Phosphorus trifluoride manufacturing device and method based on Venturi effect

Abstract

The invention provides a phosphorus trifluoride manufacturing device and method based on a Venturi effect, and belongs to the technical field of phosphorus trifluoride manufacturing. The phosphorus trifluoride manufacturing device based on the Venturi effect comprises a Venturi mixing unit, a micro-channel reactor and a gas-liquid separator. The venturi mixing unit comprises a gas conveying pipe and a liquid conveying pipe, the gas inlet end of the gas conveying pipe is communicated with a gas source, the gas source is used for providing gaseous hydrogen fluoride, the gas outlet end of the gas conveying pipe is provided with a first reducing section, the tail end of the first reducing section is provided with a gas-liquid mixing cavity, and the liquid inlet end of the liquid conveying pipe is communicated with a liquid phosphorus trichloride storage tank; the liquid outlet end of the liquid conveying pipe extends into the gas-liquid mixing cavity; a feeding hole of the micro-channel reactor is communicated with an outlet of the first reducing section; and a feeding hole of the gas-liquid separator is communicated with a discharging hole of the micro-channel reactor. The device can prepare phosphorus trifluoride with relatively high purity and yield under the condition of not continuously applying high pressure to the micro-channel reactor.

Description

Technical Field

[0001] This application relates to the field of phosphorus trifluoride manufacturing technology, and more specifically, to an apparatus and method for manufacturing phosphorus trifluoride based on the Venturi effect. Background Technology

[0002] In existing technologies, the preparation of PF3 using the reaction of liquid PCl3 and gaseous HF mainly relies on traditional batch reactors. Specifically, a batch reactor is used as the core, in which liquid PCl3 and gaseous HF are added to the reactor for contact reaction, and mixing is achieved by conventional stirring. Temperature is controlled by basic cooling (such as jacket water cooling). However, this preparation method is prone to problems such as insufficient stirring and mixing, which can lead to excessively high local concentrations of HF and cause deep fluorination side reactions (such as the formation of PF5). In addition, the batch ratio fluctuates greatly, resulting in low purity and yield of the prepared phosphorus trifluoride.

[0003] Based on this, technicians proposed using a microchannel reactor to prepare phosphorus trifluoride. While the high specific surface area of ​​the microchannel reactor can enhance the gas-liquid reaction by improving gas-liquid mass transfer, in order to ensure a relatively ideal molar ratio of liquid PCl3 to gaseous HF (the ideal molar ratio is close to 1:3), the volume of gaseous HF in the entire reaction system is usually several hundred times that of liquid PCl3. This extremely high gas-liquid volume ratio makes it easy for the gas and liquid phases to "layered flow" (i.e., liquid adheres to the wall and gas is concentrated in the center of the channel) in the microchannel reactor, resulting in insufficient gas-liquid contact. Consequently, the phosphorus trifluoride prepared by this method still has problems such as low purity and low yield.

[0004] Based on this, in order to improve the gas-liquid mass transfer effect of materials, it is usually necessary to continuously apply high pressure to the microchannel reactor. This results in problems such as low safety factor, poor process adaptability and difficulty in large-scale industrial production when using microchannel reactors to prepare phosphorus trifluoride. Summary of the Invention

[0005] The purpose of this application is to provide an apparatus and method for manufacturing phosphorus trifluoride based on the Venturi effect, which can prepare phosphorus trifluoride with high purity and yield without continuously applying high pressure to the microchannel reactor.

[0006] The embodiments of this application are implemented as follows: In a first aspect, embodiments of this application provide a phosphorus trifluoride manufacturing apparatus based on the Venturi effect, comprising a Venturi mixing unit, a microchannel reactor, and a gas-liquid separator. The Venturi mixing unit includes a gas delivery pipe and a liquid delivery pipe. The inlet end of the gas delivery pipe is connected to a gas source, which provides gaseous hydrogen fluoride. The outlet end of the gas delivery pipe has a first converging section, and the end of the first converging section has a gas-liquid mixing chamber. The inlet end of the liquid delivery pipe is connected to a liquid phosphorus trichloride storage tank, and the outlet end of the liquid delivery pipe extends into the gas-liquid mixing chamber. The inlet of the microchannel reactor is connected to the outlet of the first converging section. The inlet of the gas-liquid separator is connected to the outlet of the microchannel reactor.

[0007] In the above technical solution, the front end of the phosphorus trifluoride manufacturing apparatus includes a Venturi mixing unit. The outlet of the gas delivery pipe has a first converging section. When gaseous HF from the gas source passes through the first converging section, its flow velocity gradually increases due to the gradually decreasing inner diameter of the pipe, thereby forming a relatively stable and strong negative pressure field near the outlet of the first converging section. Simultaneously, the end of the first converging section (i.e., the position near the outlet of the first converging section) has a gas-liquid mixing chamber, and the liquid outlet of the liquid delivery pipe extends into the gas-liquid mixing chamber, allowing liquid phosphorus trichloride from the liquid phosphorus trichloride storage tank to pass through… The infusion tube reaches the gas-liquid mixing chamber, where liquid phosphorus trichloride, under the influence of a negative pressure field, mixes thoroughly with gaseous HF and forms a small-particle aerosol after passing the end of the first converging section. Based on this, the aerosol formed by the uniform mixing of liquid phosphorus trichloride and gaseous hydrogen fluoride is then passed through a microchannel reactor and a gas-liquid separator to prepare high-purity and high-yield phosphorus trifluoride. Moreover, since the liquid phosphorus trichloride and gaseous hydrogen fluoride have already been uniformly mixed before entering the microchannel reactor, it is not necessary to apply high pressure to the microchannel reactor during the reaction process.

