Production system and preparation method of phosphorus trifluoride

Abstract

The invention provides a phosphorus trifluoride production system and a preparation method thereof, and belongs to the technical field of phosphorus trifluoride manufacturing. The phosphorus trifluoride production system comprises a static reactor, a gaseous fluorine source, a liquid phosphorus source, a condenser and a collector. The static reactor comprises a static mixer and a jacket type shell wrapping the static mixer, the static mixer is used for mixing reaction raw materials and providing a reaction place, and a heat exchange cavity used for containing a heat exchange medium is formed in the jacket type shell; when the production system is used for preparing phosphorus trifluoride, the problems that the mass transfer effect between a gaseous fluorine source and a liquid phosphorus source is poor and the material distribution uniformity is poor can be effectively solved, and meanwhile, the whole material system can have better temperature consistency, so that the reaction raw materials can react more efficiently and thoroughly to form phosphorus trifluoride.

Description

Technical Field

[0001] The present application relates to the technical field of phosphorus trifluoride manufacturing, and in particular to a phosphorus trifluoride production system and a preparation method thereof. Background Art

[0002] Phosphorus trifluoride (PF2) is an inorganic compound with significant application value, widely used in semiconductor manufacturing (as a dopant), battery material synthesis, polymer material modification, and organic synthesis reactions (such as the preparation of fluorocarbon compounds). A commonly used industrial preparation route involves using a gaseous fluorine source (e.g., HF) and a liquid phosphorus source (e.g., phosphorus trichloride) as raw materials to produce PF2 via a gas-liquid reaction. However, this preparation process typically involves a batch-type stirred reactor. Due to the poor mixing and stirring characteristics of batch-type stirred reactors, the mass transfer between the gaseous fluorine source and the liquid phosphorus source, as well as the uniformity of material distribution, is poor. This also results in poor temperature consistency across various regions within the reactor, leading to low raw material utilization and significant byproduct production. Summary of the Invention

[0003] The purpose of the present application is to provide a phosphorus trifluoride production system and preparation method thereof. Utilizing the production system for preparing phosphorus trifluoride can effectively improve the mass transfer effect between the gaseous fluorine source and the liquid phosphorus source and the poor material distribution uniformity. At the same time, it can also ensure that the entire material system has good temperature consistency, thereby enabling the reaction raw materials to react more efficiently and thoroughly to form phosphorus trifluoride.

[0004] The embodiment of the present application is implemented as follows: In a first aspect, embodiments of the present application provide a phosphorus trifluoride production system, comprising a static reactor, a gaseous fluorine source, a liquid phosphorus source, a condenser, and a collector. The static reactor comprises a static mixer and a jacketed housing surrounding the static mixer. The static mixer is used to mix the reaction raw materials and provide a reaction space, and the jacketed housing contains a heat exchange cavity for accommodating a heat exchange medium. The gaseous fluorine source and the liquid phosphorus source are both connected to the static mixer to provide the reaction raw materials to the static mixer. The condenser is connected to the discharge port of the static mixer to collect liquid hydrogen chloride. The collector is connected to the condenser to collect gaseous phosphorus trifluoride.

[0005] In the above technical solution, a static mixer covered with a jacketed shell is innovatively used as a reactor, wherein the jacketed shell with a heat exchange cavity is used to heat the static mixer so that the gaseous fluorine source and the liquid phosphorus source in the static mixer can react to form phosphorus trifluoride; the static mixer is used as a place for mixing the reaction raw materials and reacting, and a spiral element is fixedly installed on the inner wall of the static mixer, which can forcibly cut the fluid and cause the fluid to form turbulence, so that the gaseous fluorine source and the liquid phosphorus source are fully contacted and evenly dispersed, and at the same time, the temperature of the entire material system is relatively consistent; in the specific preparation process, the reaction raw materials are input into the static mixer through the gaseous fluorine source and the liquid phosphorus source, and then a heat exchange medium is input into the heat exchange cavity to heat the materials in the static mixer to the reaction temperature, and then the static mixer is started. The advantages of the static mixer can be utilized to enable the reaction raw materials to react more efficiently and thoroughly to form high-purity and high-yield phosphorus trifluoride. At the same time, the hydrogen chloride generated during the reaction can be collected through a condenser to achieve the recovery and utilization of the hydrogen chloride.

[0006] In some optional embodiments, the feed port and the discharge port of the static mixer are respectively opened at opposite ends of the static mixer along the axial direction of the static mixer, and the liquid phosphorus source is connected to the feed port of the static mixer; and the side wall of the static mixer is also provided with a plurality of spaced-apart air inlets, and the plurality of air inlets are all connected to the gaseous fluorine source, and the air intake of the plurality of air inlets is configured to gradually decrease from the feed side to the discharge side of the static mixer.

[0007] In the above technical solution, the feed port and liquid outlet of the static mixer are respectively located at its axial ends, and the side wall of the static mixer is also provided with a plurality of air inlets spaced apart along its axial direction, wherein the liquid phosphorus source is connected to the feed port of the static mixer, and the plurality of air inlets are all connected to the gaseous fluorine source, and the air intake of the plurality of air inlets is configured to gradually decrease from the feed side to the discharge side of the static mixer. In the specific preparation process, the liquid phosphorus source is delivered to the static mixer through the feed port, and the gaseous fluorine source is delivered to the static mixer through multiple air inlets, and the air intake of the multiple air inlets gradually decreases from the end close to the feed port to the end far from the feed port; on the one hand, this feeding method can always maintain the mass ratio of the gaseous fluorine source to the liquid phosphorus source within a relatively suitable range (the mass of the liquid phosphorus source is the largest and the concentration is the highest when it is just input into the feed port, and its concentration gradually decreases as the reaction proceeds, that is, from the feed side to the discharge side, the concentration of the liquid phosphorus source presents a gradually decreasing distribution pattern); based on this, according to the gaseous fluorine source delivery method provided in the embodiment of the present application, that is, the air intake is from The gas concentration gradually decreases from the end close to the feed port to the end far from the feed port, so that the mass ratio of the gaseous fluorine source and the liquid phosphorus source can always be maintained within a relatively suitable range), thereby enabling the input gaseous fluorine source and the liquid phosphorus source to fully react at an appropriate ratio, which helps to improve the raw material utilization rate and the product yield; on the other hand, this feeding method can also take into account the problem of improving the side reaction caused by the contact between the high-concentration gaseous fluorine source and the liquid phosphorus source (if the gaseous fluorine source is also input into the static mixer through the feed port at one time, the corresponding gaseous fluorine source flow rate is relatively large, and the contact between a large amount of gaseous fluorine source and a large amount of liquid phosphorus source is likely to cause side reactions), thereby improving the purity of the prepared product.

