High-purity tungsten hexafluoride steel bottle

Abstract

The utility model discloses a high-purity tungsten hexafluoride steel bottle which comprises a vertical cylinder body, an upper sealing head fixedly connected to the top of the cylinder body and a lower sealing head fixedly connected to the bottom of the cylinder body, a closed storage cavity used for storing tungsten hexafluoride is formed among the upper sealing head, the cylinder body and the lower sealing head, a guide pipe is arranged in the storage cavity, and the guide pipe is connected with the cylinder body. And a jacket is arranged outside the cylinder body. Heat conduction liquid is introduced into the heat conduction liquid chamber through the liquid inlet pipe and the liquid outlet pipe on the jacket, and the temperature of the storage cavity can be controlled by controlling the temperature of the heat conduction liquid, so that the saturated vapor pressure of tungsten hexafluoride is changed, and the flow is adjusted when tungsten hexafluoride is led out; the temperature of the tungsten hexafluoride in the storage cavity can be monitored through a temperature sensor inserted into the storage cavity. And when the demand quantity of tungsten hexafluoride is large, the temperature of the heat conduction liquid can be increased to meet the demand.

Description

Technical Field

[0001] The utility model relates to the technical field of high-purity gas production, in particular to a high-purity tungsten hexafluoride steel cylinder. Background Art

[0002] In the CVD vapor deposition chamber, tungsten hexafluoride steel cylinders are used at room temperature. As the amount of tungsten hexafluoride used increases, the use of steel cylinders at room temperature will be difficult to meet the working conditions of large amounts of tungsten hexafluoride. However, the tungsten hexafluoride supply flow of ordinary steel cylinders at room temperature is low, thus limiting the scope of use of this steel cylinder.

[0003] Patent publication number CN220647833U discloses a stainless steel cylinder for tungsten hexafluoride gas. The cylinder comprises a stainless steel body, which consists of a cylinder body and a base. An outlet pipe is mounted at the top of the cylinder body, and a control valve is installed at the top of the outlet pipe. The bottom of the cylinder body extends into the base for shock absorption. However, the cylinder is only equipped with a control valve and can only be used to charge and discharge tungsten hexafluoride gas; it does not have the function of charging and discharging liquid tungsten hexafluoride.

[0004] Patent publication number CN220957934U discloses a liquid gas storage tank belonging to the field of liquid gas storage technology. The tank comprises a body, a receiving plate disposed at the bottom of the body, a base disposed below the receiving plate, a shock-absorbing assembly disposed between the receiving plate and the base, universal wheels disposed at the bottom of the base, and a bracket disposed at the upper end of the receiving plate. However, since the tank lacks a heating function, the flow rate of the liquid gas is fixed if it relies solely on room temperature, making it unable to meet the requirements of high-flow conditions. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a high-purity tungsten hexafluoride steel cylinder, which is used to solve the problem that the current tungsten hexafluoride steel cylinder has a low flow rate when used at room temperature and cannot meet the working conditions with large demand for tungsten hexafluoride.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A high-purity tungsten hexafluoride steel cylinder comprises a vertical cylinder, an upper head fixedly connected to the top of the cylinder, a lower head fixedly connected to the bottom of the cylinder, an annular mounting seat fixedly connected to the upper head, and a flange connected to the mounting seat, wherein a sealed storage chamber for storing tungsten hexafluoride is formed between the upper head, the cylinder, and the lower head, and further comprising a conduit vertically penetrating and fixedly connected to the flange, wherein the lower end of the conduit is close to the bottom of the lower head, and the upper end of the conduit is provided with a liquid phase cylinder valve, which is arranged outside the head, and a heating device for heating the tungsten hexafluoride stored in the storage chamber is provided outside the cylinder.

[0008] Furthermore, the heating device includes a jacket arranged outside the cylinder, the jacket covering the lower head and the outside of the cylinder, at least one of the upper head, cylinder and lower head is fixedly connected to the jacket, and a closed heat transfer liquid chamber is between the cylinder and the jacket, one side of the jacket is fixedly connected to a liquid inlet pipe, and the other side of the jacket is fixedly connected to a liquid outlet pipe, and both the liquid inlet pipe and the liquid outlet pipe are connected to the heat transfer liquid chamber.

[0009] Furthermore, a horizontal arc-shaped baffle is distributed in the heat transfer liquid chamber, and the baffle is fixedly connected to at least one of the cylinder, the jacket, and the lower head; a vertical partition is fixedly connected between the jacket and the cylinder in the heat transfer liquid chamber.