[0008] In some alternative implementations, the infusion tubing extends in the same direction as the gas tubing.

[0009] In the above technical solution, the extension direction of the infusion tube is the same as that of the gas infusion tube, that is, the gas infusion tube is sleeved outside the corresponding area of ​​the infusion tube, so that the entire Venturi mixing unit has advantages such as a relatively regular overall structure and easy assembly.

[0010] In some alternative implementations, the air inlet end of the gas delivery pipe includes a connecting part and an air inlet part, the connecting part is sleeved outside the infusion pipe, and the inner wall of the connecting part is threadedly sealed to the outer wall of the corresponding area of ​​the infusion pipe, and the air inlet part is connected to the gas source.

[0011] In the above technical solution, the gas inlet end of the gas delivery pipe includes a connecting part and a gas inlet part. The gas inlet part is connected to a gas source and is used to supply gaseous hydrogen fluoride to the gas delivery pipe through the gas source. The inner wall of the connecting part is threadedly connected to the outer wall of the corresponding area of ​​the liquid delivery pipe. Through the threaded connection, the position of the liquid outlet end of the liquid delivery pipe in the gas-liquid mixing chamber can be finely adjusted (for example, when it is necessary to appropriately increase the aerosol flow rate, since the negative pressure is greater closer to the opening of the first tapering section, the liquid outlet end can be moved by a micrometer-level dimension by rotating the liquid delivery pipe at a small angle towards the opening of the first tapering section; conversely, when it is necessary to appropriately decrease the aerosol flow rate, since the negative pressure is smaller further away from the opening of the first tapering section, the liquid outlet end can be moved by a micrometer-level dimension by rotating the liquid delivery pipe at a small angle in the opposite direction). This allows for flexible adjustment of the aerosol flow rate according to the actual reaction process, enabling the raw materials to react more efficiently and thoroughly.

[0012] In some alternative implementations, the outlet end of the infusion tube has a second tapered section that extends into the gas-liquid mixing chamber.

[0013] In the above technical solution, the outlet end of the infusion tube has a second tapering section that extends into the gas-liquid mixing chamber. This allows the flow rate of liquid phosphorus trichloride at the outlet of the infusion tube to gradually increase as the inner diameter of the infusion tube gradually decreases. Consequently, the liquid phosphorus trifluoride can be mixed with gaseous hydrogen fluoride in an aerosol state within the gas-liquid mixing chamber after passing through the outlet of the infusion tube, which helps to further improve the mixing efficiency and mixing effect of the two.

[0014] In some alternative implementations, the gas delivery pipe further includes an expansion section with an inner diameter larger than the outlet inner diameter of the first contraction section. One end of the expansion section is connected to the outlet of the first contraction section, and the other end is connected to the feed inlet of the microchannel reactor.

[0015] In the above technical solution, the gas pipeline is equipped with an expansion section to connect the Venturi mixing unit and the microchannel reactor. The existing microchannel reactor can be used in combination with the Venturi mixing unit. At the same time, the expansion section also has a buffering effect, which can deliver the formed aerosol to the microchannel reactor at a stable flow rate for reaction, thereby enabling the raw materials to react more efficiently and thoroughly.

[0016] In some alternative embodiments, the gas delivery pipe includes a main gas delivery section and a first tapering section connected to the main gas delivery section. The inlet end of the main gas delivery section is connected to a gas source, and the outlet end of the liquid delivery pipe extends through the main gas delivery section into the gas-liquid mixing chamber. The inner wall of the end of the expansion section opposite to the microchannel reactor is sealed to the outer wall of the corresponding area of ​​the main gas delivery section.

[0017] In the above technical solution, the outer diameter of the main gas transmission section is larger than that of the first tapering section. The inner wall of the expansion section is sealed to the outer wall of the main gas transmission pipeline, so that the connection between the two has a larger contact area, which helps to improve the structural stability of the entire gas transmission pipeline.

[0018] In some alternative implementations, the liquid phosphorus trichloride storage tank is also equipped with a heating element.

[0019] In the above technical solution, the liquid phosphorus trichloride storage tank is also equipped with a heating element. For microchannel reactors with a small liquid holding capacity, the operating characteristic is that the material in the microchannel reactor is prone to flow reduction of gaseous hydrogen fluoride due to the long residence time. The addition of a heating element to the liquid phosphorus trichloride storage tank can compensate for the deficiency of insufficient negative pressure driving force caused by the reduced flow by precisely controlling the temperature of the liquid phosphorus trichloride storage tank to form a micro-positive pressure, thereby improving the stability of the reaction system.

[0020] In some alternative implementations, the outlet of the gas-liquid separator is connected to a liquid phosphorus trichloride storage tank.

[0021] In the above technical solution, the outlet of the gas-liquid separator is connected to the liquid phosphorus trichloride storage tank, which enables the unreacted liquid phosphorus trichloride obtained by separation to be transported back to the liquid phosphorus trichloride storage tank, so as to realize the recycling of liquid phosphorus trichloride raw material.

[0022] In some alternative implementations, the gas-liquid separator further includes a first liquid level sensor and a second liquid level sensor, with the first liquid level sensor located below the second liquid level sensor.