[0008] In some optional embodiments, the gaseous fluorine source includes a storage tank, a gas main pipe and multiple gas branch pipes. The storage tank is used to store the gaseous fluorine source. The gas inlet end of the gas main pipe is connected to the storage tank, and the gas outlet end of the gas main pipe is simultaneously connected to the gas inlet ends of the multiple gas branch pipes, and the gas outlet ends of the multiple gas branch pipes are respectively connected to multiple gas inlets of the static mixer, and the multiple gas branch pipes are configured to gradually reduce the gas delivery volume from the feed side to the discharge side of the static mixer.

[0009] In the above technical solution, the storage tank and the static mixer are connected by a gas main and multiple gas branch pipes. During the specific preparation process, the storage tank is opened, and the gaseous fluorine source is controlled to be transported to the static mixer through the gas main, multiple gas branch pipes, and multiple air inlets corresponding to the gas branch pipes in sequence to mix and react with the liquid phosphorus source. This has the advantages of a relatively reasonable pipeline layout and easy operation.

[0010] In some optional embodiments, the inner diameters of the plurality of gas transmission branches are the same but the lengths gradually increase from the feed side to the discharge side of the static mixer.

[0011] In the above technical solution, multiple gas branch pipes are set to have the same inner diameter but gradually increasing length. During the specific preparation process, since the air inlet ends of the multiple gas branch pipes are connected to the air outlet end of the same gas main pipe, the air pressure at the air inlet ends of the multiple gas branch pipes is basically the same. In the subsequent transportation process, the longer the gas branch pipe, the greater the pressure drop, and its gas source transportation capacity also decreases accordingly, so that the gaseous fluorine source shows a pattern of gradually decreasing gas delivery from the feed side to the discharge side of the static mixer. This airflow control method has the advantage of being easy to operate, and the use of gas branch pipes with the same diameter also has the advantage of being easy to assemble the pipeline.

[0012] In some optional embodiments, the ratio of the lengths of any two adjacent gas transmission branches is 1:(1.1-1.5).

[0013] In the above technical solution, the ratio of the lengths of any two adjacent gas transmission branches is limited to the above range, so that the gas transmission volume has a more appropriate gradient change, thereby ensuring that the gaseous fluorine source and the liquid phosphorus source always have an appropriate mass ratio and can react efficiently.

[0014] In some optional embodiments, the gas main pipe includes a first section of gas main pipe and a second section of gas main pipe that are connected, and from the feed side to the discharge side of the static mixer, the first section of gas main pipe is connected to the middle of the second section of gas main pipe, the gas inlet end of the first section of gas main pipe is connected to the storage tank, and the gas outlet end of the second section of gas main pipe is simultaneously connected to the gas inlet ends of multiple gas branches.

[0015] In the above technical solution, the gas main pipe is arranged in the form of two sections, wherein the first section of the gas main pipe is arranged to be connected to the middle section of the second section of the gas main pipe from the feed side to the discharge side of the static mixer. During the specific preparation process, the gaseous fluorine source is controlled to be transported to both ends of the second section of the gas main pipe through the middle section and the gaseous fluorine source is simultaneously transported to each gas branch pipe. Since the air inlet end of the second section of the gas main pipe is in the middle, that is, the path from the air inlet end to the air outlet end of the second section of the gas main pipe is relatively short, so that the pressure drop of the gaseous fluorine source during the transportation process in the second section of the gas main pipe is relatively small, thereby making the gas pressure of the gaseous fluorine source reaching the air inlet end of each gas branch pipe relatively close, thereby facilitating the subsequent precise control of the gas supply volume.

[0016] In some optional embodiments, the second section of the gas main is tilted from the feed side to the discharge side of the static mixer, and in the vertical direction, one end of the second section of the gas main on the feed side is lower than the other end of the second section of the gas main on the discharge side.

[0017] In the above technical solution, the second section of the gas main pipe is arranged in an inclined form. Specifically, the end of the second section of the gas main pipe close to the feed side is lower than the end away from the feed side. This form of the second section of the gas main pipe can make a certain amount of space for the installation of multiple gas branch pipes with gradually increasing lengths, thereby completing the assembly of the gas main pipe and multiple gas branch pipes within a limited three-dimensional space.

[0018] In some optional embodiments, the ratio of the inner diameter of the gas transmission main pipe to the inner diameter of the gas transmission branch pipe is (2-5):1.

[0019] In the above technical solution, the ratio of the inner diameter of the gas main pipe to the inner diameter of the gas branch pipe is limited to the above range so that the two have an appropriate pipe diameter ratio, thereby facilitating the smooth transportation of the gaseous fluorine source in the pipeline.

[0020] In some optional embodiments, the production system further includes a premixing unit, the discharge port of the premixing unit is connected to the feed port of the static mixer, and the liquid phosphorus source is connected to the feed port of the premixing unit; the condenser includes a first-stage cold trap and a second-stage cold trap that are connected, the first-stage cold trap is connected to the discharge port of the static mixer and the feed port of the premixing unit and is used to collect liquid phosphorus trichloride and liquid hydrogen fluoride, and the second-stage cold trap is connected to the first-stage cold trap and the collector and is used to collect liquid hydrogen chloride.

[0021] In the above technical solution, a premixing unit is added to the production system and the condenser is configured to cooperate with two-stage cold traps. During the specific preparation process, the gas-liquid mixture (specifically including the generated phosphorus trifluoride product, generated hydrogen chloride, unreacted phosphorus source and fluorine source, etc.) discharged from the discharge port of the static mixer is controlled to enter the first-stage cold trap, wherein the phosphorus trifluoride product can pass through the first-stage cold trap and the second-stage cold trap in gaseous form in sequence and enter the collector for collection; the hydrogen chloride generated by the reaction can pass through the first-stage cold trap in gaseous form and then be cooled and liquefied in the second-stage cold trap before being collected; the unreacted phosphorus source and fluorine source are condensed and collected in the first-stage cold trap, and then transported to the premixing unit to mix with the newly added liquid phosphorus source. The resulting premixed liquid is then input into the static mixer to mix and react with the gaseous fluorine source. This can achieve the recycling of raw materials, thereby improving the raw material utilization rate and product yield.

