Automation Control Method for Continuous Automated Production Device of Phosphorus Pentafluoride

Abstract

The present invention provides an automatic control method for a continuous automatic production device of phosphorus pentafluoride, comprising the following steps: S10, opening the first pipeline to fill the cartridge with an inert gas, and opening the first air outlet to discharge the residual air and water vapor in the cartridge; S11, after closing the first pipeline and the first air outlet, feeding through the feed inlet, and closing the feed inlet after the feeding is completed; S12, opening the second pipeline to fill each weighing and conveying bin with an inert gas, and opening the exhaust port to discharge the residual air and water vapor in the weighing and conveying bin, and closing the second pipeline and the exhaust port; S13, opening the feed valve and the weighing and conveying unit to weigh phosphorus pentachloride and then feed it, and simultaneously opening the hydrogen fluoride supply tank to feed anhydrous HF, wherein the phosphorus pentachloride and the fluoride are fed in proportion.

Description

Technical Field

[0001] The present invention relates to an automatic control method for a continuous automatic production device of phosphorus pentafluoride. Background Art

[0002] Phosphorus pentafluoride (chemical formula: PF5) is an important inorganic compound and can be used in the electronic industry, polymer materials, and organic synthesis catalysts. Entering the new century, high-performance lithium-ion batteries have increasingly become an important field in the development of the new energy industry. As a key raw material for the production of lithium-ion batteries, lithium hexafluorophosphate has higher and higher quality requirements. How to efficiently produce high-quality phosphorus pentafluoride is of great significance for the synthesis of lithium hexafluorophosphate. At present, one of the industrial methods for producing phosphorus pentafluoride is to react phosphorus pentachloride with hydrogen fluoride gas. Phosphorus pentachloride is a yellowish crystalline powder at normal temperature and pressure, with a melting point of 179 to 181 °C, a pungent odor, and is easy to sublimate. It is highly irritating to the skin, eyes, and mucous membranes, is a compound with extremely high activity, and will react violently with moisture in the air to produce toxic and corrosive hydrogen chloride fumes.

[0003] PCl5 + H2O → POCl3 + 2HClPCl5 + 4H2O → H3PO4 + 5HCl

[0004] In the traditional preparation process of phosphorus pentafluoride, phosphorus pentachloride is manually fed, which has a relatively high labor intensity. The total amount of phosphorus pentachloride used in the overall process is large, while the consumption in a single reaction device is small. Therefore, multiple generating devices are required for multiple feedings and reactions, which affects efficiency. More importantly, the feeding process inevitably involves contact with air, generating toxic and corrosive gases, which directly affects the health of production personnel, the lifespan of production equipment, and environmental pollution. Summary of the Invention

[0005] The present invention provides an automatic control method for a continuous automatic production device of phosphorus pentafluoride, which can effectively solve the above problems.

[0006] The present invention is implemented as follows:

[0007] The present invention provides an automatic control method for a continuous automatic production device of phosphorus pentafluoride, including the following steps:

[0008] S10. Open the first pipeline to fill the cartridge with inert gas, and open the first air outlet to remove the residual air and moisture in the cartridge;

[0009] S11. After closing the first pipeline and the first air outlet, feed through the feed port, and close the feed port after the feeding is completed;

[0010] S12. Open the second pipeline to fill each weighing and conveying bin with inert gas, open the exhaust port to remove the residual air and water vapor in the weighing and conveying bin, and then close the second pipeline and the exhaust port.

[0011] S13. Open the feed valve and the weighing and conveying unit to weigh and feed phosphorus pentachloride, and at the same time open the hydrogen fluoride supply tank to feed anhydrous HF. Among them, phosphorus pentachloride and the fluoride are fed in proportion.

[0012] As a further improvement, in step S13, each time of feeding, control the conveying unit to run at a first speed uniformly for less than half a cycle to receive materials; when the material receiving is completed, then control the conveying unit to run at a second speed uniformly for less than half a cycle to dump materials.