[0023] In the above technical solution, liquid level sensors are added to the gas-liquid separator at different liquid levels. The first liquid level sensor, located at the bottom, controls the connection between the gas separator and the liquid phosphorus trichloride storage tank by detecting the amount of collected liquid phosphorus trichloride; specifically, it disconnects when the liquid level is below the level and opens when it is above the level. The second liquid level sensor, located at the top, regulates the overall reaction process by detecting the amount of collected liquid phosphorus trichloride. Specifically, if the liquid level remains consistently high, it may indicate low reaction efficiency in previous stages (e.g., low temperature or low mixing efficiency in the microchannel reactor). In this case, the reaction efficiency can be improved by appropriately increasing the microchannel reactor temperature or increasing the negative pressure driving force. Alternatively, it may indicate that the valve opening at the outlet of the gas-liquid separator is too small; in this case, the valve opening can be increased. Furthermore, the cooperation between the first and second liquid level sensors can effectively mitigate flooding or dry-tank phenomena in the gas-liquid separator.

[0024] In some alternative implementations, the gas source includes an inert gas storage tank and a gaseous hydrogen fluoride storage tank, which are connected to the gas inlet end of the gas transmission pipe via the same gas transmission branch pipe.

[0025] In the above technical solution, the gas source includes an inert gas storage tank and a gaseous hydrogen fluoride storage tank, and the two are connected by the same gas transmission branch pipe through the gas inlet end of the transmission pipe, so that the gas in the transmission pipe is a mixture of inert gas and hydrogen fluoride. When the negative pressure driving force generated near the opening of the first converging section is insufficient, under the condition that the amount of gaseous hydrogen fluoride transported remains unchanged (always maintaining its theoretical molar ratio with liquid phosphorus trichloride close to 3:1), the negative pressure driving force can be increased by increasing the transport flow rate of inert gas, thereby improving the mixing efficiency and mixing effect of gaseous hydrogen fluoride and liquid phosphorus trichloride.

[0026] In some alternative embodiments, the phosphorus trifluoride manufacturing apparatus further includes a static reactor, the inlet of which is connected to the outlet of the microchannel reactor, and the outlet of the static reactor is connected to the inlet of a gas-liquid separator.

[0027] In the above technical solution, a static reactor is added between the microchannel reactor and the gas-liquid separator in the phosphorus trifluoride manufacturing device. This allows the mixed system containing some unreacted raw materials discharged from the microchannel reactor to undergo a secondary reaction, which helps to further improve the purity and yield of the prepared phosphorus trifluoride.

[0028] Secondly, embodiments of this application provide a method for preparing phosphorus trifluoride based on the Venturi effect, using the phosphorus trifluoride manufacturing apparatus provided in the first aspect embodiment, and the preparation method includes the following steps: Gaseous hydrogen fluoride is supplied to the gas delivery pipe of the Venturi mixing unit via a gas source, and liquid phosphorus trichloride is supplied to the liquid delivery pipe of the Venturi mixing unit via a liquid phosphorus trichloride storage tank, so that the gaseous hydrogen fluoride and liquid phosphorus trichloride together form an aerosol after passing through the gas-liquid mixing chamber of the first converging section; the aerosol is then transported to a microchannel reactor for reaction to obtain reactants containing phosphorus trifluoride; the reactants containing phosphorus trifluoride are then transported to a gas-liquid separator for gas-liquid separation to obtain gaseous phosphorus trifluoride.

[0029] In the above technical solution, by using the phosphorus trifluoride manufacturing apparatus provided in the first aspect embodiment and preparing according to the above process, phosphorus trifluoride with high purity and yield can be prepared without continuously applying high pressure to the microchannel reactor.

[0030] In some alternative embodiments, the flow rate ratio of gaseous hydrogen fluoride to liquid phosphorus trichloride is (700~900):1; or / and the flow rate ratio of liquid holdup of the microchannel reactor to gaseous hydrogen fluoride is 1 mL: (2~4) mL / min.

[0031] In the above technical solution, the ratio of the flow rates of gaseous hydrogen fluoride and liquid phosphorus trichloride is limited to the above range so that the initial molar ratio of the two is close to 3:1. Under this molar ratio, the two can react more thoroughly and efficiently to produce phosphorus trifluoride. The ratio of the liquid holding capacity of the microchannel reactor to the flow rate of gaseous hydrogen fluoride is limited to the above range so that the aerosol has a more suitable residence time in the microchannel reactor, which also helps the gaseous hydrogen fluoride and liquid phosphorus trichloride to react more thoroughly and efficiently to produce phosphorus trifluoride. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of a first phosphorus trifluoride manufacturing apparatus provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the first Venturi mixing unit provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the second type of Venturi mixing unit provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of a second phosphorus trifluoride manufacturing apparatus provided in an embodiment of this application.

[0034] Icons: 10-Phosphorus trifluoride manufacturing apparatus; 100-Venturi mixing unit; 110-Gas supply pipe; 111-Main gas supply pipe section; 112-First tapering section; 112a-Gas-liquid mixing chamber; 113-Connecting part; 113a-First threaded section; 114-Gas inlet; 120-Liquid supply pipe; 121-Second tapering section; 122-Second threaded section; 130-Expanding section; 200-Microchannel reactor; 300-Gas-liquid separator; 400-Static reactor; 500-Gas source; 510-Inert gas storage tank; 520-Gaseous hydrogen fluoride storage tank; 530-Gas supply branch pipe; 600-Liquid phosphorus trichloride storage tank. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this application, it should be noted that the terms "center," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only used for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] The following provides a detailed description of the phosphorus trifluoride manufacturing apparatus and method based on the Venturi effect provided in this application.