[0022] In some optional embodiments, along the axial direction of the static mixer, the feed port and the discharge port of the static mixer are respectively opened at opposite ends of the static mixer, and the production system also includes a premixing unit, the gaseous fluorine source and the liquid phosphorus source are both connected to the feed port of the premixing unit, and the discharge port of the premixing unit is connected to the feed port of the static mixer, for providing reaction raw materials to the static mixer.

[0023] In the above technical solution, a premixing unit is added to the production system. Specifically, the gaseous fluorine source and the liquid phosphorus source are both connected to the feed port of the premixing unit, and the discharge port of the premixing unit is connected to the feed port of the static mixer. In the specific preparation process, the liquid phosphorus source and the gaseous fluorine source are first transported to the premixing unit for premixing, and then the mixed raw materials are transported to the static mixer for mixing and reaction, which is conducive to sufficient contact and reaction of the raw materials and also helps to improve the reaction stability.

[0024] In some optional embodiments, the production system also includes a tail gas treatment unit, and the tail gas treatment unit and the collector are connected through a three-way valve and a condenser; wherein the tail gas treatment unit includes a first-stage tail gas processor and a second-stage tail gas processor that are connected, the first-stage tail gas processor and the three-way valve are connected, and the tail gas pipeline between the first-stage tail gas processor and the second-stage tail gas processor is also provided with a vacuum pump in parallel.

[0025] In the above technical solution, an exhaust gas treatment unit is added to the production system. Specifically, the exhaust gas treatment unit includes a first-stage exhaust gas processor and a second-stage exhaust gas processor that are connected to each other. The first-stage exhaust gas processor is connected to a three-way valve, and the exhaust gas pipeline between the first-stage exhaust gas processor and the second-stage exhaust gas processor is also provided with a vacuum pump in parallel. In the specific preparation process, before the start of the reaction or after the end of the reaction, the reaction system can be repeatedly purged by the exhaust gas treatment unit and the inert gas source in the production system. Before the start of the reaction, the impurity gas remaining in the reaction system can be removed by purging, thereby improving the purity of the prepared product. After the reaction is completed, the acidic gas in the exhaust gas can be removed by purging, so that the exhaust gas emissions meet environmental protection standards.

[0026] In a second aspect, an embodiment of the present application provides a method for preparing phosphorus trifluoride, which is prepared using the phosphorus trifluoride production system provided in the embodiment of the first aspect, comprising the following steps: S1 opens the gaseous fluorine source and the liquid phosphorus source and inputs the reaction raw materials into the static mixer; S2 inputs the heat exchange medium into the heat exchange cavity to heat the reaction raw materials in the static mixer, and then starts the static mixer to allow the reaction raw materials to react; S3 opens the condenser and the collector in sequence to collect the gaseous phosphorus trifluoride.

[0027] In the above technical solution, the phosphorus trifluoride production system provided in the embodiment of the first aspect is adopted and prepared according to the above process. Since the spiral element in the static mixer can forcibly cut the fluid and cause the fluid to form turbulence, the gaseous fluorine source and the liquid phosphorus source can be fully contacted and evenly dispersed. At the same time, the temperature of the entire material system can be made relatively consistent, thereby enabling the reaction raw materials to react more efficiently and thoroughly to form high-purity and high-yield phosphorus trifluoride.

[0028] In some optional embodiments, the molar ratio of the gaseous fluorine source to the liquid phosphorus source in the reaction raw materials is 1:(3~4); optionally, the inner diameter of the static mixer is 10~20 mm, the length of the static mixer is 700~900 mm, the delivery rate of the liquid phosphorus source is 8.75~18.75 mol / h, and the delivery rate of the gaseous fluorine source is 33.25~75 mol / h.

[0029] In the above technical solution, the molar ratio of the gaseous fluorine source and the liquid phosphorus source is limited to the above range, so that the two have an appropriate usage ratio, thereby allowing the raw materials to relatively easily and completely form phosphorus trifluoride. Furthermore, when the inner diameter and length of the static mixer are respectively within the above ranges (i.e., when the internal volume is within the appropriate range), the delivery rates of the liquid phosphorus source and the gaseous fluorine source are respectively limited to the above ranges, which helps the liquid to fully form turbulence under the action of the spiral element.

[0030] In some optional embodiments, in the step of heating the reaction materials in the static mixer, the temperature of the reaction materials is maintained at 45-55°C.

[0031] In the above technical solution, the reaction raw materials can react relatively easily and fully to form phosphorus trifluoride within the above temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A schematic structural diagram of the first phosphorus trifluoride production system provided in an embodiment of the present application; Figure 2 A schematic structural diagram of a spiral element of a static mixer provided in an embodiment of the present application; Figure 3 for Figure 1 A partial enlarged view of point A in the middle; Figure 4 A schematic diagram of the structure of the first phosphorus trifluoride production system provided in an embodiment of the present application after a premixing unit is added; Figure 5 for Figure 1 A partial enlarged view of point B in the middle; Figure 6 This is a schematic structural diagram of the second phosphorus trifluoride production system provided in an embodiment of the present application.

[0034] Icons: 10-phosphorus trifluoride production system; 100-static reactor; 110-static mixer; 200-gaseous fluorine source; 210-storage tank; 220-gas main pipe; 221-first section gas main pipe; 222-second section gas main pipe; 230-gas branch pipe; 300-liquid phosphorus source; 400-inert gas source; 500-condenser; 510-first stage cold trap; 520-second stage cold trap; 600-collector; 700-premixing unit; 800-exhaust treatment unit; 810-first stage exhaust gas processor; 820-second stage exhaust gas processor; 830-vacuum pump. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without making any creative efforts shall fall within the scope of protection of the present application.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0038] In the description of this application, it should be noted that the terms "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended solely to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0040] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] The following is a detailed description of a phosphorus trifluoride production system and preparation method provided in this application.