[0013] As a further improvement, control the conveying unit to run uniformly for 1 / 3 cycle to receive materials; when the material receiving is completed, then control the conveying unit to run uniformly for 1 / 2 cycle to dump materials.

[0014] As a further improvement, when the conveying unit is running at a first speed uniformly, and the measurement of the weighing unit is significantly not increasing or increasing slowly, it further includes:

[0015] S131. Pass high-pressure inert gas through the first inert gas inlet to unblock the blockage of the feed valve.

[0016] The beneficial effects of the present invention are as follows: The automatic control method of the continuous automatic production device of phosphorus pentafluoride provided by the present invention. Among them, inert gas is filled into the barrel and each weighing and conveying bin through the first pipeline and the second pipeline respectively, so as to remove the residual air and water vapor in the barrel and each weighing and conveying bin, and then it can prevent and can significantly reduce the contents of POCl3, H3PO4 and water vapor in the product. The contents of POCl3, H3PO4 and water vapor in the product are reduced from the original 1 - 3 vt% to less than 0.01 vt%, improving the purity of the product. In addition, the continuous automatic production device of phosphorus pentafluoride can automatically feed multiple reactors at the same time, and multiple generating devices can carry out multiple feedings and reactions at the same time, significantly improving the efficiency and reducing the impact on the human body. In addition, through the accurate control of each feeding, accurate weighing can be achieved, improving the reaction efficiency. Further, when the conveying unit is running at a first speed uniformly, and the measurement of the weighing unit is significantly not increasing or increasing slowly, the blockage of the feed valve can be automatically judged and automatically unblocked. Description of the Drawings

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of a continuous automated production device for phosphorus pentafluoride provided by an embodiment of the present invention.

[0019] Figure 2 It is a schematic structural diagram of an automatic weighing and feeding device for phosphorus pentachloride provided by an embodiment of the present invention.

[0020] Figure 3 It is a flowchart of an automated control method for a continuous automated production device for phosphorus pentafluoride provided by an embodiment of the present invention. Specific Embodiments

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0023] Referring to Figure 1-2 As shown, an embodiment of the present invention provides a continuous automated production device for phosphorus pentafluoride, including:

[0024] An automatic weighing and feeding device for phosphorus pentachloride, which includes:

[0025] Phosphorus pentachloride silo 10, including a silo barrel 101, a feed inlet 102 and a first air outlet 103 provided at the top of the silo barrel 101, a multi-grid feeding pipe 104 provided at the bottom of the silo barrel 101 and a feeding valve 105 provided at each feeding port of the multi-grid feeding pipe 104, and a first inert gas inlet 106;

[0026] A plurality of weighing and conveying units 11, each weighing and conveying unit 11 includes a weighing and conveying bin 111 correspondingly provided at the bottom of each feeding valve 105 and communicating with the grid feeding pipe 104, a weighing unit 113 provided in the weighing and conveying bin 111, a conveying unit 112 provided on the weighing unit 113, a transfer tank 115 provided at the conveying end of the conveying unit 112, and a second inert gas inlet 117;

[0027] High-pressure inert gas unit 12, including an inert gas tank 121, a first pipeline 123 provided between the inert gas tank 121 and the first inert gas inlet 106, and a second pipeline 125 provided between the inert gas tank 121 and the second inert gas inlet 117;

[0028] Hydrogen fluoride supply tank 14;

[0029] A plurality of reactors 13 are respectively provided at the bottom of each transfer tank 115 and are connected to the hydrogen fluoride supply tank 14 through pipelines.

