A split box type fluorosulfuric reactor and a method for preparing sulfur hexafluoride using the same

Abstract

The application discloses a split box type fluorine-sulfur reactor, which comprises a lower box and an upper box detachably fixed above the lower box, the internal net height of the upper box is greater than that of the lower box, a heating assembly is arranged at the bottom of the lower box, a feeding port is fixedly arranged on the upper box and communicates with the upper box, an air inlet is fixedly arranged on the upper box and communicates with the upper box, a plurality of baffle plates extending downward are fixed on the inner top surface of the upper box, one side of the baffle plate is connected with the inner wall of the upper box, the other side of the baffle plate is away from the inner wall of the upper box, and the connecting lines of all the away sides are in S shapes, an air outlet is further fixedly arranged on the upper box, and the air inlet and the air outlet are respectively located outside the two ends of the S shape. The application solves the problem of difficult internal maintenance of the reactor in the prior art. Meanwhile, a method for preparing sulfur hexafluoride is further provided.

Description

Technical Field

[0001] This invention relates to the field of sulfur hexafluoride preparation technology, and in particular to a split-type box-type fluorine-sulfur reactor and a method for preparing sulfur hexafluoride using the system. Background Technology

[0002] Sulfur hexafluoride (SF6) is widely used in high-voltage electrical equipment insulation, semiconductor etching, and magnesium alloy smelting. Industrially, it is typically produced by the direct reaction of elemental fluorine (F2, i.e., fluorine gas) and elemental sulfur (S, i.e., solid sulfur): S + 3F2 → SF6. This reaction is highly exothermic. Existing fluorine-sulfur reactors generally include an outer shell, which is elongated and has an inlet at one end and an outlet at the other. The shell also has a feed port for solid sulfur. During the reaction, solid sulfur is added through the feed port, heated, and becomes liquid (boiling point 445℃). Sulfur vapor forms above the liquid surface. Fluorine gas is introduced through the inlet, and the fluorine reacts with the sulfur vapor to produce sulfur hexafluoride gas, which is then discharged through the outlet to a subsequent purification system. Because fluorine gas is highly corrosive, internal malfunctions are common, but the reactor is usually a single unit, making internal maintenance difficult. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a split box-type fluorine-sulfur reactor, which solves the problem of difficult internal maintenance of the reactor in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A split-type box-type fluorine-sulfur reactor includes a lower box and an upper box detachably fixed above the lower box. The internal net height of the upper box is greater than that of the lower box. A heating component is installed at the bottom of the lower box, and a feed inlet connected to it is fixedly installed on the lower box. An air inlet connected to it is fixedly installed on the upper box. Multiple downward-extending baffles are fixed on the inner top surface of the upper box. One side of the baffles is connected to the inner wall of the upper box, and the other side is separate from the inner wall of the upper box, with the connecting lines at all separation points forming an S-shape. An air outlet is also fixedly installed on the upper box, with the air inlet and outlet located at opposite ends of the S-shape. This design features a split upper and lower box structure, allowing for easy disassembly during internal maintenance, thus reducing the difficulty of internal maintenance and solving the problem of difficult internal maintenance of reactors in existing technologies.

[0006] Furthermore, a jacket shell is fixed to the outside of the upper box body, and a space between the jacket shell and the upper box body is provided. An inlet pipe and an outlet pipe that communicate with the space are fixed on the jacket shell.

[0007] Furthermore, multiple first temperature sensors are fixedly installed on the upper housing, extending vertically through the jacket shell into the upper housing. The first temperature sensors are staggered with the baffle plate.

[0008] Furthermore, multiple second temperature sensors extending into the lower housing are fixedly installed on it.

[0009] Furthermore, the upper and lower boxes are respectively fixed with a first connecting frame and a second connecting frame that are positioned opposite each other. A metal sealing gasket is also provided between the first connecting frame and the second connecting frame, and the first connecting frame, the second connecting frame and the metal sealing gasket are fixed by multiple bolts.