[0042] See Figure 1 In a first aspect, embodiments of the present application provide a phosphorus trifluoride production system 10, comprising a static reactor 100, a gaseous fluorine source 200 (hydrogen fluoride), a liquid phosphorus source 300 (phosphorus trichloride), a condenser 500, and a collector 600. The static reactor 100 comprises a static mixer 110 and a jacketed housing (not shown) surrounding the static mixer 110. The static mixer 110 is used to mix the reaction raw materials and provide a reaction space, and the jacketed housing contains a heat exchange cavity for accommodating a heat exchange medium. The gaseous fluorine source 200 and the liquid phosphorus source 300 are both connected to the static mixer 110 to provide the reaction raw materials to the static mixer 110. The condenser 500 is connected to the discharge port of the static mixer 110 to collect liquid hydrogen chloride. The collector 600 is connected to the condenser 500 to collect gaseous phosphorus trifluoride.

[0043] In the present application, a static mixer 110 coated with a jacketed shell is innovatively used as a reactor, wherein the jacketed shell with a heat exchange cavity is used to heat the static mixer 110 so that the gaseous fluorine source 200 and the liquid phosphorus source 300 in the static mixer 110 can react to generate phosphorus trifluoride; the static mixer 110 is used as a place for mixing reaction raw materials and reacting, and a spiral element is fixedly installed on the inner wall of the static mixer 110, which can forcibly cut the fluid and cause the fluid to form turbulence, so that the gaseous fluorine source 200 and the liquid phosphorus source 300 are fully in contact and evenly dispersed. At the same time, It also makes the temperature of the entire material system more consistent. In the specific preparation process, the reaction raw materials are input into the static mixer 110 through the gaseous fluorine source 200 and the liquid phosphorus source 300, and then the heat exchange medium is input into the heat exchange cavity to heat the materials in the static mixer 110 to the reaction temperature. Then, the static mixer 110 is started. The advantages of the static mixer 110 can be utilized to enable the reaction raw materials to react more efficiently and thoroughly to form high-purity and high-yield phosphorus trifluoride. At the same time, the hydrogen chloride generated during the reaction process can be collected through the condenser 500 to achieve the recovery and utilization of the hydrogen chloride.

[0044] It should be noted that the type of the static mixer 110 is not limited, for example, it can be any of the SV type, SK type, SX type and SH type, and the specific manufacturer is also not limited, for example, the manufacturer can be Kenics static mixer 110, Esska static mixer 110 or Koflo static mixer 110; specifically in the embodiment of the present application, the static mixer 110 is a SK type static mixer (wherein the structural diagram of the spiral element in the SK type static mixer can be seen Figure 2 ), and the static mixer has an inner diameter of 15 mm, a length of 800 mm, and is built with 8 sections of stainless steel spiral elements sprayed with PTFE.

[0045] It should be noted that the type of heat exchange medium used is not limited, for example, it can be at least one of water and oil; in the embodiment of the present application, oil is used as the heat exchange medium, which has the advantage of relatively stable temperature control.

[0046] See Figure 1 It should be noted that the production system also includes an inert gas source 400 (such as nitrogen or argon) for assisting in purging the entire production system before and after the reaction, and the inert gas source 400 and the gaseous fluorine source 200 share a set of gas pipelines.

[0047] See Figure 3 As an example, along the axial direction of the static mixer 110, the feed port and the discharge port of the static mixer 110 are respectively opened at opposite ends of the static mixer 110, and the liquid phosphorus source 300 is connected to the feed port of the static mixer 110; and the side wall of the static mixer 110 is also provided with a plurality of spaced air inlets, and the plurality of air inlets are all connected to the gaseous fluorine source 200, and the air intake of the plurality of air inlets is configured to gradually decrease from the feed side to the discharge side of the static mixer 110.

[0048] In this embodiment, the feed port and liquid outlet of the static mixer 110 are respectively located at its axial ends, and the side wall of the static mixer 110 is also provided with a plurality of air inlets spaced apart along its axial direction, wherein the liquid phosphorus source 300 is connected to the feed port of the static mixer 110, and the plurality of air inlets are all connected to the gaseous fluorine source 200, and the air intake of the plurality of air inlets is configured to gradually decrease from the feed side to the discharge side of the static mixer 110. In the specific preparation process, the liquid phosphorus source 300 is delivered to the static mixer 110 through the feed port, and the gaseous fluorine source 200 is delivered to the static mixer 110 through multiple air inlets, and the air intake of the multiple air inlets gradually decreases from the end close to the feed port to the end far from the feed port. On the one hand, this feeding method can always maintain the mass ratio of the gaseous fluorine source 200 and the liquid phosphorus source 300 within a relatively suitable range (the mass of the liquid phosphorus source 300 is the largest and the concentration is the highest when it is just input into the feed port. As the reaction proceeds, its concentration gradually decreases, that is, from the feed side to the discharge side, the concentration of the liquid phosphorus source 300 shows a distribution pattern of gradually decreasing; based on this, according to the method for delivering the gaseous fluorine source 200 provided in the embodiment of the present application, that is, the air intake decreases from the end close to the feed port to the end far from the feed port). The gaseous fluorine source 200 gradually decreases from one end of the feed port to the end away from the feed port, so that the mass ratio of the gaseous fluorine source 200 and the liquid phosphorus source 300 can always be maintained within a relatively suitable range), so that the input gaseous fluorine source 200 and the liquid phosphorus source 300 can fully react at an appropriate ratio, which helps to improve the raw material utilization rate and the product yield; on the other hand, this feeding method can also take into account the problem of improving the side reaction caused by the contact between the high-concentration gaseous fluorine source and the liquid phosphorus source 300 (if the gaseous fluorine source 200 is also input into the static mixer 110 at one time through the feed port, the corresponding flow rate of the gaseous fluorine source 200 is relatively large, and the contact between a large amount of gaseous fluorine source 200 and a large amount of liquid phosphorus source 300 is likely to cause side reactions), thereby improving the purity of the prepared product.

[0049] See Figure 3 As an example, the gaseous fluorine source 200 includes a storage tank 210, a gas main pipe 220 and multiple gas branch pipes 230. The storage tank 210 is used to store the gaseous fluorine source 200. The gas inlet end of the gas main pipe 220 is connected to the storage tank 210, and the gas outlet end of the gas main pipe 220 is simultaneously connected to the gas inlet ends of the multiple gas branch pipes 230, and the gas outlet ends of the multiple gas branch pipes 230 are respectively connected to multiple gas inlets of the static mixer 110, and from the feed side to the discharge side of the static mixer 110, the multiple gas branch pipes 230 are configured so that the gas delivery volume gradually decreases.

