Phosphorus trichloride rectification apparatus and cleaning method
By designing phosphorus trichloride distillation equipment and cleaning methods, and using pipelines to transport and clean inorganic acids and strong oxidizing solutions, the problems of long cleaning time and high cost of traditional cleaning methods have been solved, achieving efficient and safe cleaning results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PIONEER ORIGINAL (SHANGHAI) NEW TECHNOLOGY RESEARCH CO LTD
- Filing Date
- 2024-11-29
- Publication Date
- 2026-05-29
AI Technical Summary
Traditional phosphorus trichloride distillation equipment requires disassembly for cleaning, which consumes a lot of manpower, takes a long time, and is prone to introducing impurities, which is not conducive to the continuous production of high-purity phosphorus trichloride.
Design a phosphorus trichloride distillation device that uses inorganic acid and strong oxidizing solution transported through pipelines, utilizes heating reaction to transform residues, and cleans the device through a closed pipeline system and pumping method, avoiding disassembly of the device.
It shortens cleaning time, reduces labor costs, maintains product purity, reduces safety hazards, and ensures the good working condition of the distillation equipment.
Smart Images
Figure CN122098005A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of phosphorus trichloride distillation equipment technology, and in particular to a phosphorus trichloride distillation equipment and cleaning method. Background Technology
[0002] Phosphorus trichloride (PCl3) is a colorless, clear, fuming liquid with a corrosive and pungent odor and a relative density of 1.574 g / cm³. 3 Phosphorus trichloride (PTC) has a melting point of -112℃ and a boiling point of 75.5℃. Its reaction with water is a typical hydrolysis reaction, which is vigorous and produces a large amount of heat and dense fumes. In laboratory or industrial operations, phosphorus trichloride is generally not allowed to come into direct contact with water. High-purity phosphorus trichloride is mainly used to prepare high-purity phosphorus, which is a key raw material for manufacturing III-V compound semiconductor materials, such as gallium phosphide (GaP) and indium phosphide (InP). These compound semiconductors play an important role in electronic and microwave technologies and are widely used in the manufacture of display components such as light-emitting diodes, audio devices, home appliances, and automotive metering devices. With the development of the semiconductor materials industry, especially the rapid progress of the gallium phosphide and indium phosphide industries, the quality requirements for high-purity phosphorus are gradually increasing.
[0003] The distillation purification technology of phosphorus trichloride is a key prerequisite for the preparation of high-purity phosphorus. However, during the distillation purification process, small amounts of air and water are inevitably introduced during the feeding and nitrogen introduction steps. Under the high-temperature environment of distillation, water and oxygen from the air react chemically with phosphorus trichloride. The mixture of reaction products and solid impurities presents a yellow, muddy form, mainly composed of various phosphorus oxides, phosphorus, and phosphorus trichloride. This muddy substance easily adheres to the bottom of the distillation vessel and other areas of the distillation apparatus, thus affecting the performance of the equipment. Therefore, regular cleaning of the distillation apparatus is necessary to restore its performance. The traditional cleaning method involves disassembling and cleaning small parts, followed by reassembly. This method requires large hoisting equipment for disassembly, consumes a lot of manpower, is time-consuming, costly, and easily introduces impurities, which is detrimental to the continuous production of high-purity phosphorus trichloride. Summary of the Invention
[0004] The technical problem to be solved by this invention is that the cleaning of traditional distillation equipment requires the use of large hoisting equipment for disassembly, which consumes a lot of manpower, takes a long time, has high costs, and is prone to introducing impurities, which is not conducive to the continuous production of high-purity phosphorus trichloride.
[0005] To address the aforementioned technical problems, this invention provides a phosphorus trichloride distillation apparatus and a cleaning method.
[0006] In a first aspect, the present invention provides a phosphorus trichloride distillation apparatus, comprising a distillation kettle, a heating element, and a cleaning device. The cleaning device includes a liquid loading assembly for providing an inorganic acid solution or a strong oxidizing solution, a first pipeline, a first control valve, a collection assembly for collecting cleaning waste residue, a second pipeline, and a second control valve. The distillation kettle is disposed within the heating element. The liquid loading assembly is connected to a first interface of the distillation kettle via the first pipeline to introduce the inorganic acid solution or the strong oxidizing solution into the distillation kettle. The first control valve is disposed within the first pipeline. The collection assembly is connected to a second interface of the distillation kettle via the second pipeline. The second control valve is disposed within the second pipeline.