[0010] Furthermore, the metal gasket includes a stainless steel layer and a flexible graphite layer wrapped around the stainless steel layer.

[0011] Furthermore, the metal sealing gasket includes a stainless steel layer, the stainless steel layer includes a toothed plate segment and a support segment, the support segment is wrapped with a flexible graphite layer, the upper and lower walls of the toothed plate segment are respectively fixed with an upper toothed belt and a lower toothed belt, and the first connecting frame and the second connecting frame are respectively fixed with a first toothed belt and a second toothed belt that can mesh with the upper toothed belt and the lower toothed belt respectively.

[0012] Furthermore, initially, the flexible graphite layer has an upper top surface that is higher than the highest position of the upper toothed belt and a lower bottom surface that is lower than the lowest position of the lower toothed belt.

[0013] Furthermore, the heating assembly is characterized by including an electric heating plate fixed to the bottom surface of the lower housing.

[0014] According to the embodiments, a method for preparing sulfur hexafluoride using the above-described split-box fluorine-sulfur reactor is also provided, which includes the following steps:

[0015] Solid sulfur is fed into the lower chamber through the feeding port, the heating components are activated to heat it, forming liquid sulfur, and the liquid surface is controlled to contact the baffle plate.

[0016] Fluorine gas is introduced through the inlet. Under the obstruction and guidance of the baffle plate, the fluorine gas moves in an S-shape to the other end. During the process, it reacts with the sulfur vapor above the liquid surface to generate sulfur hexafluoride gas, which is then discharged through the outlet.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The reactor consists of a detachable upper and lower housing, which can be easily disassembled when maintenance is required, thereby reducing the difficulty of internal maintenance and solving the problem of difficult internal maintenance of reactors in the prior art. The feed port is fixed on the lower housing, making it more convenient to add solid sulfur. At the same time, the connection between the upper and lower housings is located below the liquid surface, so the impact of fluorine gas on the connection is smaller, which can reduce the failure rate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the internal structure of this embodiment;

[0020] Figure 2 This is a partial structural diagram of this embodiment;

[0021] Figure 3 This is a schematic diagram of the first type of metal sealing gasket structure in this embodiment;

[0022] Figure 4 This is a schematic diagram of the second type of metal sealing gasket structure in this embodiment.

[0023] The reference numerals in the accompanying drawings include:

[0024] 1. Lower housing; 2. Upper housing; 3. First connecting frame; 4. Second connecting frame; 5. Metal sealing gasket; 6. Bolt; 7. Flexible graphite layer; 8. Stainless steel layer; 9. Toothed plate section; 10. Support section; 11. Upper toothed belt; 12. Lower toothed belt; 13. Electric heating plate; 14. Feed port; 15. Baffle plate; 16. Drain port; 17. Air inlet; 18. Air outlet; 19. Fluorine inlet area; 20. Pre-reaction zone; 21. Middle reaction zone; 22. Post-reaction zone; 23. Outlet zone; 24. Jacket shell; 25. Interlayer space; 26. Inlet pipe; 27. Outlet pipe; 28. First thermometer; 29. ​​Second thermometer. Detailed Implementation

[0025] The present invention will be further described in detail below through specific embodiments:

[0026] Example 1

[0027] like Figure 1-4As shown, this solution provides a split-type box-type fluorine-sulfur reactor, which includes a lower box 1 and an upper box 2 located above the lower box 1 and detachably connected thereto. The upper box 2 and the lower box 1 are respectively fixed with an upper connecting frame 3 and a second connecting frame 4 positioned vertically opposite each other. A metal sealing gasket 5 is also provided between the first connecting frame 3 and the second connecting frame 4, and they are fastened together by multiple bolts 6. This allows for easy disassembly during internal maintenance, thereby reducing maintenance difficulty and solving the problem of difficult internal maintenance of reactors in the prior art. Furthermore, the metal sealing gasket 5 in this solution comprises flexible graphite. Layer 7, with a portion located internally, allows the liquid sulfur to submerge the flexible graphite layer 7 during the reaction. The flexible graphite layer 7 resists corrosion from the liquid sulfur and also enhances the metal gasket 5's resistance to fluorine and sulfur hexafluoride corrosion (although the liquid level is higher than the metal gasket 5 during the reaction, some fluorine or sulfur hexafluoride may still enter the liquid sulfur and contact the metal gasket 5, or fluorine and sulfur hexafluoride may contact the metal gasket 5 when the liquid sulfur level is low). More specifically, the metal gasket 5 can have various structures, such as:

