the process gas in the circumferential direction from the inside to the outside. At the same time, a retaining plate 10 is laid at the bottom of the heat exchanger 3. When the process gas enters the middle air inlet of the heat exchanger 3 through the top deflector 6 of the heat exchanger 3, due to the change in the flow direction, most of the catalyst debris and iron filings fall onto the retaining plate 10 at the bottom of the heat exchanger 3 due to the flow direction turning, thus reducing the occurrence of blocking the fins of the heat exchanger 3 and having the following advantages:

[0031] 1. Solve the interception and collection of catalyst debris and iron rust filings generated during the internal operation of the SO 2 converter, avoid the increase of the pressure difference resistance drop caused by the blockage of the heat exchanger fins, enable the process gas to flow smoothly during operation, react evenly, achieve the optimal operation energy consumption and conversion rate, and reduce the risk of process gas leakage.

[0032] 2. Reduce the frequency of cleaning the heat exchanger fins during parking, reduce the start-up and shutdown costs, and reduce the risks of safety, environmental protection, and equipment corrosion.

[0033] 3. Reduce the blockage of the heat exchanger, increase the heat exchange efficiency, improve the heat recovery rate, and increase the steam output.

[0034] Specifically, the heat exchanger 3 is a cubic structure composed of four vertical heat exchange fins, and the heat exchange fins are connected to each other in pairs; the angle at which the heat exchange fins are connected is 90°, and the heat exchanger 3 is a cuboid structure.

[0035] As a preferred embodiment of the present invention, a dust baffle 5 is provided at the top of the heat exchanger 3, and the dust baffle 5 is vertically arranged at the outer extension of the top of the heat exchanger 3; the height of the dust baffle 5 is 150 - 200 mm. A flow guide plate 6 is provided at the top of the heat exchanger 3. One side of the flow guide plate 6 is connected to the outer extension of the top of the heat exchanger 3, and the other side is connected to the inner side of the outer skin of the reaction tower. The height of the flow guide plate 6 connected to the inner side of the outer skin of the reaction tower is higher than that of the flow guide plate 6 connected to the outer extension of the top of the heat exchanger 3.

[0036] SO 2 I-beams and a flow guide plate 6 are provided below the catalyst bed 2 of the converter. The steam heat exchanger 3 is installed on the I-beams in a vertical manner, surrounding a week on four sides. There is no gap left between the heat exchangers 3 in each direction after full welding. The process gas enters from the middle and exits from the inner to the outer four directions.

[0037] A steel plate is laid at the bottom of the heat exchanger 3. The upper part of the heat exchanger 3 is welded to the flow guide plate 6, and the lower part is welded to the load-bearing I-beam. All the process gas passes through the flow guide plate 6 and enters the heat exchanger 3. A dust baffle 5 with a height of 150 mm is provided at the welding joint between the flow guide plate 6 and the heat exchanger 3. Its main function is to block a part of the catalyst particles and iron filings from falling into the heat exchanger 3, making the first shielding and interception to intercept some larger particle size particles. When the process gas enters the middle air inlet of the heat exchanger 3 through the flow guide plate 6 at the top of the heat exchanger 3, due to the change in flow direction, most of the catalyst debris and iron filings fall onto the steel plate at the bottom of the heat exchanger 3 due to the flow deflection, thereby reducing the possibility of entering the fins of the heat exchanger 3 and making the second interception. Subsequently, as long as the opportunity of parking for maintenance is utilized to synchronously clean the catalyst debris and iron filings accumulated at the dust baffle 5 at the flow guide plate 6 and the bottom plate of the heat exchanger 3.

[0038] The inlet flow guide plate 6 of the heat exchanger 3 is set as a transition piece from round to square. The upper round opening is welded to the I-beam, and the edge of the lower square opening is welded to the periphery of the heat exchanger 3.

[0039] As a preferred embodiment of the present invention, see Figure 3, a process gas distribution plate 7 is provided below the heat exchanger 3. A number of round holes of the same size are provided on the process gas distribution plate 7, and the structure of the process gas distribution plate 7 is a conical structure. The process gas distribution plate 7 is welded to the I-beam, and an I-beam support beam is provided at the bottom.

[0040] The process gas coming out from around the heat exchanger 3 enters the process gas distribution plate 7 below the heat exchanger 3 to achieve uniform distribution (hole diameter φ100mm), ensuring uniform reaction when entering the lower-layer catalyst without occurrence of uneven flow.

[0041] Specifically, a maintenance hole 8 is provided at the bottom of the heat exchanger 3. The provision of the maintenance hole 8 at the bottom of the heat exchanger 3 facilitates the cleaning of the debris accumulated at the bottom.