[0007] Secondly, the present invention also provides a cleaning method applied to the phosphorus trichloride distillation equipment as described above, the cleaning method comprising the following steps:
[0008] Open the first control valve to supply 1-50L of inorganic acid solution to the bottom of the distillation vessel. When the amount of inorganic acid solution supplied reaches the preset amount, close the first control valve. The mass fraction of the inorganic acid solution is 1%-38%.
[0009] Turn on the heating element to raise the temperature of the liquid in the distillation vessel to 40-200℃ and keep it at this temperature for 2-50 hours to react with the residue in the distillation vessel and convert the residue into liquid phosphoric acid;
[0010] After the heat preservation is completed, the temperature inside the distillation vessel is completely cooled to room temperature;
[0011] Open the first control valve and supply 1-50L of the strong oxidizing solution to the bottom of the distillation vessel. When the amount of the strong oxidizing solution supplied reaches the preset amount, close the first control valve. The mass fraction of the strong oxidizing solution is 1%-60%.
[0012] The distillation vessel is kept at room temperature for 2-30 hours to allow the strong oxidizing solution to mix with the inorganic acid solution, releasing a strong oxidizing gas to remove unreacted residues and completely dissolve them.
[0013] After cleaning, the second control valve is opened to direct all the liquid at the bottom of the distillation vessel into the collection assembly.
[0014] Compared with the prior art, the phosphorus trichloride distillation equipment and cleaning method of this invention have the following advantages:
[0015] The feeding and discharging method of this invention uses pipeline transportation to minimize air entry, helping to maintain product purity and prevent impurities from contaminating. Since it eliminates the need for disassembling the entire unit for cleaning, downtime is reduced, production efficiency is improved, and the need for large hoisting equipment is eliminated, thus reducing labor costs. Furthermore, the added inorganic acid solution or strong oxidizing solution effectively removes stubborn deposits through chemical reactions, including residues adhering to the bottom of the vessel and other parts, ensuring the distillation equipment operates in good condition. In addition, this method reduces the intensity of the reaction between phosphorus trichloride and water, lowering safety hazards during the cleaning process. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of the phosphorus trichloride distillation equipment provided in an embodiment of the present invention;
[0017] Figure 2 This is a top view of the distillation vessel provided in an embodiment of the present invention;
[0018] In the diagram, 1. Distillation vessel; 101. First interface; 102. Second interface; 103. Temperature measuring port; 104. Air inlet; 2. Heating element; 3. Cleaning device; 301. Liquid loading assembly; 302. First pipeline; 303. First control valve; 304. Collection assembly; 30401. Third vessel; 30402. Second pump body; 305. Second pipeline; 306. Second control valve; 307. First flow meter; 308. First pump body; 309. Temperature detection element; 4. Distillation column; 5. Connection port; 6. Raw material vessel; 7. Third pipeline; 8. Third control valve; 9. Second flow meter; 10. Third pump body; 11. Double-ended connector; 1101. Fourth pipeline; 1102. Fifth pipeline; 12. Fourth control valve. Detailed Implementation
[0019] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.
[0020] like Figure 1As shown, the present invention provides a phosphorus trichloride distillation apparatus, including a distillation kettle 1, a heating element 2, and a cleaning device 3. The cleaning device 3 includes a liquid loading assembly 301 for providing an inorganic acid solution or a strong oxidizing solution, a first pipe 302, a first control valve 303, a collection assembly 304 for collecting cleaning waste residue, a second pipe 305, and a second control valve 306. The distillation kettle 1 is disposed in the heating element 2. The liquid loading assembly 301 is connected to the first interface 101 of the distillation kettle 1 through the first pipe 302 to introduce an inorganic acid solution or a strong oxidizing solution into the distillation kettle 1. The first control valve 303 is disposed in the first pipe 302. The collection assembly 304 is connected to the second interface 102 of the distillation kettle 1 through the second pipe 305. The second control valve 306 is disposed in the second pipe 305.