[0050] In this embodiment, the storage tank 210 and the static mixer 110 are connected via a gas main pipe 220 and multiple gas branch pipes 230. During the specific preparation process, the storage tank 210 is opened, and the gaseous fluorine source 200 is controlled to be transported to the static mixer 110 through the gas main pipe 220, multiple gas branch pipes 230, and multiple air inlets corresponding to the gas branch pipes 230 in sequence to mix and react with the liquid phosphorus source 300. This has the advantages of a relatively reasonable pipeline layout and easy operation.

[0051] In other possible implementations, the multiple air inlets may also be directly connected to the storage tank 210 through one air pipeline respectively.

[0052] It should be noted that the implementation method of "from the feed side to the discharge side of the static mixer 110, multiple gas branch pipes 230 are configured to gradually reduce the gas delivery volume" is not limited. For example, the inner diameters of the multiple gas branch pipes 230 can be the same but the lengths gradually increase, or the lengths of the multiple gas branch pipes 230 can be the same but the inner diameters gradually decrease, or each gas branch pipe 230 can be individually provided with a flow control valve.

[0053] See Figure 3 As an example, from the feed side to the discharge side of the static mixer 110 , the inner diameters of the plurality of gas transmission branches 230 are the same but the lengths gradually increase.

[0054] In this embodiment, multiple gas branch pipes 230 are set to have the same inner diameter but gradually increasing length. During the specific preparation process, since the air inlet ends of the multiple gas branch pipes 230 are connected to the air outlet end of the same gas main pipe 220, the air pressure at the air inlet ends of the multiple gas branch pipes 230 is basically the same. During the subsequent transportation process, the longer the gas branch pipe 230, the greater the pressure drop, and its gas source transportation capacity also decreases accordingly, so that the gaseous fluorine source 200 shows a pattern of gradually decreasing gas delivery from the feed side to the discharge side of the static mixer 110. This airflow control method has the advantage of being easy to operate, and the use of gas branch pipes 230 with the same pipe diameter also has the advantage of being easy to assemble the pipeline.

[0055] It should be noted that the ratio of the lengths of any two adjacent gas transmission branches 230 from the feed side to the discharge side of the static mixer 110 is not limited and can be adaptively adjusted according to actual needs.

[0056] As an example, the ratio of the lengths of any two adjacent gas transmission branches 230 is 1:(1.1~1.5), for example, but not limited to, any one of 1:1.1, 1:1.2, 1:1.3, 1:1.4 and 1:1.5, or a range of values ​​between any two of them.

[0057] In this embodiment, the ratio of the lengths of any two adjacent gas delivery branches 230 is limited to the above range so that the gas delivery volume has a more appropriate gradient change, thereby ensuring that the gaseous fluorine source 200 and the liquid phosphorus source 300 always have an appropriate mass ratio and can react efficiently.

[0058] See Figure 3 As an example, the gas main pipe 220 includes a first section of the gas main pipe 221 and a second section of the gas main pipe 222 that are connected, and from the feed side to the discharge side of the static mixer 110, the middle part of the first section of the gas main pipe 221 is connected to the second section of the gas main pipe 222, the gas inlet end of the first section of the gas main pipe 221 is connected to the storage tank 210, and the gas outlet end of the second section of the gas main pipe 222 is simultaneously connected to the gas inlet ends of multiple gas branches 230.

[0059] In this embodiment, the gas main pipe 220 is configured in the form of two sections, wherein, from the feed side to the discharge side of the static mixer 110, the first section of the gas main pipe 221 is configured to be connected to the middle of the second section of the gas main pipe 222. During the specific preparation process, the gaseous fluorine source 200 is controlled to be transported to both ends of the second section of the gas main pipe 222 through the middle thereof and the gaseous fluorine source 200 is simultaneously transported to each gas branch pipe 230. Since the air inlet end of the second section of the gas main pipe 222 is in the middle thereof, that is, the path from the air inlet end to the air outlet end of the second section of the gas main pipe 222 is relatively short, so that the pressure drop of the gaseous fluorine source 200 during transportation in the second section of the gas main pipe 222 is relatively small, thereby making the gas pressure of the gaseous fluorine source 200 reaching the air inlet end of each gas branch pipe 230 relatively close, thereby facilitating the subsequent precise control of the gas supply volume.

[0060] In other possible implementations, the air inlet end of the second section of the air transmission main pipe 222 may also be disposed at one axial end thereof.

[0061] See Figure 3 As an example, from the feed side to the discharge side of the static mixer 110, the second section of the gas main pipe 222 is tilted, and in the vertical direction, one end of the second section of the gas main pipe 222 on the feed side is lower than the other end of the second section of the gas main pipe 222 on the discharge side.

[0062] In this embodiment, the second section of the gas main pipe 222 is arranged to be inclined. Specifically, the end of the second section of the gas main pipe 222 close to the feed side is lower than the end away from the feed side. This form of the second section of the gas main pipe 222 can make a certain space for the installation of multiple gas branch pipes 230 with gradually increasing lengths, thereby completing the assembly of the gas main pipe 220 and the multiple gas branch pipes 230 within a limited three-dimensional space.

[0063] In other possible implementations, the second section of the gas transmission main 222 may also be arranged horizontally.

[0064] It should be noted that the ratio of the inner diameters of the gas transmission main pipe 220 and the gas transmission branch pipe 230 is not limited and can be adaptively adjusted according to actual needs.

[0065] As an example, the ratio of the inner diameter of the gas transmission main pipe 220 to the inner diameter of the gas transmission branch pipe 230 is (2-5):1, for example, but not limited to, the inner diameter ratio is any one of 2:1, 3:1, 4:1 and 5:1, or a range between any two of them.

[0066] In this embodiment, the ratio of the inner diameter of the gas transmission main pipe 220 to the inner diameter of the gas transmission branch pipe 230 is limited to the above range so that the two have an appropriate pipe diameter ratio, thereby facilitating smooth transportation of the gaseous fluorine source 200 in the pipeline.