[0030] The phosphorus pentachloride silo 10 is used to store the phosphorus pentachloride raw material. The interior of the phosphorus pentachloride silo 10 can be passivated to prevent reaction with the phosphorus pentachloride raw material. In one embodiment, the phosphorus pentachloride silo 10 is a stainless steel silo passivated with fluorine gas. Introducing inert gas through the first inert gas inlet 106 can be used to expel the residual air, water vapor, etc. in the cartridge 101. Further, the first inert gas inlet 106 can be provided at the grid feed pipe 104. When the grid feed pipe 104 is blocked, introducing high-pressure inert gas through the first inert gas inlet 106 can be used to clear the blockage of the grid feed pipe 104. In the process of preparing phosphorus pentafluoride, the total consumption of phosphorus pentachloride is large, while the consumption of a single reaction device is small, so multiple reactors are required for multiple feedings and reactions. Therefore, the multi-grid feed pipe 104 can feed multiple reactors 13 simultaneously. The multi-grid feed pipe 104 has multiple grid-shaped feed pipes, and a feed valve 105 is correspondingly provided at the feed port of each grid-shaped feed pipe to control the feeding of each feed pipe respectively. The number of feed pipes of the multi-grid feed pipe 104 is not limited and can be 2 to 20. In one embodiment, the multi-grid feed pipe 104 has 6 feed pipes, corresponding to 6 weighing and conveying units 11 and 6 reactors 13 respectively.

[0031] In other embodiments, an observation window 107 is further provided at the bottom of the cartridge 101 to judge the remaining material condition of the cartridge 101. As a further improvement, in other embodiments, a vision sensor can be further provided outside the observation window 107 to detect the height of the material in the cartridge 101, so as to further realize fully automated control. The vision sensor is mainly used to judge whether the material in the cartridge 101 is lower than the set value to remind further feeding, etc.

[0032] The weighing and conveying unit 11 can be arranged side by side or in a matrix, which will not be elaborated here. The weighing unit 113 is used to weigh the weight of the conveying unit 112 and the input materials. The conveying unit 112 can be a conveyor belt or the like. The conveyor belt is coated with an inert material such as Teflon to prevent it from being corroded by phosphorus pentachloride. The inside of the transfer tank 115 can also be passivated to prevent reaction with the phosphorus pentachloride raw material. The top of the weighing and conveying bin 111 is further provided with an exhaust port 114 for exhausting residual air and moisture when the second pipeline 125 introduces inert gas. Further, the second inert gas inlet 117 can be arranged at the bottom of the transfer tank 115. In one embodiment, the second inert gas inlet 117 is connected to the bottom of the transfer tank 115, so that when the bottom of the transfer tank 115 is blocked, high-pressure inert gas can be introduced through the second inert gas inlet 117 to dredge the blockage at the bottom of the transfer tank 115.

[0033] In other embodiments, as a further improvement, the transfer tank 115 can be further provided with an observation window 118 for judging the remaining material situation in the transfer tank 115. As a further improvement, in other embodiments, a visual sensor can be further arranged outside the observation window 107 for detecting the height of the material in the transfer tank 115, so as to further realize full automation control. The visual sensor is mainly used to judge whether the material in the transfer tank 115 decreases, so as to judge whether there is a blockage.

[0034] The high-pressure inert gas unit 12 can further include an inflation pipeline 127 and a valve 126 arranged on the inflation pipeline 127 for replenishing inert gas when the gas in the high-pressure inert gas unit 12 is exhausted. The high-pressure inert gas unit 12 can further include a first valve 122 arranged on the first pipeline 123 and a second valve 124 arranged on the second pipeline 125. In one embodiment, the inert gas is selected from nitrogen. The air pressure of the high-pressure inert gas unit 12 can be 0.2 - 2 MPa. Preferably, the air pressure of the high-pressure inert gas unit 12 can be 0.5 - 1 MPa. In one embodiment, the air pressure of the high-pressure inert gas unit 12 is about 0.6 MPa, so as to realize the function of dredging the blockage.

[0035] The hydrogen fluoride supply tank 14 is used to provide high-purity hydrogen fluoride gas.

