A bubble-breaking distillation tower and control method for preparing high-purity electronic-grade molybdenum hexafluoride

Abstract

This invention relates to a defoaming distillation column and control method for preparing high-purity electronic-grade molybdenum hexafluoride, comprising: several bubble stretching and thinning mechanisms, each including a gas guiding frame, a fixed plate, and a bubble attachment plate. The gas guiding frame and the fixed plate are spaced apart on a first mounting bracket. The middle part of the bubble attachment plate is laterally hinged to the top of the fixed plate. When the bubble attachment plate is not under stress, it blocks the opening of the gas guiding frame. A gap is provided between the gas guiding frame and the bubble attachment plate. Several liquid driving devices are mounted on a second mounting bracket. The liquid driving devices output liquid toward the top of the bubble attachment plate. During the rapid oscillation of the bubble attachment plate, the contact line between the foam and the fixed plate and the bubble attachment plate is stretched and thinned. After an opening appears between the bubble attachment plate and the gas guiding frame, the bubble attachment plate drives air into the opening, thereby breaking the stretched and thinned portion.

Description

Technical Field

[0001] This invention relates to the field of molybdenum hexafluoride distillation, specifically to a defoaming distillation column and control method for preparing high-purity electronic-grade molybdenum hexafluoride. Background Technology

[0002] Molybdenum hexafluoride (MoF6) can be produced by reacting molybdenum powder with fluorine gas. The resulting crude MoF6 gas contains other impurities. After condensation and filtration to remove some solid impurities, crude MoF6 liquid is obtained. The impurities include liquid molybdenum tetrafluoride, molybdenum pentafluoride, and molybdenum oxyfluoride. These impurities have higher boiling points than MoF6, so the crude MoF6 liquid needs to be purified by distillation in a distillation column to obtain high-purity MoF6.

[0003] Molybdenum hexafluoride has a boiling point of around 34°C, while the boiling points of other impurities are much higher. Furthermore, during purification, on the one hand, the distillation column employs low-temperature distillation, with the bottom temperature typically controlled at around 40°C, resulting in a slow heating rate. On the other hand, during distillation, a large amount of molybdenum hexafluoride accumulates at the top of the column, leaving impurities such as molybdenum tetrafluoride, molybdenum pentafluoride, and molybdenum oxyfluoride at the bottom. These impurities are viscous, and during low-temperature heating, the viscous bottom liquid slowly forms large bubbles. As the internal pressure of these large bubbles slowly rises and they burst, the high-pressure gas inside is ejected outwards. This ejection process easily carries impurities from the bottom liquid into the gas phase, leading to poor distillation efficiency. Current technologies typically employ defoaming devices or filter plates to reduce bubbles; however, these methods are ineffective against slowly increasing, viscous bubbles at low temperatures.

[0004] The purpose of this invention is to design a defoaming distillation column and control method for preparing high-purity electronic-grade molybdenum hexafluoride, addressing the problems existing in the prior art. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a defoaming distillation column and control method for preparing high-purity electronic-grade molybdenum hexafluoride, which can effectively solve at least one of the problems existing in the prior art.

[0006] The technical solution of the present invention is:

[0007] A defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride, comprising:

[0008] The distillation column body has a heavy component reflux port and a vapor return port at the bottom and a light component reflux port and a vapor outlet at the top. Several guide plates are installed inside the distillation column body. A first mounting bracket and a second mounting bracket are installed at the bottom of the distillation column body, with the second mounting bracket positioned above the first mounting bracket.

[0009] The distillation column condenser, connected to the steam outlet, is used to condense the gaseous stream at the top of the distillation column to form reflux liquid;

[0010] A reflux tank, connected between the distillation column condenser and the light component reflux port, is used to store and reflux liquid;

[0011] A reboiler is connected between the heavy component reflux port and the vapor return port and is used to heat and vaporize the heavy component liquid at the bottom of the distillation column.

[0012] A bubble stretching and thinning mechanism, comprising a gas guide frame, a fixed plate, and a bubble attachment plate, wherein a first mounting bracket is provided with a number of bubble rising through holes, the gas guide frame and the fixed plate are spaced apart on the first mounting bracket, the middle part of the bubble attachment plate is laterally hinged to the top of the fixed plate, and the bubble attachment plate blocks the opening of the gas guide frame when not under stress, and a gap is provided between the gas guide frame and the bubble attachment plate;

[0013] Several liquid driving devices are installed on the second mounting bracket. The liquid driving devices are used to output liquid toward the top of the bubble attachment plate, thereby driving the bubble attachment plate to swing away from the fixed plate. During the rapid swing of the bubble attachment plate, the contact line between the foam and the fixed plate is stretched and thinned. After the bubble attachment plate and the gas guide frame have an opening, the bubble attachment plate drives air to flow into the opening, thereby breaking the stretched and thinned part.