[0042] Specifically, the intercepting plate 10 is a steel plate, and a number of manholes 9 are provided on the reaction tower; two catalyst beds 2 and a heat exchanger 3 are provided inside the reaction tower. The reaction tower is provided with a process gas inlet 1, a catalyst bed 2, a heat exchanger 3, a catalyst bed 2, a heat exchanger 3, and a process gas outlet 4 from top to bottom; the distance between two adjacent heat exchangers 3 is ≥800mm.

[0043] Key points of the present utility model

[0044] 1. A dust baffle 5 is provided for the heat exchanger 3 and the process gas guide plate 6, and full welding of a steel plate is carried out at the bottom of the heat exchanger 3 to ensure that catalyst debris, iron filings and other dust are intercepted here.

[0045] 2. The heat exchanger 3 is changed from the previous conventional horizontal overlapping placement to vertical placement. The process gas enters the fins of the heat exchanger 3 horizontally. Catalyst debris, iron filings and other dust fall to the bottom due to gravity and cannot enter the fins. In addition, by adopting the vertical placement method, compared with the horizontal placement method, the number of stacked layers of the heat exchanger 3 can be reduced, which is convenient for purging and cleaning the fins of the heat exchanger 3.

[0046] 3. The process gas distribution plate 7 is provided below the heat exchanger 3, which can uniformly distribute the process gas and ensure uniform reaction of the catalyst.

[0047] 4. The round-on-square process gas guide plate 6 is provided for the heat exchanger 3, which can divert all the process gas into the heat exchanger 3 for heat exchange.

[0048] 5. According to the heat exchange requirement and the steam temperature requirement at the outlet of the heat exchanger 3, two or three layers of heat exchangers 3 can be provided. The combination method is flexible, but the distance between two layers of heat exchangers 3 is at least ≥800mm, and a maintenance hole 8 is provided for convenient cleaning.

[0049] Effects of the present utility model are as follows

[0050] 1. Solve SO 2During the internal operation of the converter, the interception and collection of catalyst debris and rust debris are carried out to avoid the blockage of the heat exchanger fins, which causes an increase in the pressure difference resistance drop, so that the process gas can flow smoothly during operation, react evenly, achieve the optimal operation energy consumption and conversion rate, and reduce the risk of process gas leakage.

[0051] 2. Reduce the number of times of cleaning the heat exchanger fins during shutdown, reduce the start-up and shutdown costs, and reduce the risks of safety, environmental protection and equipment corrosion.

[0052] 3. Reduce the blockage of the heat exchanger, increase the heat exchange efficiency, improve the heat recovery rate, and increase the steam output.

[0053] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches are also regarded as the protection scope of the present invention.

Claims

1. A SO2 converter, comprising a reaction tower, wherein a catalyst bed and a heat exchanger are arranged in the reaction tower, characterized in that: The heat exchanger is a hollow structure surrounded by heat exchange fins, and a retention plate is laid on the bottom of the heat exchanger.

2. The SO2 converter according to claim 1, characterized in that: The heat exchanger is a cubic structure composed of four vertical heat exchange fins, and the heat exchange fins are connected in pairs.

3. The SO2 converter according to claim 2, characterized in that: The angle between the heat exchange fins is 90°, and the heat exchanger is a rectangular parallelepiped structure.

4. A SO2 converter according to claim 1 or 3, characterized in that: A dust shield is arranged on the top of the heat exchanger, and the dust shield is vertically arranged on the extension of the top of the heat exchanger.

5. The SO2 converter according to claim 4, characterized in that: The height of the dust shield is 150-200 mm.

6. A SO2 converter according to claim 1, 3 or 5, characterized in that: A guide plate is arranged on the top of the heat exchanger, one side of the guide plate is connected to the extension of the top of the heat exchanger, and the other side is connected to the inner side of the outer skin of the reaction tower. The height of the guide plate connected to the inner side of the outer skin of the reaction tower is higher than the guide plate connected to the extension of the top of the heat exchanger.

7. The SO2 converter according to claim 6, characterized in that: A process gas distribution plate is arranged below the heat exchanger. A plurality of circular holes of the same size are arranged on the process gas distribution plate. The structure of the process gas distribution plate is a conical structure.

8. A SO2 converter according to claim 1 or 7, characterized in that: An inspection hole is arranged at the bottom of the heat exchanger.

9. The SO2 converter according to claim 8, characterized in that: The interception plate is a steel plate, and the reaction tower is provided with a plurality of individual holes.

10. A SO2 converter according to claim 1 or 9, characterized in that: The reaction tower is provided with two catalyst beds and a heat exchanger. From top to bottom, the reaction tower is provided with a process gas inlet, a catalyst bed, a heat exchanger, a catalyst bed, a heat exchanger, and a process gas outlet. The distance between the heat exchangers is ≥800mm.

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