[0028] The first structure could be:

[0029] The metal sealing gasket 5 includes a stainless steel layer 8 and a flexible graphite layer 7 wrapped around the stainless steel layer 8. After installation, the first connecting frame 3 and the second connecting frame 4 respectively contact the upper and lower surfaces of the flexible graphite layer 7 and press the flexible graphite layer 7 tightly to achieve a sealing effect and improve the corrosion resistance of the connection.

[0030] The second structure could be:

[0031] The metal sealing gasket 5 includes a stainless steel layer 8, which includes a toothed plate segment 9 and a support segment 10. The support segment 10 is wrapped with a flexible graphite layer 7. An upper toothed belt 11 and a lower toothed belt 12 are fixedly installed on the upper and lower walls of the toothed plate segment 9, respectively. A first toothed belt and a second toothed belt, capable of meshing with the upper toothed belt 11 and the lower toothed belt 12, are fixedly installed on the first connecting frame 3 and the second connecting frame 4, respectively. The upper toothed belt 11 and the lower toothed belt 12 are integral with the stainless steel layer 8, and the first toothed belt and the second toothed belt are integral with the first connecting frame 3 and the second connecting frame 4, respectively. The interlocking mechanism enables more precise assembly without misalignment. The first connecting frame 3 and the second connecting frame 4 also have a portion that presses the flexible graphite layer 7. That is, when the first connecting frame 3, the second connecting frame 4 and the toothed plate segment 9 are engaged, the flexible graphite layer 7 is pressed (i.e., initially, the flexible graphite layer 7 has an upper top surface higher than the highest position of the upper toothed belt 11 and a lower bottom surface lower than the lowest position of the lower toothed belt 12), while not being over-pressed (the engagement structure limits further compression), ensuring sealing while also improving the corrosion resistance of the connection.

[0032] like Figure 1-4 As shown in the detailed scheme, an electric heating plate 13 is fixed to the bottom of the lower chamber 1 to heat the interior of the lower chamber 1. Feed ports 14, communicating with the interior, are fixed to both sides of the lower chamber 1 for feeding solid sulfur. The feed ports 14 have an inlet located at a higher position (specifically higher than the lower edge of the baffle 15 described later). A drain port 16, communicating with the bottom of the lower chamber 1, is also fixed to the bottom for discharging the remaining sulfur after the reaction. An air inlet 17 and an air outlet 18, communicating with the upper chamber 2, are fixed to the upper chamber 2 (there can be multiple air inlets 17, such as three, and one air outlet 18). Multiple downward-extending baffles 15, specifically four baffles 15, are fixed to the inner top surface of the upper chamber 2. One side of each baffle 15 is connected to the inner wall of the upper chamber 2, and the other side is separate from the inner wall of the upper chamber 2. The connection at the point is S-shaped, with the inlet 17 and outlet 18 located at the two ends of the S-shape. Fluorine gas is introduced through the inlet 17, while the heated liquid sulfur surface is in contact with the baffle 15 (i.e., the lower edge of the baffle 15 extends below or contacts the liquid surface). Thus, the baffle 15, the upper chamber 2, and the liquid surface enclose an S-shaped channel, which consists of a fluorine gas inlet area 19, a pre-reaction area 20, a middle reaction area 21, a post-reaction area 22, and an outlet area 23. The inlet 17 is connected to the fluorine gas inlet area 19, and the outlet area 23 is connected to the outlet 18 (the outlet 18 can be set on the top surface of the upper chamber 2 to facilitate the upward exit of the gas). This arrangement allows the incoming fluorine gas to come into contact with the sulfur vapor evaporating near the liquid sulfur surface during its movement in the S-shaped channel and react to generate sulfur hexafluoride, which is then discharged from the outlet 18.