[0014] Furthermore, the liquid driving device includes a liquid receiving chamber, a liquid receiving port is provided at the top of the liquid receiving chamber, a nozzle is provided at the bottom of the liquid receiving chamber, the nozzle faces the upper end of one of the bubble attachment plates, and a movable plug is provided inside the liquid receiving chamber, which is driven by a corresponding movable plug driving cylinder.

[0015] Furthermore, the liquid receiving port is located on the second mounting bracket near the inner wall of the distillation column, and the nozzle is located on the second mounting bracket away from the inner wall of the distillation column. After the movable plug moves away from the nozzle, the liquid receiving port communicates with the liquid receiving cavity.

[0016] Furthermore, a blocking ball is provided at the opening of the nozzle by means of a contraction spring. The blocking ball has a tendency to move closer to the opening of the nozzle, and the blocking ball has a liquid channel toward the upper end of one of the bubble attachment plates.

[0017] When the moving piston is driven by the cylinder to move at low speed, the blocking ball blocks the opening of the nozzle, and the liquid in the liquid receiving chamber is concentratedly sprayed onto the upper end of the bubble attachment plate through the liquid channel, thereby driving the bubble attachment plate to swing.

[0018] When the moving piston is driven by the cylinder, the liquid in the liquid receiving chamber will push the blocking ball away from the nozzle opening. After the liquid flows out of the nozzle opening, it will spread outwards under the action of the blocking ball.

[0019] Furthermore, the upper part of the bubble-attached plate is coated with an oleophobic layer.

[0020] Furthermore, the gas guide frame and the bubble attachment plate are respectively provided with serrated edges.

[0021] Furthermore, the serrated edges are acute-angled serrations, and the serrated edges of the gas guide frame and the serrated edges of the bubble attachment plate are complementary serrations.

[0022] Furthermore, the width of the gas guiding frame is greater than the thickness of the bubble attachment plate.

[0023] Furthermore, the lower surface of the first mounting bracket is provided with an oleophilic layer.

[0024] Furthermore, a method for controlling a defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride is provided, based on a defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride, comprising the following steps:

[0025] Every first distillation time, the following is executed: control the liquid drive device to concentrate the liquid spray towards the top of the bubble attachment plate, thereby driving the bubble attachment plate to swing and cause the bubbles to burst.

[0026] Every second distillation time, the liquid is output in a manner that controls the liquid drive device to spread outwards, thereby rinsing the surface of the bubble stretching and thinning mechanism. The second distillation time is longer than the first distillation time.

[0027] Therefore, the present invention provides the following effects and / or advantages:

[0028] This application utilizes the characteristics of molybdenum hexafluoride distillation, which is carried out at low temperatures and the remaining impurities in the bottom liquid are viscous, making it easy to slowly generate large bubbles. By driving the bubble attachment plate to swing rapidly through the liquid impact force, shear force is generated at the bubble contact line, which is rapidly stretched, thereby thinning the sidewall of the bubble. The bubble is then broken by the flow of air inside the bubble, achieving mechanical breakage of the bubble before it rises, reducing the problem of high-pressure ejection of impurities after the bubble naturally breaks up.

[0029] This application achieves the ability of the nozzle to spray in a straight line or in an umbrella shape by setting a structure for the clogging ball. The straight line spray can drive the bubble adhesion plate, and the umbrella spray can clean the bubble stretching and thinning mechanism.

[0030] The bubble attachment plate of this application is provided with an oleophobic layer, which makes it difficult for the oil phase inside the bubble to spread on the surface of the bubble attachment plate, thus helping to maintain the spherical shape of the bubble on the bubble attachment plate.

[0031] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0032] It should be understood that the above summary and the following detailed description of the invention are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an embodiment of the present invention.

[0034] Figure 2 This is a cross-sectional view of an embodiment of the present invention.

[0035] Figure 3 for Figure 2 A magnified view of part B.

[0036] Figure 4 This is a schematic diagram of the bubble stretching and thinning mechanism and the liquid driving device.

[0037] Figure 5 This is a schematic diagram of the nozzle structure.

[0038] Figure 6 This is a schematic diagram of the working state when the nozzle is blocked and the ball has not left the opening.