[0041] See Figure 1 and Figure 2In one aspect, embodiments of this application provide a phosphorus trifluoride manufacturing apparatus 10 based on the Venturi effect, including a Venturi mixing unit 100, a microchannel reactor 200, and a gas-liquid separator 300. The Venturi mixing unit 100 includes a gas supply pipe 110 and a liquid supply pipe 120. The gas supply pipe 110 has an inlet end connected to a gas source 500, which provides gaseous hydrogen fluoride. The gas supply pipe 110 has an outlet end with a first tapered section 112, and the end of the first tapered section 112 has a gas-liquid mixing chamber 112a (i.e., the section of the first tapered section 112 near its outlet). The liquid supply pipe 120 has an inlet end connected to a liquid phosphorus trichloride storage tank 600, and the liquid supply pipe 120 extends into the gas-liquid mixing chamber 112a. The inlet of the microchannel reactor 200 is connected to the outlet of the first tapered section 112. The inlet of the gas-liquid separator 300 is connected to the outlet of the microchannel reactor 200.

[0042] It should be noted that the "Venturi effect" refers to the physical phenomenon that when a fluid (liquid or gas) passes through a constricted pipe (the first tapering section 112 in this embodiment of the application), its flow velocity increases while its static pressure decreases. This phenomenon generates a negative pressure driving force in the corresponding area.

[0043] Understandably, the entire material of the Venturi mixing unit 100 is made of acid-resistant material, such as PFA.

[0044] In this application, the front end of the phosphorus trifluoride manufacturing apparatus 10 includes a Venturi mixing unit 100. The outlet end of the gas delivery pipe 110 has a first converging section 112. When gaseous HF from the gas source 500 passes through the first converging section 112, its flow velocity gradually increases due to the gradually decreasing inner diameter of the pipe, thereby forming a relatively stable and strong negative pressure field in the area near the outlet of the first converging section 112. Simultaneously, the end of the first converging section 112 (i.e., the position near the outlet of the first converging section 112) has a gas-liquid mixing chamber 112a, and the outlet end of the liquid delivery pipe 120 extends into the gas-liquid mixing chamber 112a, allowing liquid phosphorus trichloride from the liquid phosphorus trichloride storage tank 600 to reach the gas-liquid mixture via the liquid delivery pipe 120. Inside the mixing chamber 112a, under the influence of a negative pressure field, liquid phosphorus trichloride and gaseous HF are fully mixed in the gas-liquid mixing chamber 112a and form a small-particle-size aerosol after passing through the end of the first tapering section 112, thereby greatly improving the mixing efficiency and mixing effect of liquid phosphorus trichloride and gaseous hydrogen fluoride. Based on this, the aerosol formed by the uniform mixing of liquid phosphorus trichloride and gaseous hydrogen fluoride can be used to prepare high-purity and high-yield phosphorus trifluoride by passing the microchannel reactor 200 and the gas-liquid separator 300 in sequence. Moreover, since the liquid phosphorus trichloride and gaseous hydrogen fluoride have already been uniformly mixed before entering the microchannel reactor 200, it is not necessary to apply high pressure to the microchannel reactor 200 during the reaction process.

[0045] Understandably, in order to continuously collect the prepared phosphorus trifluoride, the outlet of the gas-liquid separator 300 is also connected to a phosphorus trifluoride collection tank.

[0046] It should be noted that the detailed dimensions of the first tapered section 112 are not specifically limited and can be adjusted adaptively according to actual process requirements.

[0047] As an example, the outlet inner diameter of the first tapering section 112 is less than 1 mm.

[0048] In this embodiment, limiting the outlet inner diameter of the first tapering section 112 to the above-mentioned range enables liquid phosphorus trichloride and gaseous hydrogen fluoride to form micron-sized aerosols after passing through the first tapering section 112, which helps the two to react more efficiently and thoroughly.

[0049] As an example, the ratio of the inlet inner diameter of the first tapered section 112 to the outlet inner diameter of the first tapered section 112 is (4~8):1, for example, but not limited to any one of the ratios 4:1, 5:1, 6:1, 7:1 and 8:1 or any range between the two.

[0050] In this embodiment, the ratio of the inlet inner diameter to the outlet inner diameter of the first tapering section 112 is limited to the above-mentioned range so that the airflow can form a negative pressure of a suitable size after passing through the opening, which helps to better improve the mixing efficiency and mixing effect of liquid phosphorus trichloride and gaseous hydrogen fluoride.

[0051] See Figure 2 As an example, the extension direction of the infusion tube 120 is the same as that of the gas infusion tube 110.

[0052] In this embodiment, the extension direction of the infusion tube 120 is the same as the extension direction of the gas infusion tube 110, that is, the gas infusion tube 110 is sleeved outside the corresponding area of ​​the infusion tube 120, so that the entire Venturi mixing unit 100 has advantages such as a relatively regular overall structure and easy assembly.

[0053] See Figure 2 As an example, the air inlet end of the gas supply pipe 110 includes a connecting part 113 and an air inlet part 114. The connecting part 113 is sleeved outside the infusion pipe 120, and the inner wall of the connecting part 113 is threadedly sealed to the outer wall of the corresponding area of ​​the infusion pipe 120. The air inlet part 114 is connected to the gas source 500.