[0067] See Figure 4 As an example, the production system further includes a premixing unit 700, the discharge port of the premixing unit 700 is connected to the feed port of the static mixer 110, and the liquid phosphorus source 300 is connected to the feed port of the premixing unit 700; the condenser 500 includes a first-stage cold trap 510 and a second-stage cold trap 520 that are connected (wherein the temperature of the first-stage cold trap 510 is maintained at -75~-85°C, and the temperature of the second-stage cold trap 520 is maintained at -90~-95°C), the first-stage cold trap 510 is connected to the discharge port of the static mixer 110 and the feed port of the premixing unit 700 and is used to collect liquid phosphorus trichloride and liquid hydrogen fluoride, and the second-stage cold trap 520 is connected to the first-stage cold trap 510 and the collector 600 and is used to collect liquid hydrogen chloride.

[0068] In this embodiment, the production system is further provided with a premixing unit 700 and the condenser 500 is configured to cooperate with two-stage cold traps. During the specific preparation process, the gas-liquid mixture (specifically including the generated phosphorus trifluoride product, generated hydrogen chloride, unreacted phosphorus source and fluorine source, etc.) discharged from the discharge port of the static mixer 110 is controlled to enter the first-stage cold trap 510. The phosphorus trifluoride product can pass through the first-stage cold trap 510 and the second-stage cold trap 520 in gaseous form and enter the collector 600 for collection. The hydrogen chloride generated by the reaction can pass through the first-stage cold trap 510 in gaseous form and then be cooled and liquefied in the second-stage cold trap 520 before being collected. The unreacted phosphorus source and fluorine source are condensed and collected in the first-stage cold trap 510 and then transported to the premixing unit 700 for mixing with the newly added liquid phosphorus source 300. The resulting premixed liquid is then input into the static mixer 110 for mixing and reacting with the gaseous fluorine source 200. This can achieve the recycling of raw materials, thereby improving the raw material utilization rate and product yield.

[0069] It should be noted that, in the process of preparing phosphorus trifluoride, the specific circulation ratio (i.e., the volume ratio of the newly added liquid phosphorus source 300 to the collected liquid in the premixing unit 700) is not limited and can be adaptively adjusted according to actual needs. For example, the circulation ratio can be 1:(1.5-2), such as, but not limited to, any one of 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 and 1:2, or a range between any two of the circulation ratios.

[0070] As an example, a peristaltic pump is provided between the first-stage cold trap 510 and the premixing unit 700 , and between the liquid phosphorus source 300 and the premixing unit 700 .

[0071] In this embodiment, the addition of a peristaltic pump facilitates stable and efficient delivery of the liquid.

[0072] As an example, the bottom of the second-stage cold trap 520 is also connected to a hydrogen chloride storage tank.

[0073] In this embodiment, the second-stage cold trap 520 is additionally provided with a hydrogen chloride storage tank to facilitate the storage of the collected hydrogen chloride and subsequent utilization.

[0074] See Figure 5 As an example, the production system also includes an exhaust gas treatment unit 800, and the exhaust gas treatment unit 800 and the collector 600 are connected to the condenser 500 through a three-way valve; wherein the exhaust gas treatment unit 800 includes a first-stage exhaust gas processor 810 and a second-stage exhaust gas processor 820 that are connected, the first-stage exhaust gas processor 810 and the three-way valve are connected, and the exhaust gas pipeline between the first-stage exhaust gas processor 810 and the second-stage exhaust gas processor 820 is also connected in parallel with a vacuum pump 830 (the vacuum pump 830 is connected in parallel with the exhaust gas pipeline between the first-stage exhaust gas processor 810 and the second-stage exhaust gas processor 820, so that the exhaust gas that has been purified once will pass through the vacuum pump 830 only when vacuuming, so that the vacuum pump 830 has a longer service life).

[0075] In this embodiment, the production system is additionally provided with an exhaust gas treatment unit 800. Specifically, the exhaust gas treatment unit 800 includes a first-stage exhaust gas processor 810 and a second-stage exhaust gas processor 820 that are connected to each other. The first-stage exhaust gas processor 810 is connected to a three-way valve, and the exhaust gas pipeline between the first-stage exhaust gas processor 810 and the second-stage exhaust gas processor 820 is also provided with a vacuum pump 830 in parallel. In the specific preparation process, before the reaction starts or after the reaction ends, the reaction system can be repeatedly purged by the exhaust gas treatment unit 800 and the inert gas source 400 in the production system. Before the reaction starts, the impurity gas remaining in the reaction system can be removed by purging, thereby improving the purity of the prepared product. After the reaction ends, the acid gas in the exhaust gas can be removed by purging, so that the exhaust gas emissions meet environmental protection standards.

[0076] See Figure 5 As an example, the collector 600 is connected to the three-way valve through a feed pipe, and the feed pipe is configured to be selectively connected to the vacuum pump 830 and the second-stage exhaust gas processor 820.

[0077] In this embodiment, the material conveying pipe in front of the collector 600 is set to be selectively connected to the vacuum pump 830 and the second-stage exhaust gas processor 820. During the specific preparation process, the material conveying pipe on the side of the collector 600 can also be repeatedly purged with the help of the inert gas source 400 and the exhaust gas treatment unit 800, which also helps to improve the purity of the product.

[0078] As an example, the first-stage exhaust gas processor 810 is an adsorption-type exhaust gas processor, in which the material of the adsorbent used is an alkaline solid (such as soda lime), and the second-stage exhaust gas processor 820 is a washing-type exhaust gas processor, in which the material of the detergent used is an alkaline liquid (such as potassium hydroxide or sodium hydroxide).

[0079] It should be noted that, in addition to being fed separately, the gaseous fluorine source 200 and the liquid phosphorus source 300 may also be fed simultaneously, which is described below with reference to a possible structural diagram.

[0080] See Figure 6 As an example, along the axial direction of the static mixer 110, the feed port and the discharge port of the static mixer 110 are respectively opened at two opposite ends of the static mixer 110, and the production system also includes a premixing unit 700, the gaseous fluorine source 200 and the liquid phosphorus source 300 are both connected to the feed port of the premixing unit 700, and the discharge port of the premixing unit 700 is connected to the feed port of the static mixer 110, for providing reaction raw materials to the static mixer 110.