[0010] Furthermore, the flange is fixedly connected to a gas phase bottle valve beside the liquid phase bottle valve, and the gas phase bottle valve is communicated with the top of the storage chamber.

[0011] Furthermore, a bottle cap is detachably connected to the flange, and the gas phase bottle valve and the liquid phase bottle valve are both covered in the bottle cap.

[0012] Furthermore, a temperature sensor is provided in the storage cavity, and a temperature sensing element of the temperature sensor is close to the bottom of the storage cavity.

[0013] Furthermore, a protective cover is detachably connected to the outside of the upper head, and the flange, the mounting seat and the bottle cap are all covered in the protective cover.

[0014] Furthermore, the storage chamber has a volume of 0.5-5m 3 The cylinder, upper head and lower head are made of metal materials with polished inner walls.

[0015] The positive effects of this utility model are:

[0016] 1. The present invention comprises an upper end cap, a lower end cap, and a cylindrical body. A jacket is provided on the outer surface of the cylindrical body and the lower end cap. A storage chamber for storing tungsten hexafluoride is formed between the upper end cap, the lower end cap, and the cylindrical body. A conduit for discharging tungsten hexafluoride is provided on the upper end cap, and a thermal fluid is passed through the jacket. Thermal fluid having a temperature higher than room temperature is introduced into the thermal fluid chamber via the inlet and outlet pipes on the jacket. By controlling the temperature of the thermal fluid, the temperature of the storage chamber can be controlled, thereby varying the saturated vapor pressure of tungsten hexafluoride to adjust the flow rate during tungsten hexafluoride discharging. The temperature of the tungsten hexafluoride within the storage chamber can be monitored by a temperature sensor inserted therein. When the demand for tungsten hexafluoride is high, the temperature of the thermal fluid can be increased to meet demand.

[0017] 2. When filling tungsten hexafluoride into the storage chamber, a heat transfer liquid with a temperature lower than room temperature can be introduced into the heat transfer liquid chamber through the liquid inlet pipe and the liquid outlet pipe to cool the storage chamber, and the flow rate of tungsten hexafluoride during filling can be controlled by controlling the temperature of the heat transfer liquid.

[0018] 3. When the storage chamber volume is large, the inner wall of the cylinder is electrolytically polished to meet the requirements of large-capacity storage of high-purity tungsten hexafluoride. The shelf life of tungsten hexafluoride can reach 24 months. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the utility model;

[0020] Figure 2 yes Figure 1 Enlarged view of the upper middle part;

[0021] Figure 3 yes Figure 1 Cross-sectional view of the middle AA part;

[0022] In the picture:

[0023] 1. Base; 2. Bracket; 3. Lower head; 4. Cylinder; 5. Upper head; 6. Protective cover; 7. Mounting seat; 8. Flange; 9. Liquid phase bottle valve; 10. Gas phase bottle valve; 11. Bottle cap; 12. Thermal fluid chamber; 13. Temperature sensor; 14. Conduit; 15. Jacket; 16. Liquid outlet pipe; 17. Liquid inlet pipe; 18. Baffle; 19. Storage chamber; 20. Partition. DETAILED DESCRIPTION

[0024] Example 1

[0025] like Figures 1 to 3 As shown, a high-purity tungsten hexafluoride steel cylinder includes a vertical cylindrical body 4, an upper head 5 with a semi-elliptical cross-section welded to the top of the body 4, a lower head 3 with a semi-elliptical cross-section welded to the bottom of the body 4, an annular mounting seat 7 welded to the top center of the upper head 5, and a flange 8 bolted to the mounting seat 7. A sealed storage chamber 19 for storing tungsten hexafluoride is formed between the upper head 5, the body 4, and the lower head 3.

[0026] A conduit 14 is welded vertically through the flange 8. The lower end of the conduit 14 is close to the bottom of the lower head 3. The upper end of the conduit 14 is provided with a liquid phase bottle valve 9, which is arranged outside the head. After opening the liquid phase bottle valve 9, the liquid tungsten hexafluoride in the cylinder can be discharged.

[0027] The flange 8 is fixedly connected to a gas phase bottle valve 10 beside the liquid phase bottle valve 9. The gas phase bottle valve 10 is communicated with the top of the storage chamber 19. High-purity tungsten hexafluoride can be filled into the storage chamber 19 through the gas phase bottle valve 10.