[0054] In this embodiment, the inlet end of the gas delivery pipe 110 includes a connecting part 113 and an inlet part 114. The inlet part 114 is connected to the gas source 500 and is used to supply gaseous hydrogen fluoride to the gas delivery pipe 110 through the gas source 500. The inner wall of the connecting part 113 is threadedly connected to the outer wall of the corresponding area of ​​the liquid delivery pipe 120. The position of the liquid outlet end of the liquid delivery pipe 120 in the gas-liquid mixing chamber 112a can be finely adjusted by the threaded connection (for example, when it is necessary to appropriately increase the flow rate of the aerosol, the closer it is to the opening of the first tapering section 112, the higher the corresponding flow rate). The greater the negative pressure, the more the outlet end can be moved by a micrometer-sized amount closer to the opening of the first converging section 112 by rotating the infusion tube 120 at a small angle. Conversely, when it is necessary to appropriately reduce the aerosol flow rate, since the negative pressure is smaller the farther away from the opening of the first converging section 112, the outlet end can be moved by a micrometer-sized amount further away from the opening of the first converging section 112 by rotating the infusion tube 120 at a small angle in the opposite direction. This allows for flexible adjustment of the aerosol flow rate according to the actual reaction process, enabling the raw materials to react more efficiently and thoroughly.

[0055] It should be noted that the specific method of threaded sealing connection between the inner wall of the connecting part 113 and the outer wall of the corresponding area of ​​the infusion tube 120 is not limited. For example, the inner peripheral wall of the connecting part 113 may be provided with a first threaded section 113a, and the outer peripheral wall of the corresponding area of ​​the infusion tube 120 may be provided with a second threaded section 122 corresponding to the first threaded section 113a.

[0056] It should be noted that the form of the air intake 114 is not limited, as long as it can be connected to the air source 500 to deliver gaseous hydrogen fluoride into the air supply pipe 110.

[0057] See Figure 2 As an example, the air intake 114 is an air nozzle provided on the side wall of the air supply pipe 110. The air nozzle is connected to the inside of the air supply pipe 110, and the opening direction of the air nozzle is perpendicular to the extension direction of the air supply pipe 110.

[0058] It should be noted that, in order to facilitate the adjustment of the relative position of the liquid outlet end of the infusion pipe 120 within the gas-liquid mixing chamber 112a through the threaded connection structure, the liquid inlet end of the infusion pipe 120 can also be connected to the liquid pipeline of the liquid phosphorus trichloride storage tank 600 by a threaded sealing connection, so that the infusion pipe 120 as a whole also has a certain degree of freedom of movement relative to the liquid pipeline of the liquid phosphorus trichloride storage tank 600.

[0059] See Figure 3 As an example, the outlet end of the infusion tube 120 has a second tapered section 121, and the second tapered section 121 extends into the gas-liquid mixing chamber 112a.

[0060] In this embodiment, the outlet end of the infusion tube 120 has a second tapered section 121 that extends into the gas-liquid mixing chamber 112a. This allows the flow rate of liquid phosphorus trichloride at the outlet of the infusion tube 120 to gradually increase as the inner diameter of the infusion tube 120 gradually decreases. This enables the liquid phosphorus trifluoride to mix with gaseous hydrogen fluoride in an aerosol state within the gas-liquid mixing chamber 112a after passing through the outlet of the infusion tube 120, which helps to further improve the mixing efficiency and mixing effect of the two.

[0061] It should be noted that the detailed dimensions of the second tapered section 121 are not specifically limited and can be adjusted adaptively according to actual process requirements.

[0062] As an example, the ratio of the inlet inner diameter of the second tapered section 121 to the outlet inner diameter of the second tapered section 121 is (2~6):1, for example, but not limited to any one of the ratios 2:1, 3:1, 4:1, 5:1 and 6:1 or any range between the two.

[0063] In this embodiment, the ratio of the inlet inner diameter to the outlet inner diameter of the second tapering section 121 is limited to the above-mentioned range so that liquid phosphorus trichloride can form a suitable negative pressure after passing through the opening, which facilitates the liquid phosphorus trichloride to enter the gas-liquid mixing chamber 112a and mix efficiently with gaseous hydrogen fluoride.

[0064] As an example, the ratio of the inner diameter of the opening of the second tapered section 121 to the inner diameter of the opening of the first tapered section 112 is 1:(2~6), for example, but not limited to any one of the ratios of 1:2, 1:3, 1:4, 1:5 and 1:6 or any range between the two.

[0065] In this embodiment, the ratio of the inner diameter of the opening of the second tapered section 121 to the inner diameter of the opening of the first tapered section 112 is limited to the above range, so that after the gaseous hydrogen fluoride forms a stable negative pressure at the opening of the first tapered section 112, it can better draw in phosphorus trichloride from the second tapered section 121, thereby improving the mixing efficiency and mixing effect of the two.

[0066] In other possible implementations, the outlet end of the infusion tube 120 may not have the second tapering section 121.

[0067] See Figure 3 As an example, the gas supply pipe 110 also includes an expansion section 130, the inner diameter of which is larger than the outlet inner diameter of the first tapering section 112. One end of the expansion section 130 is connected to the outlet of the first tapering section 112, and the other end is connected to the feed inlet of the microchannel reactor 200.

[0068] In this embodiment, the gas delivery pipe 110 is equipped with an expansion section 130 to connect the Venturi mixing unit 100 and the microchannel reactor 200. The existing structure of the microchannel reactor 200 can be used in combination with the Venturi mixing unit 100. At the same time, the expansion section 130 also has a buffering effect, which can deliver the formed aerosol to the microchannel reactor 200 at a stable flow rate for reaction, thereby enabling the raw materials to react more efficiently and thoroughly.