[0039] Figure 7 This is a schematic diagram of the working state when the clogging ball of the nozzle leaves the opening.

[0040] Explanation of reference numerals in the attached figures:

[0041] Distillation column body 41, heavy component reflux port 411, steam return port 412, light component reflux port 413, steam outlet 414, guide plate 415, first mounting bracket 416, bubble rising through hole 4161, second mounting bracket 417, distillation column condenser 42, reflux tank 43, reboiler 44, bubble stretching and thinning mechanism 45, gas guide frame 451, fixed plate 452, bubble attachment plate 453, liquid driving device 46, liquid receiving chamber 461, liquid receiving port 462, nozzle 464, movable plug 465, movable plug driving cylinder 466, liquid channel 467, blocking ball 468, contraction spring 469. Detailed Implementation

[0042] To facilitate understanding by those skilled in the art, the structure of the present invention will now be described in further detail with reference to the accompanying drawings:

[0043] refer to Figure 1-5 A defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride, comprising:

[0044] The distillation column body 41 has a heavy component reflux port 411 and a vapor return port 412 at its bottom end, a light component reflux port 413 and a vapor outlet 414 at its top end, a raw material inlet at its middle position, and several guide plates 415 inside the distillation column body 41. A first mounting bracket 416 and a second mounting bracket 417 are provided at the bottom of the distillation column body 41, with the second mounting bracket 417 positioned above the first mounting bracket 416.

[0045] The distillation column condenser 42 is connected to the steam outlet 414 and is used to condense the gaseous stream at the top of the distillation column body 41 to form reflux liquid.

[0046] The reflux tank 43 is connected between the distillation column condenser 42 and the light component reflux port 413, and is used to store and reflux the reflux liquid;

[0047] The reboiler 44 is connected between the heavy component reflux port 411 and the vapor return port, and is used to heat and vaporize the heavy component liquid at the bottom of the distillation column body 41.

[0048] In this embodiment, the distillation column body 41, distillation column condenser 42, reflux tank 43, and reboiler 44 are directly adopted from existing technologies. The principle in this embodiment is to continuously heat and vaporize the liquid at the bottom of the column using the reboiler 44, causing the liquid to vaporize and flow towards the top of the column. The distillation column condenser 42 condenses the vapor stream from the top of the column to form reflux liquid, which then returns to the top of the column through the light component reflux port 413 and flows downwards from the top. During the downward flow of the reflux liquid, it comes into contact with the vapor stream generated by the reboiler 44, exchanging energy. Part of the energy in the vapor stream is transferred to the reflux liquid, causing part of the reflux liquid to vaporize during the downward flow and part of the vapor stream to liquefy during the upward flow. By continuously repeating the above process, the lighter and lower boiling point components in the liquid at the bottom of the column can be separated to the top of the column and condensed and stored in the reflux tank 43, thereby achieving a purification effect.

[0049] A number of bubble stretching and thinning mechanisms 45 are provided. Each bubble stretching and thinning mechanism 45 includes a gas guiding frame 451, a fixed plate 452, and a bubble attachment plate 453. A first mounting bracket 416 is provided with a number of bubble rising through holes 4161. The gas guiding frame 451 and the fixed plate 452 are spaced apart on the first mounting bracket 416. The middle part of the bubble attachment plate 453 is laterally hinged to the top of the fixed plate 452. When the bubble attachment plate 453 is not under force, it blocks the opening of the gas guiding frame 451. The gas guiding frame 451 and the bubble attachment plate 453 are spaced apart.

[0050] In this embodiment, the bottom liquid is a viscous, high-concentration impurity composed of molybdenum tetrafluoride, molybdenum pentafluoride, and molybdenum oxyfluoride, while the top liquid is a liquid with a low boiling point, molybdenum hexafluoride. Bubbles generated in the bottom liquid slowly expand upwards. A bubble rising through-hole 4161 provides a pathway for the upward expansion of these bubbles. After expansion, the gas guide frame 451 and the fixed plate 452 are spaced apart, allowing the expanded bubbles to extend into the space between them and adhere to the space between them. The gas guide frame 451 and the fixed plate 452 are also spaced apart, creating a contact line at their interface. During the oscillation of the bubble attachment plate 453, a shearing and tensile force is generated at the contact line of the bubbles.