[0033] like Figure 1-4As shown in the more detailed scheme, a jacket shell 24 is fixed to the outside of the upper housing 2. A sandwich space 25 is provided between the jacket shell 24 and the upper housing 2. An inlet pipe 26 and an outlet pipe 27 communicating with the sandwich space 25 are fixed on the jacket shell 24. More specifically, the inlet pipe 26 is located at the end where the air outlet 18 is set, and the outlet pipe 27 is located at the end where the air inlet 17 is set. Cooling medium (such as cooling water) is introduced into the sandwich space 25 through the inlet pipe 26, which can better absorb and transfer the heat generated during the reaction process to prevent overheating. Furthermore, this scheme also sets multiple temperature measuring points. Specifically, vertically penetrating the jacket shell 24 is also fixed on the upper housing 2. 4. Multiple first temperature sensors 28 extend into the upper chamber 2. The first temperature sensors 28 are staggered with the baffle 15. First temperature sensors 28 are respectively installed in the fluorine inlet area 19, the front reaction area 20, the middle reaction area 21, the rear reaction area 22, and the outlet area 23. This allows for convenient detection of temperature changes in different reaction areas, enabling timely adjustment of the fluorine flow rate or cooling medium flow rate based on the temperature distribution, thus avoiding local overheating or incomplete reaction. Temperature measuring points are also provided on the lower chamber 1. Specifically, multiple second temperature sensors 29 are fixedly installed on the lower chamber 1 and extend into it to detect the temperature inside the lower chamber 1. The first temperature sensors 28 and the second temperature sensors 29 can be armored thermocouples.

[0034] A pressure gauge and vacuum interface (not shown in the figure) are installed on the top of the upper housing 2. During operation, it can maintain normal pressure or slight negative pressure (-500 to +500 Pa gauge pressure).

[0035] Example 2

[0036] like Figure 1-4 As shown, this embodiment provides a method for preparing sulfur hexafluoride using the above-described split-box fluorine-sulfur reactor, comprising the following steps:

[0037] Preparation stage: Add sufficient solid sulfur (about 800 kg) to the lower box 1 through the feeding port 14, start the electric heating plate 13 to heat the sulfur to 130~140℃, and completely melt it into liquid. The lower end of the baffle plate 15 extends below the liquid surface and introduces room temperature cooling water into the interlayer space 25.

[0038] Ventilation reaction: Fluorine gas is introduced horizontally through three fluorine gas inlets. The total flow rate is controlled at 102%~105% of the theoretical amount required for the reaction. After the fluorine gas enters the upper chamber 2 horizontally, it first comes into contact with the sulfur liquid surface and undergoes a violent reaction to generate sulfur hexafluoride. The reaction is exothermic, causing the local temperature to rise, but it is carried away by the cooling water in time.

[0039] Baffle and full reaction: Fluorine gas and generated sulfur hexafluoride flow in an S-shape towards the outlet 18 under the guidance of baffle plate 15. During the flow, unreacted fluorine gas repeatedly comes into contact with the sulfur liquid surface at different positions below to ensure complete reaction.

[0040] Temperature monitoring and regulation: Operators read the temperature of different reaction zones in real time through five temperature measuring points. During normal operation, the temperature of each zone should be maintained between 200 and 350°C. If the temperature of a certain zone is too high, the cooling water flow rate should be increased or the fluorine gas introduction rate should be appropriately reduced. If the temperature is too low (such as below 150°C), the cooling water flow rate should be reduced or the sulfur liquid level should be checked.

[0041] Product extraction: The final generated sulfur hexafluoride gas is extracted from the top outlet 18 and enters subsequent alkaline washing, drying, compression and other processes.