[0069] See Figure 3 As an example, the gas supply pipe 110 includes a main gas supply section 111 and a first tapered section 112 connected to the main gas supply section 111. The inlet end of the main gas supply section 111 is connected to the gas source 500, and the outlet end of the liquid supply pipe 120 extends through the main gas supply section 111 into the gas-liquid mixing chamber 112a. The inner wall of the end of the expansion section 130 facing away from the microchannel reactor 200 is sealed to the outer wall of the corresponding area of ​​the main gas supply section 111.

[0070] In this embodiment, the outer diameter of the main gas transmission pipe section 111 is larger than that of the first tapering section 112. The inner wall of the expansion section 130 is sealed to the outer wall of the main gas transmission pipe, so that the connection between the two has a larger contact area, which helps to improve the structural stability of the entire gas transmission pipe 110.

[0071] It should be noted that when the gas transmission pipe 110 includes the main gas transmission section 111 and the first tapering section 112, the air inlet end of the gas transmission pipe 110 is the air inlet end of the main gas transmission section 111.

[0072] As an example, the liquid phosphorus trichloride storage tank 600 is also equipped with a heating element (not shown in the figure).

[0073] In this embodiment, the liquid phosphorus trichloride storage tank 600 is also equipped with a heating element. For the microchannel reactor 200 with a small liquid holding capacity, its operating characteristic is that the material in the microchannel reactor 200 is prone to flow reduction of gaseous hydrogen fluoride due to the long residence time. The addition of a heating element to the liquid phosphorus trichloride storage tank 600 can form a micro-positive pressure by precisely controlling the temperature of the liquid phosphorus trichloride storage tank 600 to compensate for the defect of insufficient negative pressure driving force caused by the reduced flow rate, thereby improving the stability of the reaction system.

[0074] See Figure 4 As an example, the outlet of the gas-liquid separator 300 is connected to the liquid phosphorus trichloride storage tank 600.

[0075] In this embodiment, the outlet of the gas-liquid separator 300 is connected to the liquid phosphorus trichloride storage tank 600, which enables the unreacted liquid phosphorus trichloride obtained by separation to be transported back to the liquid phosphorus trichloride storage tank 600, so as to realize the recycling of liquid phosphorus trichloride raw material.

[0076] It should be noted that the connection method between the liquid outlet of the gas-liquid separator 300 and the liquid phosphorus trichloride storage tank 600 is not limited and can be set according to the conventional selection in this field.

[0077] As an example, the outlet of the gas-liquid separator 300 is connected to the liquid phosphorus trichloride storage tank 600 via a peristaltic pump.

[0078] As an example, the gas-liquid separator 300 also includes a first liquid level sensor and a second liquid level sensor, with the first liquid level sensor located below the second liquid level sensor.

[0079] In this embodiment, the gas-liquid separator 300 is equipped with level sensors at different liquid levels. The first level sensor, located at the bottom, controls the connection between the gas separator and the liquid phosphorus trichloride storage tank 600 by detecting the amount of collected liquid phosphorus trichloride; specifically, it disconnects when the liquid level is below the level and opens when it is above the level. The second level sensor, located at the top, regulates the overall reaction process by detecting the amount of collected liquid phosphorus trichloride. Specifically, if the liquid level remains consistently high, it may indicate low reaction efficiency in previous stages (e.g., low temperature or low mixing efficiency in the microchannel reactor 200). In this case, the reaction efficiency can be improved by appropriately increasing the temperature of the microchannel reactor 200 or appropriately increasing the negative pressure driving force. Alternatively, it may indicate that the valve opening at the outlet of the gas-liquid separator 300 is too small; in this case, the valve opening can be increased. Furthermore, the cooperation between the first and second level sensors can effectively mitigate flooding or dry-tank phenomena in the gas-liquid separator 300.

[0080] It should be noted that the liquid level depths corresponding to the first and second liquid level sensors are not limited and can be adjusted adaptively according to actual needs. For example, the liquid level depth corresponding to the first liquid level sensor is 30 mm and the liquid level depth corresponding to the second liquid level sensor is 100 mm.

[0081] See Figure 4 As an example, the gas source 500 includes an inert gas storage tank 510 and a gaseous hydrogen fluoride storage tank 520, which are connected to the gas inlet of the gas pipeline 110 through the same gas supply branch pipe 530.

[0082] In this embodiment, the gas source 500 includes an inert gas storage tank 510 and a gaseous hydrogen fluoride storage tank 520, which are connected by the same gas supply branch pipe 530 through the gas inlet end of the gas supply pipe 110, so that the gas in the gas supply pipe 110 is a mixture of inert gas (e.g., nitrogen) and hydrogen fluoride. When the negative pressure driving force generated near the opening of the first converging section 112 is insufficient, under the condition that the amount of gaseous hydrogen fluoride delivered remains unchanged (always maintaining its theoretical molar ratio with liquid phosphorus trichloride close to 3:1), the negative pressure driving force can be increased by increasing the delivery flow rate of the inert gas, thereby improving the mixing efficiency and mixing effect of gaseous hydrogen fluoride and liquid phosphorus trichloride.

[0083] See Figure 4 As an example, the phosphorus trifluoride manufacturing apparatus 10 also includes a static reactor 400, the inlet of which is connected to the outlet of the microchannel reactor 200, and the outlet of the static reactor 400 is connected to the inlet of the gas-liquid separator 300.

[0084] In this embodiment, a static reactor 400 is added between the microchannel reactor 200 and the gas-liquid separator 300 in the phosphorus trifluoride manufacturing apparatus 10. This allows the mixed system containing some unreacted raw materials discharged from the microchannel reactor 200 to undergo a secondary reaction, which helps to further improve the purity and yield of the prepared phosphorus trifluoride.