[0028] The flange 8 is detachably connected to a bottle cap 11 by screws, and the gas phase bottle valve 10 and the liquid phase bottle valve 9 are both covered in the bottle cap 11. The bottle cap 11 is used to protect the gas phase bottle valve 10 and the liquid phase bottle valve 9 to prevent the gas phase bottle valve 10 and the liquid phase bottle valve 9 from being bumped.

[0029] The upper head 5 is detachably connected to a protective cover 6 by screws. The flange 8, the mounting seat 7 and the bottle cap 11 are all covered in the protective cover 6. The protective cover 6 provides protection for the flange 8, the mounting seat 7 and the bottle cap 11.

[0030] The cylinder 4 is provided with a jacket 15, which covers the lower head 3 and the cylinder 4. The bottom of the jacket 15 is welded to a bracket 2, and the bottom of the bracket 2 is bolted to the base 1. The upper head 5 is welded to the top of the jacket 15. Between the cylinder 4 and the jacket 15 is a closed thermal fluid chamber 12. The right side of the jacket 15 is welded to a liquid inlet pipe 17, and the left side of the jacket 15 is welded to a liquid outlet pipe 16. Both the liquid inlet pipe 17 and the liquid outlet pipe 16 are in communication with the thermal fluid chamber 12.

[0031] A long rod-shaped temperature sensor 13 is provided in the storage cavity 19 and is fixedly connected to the flange 8. The temperature sensing element of the temperature sensor 13 is a platinum resistor and is located near the bottom of the storage cavity 19.

[0032] A thermal fluid with a temperature higher than room temperature is introduced into the thermal fluid chamber 12 via the inlet pipe 17 and the outlet pipe 16. The thermal fluid can be thermal oil, water, or another liquid. By controlling the temperature of the thermal fluid, the temperature of the storage chamber 19 can be controlled, thereby varying the saturated vapor pressure of tungsten hexafluoride and adjusting the flow rate of tungsten hexafluoride during its discharge. The temperature of the tungsten hexafluoride within the storage chamber 19 can be monitored by a temperature sensor 13. When demand for tungsten hexafluoride is high, the temperature of the thermal fluid can be increased to meet demand.

[0033] When filling tungsten hexafluoride into the storage chamber 19, heat transfer liquid with a temperature lower than room temperature can be introduced into the heat transfer liquid chamber 12 through the liquid inlet pipe 17 and the liquid outlet pipe 16, and the flow rate of tungsten hexafluoride during filling can be controlled by controlling the temperature of the heat transfer liquid.

[0034] Example 2

[0035] The difference between this embodiment and embodiment 1 is that:

[0036] A horizontal, arcuate baffle 18 is disposed within the thermal fluid chamber 12. The baffle 18 is fixedly connected to the barrel 4 and the jacket 15. The width of the baffle 18 is less than half the width of the gap between the barrel 4 and the jacket 15. The baffle 18 on the barrel 4 and the baffle 18 on the jacket 15 are vertically staggered. Vertical partitions 20 are fixedly connected between the jacket 15 and both sides of the barrel 4 within the thermal fluid chamber 12.

[0037] Two partitions 20 divide the upper portion of the thermal fluid chamber 12 into two sections, the bottoms of which are connected. After the thermal fluid enters the right half of the thermal fluid chamber 12 through the inlet pipe 17, it flows downward from top to bottom. Baffles 18 block the flow, creating turbulent flow within the chamber 12 to enhance heat exchange. The thermal fluid then flows from the bottom of the lower end cap 3 to the left half of the chamber 12, then flows upward and out of the chamber 12 through the outlet pipe 16.

[0038] The baffle 18 can increase the heat exchange area between the heat-conducting liquid and the cylinder 4, thereby improving the heat transfer efficiency.

[0039] Example 3

[0040] In this embodiment, the volume of the storage chamber 19 is 0.5m 3 The temperature in the storage chamber 19 rises to 40°C in 10 minutes, and the tungsten hexafluoride extraction rate in the cylinder is 20 kg / h. The upper head 5, lower head 3, and cylinder 4 are made of polished metal with a surface roughness of Ra = 0.1 μm.

[0041] The timing began when the cylinder was first filled with tungsten hexafluoride. The gas in the cylinder was analyzed after the cylinder was stored at room temperature for 12 months (testing time: 12 months) and again after the cylinder was stored at room temperature for 24 months (testing time: 24 months). The qualified indicators and analysis results are shown in Tables 1 and 2. The data in Tables 1 and 2 show that the gas analysis and metal ion analysis results remained qualified after the cylinder was stored with tungsten hexafluoride for 24 months.