[0081] In this embodiment, a premixing unit 700 is added to the production system. Specifically, the gaseous fluorine source 200 and the liquid phosphorus source 300 are both connected to the feed port of the premixing unit 700, and the discharge port of the premixing unit 700 is connected to the feed port of the static mixer 110. In the specific preparation process, the liquid phosphorus source 300 and the gaseous fluorine source 200 are first transported to the premixing unit 700 for premixing, and then the mixed raw materials are transported to the static mixer 110 for mixing and reaction, which is conducive to full contact and reaction of the raw materials and also helps to improve the reaction stability.

[0082] It should be noted that all functional components in the production system are made of corrosion-resistant materials.

[0083] It should be noted that any functional units or components not specifically described in the production system may be configured according to conventional options in the art.

[0084] In a second aspect, an embodiment of the present application provides a method for preparing phosphorus trifluoride, which is prepared using the phosphorus trifluoride production system provided in the embodiment of the first aspect, comprising the following steps: S1 opens the gaseous fluorine source and the liquid phosphorus source and inputs the reaction raw materials into the static mixer; S2 inputs the heat exchange medium into the heat exchange cavity to heat the reaction raw materials in the static mixer, and then starts the static mixer to allow the reaction raw materials to react; S3 opens the condenser and the collector in sequence to collect the gaseous phosphorus trifluoride.

[0085] In the present application, the phosphorus trifluoride production system provided in the embodiment of the first aspect is used and prepared according to the above process. Since the spiral element in the static mixer can forcibly cut the fluid and cause the fluid to form turbulence, the gaseous fluorine source and the liquid phosphorus source can be fully contacted and evenly dispersed. At the same time, the temperature of the entire material system can be made relatively consistent, thereby enabling the reaction raw materials to react more efficiently and thoroughly to form high-purity and high-yield phosphorus trifluoride.

[0086] As an example, in the reaction raw materials, the molar ratio of the gaseous fluorine source to the liquid phosphorus source is 1:(3~4), for example, but not limited to, the molar ratio is any point value among 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8 and 1:4, or a range value between any two of them.

[0087] In this embodiment, the molar ratio of the gaseous fluorine source to the liquid phosphorus source is limited to the above range, so that the two have an appropriate usage ratio, thereby allowing the raw materials to form phosphorus trifluoride more easily and completely.

[0088] As an example, the inner diameter of the static mixer is 10-20 mm (for example, but not limited to, the inner diameter is any one of 10 mm, 12 mm, 14 mm, 16 mm, 18 mm and 20 mm, or a range between any two of them), the length of the static mixer is 700-900 mm (for example, but not limited to, the length is any one of 700 mm, 750 mm, 800 mm, 850 mm and 900 mm, or a range between any two of them), the delivery rate of the liquid phosphorus source is 8.75-18.75 mol / h (for example, but not limited to, the delivery rate is any one of 8.75 mol / h, 10 mol / h, 12 mol / h, 14 mol / h, 16 mol / h and 18.75 mol / h, or a range between any two of them), and the delivery rate of the gaseous fluorine source is 33.25-75 mol / h (for example, but not limited to, the delivery rate is 33.25 mol / h, 40 mol / h, 50 mol / h, 60 mol / h, 80 mol / h, 90 mol / h, 100 mol / h, 120 mol / h, 140 mol / h, 160 mol / h and 180 mol / h, or a range between any two of them). mol / h, 60 mol / h, 70 mol / h and 75 mol / h, or any range between them).

[0089] In this embodiment, when the inner diameter and length of the static mixer are respectively within the above ranges (i.e., when the internal volume is within the appropriate range), the delivery rates of the liquid phosphorus source and the gaseous fluorine source are respectively limited within the above ranges, which helps the liquid to fully form turbulence under the action of the spiral element.

[0090] As an example, in the step of heating the reaction raw materials in the static mixer, the temperature of the reaction raw materials is maintained at 45~55°C, for example, but not limited to, any one of 45°C, 48°C, 50°C, 52°C and 55°C or a range between any two of them.

[0091] In this embodiment, the reaction raw materials can react relatively easily and sufficiently to form phosphorus trifluoride within the above temperature range.

[0092] It should be noted that any process or step not specifically described or limited in the preparation process may be arranged according to conventional selection in the art.

[0093] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0094] Example 1 The present invention provides a method for preparing phosphorus trifluoride. For a schematic diagram of the structure of the phosphorus trifluoride production system, please refer to Figures 1 to 5 , specifically including the following steps: S1 Before adding the reaction raw materials to the static mixer, the entire production system is repeatedly purged through the inert gas source and the vacuum pump in the tail gas treatment unit to replace the air in the production system until the water content is <5 ppm.

[0095] After the S2 purge is completed, the liquid phosphorus source enters the static mixer through the premixing unit and the feed port of the static mixer at a delivery rate of 12.5 mol / h, and the gaseous fluorine source enters the static mixer through the gas main pipe, multiple gas branch pipes, and multiple spaced-apart gas inlets of the static mixer at a delivery rate of 40 mol / h. The static mixer is an SK type static mixer with an inner diameter of 15 mm, a length of 800 mm, and 8 built-in spiral elements made of stainless steel sprayed with PTFE.

[0096] S3: A gaseous heat exchange medium (oil) is supplied to the cavity of the jacketed housing to maintain the temperature of the reaction materials in the static mixer at 50°C. The static mixer is then started to react the reaction materials. The generated phosphorus trifluoride product passes through a first-stage cold trap (temperature of -80°C) and a second-stage cold trap (temperature of -95°C) in gaseous form before being collected by a collector (the gaseous phosphorus trifluoride entering the collector is liquefied by cooling the collector to below -105°C). The generated hydrogen chloride passes through the first-stage cold trap in gaseous form and is cooled and liquefied in a second-stage cold trap before being collected. The unreacted phosphorus source and fluorine source are condensed and collected in the first-stage cold trap and then transported to a premixing unit for mixing with a newly added liquid phosphorus source (the volume ratio of the newly added liquid phosphorus source to the collected liquid in the premixing unit is 1:2). The resulting premixed liquid is then reintroduced into the static mixer for mixing and reacting with the gaseous fluorine source. This cycle is repeated until the reaction is complete.

[0097] S4 After the reaction is complete, stop heating the static mixer, and then repeatedly purge the entire production system through the inert gas source and the vacuum pump in the tail gas treatment unit to replace the air in the production system until the water content is less than 5ppm, preparing for the next batch of production.