[0085] It should be emphasized that after the addition of the static reactor 400 to the phosphorus trifluoride manufacturing unit 10, the overall effect of the entire unit is as follows: the Venturi mixing unit 100 causes liquid phosphorus trichloride and gaseous hydrogen fluoride to form small-particle aerosols, which, combined with the turbulence effect of the microchannel reactor 200 and the turbulence effect of the static reactor 400, enables the gas-liquid contact area to exceed 5000 m². 2 / m 3 This process ultimately yielded phosphorus trifluoride with both high yield and purity.

[0086] It should be noted that the structural or functional units in the phosphorus trifluoride manufacturing apparatus 10 that are not specifically described or limited can be set up in accordance with conventional selections in the art.

[0087] Secondly, embodiments of this application provide a method for preparing phosphorus trifluoride based on the Venturi effect, using the phosphorus trifluoride manufacturing apparatus provided in the first aspect embodiment, and the preparation method includes the following steps: Gaseous hydrogen fluoride is supplied to the gas delivery pipe of the Venturi mixing unit via a gas source, and liquid phosphorus trichloride is supplied to the liquid delivery pipe of the Venturi mixing unit via a liquid phosphorus trichloride storage tank, so that the gaseous hydrogen fluoride and liquid phosphorus trichloride together form an aerosol after passing through the gas-liquid mixing chamber of the first converging section; the aerosol is then transported to a microchannel reactor for reaction to obtain reactants containing phosphorus trifluoride; the reactants containing phosphorus trifluoride are then transported to a gas-liquid separator for gas-liquid separation to obtain gaseous phosphorus trifluoride.

[0088] In this application, by using the phosphorus trifluoride manufacturing apparatus provided in the first aspect embodiment and preparing according to the above process, phosphorus trifluoride with high purity and yield can be prepared without continuously applying high pressure to the microchannel reactor.

[0089] It should be noted that the magnitude of the negative pressure driving force formed at the first tapering section is related not only to the inner diameter of the opening of the first tapering section but also to the material conveying flow rate. Therefore, when the inner diameter of the opening of the first tapering section is set to be less than 1 mm, it is also necessary to match it with the material conveying flow rate.

[0090] As an example, the ratio of the flow rates of gaseous hydrogen fluoride to liquid phosphorus trichloride is (700~900):1, for example, but not limited to any one of the flow rate ratios of 700:1, 750:1, 800:1, 850:1 and 900:1 or any range between the two.

[0091] In this embodiment, the ratio of the flow rates of gaseous hydrogen fluoride and liquid phosphorus trichloride is limited to the above-mentioned range so that the initial molar ratio of the two is close to 3:1. At this molar ratio, the two can react more thoroughly and efficiently to produce phosphorus trifluoride. In addition, when the inner diameter of the opening of the first tapering section is set to be less than 1 mm, and the ratio of the flow rates of gaseous hydrogen fluoride and liquid phosphorus trichloride is limited to the above-mentioned range, an aerosol with a particle size of about 8 to 10 μm can be formed after passing through the opening of the first tapering section, thereby enabling gaseous hydrogen fluoride and liquid phosphorus trichloride to react more thoroughly and fully to produce phosphorus trifluoride.

[0092] As an example, the ratio of liquid holdup to gaseous hydrogen fluoride flow rate in the microchannel reactor is 1 mL: (2~4) mL / min, for example, but not limited to any one of the following ratios or a range between any two: 1 mL: 2 mL / min, 1 mL: 2.5 mL / min, 1 mL: 3 mL / min, 1 mL: 3.5 mL / min and 1 mL: 4 mL / min.

[0093] In this embodiment, the ratio of the liquid holding capacity of the microchannel reactor to the flow rate of gaseous hydrogen fluoride is limited to the above range so that the aerosol has a suitable residence time in the microchannel reactor, which also helps the gaseous hydrogen fluoride and liquid phosphorus trichloride to react more thoroughly and efficiently to produce phosphorus trifluoride.

[0094] It should be noted that, for the preparation process of phosphorus trifluoride, unless otherwise specified or limited, the process can be set according to the conventional selection in this field.

[0095] To better understand the advantages of the phosphorus trifluoride manufacturing apparatus provided in the embodiments of this application, the following explanation is provided in conjunction with the specific preparation process.