[0042] Table 1 Gas analysis results in cylinders

[0043]

[0044] Table 2 Analysis results of metal ions in cylinders

[0045]

[0046]

[0047] Therefore, when the storage chamber volume is large (0.5 to 5m 3 ) When the inner wall of the cylinder is electrolytically polished, it can meet the requirements of large-capacity storage of high-purity tungsten hexafluoride. The shelf life of tungsten hexafluoride can reach 24 months.

[0048] Example 4

[0049] In this embodiment, based on the third embodiment, the volume of the high-purity tungsten hexafluoride steel bottle is increased to 3m 3 The cylinder required 30 minutes to heat to 50°C, and the tungsten hexafluoride was extracted from the cylinder at a rate of 40 kg / h. The cylinder's polished quality was Ra = 0.05 μm. The qualified indicators and analysis results are shown in Tables 3 and 4. The data in Tables 3 and 4 demonstrate that the gas analysis results remained qualified after 24 months of storage of tungsten hexafluoride in the cylinder of this example.

[0050] Table 3 Gas analysis results in cylinders

[0051]

[0052] Table 4 Analysis results of metal ions in cylinders

[0053]

[0054]

[0055] Example 5

[0056] In this embodiment, based on the third embodiment, the volume of the high-purity tungsten hexafluoride steel bottle is increased to 5m 3 Heating the cylinder to 60°C took 40 minutes, and the tungsten hexafluoride was extracted from the cylinder at a rate of 55 kg / h. The polished quality of the cylinder was Ra = 0.1 μm. The qualified indicators and analysis results are shown in Tables 5 and 6. The data in Tables 5 and 6 show that the gas analysis results of the cylinder in this example remained qualified after storing tungsten hexafluoride for 24 months.

[0057] Table 5 Gas analysis results in cylinders

[0058]

[0059]

[0060] Table 6 Analysis results of metal ions in cylinders

[0061] Metal ion index 0 12 months 24 months Al / ppbW(≤5) 0.002 <0.000 0.002 As / ppbW(≤5) 0.045 0.066 0.024 B / ppbW(≤5) 3.101 1.332 2.366 Ca / ppbW(≤5) 1.581 0.808 0.906 Cd / ppbW(≤2) 0.577 0.276 0.611 Cr / ppbW(≤5) 7.69 <0.000 7.835 Fe / ppbW(≤5) 1.124 1.254 1.225 K / ppbW(≤5) 1.474 1.148 2.174 Mn / ppbW(≤5) 2.449 1.819 2.658 Na / ppbW(≤5) 0.041 0.023 0.112 Th / ppbW(≤0.1) 0.015 0.014 0.009 Ti / ppbW(≤5) 0.154 0.122 0.133 Li / ppbW(≤5) 2.502 1.54 2.649 U / ppbW(≤0.05) 0.019 0.014 0.009 Zn / ppbW(≤5) 0.578 0.344 0.452 Si / ppbW(≤5) 0.498 0.105 0.364 Pb / ppbW(≤5) 0.556 0.366 0.574 P / ppbW(≤2) 0.011 0.004 0.033 Mg / ppbW(≤5) 0.129 0.06 0.039 Ni / ppbW(≤10) 0.003 0.001 0.002 Cu / ppbW(≤5) 0.009 0.017 0.019 Mo / ppbW(≤10) 0.002 <0.000 0.002

[0062] Comparative Example 1

[0063] For example, in Example 3, the inner wall polishing quality of the upper end cap 5, lower end cap 3, and cylinder 4 was adjusted to Ra = 0.2 μm. The cylinder was heated using ambient heating, and the temperature inside the cylinder reached 40°C in 45 minutes. The qualified indicators and analysis results are shown in Table 4. The data in Tables 7 and 8 show that the gas analysis and metal ion analysis results of the cylinders in this comparative example failed after 12 and 24 months of storage of tungsten hexafluoride. When the inner wall polishing quality of the cylinder is Ra = 0.2 μm, the shelf life of the stored tungsten hexafluoride is less than 12 months.

[0064] The reason is that high-purity tungsten hexafluoride has extremely stringent requirements on the cleanliness of the storage device, and the total impurity content is required to be controlled within 1×10 -6 The following is true: WF6 is easily hydrolyzed to produce HF when in contact with water. Water in the cylinder will cause the HF index mixed into the tungsten hexafluoride to increase. Therefore, the requirements for the cylinder are extremely high. When the inner wall roughness of the cylinder is high, the inner wall surface will adsorb impurities such as oxygen, nitrogen, and water, which will cause the oxygen, nitrogen, and HF content in the gas to increase during cylinder gas analysis. A small amount of HF in the cylinder will corrode the inner wall of the cylinder, resulting in an increase in the metal ion content. The polishing quality of the inner wall of a 40L tungsten hexafluoride cylinder needs to reach Ra = 0.3μm, but the inner wall of a large-capacity cylinder is larger, and the polishing quality requirements are higher. Impurities generated by improper treatment of the inner wall of the cylinder will shorten the shelf life of the tungsten hexafluoride in the bottle, which can easily affect the customer.