[0036] The reactor 13 is used to react hydrogen fluoride gas provided by the hydrogen fluoride supply tank 14 with phosphorus pentachloride provided by the automatic weighing and feeding equipment of phosphorus pentachloride to prepare phosphorus pentafluoride gas, which is stored in the storage tank 15. The reactor 13 includes a reaction chamber 131, a cooling jacket 134 arranged outside the reaction chamber 131, a stirring device 135 arranged in the middle of the reaction chamber 131, a tail gas discharge port 131 and a product discharge port 132 arranged at the top of the reaction chamber 131, and a hydrogen fluoride gas buffer chamber 136 arranged at the bottom of the reaction chamber 131. The gas at the product discharge port 132 is filled into the storage tank 15. The hydrogen fluoride gas enters the hydrogen fluoride gas buffer chamber 136 from the bottom air inlet, and then uniformly enters the reaction chamber 131 through the mesh holes of the porous surface structure. The hydrogen fluoride gas passes through the phosphorus pentachloride powder reaction bed from bottom to top, significantly improving the gas-solid contact area and contact time, making the reaction proceed more completely and significantly enhancing the conversion rate of anhydrous hydrogen fluoride. In addition, hydrogen fluoride is introduced into the reaction chamber 131 from the bottom of the reaction chamber 131 and is in full contact with phosphorus pentachloride, avoiding the problem of low utilization rate of hydrogen fluoride due to the easy gasification of anhydrous hydrogen fluoride and its easy discharge from the reactor along with the generated phosphorus pentafluoride and hydrogen chloride gases in the prior art. For the specific structure of the reactor 13, reference can be made to the Chinese invention patent with the application number 201922288722.2 and the title "A Phosphorus Pentafluoride Reactor", which will not be elaborated here.

[0037] Please refer to Figure 3 , the embodiment of the present invention further provides an automatic control method for a continuous automatic production device of phosphorus pentafluoride, including the following steps:

[0038] S10, open the first pipeline 123 to fill the cartridge 101 with inert gas, and open the first air outlet 103 to discharge the residual air and moisture in the cartridge 101;

[0039] S11, after closing the first pipeline 123 and the first air outlet 103, feed through the feed port 102, and close the feed port 102 after the feeding is completed;

[0040] S12, open the second pipeline 125 to fill each weighing and conveying bin 111 with inert gas, and open the exhaust port 114 to discharge the residual air and moisture in the weighing and conveying bin 111, and then close the second pipeline 125 and the exhaust port 114;

[0041] S13, open the feed valve 105 and the weighing and conveying unit 11 to weigh and feed phosphorus pentachloride, and at the same time open the hydrogen fluoride supply tank 14 to feed anhydrous HF, wherein the phosphorus pentachloride and the hydrogen fluoride are fed in proportion.

[0042] In step S10, preferably, the content of the inert gas in the first air outlet 103 can be detected to determine whether the residual air and water vapor in the cartridge 101 have been completely removed. More preferably, when the content of the inert gas in the first air outlet 103 is higher than 99 vt%, it can be basically determined that the residual air and water vapor in the cartridge 101 have been completely removed.

[0043] In step S11, since the cartridge 101 forms a closed cavity, the feeding height should not be too high. Preferably, the feeding height is 80%-90% of the height of the cartridge 101, so as to prevent a large negative pressure from being formed during the subsequent feeding process, which affects the feeding.

[0044] In step S12, the content of the inert gas in the exhaust port 114 can be detected to determine whether the residual air and water vapor in the weighing and conveying bin 111 have been completely removed. More preferably, when the content of the inert gas in the exhaust port 114 is higher than 99 vt%, it can be basically determined that the residual air and water vapor in the weighing and conveying bin 111 have been completely removed.

[0045] As a further improvement, the second pipeline 125 can be further opened to fill the reactor 13 with inert gas, and the exhaust gas discharge port 131 can be opened to remove the residual air and water vapor in the reactor 13. Of course, the content of the inert gas in the exhaust gas discharge port 131 can also be detected to determine whether the residual air and water vapor in the reactor 13 have been completely removed.