[0098] The phosphorus trifluoride gas finally collected in Example 1 was tested by gas chromatography to have a purity of 98.5% and a calculated yield of 92%. Meanwhile, according to statistics, the product purity and yield standards of conventional batch reactors using a reactor are generally 90-96% and 70-80%, respectively. This indicates that the use of a static mixer as a gas-liquid reactor to prepare phosphorus trifluoride can effectively improve the mass transfer effect between the gaseous fluorine source and the liquid phosphorus source and the poor uniformity of material distribution. At the same time, it can also provide the entire material system with good temperature consistency, thereby allowing the reaction raw materials to react more efficiently and thoroughly to form phosphorus trifluoride.

[0099] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A phosphorus trifluoride production system, characterized in that: include: A static reactor comprising a static mixer and a jacketed housing covering the static mixer, wherein the static mixer is used to mix reaction materials and provide a reaction site, and the jacketed housing has a heat exchange cavity for accommodating a heat exchange medium; a gaseous fluorine source and a liquid phosphorus source, both of which are in communication with the static mixer and are used to provide the reaction raw materials to the static mixer; a condenser, the condenser being in communication with the discharge port of the static mixer and being used for collecting liquid hydrogen chloride; A collector is communicated with the condenser and is used to collect gaseous phosphorus trifluoride.

2. The phosphorus trifluoride production system according to claim 1, characterized in that: Along the axial direction of the static mixer, the feed port and the discharge port of the static mixer are respectively opened at opposite ends of the static mixer, and the liquid phosphorus source is connected to the feed port of the static mixer; and the side wall of the static mixer is also provided with a plurality of spaced-apart air inlets, and the plurality of air inlets are all connected to the gaseous fluorine source, and the air intake of the plurality of air inlets is configured to gradually decrease from the feed side to the discharge side of the static mixer.

3. The phosphorus trifluoride production system according to claim 2, characterized in that: The gaseous fluorine source includes a storage tank, a gas main pipe and multiple gas branch pipes. The storage tank is used to store the gaseous fluorine source. The gas inlet end of the gas main pipe is connected to the storage tank, and the gas outlet end of the gas main pipe is simultaneously connected to the gas inlet ends of the multiple gas branch pipes. The gas outlet ends of the multiple gas branch pipes are respectively connected to the multiple gas inlets of the static mixer, and the multiple gas branch pipes are configured so that the gas delivery volume gradually decreases from the feed side to the discharge side of the static mixer.

4. The phosphorus trifluoride production system according to claim 3, characterized in that: From the feed side to the discharge side of the static mixer, the inner diameters of the plurality of gas transmission branches are the same but the lengths gradually increase.

5. The phosphorus trifluoride production system according to claim 4, characterized in that: The ratio of the lengths of any two adjacent gas transmission branch pipes is 1:(1.1-1.5).

6. The phosphorus trifluoride production system according to claim 4, characterized in that: The gas main pipe includes a first section of gas main pipe and a second section of gas main pipe that are connected, and from the feed side to the discharge side of the static mixer, the first section of gas main pipe is connected to the middle of the second section of gas main pipe, the gas inlet end of the first section of gas main pipe is connected to the storage tank, and the gas outlet end of the second section of gas main pipe is simultaneously connected to the gas inlet ends of multiple gas branch pipes.

7. The phosphorus trifluoride production system according to claim 6, characterized in that: From the feed side to the discharge side of the static mixer, the second section of the gas main pipe is tilted, and in the vertical direction, one end of the second section of the gas main pipe on the feed side is lower than the other end of the second section of the gas main pipe on the discharge side.

8. The phosphorus trifluoride production system according to claim 4, characterized in that: The ratio of the inner diameter of the gas transmission main pipe to the inner diameter of the gas transmission branch pipe is (2-5):

1.

9. The phosphorus trifluoride production system according to any one of claims 2 to 8, characterized in that: The production system also includes a premixing unit, the discharge port of the premixing unit is connected to the feed port of the static mixer, and the liquid phosphorus source is connected to the feed port of the premixing unit; the condenser includes a first-stage cold trap and a second-stage cold trap that are connected to each other, the first-stage cold trap is connected to the discharge port of the static mixer and the feed port of the premixing unit and is used to collect liquid phosphorus trichloride and liquid hydrogen fluoride, and the second-stage cold trap is connected to the first-stage cold trap and the collector and is used to collect liquid hydrogen chloride.

10. The phosphorus trifluoride production system according to claim 1, characterized in that: Along the axial direction of the static mixer, the feed port and the discharge port of the static mixer are respectively opened at opposite ends of the static mixer, and the production system also includes a premixing unit, the gaseous fluorine source and the liquid phosphorus source are both connected to the feed port of the premixing unit, and the discharge port of the premixing unit is connected to the feed port of the static mixer, for providing the reaction raw materials to the static mixer.

11. The phosphorus trifluoride production system according to claim 1 or 10, characterized in that: The production system also includes a tail gas treatment unit, which is connected to the collector and the condenser through a three-way valve; wherein the tail gas treatment unit includes a first-stage tail gas processor and a second-stage tail gas processor that are connected, the first-stage tail gas processor is connected to the three-way valve, and the tail gas pipeline between the first-stage tail gas processor and the second-stage tail gas processor is also provided with a vacuum pump in parallel.

12. A method for preparing phosphorus trifluoride, characterized in that: The preparation is carried out using the phosphorus trifluoride production system according to any one of claims 1 to 11, comprising the following steps: S1: opening the gaseous fluorine source and the liquid phosphorus source, and feeding the reaction raw materials into the static mixer; S2: inputting the heat exchange medium into the heat exchange cavity to heat the reaction materials in the static mixer, and then starting the static mixer to allow the reaction materials to react; S3: Open the condenser and the collector in sequence to collect gaseous phosphorus trifluoride.

13. The method for preparing phosphorus trifluoride according to claim 12, characterized in that: In the reaction raw materials, the molar ratio of the gaseous fluorine source to the liquid phosphorus source is 1:(3-4); Optionally, the inner diameter of the static mixer is 10-20 mm, the length of the static mixer is 700-900 mm, the delivery rate of the liquid phosphorus source is 8.75-18.75 mol / h, and the delivery rate of the gaseous fluorine source is 33.25-75 mol / h.

14. The method for preparing phosphorus trifluoride according to claim 12, characterized in that: In the step of heating the reaction raw materials in the static mixer, the temperature of the reaction raw materials is maintained at 45-55°C.

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