[0042] Inspection and maintenance: After running for a period of time, if cleaning or maintenance is required, stop heating and ventilation. After the reaction stops, drain the sulfur through the drain port 16 at the bottom of the reactor, loosen the bolts 6, and use lifting equipment to lift the upper part as a whole. Then, the internal baffle plate 15, sealing structure (metal sealing gasket 5), inner wall of the lower box 1 and electric heating plate 13 can be inspected and maintained.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A split-type box-type fluorine-sulfur reactor, characterized in that, It includes a lower box and an upper box that is detachably fixed above the lower box. The internal net height of the upper box is greater than that of the lower box. A heating component is installed at the bottom of the lower box. A feeding port connected to the lower box is fixedly installed on the lower box and an air inlet connected to the upper box is fixedly installed on the upper box. Multiple downward-extending baffles are fixedly installed on the inner top surface of the upper box. One side of the baffle is connected to the inner wall of the upper box, and the other side is separated from the inner wall of the upper box. The connecting lines of all the separated points form an S-shape. An air outlet is also fixedly installed on the upper box. The air inlet and the air outlet are located at the two ends of the S-shape, respectively.

2. The split-type box-type fluorine-sulfur reactor as described in claim 1, characterized in that, The upper box is also fixed with a jacket shell, and a space between the jacket shell and the upper box is provided. The jacket shell is fixed with an inlet pipe and an outlet pipe that communicate with the space.

3. The split-type box-type fluorine-sulfur reactor as described in claim 2, characterized in that, Multiple first temperature sensors are also fixedly installed on the upper housing, extending vertically through the jacket shell into the upper housing. The first temperature sensors are staggered with the baffle plate.

4. The split-type box-type fluorine-sulfur reactor as described in claim 1, characterized in that, Multiple second temperature sensors extending into the lower housing are fixedly installed on it.

5. The split-type box-type fluorine-sulfur reactor as described in claim 1, characterized in that, The upper and lower boxes are respectively fixed with a first connecting frame and a second connecting frame that are positioned opposite each other. A metal sealing gasket is also placed between the first connecting frame and the second connecting frame, and the first connecting frame, the second connecting frame and the metal sealing gasket are fixed by multiple bolts.

6. The split-type box-type fluorine-sulfur reactor as described in claim 5, characterized in that, The metal gasket consists of a stainless steel layer and a flexible graphite layer wrapped around the stainless steel layer.

7. The split-type box-type fluorine-sulfur reactor as described in claim 5, characterized in that, The metal sealing gasket includes a stainless steel layer, which includes a toothed plate segment and a support segment. The support segment is wrapped with a flexible graphite layer. An upper toothed belt and a lower toothed belt are fixedly installed on the upper and lower walls of the toothed plate segment, respectively. A first toothed belt and a second toothed belt that can mesh with the upper toothed belt and the lower toothed belt are fixedly installed on the first connecting frame and the second connecting frame, respectively.

8. The split-type box-type fluorine-sulfur reactor as described in claim 7, characterized in that, Initially, the flexible graphite layer has an upper top surface that is higher than the highest position of the upper toothed belt and a lower bottom surface that is lower than the lowest position of the lower toothed belt.

9. The split-type box-type fluorine-sulfur reactor as described in any one of claims 1-8, characterized in that, The heating assembly includes an electric heating plate fixed to the bottom surface of the lower housing.

10. A method for preparing sulfur hexafluoride using a split-box type fluorine-sulfur reactor as described in any one of claims 1-9, characterized in that, Including the following steps: Solid sulfur is fed into the lower chamber through the feeding port, the heating components are activated to heat it, forming liquid sulfur, and the liquid surface is controlled to contact the baffle plate. Fluorine gas is introduced through the inlet. Under the obstruction and guidance of the baffle plate, the fluorine gas moves in an S-shape to the other end. During the process, it reacts with the sulfur vapor above the liquid surface to generate sulfur hexafluoride gas, which is then discharged through the outlet.

Images