[0046] In step S13, in order to accurately feed the phosphorus pentachloride raw material, preferably, each time of feeding, the conveying unit 112 is controlled to run at a first speed uniformly for less than half a week to receive the material, that is, to run for less than half a cycle; after the material receiving is completed, the conveying unit 112 is then controlled to run at a second speed uniformly for less than half a week to dump the material. Preferably, each time of feeding, the conveying unit 112 is controlled to run uniformly for 1 / 3 week to receive the material; after the material receiving is completed, the conveying unit 112 is then controlled to run uniformly for 1 / 2 week to dump the material, so as to ensure that the material is completely dumped. As a further improvement, after running for 1 / 3 week, the weighing unit 113 weighs whether the material of the conveying unit 112 reaches the set value. If so, the feeding valve 105 is controlled to close, and then the conveying unit 112 is controlled to run uniformly for 1 / 2 week to dump the material; otherwise, the feeding valve 105 is controlled to remain open for feeding until the set value is reached, and then the conveying unit 112 is controlled to run uniformly for 1 / 2 week to dump the material.

[0047] The phosphorus pentachloride and the anhydrous HF are generally fed and mixed at a mass ratio of about 1:2. However, since the anhydrous HF will volatilize and cause certain losses, preferably, the phosphorus pentachloride and the anhydrous HF are generally fed and mixed at a mass ratio of about 1:2.1 to 2.4. In one embodiment, the phosphorus pentachloride and the anhydrous HF are generally fed and mixed at a molar ratio of about 1:2.1.

[0048] As a further improvement, when the conveying unit 112 is running at a constant speed at the first speed, and the measurement of the weighing unit 113 does not increase significantly or increases slowly, it indicates that the feeding valve 105 is blocked. At this time, it may further include:

[0049] S131, introducing high-pressure inert gas through the first inert gas inlet 106 to unblock the feeding valve 105. At this time, it can be further judged whether it has been unblocked through the measurement change of the weighing unit 113. Otherwise, continuously introduce high-pressure inert gas or give an alarm for manual unblocking.

[0050] As a further improvement, when the feeding valve 105 is continuously opened for feeding, and the measurement of the weighing unit 113 does not increase significantly or increases slowly, it indicates that the feeding valve 105 is blocked. At this time, it may further include:

[0051] S132, introducing high-pressure inert gas through the first inert gas inlet 106 to unblock the feeding valve 105. At this time, it can be further judged whether it has been unblocked through the measurement change of the weighing unit 113. Otherwise, continuously introduce high-pressure inert gas or give an alarm for manual unblocking.

[0052] When the material dumping is completed, the remaining material situation of the transfer tank 115 can be further judged through the observation window 118 on the transfer tank 115. When the remaining material in the transfer tank 115 does not decrease or decreases too slowly, it can be judged that the bottom of the transfer tank 115 is blocked. At this time, it may further include:

[0053] S133, introducing high-pressure inert gas through the second inert gas inlet 117 to unblock the blockage at the bottom of the transfer tank 115.

[0054] After step S13, discharging can be carried out through the discharge port 132 at the top of the reactor 13. After the discharging is completed, it may further include:

[0055] Opening the second pipeline 125 to fill the reactor 13 with inert gas and opening the waste gas discharge port 133 to discharge the residual gas in the reactor 13.

[0056] In the actual production process, the content of POCl3, H3PO4, and water vapor in the product can be significantly reduced through automated feed control. The content of POCl3, H3PO4, and water vapor in the product is reduced from the original 1-3 vt% to less than 0.01 vt%, improving the purity of the product.