[0065] Table 7 Comparative Example 1 Gas Analysis Results in the Cylinder

[0066]

[0067] Table 8 Analysis results of metal ions in steel cylinders of Comparative Example 1

[0068]

[0069]

[0070] The above-mentioned embodiments are described in a relatively detailed and specific manner, expressing preferred embodiments of the present invention. They are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. However, they are not limited to the present invention alone, and the patent scope of the present invention cannot be limited solely by these embodiments. That is, any equivalent changes or modifications made to the spirit disclosed by the present invention, for researchers or technicians in this field, without departing from the structure of the present invention, local improvements within the system and changes and conversions between subsystems, etc., are still within the patent scope of the present invention.

Claims

1. A high-purity tungsten hexafluoride steel cylinder, comprising a vertical cylinder (4), an upper head (5) fixedly connected to the top of the cylinder (4), a lower head (3) fixedly connected to the bottom of the cylinder (4), an annular mounting seat (7) fixedly connected to the upper head (5), and a flange (8) connected to the mounting seat (7), wherein a sealed storage chamber (19) for storing tungsten hexafluoride is formed between the upper head (5), the cylinder (4), and the lower head (3), characterized in that: The invention also includes a conduit (14) vertically penetrating and fixedly connected to the flange (8), the lower end of the conduit (14) is close to the bottom of the lower head (3), the upper end of the conduit (14) is provided with a liquid phase bottle valve (9), and the liquid phase bottle valve (9) is arranged outside the head. A heating device for heating tungsten hexafluoride stored in the storage chamber (19) is provided outside the cylinder (4).

2. A high-purity tungsten hexafluoride steel cylinder according to claim 1, characterized in that: The heating device comprises a jacket (15) arranged outside the cylinder (4), the jacket (15) covering the outside of the lower head (3) and the cylinder (4), at least one of the upper head (5), the cylinder (4) and the lower head (3) is fixedly connected to the jacket (15), a closed heat transfer liquid chamber (12) is formed between the cylinder (4) and the jacket (15), one side of the jacket (15) is fixedly connected to a liquid inlet pipe (17), and the other side of the jacket (15) is fixedly connected to a liquid outlet pipe (16), and both the liquid inlet pipe (17) and the liquid outlet pipe (16) are in communication with the heat transfer liquid chamber (12).

3. A high-purity tungsten hexafluoride steel cylinder according to claim 2, characterized in that: A horizontal arc-shaped baffle (18) is distributed in the heat transfer liquid chamber (12), and the baffle (18) is fixedly connected to at least one of the cylinder (4), the jacket (15), and the lower head (3); a vertical partition (20) is fixedly connected between the jacket (15) and the cylinder (4) in the heat transfer liquid chamber (12).

4. A high-purity tungsten hexafluoride steel cylinder according to claim 1, characterized in that: The flange (8) is fixedly connected to a gas phase bottle valve (10) beside the liquid phase bottle valve (9), and the gas phase bottle valve (10) is communicated with the top of the storage chamber (19).

5. A high-purity tungsten hexafluoride steel cylinder according to claim 4, characterized in that: The flange (8) is detachably connected to a bottle cap (11), and the gas phase bottle valve (10) and the liquid phase bottle valve (9) are both covered in the bottle cap (11).

6. A high-purity tungsten hexafluoride steel cylinder according to claim 2, characterized in that: A temperature sensor (13) is provided in the storage cavity (19), and a temperature sensing element of the temperature sensor (13) is close to the bottom of the storage cavity (19).

7. A high-purity tungsten hexafluoride steel cylinder according to claim 5, characterized in that: The upper sealing head (5) is detachably connected to a protective cover (6), and the flange (8), the mounting seat (7) and the bottle cap (11) are all covered in the protective cover (6).

8. A high-purity tungsten hexafluoride steel cylinder according to claim 1, characterized in that: The storage chamber (19) has a volume of 0.5-5m 3 The cylinder (4), the upper head (5) and the lower head (3) are made of metal materials with polished inner walls.

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