[0051] Several liquid driving devices 46 are disposed on the second mounting bracket 417. The liquid driving devices 46 are used to output liquid toward the top of the bubble attachment plate 453, thereby driving the bubble attachment plate 453 to swing away from the fixed plate 452. During the rapid swinging process, the bubble attachment plate 453 stretches and thins the contact line between the foam and the fixed plate 452 and the bubble attachment plate 453. After the bubble attachment plate 453 and the gas guide frame 451 form an opening, the bubble attachment plate 453 drives air to flow into the opening, thereby breaking the stretched and thinned part.

[0052] The above describes how, after a bubble adheres to the gas guide frame 451 and the bubble attachment plate 453, a contact line is formed at the interface. At this time, the liquid driving device 46 drives the bubble attachment plate 453 to swing away from the fixed plate 452. This rapidly increases the distance between the bubble attachment plate 453 and the fixed plate 452, stretching the contact line of the bubble. The viscous liquid along the contact line is rapidly stretched, thinning the contact line. Furthermore, since the bubble is attached between the bubble attachment plate 453 and the fixed plate 452, its volume can be considered constant at the moment of stretching. As the bubble attachment plate 453 swings outward, the distance between it and the gas guide frame 451 increases, and the air inside the bubble is guided into the increased space created by the swinging of the bubble attachment plate 453. Then, after the bubble attachment plate 453 and the gas guide frame 451 form an opening, the air inside the bubble is guided to the opening of the bubble attachment plate 453 and the gas guide frame 451. The internal air breaks through the contact line and is stretched to cover the part at the opening, so that the bubble can rupture when the internal pressure is low. Therefore, the bubble can rupture under low pressure, preventing the high pressure inside the bubble from causing the ejection effect after rupture, and preventing other impurities from being ejected outward to form gaseous impurities.

[0053] Furthermore, the liquid driving device 46 includes a liquid receiving cavity 461, with a liquid receiving port 462 at the top and a nozzle 464 at the bottom, the nozzle 464 facing the upper end of one of the bubble attachment plates 453. A movable plug 465 is provided inside the liquid receiving cavity 461, and the movable plug 465 is driven by a corresponding movable plug driving cylinder 466.

[0054] In this embodiment, the liquid receiving chamber 461 and the movable plug 465 form a structure similar to a syringe. When the movable plug 465 moves toward the nozzle 464, the movable plug 465 outputs the liquid in the liquid receiving chamber 461 through the nozzle 464. The liquid receiving port 462 is located at the top of the liquid receiving chamber 461. During the distillation process, the liquid phase flows downward from the top of the distillation column body 41 and enters the liquid receiving chamber 461 through the liquid receiving port 462, where it is temporarily stored.

[0055] Furthermore, the liquid receiving port 462 is located on the second mounting bracket 417 near the inner wall of the distillation column body 41, and the nozzle 464 is located on the second mounting bracket 417 away from the inner wall of the distillation column body 41. After the movable plug 465 moves away from the nozzle 464, the liquid receiving port 462 communicates with the liquid receiving cavity 461.

[0056] In this embodiment, the position of the liquid receiving port 462 allows the liquid received by the liquid receiving port 462 to flow into the liquid receiving cavity 461 after the movable plug 465 retracts from the position of the liquid receiving port 462. At the same time, the drive cylinder extends into the liquid receiving cavity 461 and connects with the movable plug 465 through a sealed connection, thereby preventing the internal liquid from flowing out.

[0057] Furthermore, a blocking ball 468 is provided at the opening of the nozzle 464 by means of a contraction spring 469. The blocking ball 468 has a tendency to move closer to the opening of the nozzle 464. The blocking ball 468 has a liquid channel 467 facing the upper end of one of the bubble attachment plates 453.

[0058] refer to Figure 6 When the movable plug driving cylinder 466 drives the movable plug 465 to move at a low speed, the blocking ball 468 blocks the opening of the nozzle 464, and the liquid in the liquid receiving chamber 461 is concentratedly sprayed onto the upper end of the bubble attachment plate 453 through the liquid channel 467, thereby driving the bubble attachment plate 453 to swing.

[0059] refer to Figure 7 When the movable plug driving cylinder 466 drives the movable plug 465 to move at high speed, the liquid in the liquid receiving cavity 461 pushes the blocking ball 468 away from the opening of the nozzle 464. After the liquid flows out of the opening of the nozzle 464, it spreads outward under the action of the blocking ball 468.