[0057] The above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An automatic control method for a continuous automatic production device of phosphorus pentafluoride. The continuous automatic production device of phosphorus pentafluoride includes an automatic weighing and feeding device for phosphorus pentachloride, which comprises: Phosphorus pentachloride silo, comprising a silo barrel, a feed inlet and a first air outlet arranged at the top of the silo barrel, a multi-grid feeding pipe arranged at the bottom of the silo barrel and a feeding valve arranged on each feeding port of the multi-grid feeding pipe, and a first inert gas inlet; a plurality of weighing and conveying units, each weighing and conveying unit includes a weighing and conveying bin correspondingly arranged at the bottom of each feeding valve and communicated with the grid feeding pipe, a weighing unit arranged in the weighing and conveying bin, a conveying unit arranged on the weighing unit, a transfer tank arranged at the conveying end of the conveying unit, and a second inert gas inlet; a high-pressure inert gas unit, including an inert gas tank, a first pipeline arranged between the inert gas tank and the first inert gas inlet, a second pipeline arranged between the inert gas tank and the second inert gas inlet; a hydrogen fluoride supply tank; a plurality of reactors, respectively arranged at the bottom of each transfer tank and communicated with the hydrogen fluoride supply tank through a pipeline, the method comprising the following steps: S10, open the first pipeline to fill the silo barrel with inert gas, and open the first air outlet to discharge the residual air and water vapor in the silo barrel, so as to reduce the contents of POCl3, H3PO4 and water vapor in the product; S11, after closing the first pipeline and the first air outlet, feed through the feed inlet, and close the feed inlet after the feeding is completed; S12, open the second pipeline to fill each weighing and conveying bin with inert gas, and open the exhaust port to discharge the residual air and water vapor in the weighing and conveying bin, and close the second pipeline and the exhaust port; S13, open the feeding valve and the weighing and conveying unit to weigh and feed phosphorus pentachloride, and at the same time open the hydrogen fluoride supply tank to feed anhydrous HF, wherein the phosphorus pentachloride and the hydrogen fluoride are fed in proportion.

2. The automatic control method of the continuous automatic production device of phosphorus pentafluoride according to claim 1, characterized in that In step S10, the content of the inert gas in the first air outlet is detected to judge whether the residual air and water vapor in the silo barrel are discharged completely.

3. The automatic control method of the continuous automatic production device of phosphorus pentafluoride according to claim 1, characterized in that, In step S11, the feeding height is 80%-90% of the height of the silo barrel.

4. The automatic control method of the continuous automatic production device of phosphorus pentafluoride according to claim 1, characterized in that In step S13, each time of feeding, control the conveying unit to run at a first speed uniformly for less than half a week to receive materials; after the materials are received, then control the conveying unit to run at a second speed uniformly for less than half a week to dump materials.

5. The automatic control method of the continuous automatic production device of phosphorus pentafluoride according to claim 4, characterized in that, Control the conveying unit to run uniformly for 1 / 3 week to receive materials; after the materials are received, then control the conveying unit to run uniformly for 1 / 2 week to dump materials.

6. The automatic control method of the continuous automatic production device of phosphorus pentafluoride according to claim 4, characterized in that When the conveying unit is running at a first speed uniformly, and the measurement of the weighing unit does not increase significantly or increases slowly, it further includes: S131, introduce high-pressure inert gas through the first inert gas inlet to dredge the blockage of the feeding valve.

7. The automated control method of the continuous automated production device of phosphorus pentafluoride according to claim 4, characterized in that, When controlling the feeding valve to be continuously opened for feeding, and the measurement of the weighing unit does not increase significantly or increases slowly, it further includes: S132, introduce high-pressure inert gas through the first inert gas inlet to dredge the blockage of the feeding valve.

8. The automatic control method of the continuous automatic production device of phosphorus pentafluoride according to claim 4, characterized in that, When the remaining materials in the transfer tank do not decrease or decrease too slowly, it further includes: S133, introduce high-pressure inert gas through the second inert gas inlet to dredge the blockage at the bottom of the transfer tank.

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