[0096] Example 1 This application provides a method for preparing phosphorus trifluoride, comprising the following steps: Gaseous hydrogen fluoride is supplied to the gas delivery pipe of the Venturi mixing unit via a gas source, with a flow rate of 750 mL / min, an outlet inner diameter (i.e., opening inner diameter) of the first converging section of 0.6 mm, and a ratio of the inlet inner diameter to the outlet inner diameter of the first converging section of 6:1. Liquid phosphorus trichloride is supplied to the liquid delivery pipe of the Venturi mixing unit via a liquid phosphorus trichloride storage tank of 57.75 mL / h, with an outlet inner diameter (i.e., opening inner diameter) of the second converging section of 0.2 mm and a ratio of the inlet inner diameter to the outlet inner diameter of the second converging section of 3:1. This allows the gaseous hydrogen fluoride and liquid phosphorus trichloride to form an aerosol with an average particle size of 9 μm after passing through the gas-liquid mixing chamber of the first converging section. The aerosol is then transported to a microchannel reactor for reaction, where the microchannel reactor has a liquid holdup of 250 mL / min. The reaction was carried out at 50℃, and a reaction temperature of mL was set to obtain a reactant containing phosphorus trifluoride. The reactant was then transferred to a static mixer for further reaction, and then transferred to a gas-liquid separator for gas-liquid separation. The entire apparatus was run continuously for 72 h to obtain gaseous phosphorus trifluoride. Finally, the purity and yield of the prepared phosphorus trifluoride were statistically analyzed, and the purity and yield of phosphorus trifluoride were found to be 99.2%, both of which are much higher than those of conventional batch reactor processes (purity and yield are not higher than 85%), and it does not require continuous high pressure to be applied to the microchannel reactor.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A device for producing phosphorus trifluoride based on the Venturi effect, characterized in that, The device comprises: a Venturi mixing unit, comprising a gas conveying pipe and a liquid conveying pipe, an inlet end of the gas conveying pipe being in communication with a gas source for providing gaseous hydrogen fluoride, an outlet end of the gas conveying pipe having a first tapered section, and a terminal end of the first tapered section having a gas-liquid mixing cavity, an inlet end of the liquid conveying pipe being in communication with a liquid phosphorus trichloride storage tank, and an outlet end of the liquid conveying pipe extending into the gas-liquid mixing cavity; a micro-channel reactor, a feed inlet of the micro-channel reactor being in communication with an outlet of the first tapered section; a gas-liquid separator, a feed inlet of the gas-liquid separator being in communication with an outlet of the micro-channel reactor.

2. The phosphorus trifluoride production apparatus according to claim 1, wherein The liquid conveying pipe and the gas conveying pipe extend in the same direction.

3. The phosphorus trifluoride production apparatus according to claim 2, wherein The inlet end of the gas conveying pipe comprises a connecting portion and an inlet portion, the connecting portion being sleeved on the liquid conveying pipe, and an inner wall of the connecting portion being threadedly connected with an outer wall of a corresponding area of the liquid conveying pipe, the inlet portion being in communication with the gas source.

4. The phosphorus trifluoride production apparatus according to claim 2, wherein The outlet end of the liquid conveying pipe has a second tapered section, and the second tapered section extends into the gas-liquid mixing cavity.

5. The phosphorus trifluoride production apparatus according to claim 1, wherein The gas conveying pipe further comprises a diameter expanding section, an inner diameter of the diameter expanding section being larger than an inner diameter of the outlet of the first tapered section, one end of the diameter expanding section being in communication with the outlet of the first tapered section, and an opposite end being in communication with the feed inlet of the micro-channel reactor.

6. The phosphorus trifluoride production apparatus according to claim 5, wherein The gas conveying pipe comprises a gas conveying main pipe section and the first tapered section in communication with the gas conveying main pipe section, the inlet end of the gas conveying main pipe section being in communication with the gas source, the outlet end of the liquid conveying pipe extending into the gas-liquid mixing cavity via the gas conveying main pipe section, and an inner wall of one end of the diameter expanding section being in sealing connection with an outer wall of a corresponding area of the gas conveying main pipe section.

7. The phosphorus trifluoride production apparatus according to any one of claims 1 to 6, characterized by The liquid phosphorus trichloride storage tank is further provided with a heating element.

8. The phosphorus trifluoride production apparatus according to any one of claims 1 to 6, characterized by An outlet of the gas-liquid separator is in communication with the liquid phosphorus trichloride storage tank. Optionally, the gas-liquid separator further comprises a first liquid level sensor and a second liquid level sensor, the first liquid level sensor being located below the second liquid level sensor.

9. The phosphorus trifluoride production apparatus according to any one of claims 1 to 6, characterized by The gas source comprises an inert gas storage tank and a gaseous hydrogen fluoride storage tank, the inert gas storage tank and the gaseous hydrogen fluoride storage tank being in communication with the inlet end of the gas conveying pipe via a same gas conveying branch pipe.

10. The phosphorus trifluoride production apparatus according to any one of claims 1 to 6, characterized by The phosphorus trifluoride manufacturing device further comprises a static reactor, a feed inlet of the static reactor being in communication with an outlet of the micro-channel reactor, and an outlet of the static reactor being in communication with a feed inlet of the gas-liquid separator.

11. A method for the preparation of phosphorus trifluoride based on the Venturi effect, characterized by, The phosphorus trifluoride manufacturing device is used for preparation, and the preparation method comprises the following steps: gaseous hydrogen fluoride is delivered into the gas conveying pipe of the Venturi mixing unit by the gas source, and liquid phosphorus trichloride is delivered into the liquid conveying pipe of the Venturi mixing unit by the liquid phosphorus trichloride storage tank, so that the gaseous hydrogen fluoride and the liquid phosphorus trichloride form an aerosol after passing through the gas-liquid mixing cavity of the first tapered section together; the aerosol is delivered into the micro-channel reactor for reaction to obtain a reaction product containing phosphorus trifluoride; and the reaction product containing phosphorus trifluoride is delivered into the static reactor for reaction to obtain phosphorus trifluoride. The phosphorus trifluoride-containing reactant is transported into the gas-liquid separator for gas-liquid separation to obtain gaseous phosphorus trifluoride.

12. The process for the preparation of phosphorus trifluoride according to claim 11, characterized in that, The ratio of the transportation flow rate of the gaseous hydrogen fluoride to the transportation flow rate of the liquid phosphorus trichloride is (700-900): 1; or / and the ratio of the holdup of the micro-channel reactor to the transportation flow rate of the gaseous hydrogen fluoride is 1 mL:(2-4) mL / min.

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