[0060] In this embodiment, the flow pattern of liquid from nozzle 464 can be controlled by controlling the moving speed of the movable plug 465. A blocking ball 468 is installed at the opening of nozzle 464 via a contraction spring 469. When the movable plug 465 moves at low speed, the liquid pressure is insufficient to force the blocking ball 468 out of the nozzle 464 opening, allowing liquid to spray out from the liquid channel 467 of the blocking ball 468, forming a long, high-speed liquid stream that can spray the top of the bubble attachment plate 453, causing the bubble attachment plate 453 to oscillate. When the movable plug 465 moves at high speed, the liquid pressure forces the blocking ball 468 out of the nozzle 464 opening. At this time, the liquid flowing out of nozzle 464 is dispersed into an umbrella-like structure by the surface of the blocking ball 468 and sprayed outwards at a relatively large flow rate. In this state, nozzle 464 can flush the bubble stretching and thinning mechanism 45 with the dispersed liquid, preventing the viscous bottom liquid from continuously adhering to the surface of the bubble stretching and thinning mechanism 45 and affecting its working effect.

[0061] Furthermore, the upper portion of the bubble attachment plate 453 is coated with an oleophobic layer.

[0062] In this embodiment, the oleophobic layer can prevent bubbles from adhering and quickly climbing to the upper part of the bubble attachment plate 453, thereby generating larger bubbles. In this way, the oil phase inside the oily bubbles is not easy to spread on the surface of the bubble attachment plate 453, which is beneficial to maintaining the stability of the spherical shape of the bubbles between the bubble attachment plate 453 and the gas guide frame 451.

[0063] Furthermore, the gas guide frame 451 and the bubble attachment plate 453 are respectively provided with serrated edges.

[0064] Furthermore, the serrated edge is an acute-angled serration, and the serrated edge of the gas guide frame 451 and the serrated edge of the bubble attachment plate 453 are complementary serrations.

[0065] In this embodiment, the serrated edge can increase the local curvature of the bubble at the contact line, restricting the spread of the bubble at the structural edges of the gas guide frame 451 and the bubble attachment plate 453, thereby forming a situation where the corresponding edge of the bubble will break when the bubble attachment plate 453 swings rapidly.

[0066] Furthermore, the width of the gas guiding frame 451 is greater than the thickness of the bubble attachment plate 453.

[0067] In this embodiment, the width of the gas guiding frame 451 is relatively large. In the initial stage of the bubble attachment plate 453 swinging, the movement of the bubble attachment plate 453 can drive the air inside the bubble to flow into the gas guiding frame 451 and the bubble attachment plate 453, forming a vortex. In the latter half of the swinging stage of the bubble attachment plate 453, a part of the bubble attachment plate 453 leaves the guiding frame, at which time an opening is generated. Gas rushes into the opening to form a transient vortex and breaks through the bubble sidewall corresponding to the opening, which is more conducive to bubble rupture.

[0068] Furthermore, the lower surface of the first mounting bracket 416 is provided with an oleophilic layer.

[0069] In this embodiment, the oleophilic layer provided on the first mounting bracket 416 can attract the bubbles generated by the bottom liquid to the area below the first mounting bracket 416, and through the gradual expansion of the bubbles, the bubbles can be concentrated more in the bubble stretching and thinning mechanism 45.

[0070] Furthermore, a method for controlling a defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride is provided. Based on the aforementioned defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride, the method includes the following steps:

[0071] Every first distillation time, the following is performed: control the liquid driving device 46 to concentrate the liquid spray towards the top of the bubble attachment plate 453, thereby driving the bubble attachment plate 453 to swing and cause the bubbles to burst.

[0072] Every second distillation time, the liquid driving device 46 is controlled to output liquid in a manner that disperses in all directions, thereby rinsing the surface of the bubble stretching and thinning mechanism 45, wherein the second distillation time is longer than the first distillation time.

[0073] In this embodiment, by lifting and switching the liquid output mode of the liquid driving device 46, the device can periodically switch between driving the bubble attachment plate 453 to swing and rinsing the surface of the bubble stretching and thinning mechanism 45, thereby achieving the cleaning effect on the bubble attachment plate 453.

[0074] It should be noted that any reference signs placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0075] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride, characterized in that: include: The distillation column body (41) is provided with a heavy component reflux port (411) and a vapor return port (412) at the bottom end, and a light component reflux port (413) and a vapor outlet (414) at the top end. Several guide plates (415) are provided inside the distillation column body (41). A first mounting bracket (416) and a second mounting bracket (417) are provided at the bottom of the distillation column body (41). The second mounting bracket (417) is located above the first mounting bracket (416). A distillation column condenser (42) is connected to the steam outlet (414) for condensing the gaseous stream at the top of the distillation column body (41) to form reflux liquid; A reflux tank (43) is connected between the distillation column condenser (42) and the light component reflux port (413) for storing and refluxing the reflux liquid; A reboiler (44) is connected between the heavy component reflux port (411) and the vapor return port, and is used to heat and vaporize the heavy component liquid at the bottom of the distillation column body (41); A bubble stretching and thinning mechanism (45) is provided in several parts. The bubble stretching and thinning mechanism (45) includes a gas guide frame (451), a fixed plate (452), and a bubble attachment plate (453). The first mounting bracket (416) is provided with several bubble rising through holes (4161). The gas guide frame (451) and the fixed plate (452) are arranged at intervals on the first mounting bracket (416). The middle part of the bubble attachment plate (453) is horizontally hinged to the top of the fixed plate (452). The bubble attachment plate (453) blocks the opening of the gas guide frame (451) when it is not under force. The gas guide frame (451) and the bubble attachment plate (453) are separated by a gap. A number of liquid driving devices (46) are provided on the second mounting bracket (417). The liquid driving devices (46) are used to output liquid toward the top of the bubble attachment plate (453), thereby driving the bubble attachment plate (453) to swing away from the fixed plate (452). During the rapid swinging process, the bubble attachment plate (453) stretches and thins the contact line between the fixed plate (452) and the bubble attachment plate (453) corresponding to the foam. After the bubble attachment plate (453) and the gas guide frame (451) have an opening, the bubble attachment plate (453) drives air to flow into the opening, thereby breaking the stretched and thinned part.

2. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 1, characterized in that: The liquid drive device (46) includes a liquid receiving cavity (461), a liquid receiving port (462) is provided at the top of the liquid receiving cavity (461), a nozzle (464) is provided at the bottom of the liquid receiving cavity (461), the nozzle (464) faces the upper end of one of the bubble attachment plates (453), and a movable plug (465) is provided in the liquid receiving cavity (461), the movable plug (465) is driven by a corresponding movable plug drive cylinder (466).

3. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 2, characterized in that: The liquid receiving port (462) is located on the second mounting bracket (417) near the inner wall of the distillation column body (41), and the nozzle (464) is located on the second mounting bracket (417) away from the inner wall of the distillation column body (41). After the movable plug (465) moves away from the nozzle (464), the liquid receiving port (462) communicates with the liquid receiving cavity (461).

4. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 2, characterized in that: The nozzle (464) has a blocking ball (468) provided at its opening by a compression spring (469). The blocking ball (468) has a tendency to move closer to the opening of the nozzle (464). The blocking ball (468) has a liquid channel (467) opening toward the upper end of one of the bubble attachment plates (453). When the movable plug drive cylinder (466) drives the movable plug (465) to move at a low speed, the blocking ball (468) blocks the opening of the nozzle (464), and the liquid in the liquid receiving chamber (461) is concentratedly sprayed onto the upper end of the bubble attachment plate (453) through the liquid channel (467), thereby driving the bubble attachment plate (453) to swing. When the movable plug driving cylinder (466) drives the movable plug (465) to move at high speed, the liquid in the liquid receiving cavity (461) pushes the blocking ball (468) away from the opening of the nozzle (464). After the liquid flows out of the opening of the nozzle (464), it spreads outward under the action of the blocking ball (468).

5. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 1, characterized in that: The upper part of the bubble attachment plate (453) is coated with an oleophobic layer.

6. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 1, characterized in that: The gas guide frame (451) and the bubble attachment plate (453) are respectively provided with serrated edges.

7. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 6, characterized in that: The serrated edge is an acute serrated edge, and the serrated edge of the gas guide frame (451) and the serrated edge of the bubble attachment plate (453) are complementary serrations.

8. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 1, characterized in that: The width of the gas guide frame (451) is greater than the thickness of the bubble attachment plate (453).

9. The defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 1, characterized in that: The lower surface of the first mounting bracket (416) is provided with an oleophilic layer.

10. A method for controlling the defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride, characterized in that: A defoaming distillation column for preparing high-purity electronic-grade molybdenum hexafluoride according to claim 4 includes the following steps: Every first distillation time, the following is performed: control the liquid driving device (46) to concentrate the liquid spray towards the top of the bubble attachment plate (453), thereby driving the bubble attachment plate (453) to swing and cause the bubbles to burst; Every second distillation time, the liquid driving device (46) is controlled to output liquid in a manner that spreads outwards, thereby rinsing the surface of the bubble stretching and thinning mechanism (45), wherein the second distillation time is longer than the first distillation time.

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