[0021] Based on the above structure, in this embodiment, the first control valve 303 controls the opening of the first pipe 302 to introduce an inorganic acid solution or a strong oxidizing solution into the distillation vessel 1. The heating element 2 causes the inorganic acid solution to react with the yellow mud-like substance (mainly composed of phosphorus oxides), converting it into liquid phosphoric acid, which is then discharged from the second port 102. Subsequently, a strong oxidizing solution is introduced. After the strong oxidizing solution mixes with the inorganic acid solution, it releases a strong oxidizing gas, which further oxidizes the phosphorus element in the unreacted yellow mud-like substance to a positive five-valent state and dissolves it, ensuring thorough removal of the sediment. Then, the second control valve 306 controls the opening of the second channel to introduce all the liquids (including waste liquid and waste residue mixtures) in the distillation vessel 1 into the collection component 304.
[0022] In this embodiment, the material is transported via pipelines to minimize air ingress, thus helping to maintain product purity and prevent impurities from contaminating. Since the entire unit does not need to be disassembled for cleaning, downtime is reduced, production efficiency is improved, and the need for large hoisting equipment is eliminated, reducing labor costs. Furthermore, the added inorganic acid solution or strong oxidizing solution effectively removes stubborn deposits through chemical reactions, including residues adhering to the bottom of the vessel and other parts, ensuring the distillation equipment operates in good condition. Additionally, this method reduces the intensity of the reaction between phosphorus trichloride and water, minimizing safety hazards during the cleaning process.
[0023] Furthermore, the liquid loading assembly 301 includes a first vessel for providing an inorganic acid solution and a second vessel for providing a strong oxidizing solution. The first vessel is detachably connected to the first pipe 302 to allow the inorganic acid solution to be introduced into the distillation vessel 1 for cleaning.
[0024] Understandably, in this embodiment, an inorganic acid solution is delivered to the distillation vessel 1 through the connection between the first vessel and the first pipe 302, so that it reacts with the residues (mainly yellow mud-like substances) in the distillation vessel 1 and converts these residues into liquid phosphoric acid, which can then be discharged from the distillation vessel 1, while reducing the adhesion of solid deposits to the equipment.
[0025] The second vessel is detachably connected to the first pipe 302 to introduce a strong oxidizing solution and an inorganic acid solution into the distillation vessel 1 to release a strong oxidizing gas and remove residues.
[0026] Understandably, in this embodiment, a strong oxidizing solution is supplied to the distillation vessel 1 through the connection between the second vessel and the first pipe 302. When mixed with the inorganic acid solution, the solution releases a strong oxidizing gas. This gas can clean areas that the inorganic acid solution cannot reach, such as dissolving some solid impurities, such as phosphorus (P). The solid impurities (i.e., unreacted residues) react with hydrochloric acid under high conditions and still adhere to the bottom of the distillation vessel 1. The gas can oxidize the above substances into pentavalent phosphorus and dissolve them, which helps to thoroughly remove the remaining deposits.
[0027] It should be noted that the liquid filling assembly 301 in this embodiment includes two containers containing different solutions, and the different solutions are introduced by means of the detachable connection between the container and the first pipe 302. In addition, the liquid filling assembly 301 in this embodiment may also have two cavities containing different solutions, and the different solutions are introduced by adjusting the position of the first pipe 302; or, the different solutions are introduced by means of the cooperation of the adapter and the valve body. No particular limitation is made here.
[0028] Furthermore, the cleaning device 3 also includes a first flow meter 307, which is installed in the first pipe 302 to measure the flow rate of the liquid flowing through the pipe. Using the data (i.e. flow rate) provided by the flow meter and the transportation time, the actual amount of inorganic acid solution (or strong oxidizing solution) entering the bottom of the distillation vessel 1 can be calculated to help the operator understand the current flow rate and adjust the working status of the pump or other relevant parameters accordingly.
[0029] The cleaning device 3 also includes a first pump body 308, which is installed in the first pipe 302. In this embodiment, the first pump body 308 provides the necessary pressure to overcome pipe resistance, ensuring that the liquid can flow in a predetermined direction to deliver the inorganic acid solution from the first vessel (or the strong oxidizing solution from the second vessel) to the bottom of the distillation vessel 1. The first pump body 308 is the core device in the liquid delivery system. It is understood that if the installation height of the first and second vessels is higher than the height of the first interface 101, the first pump body 308 may not be required.
[0030] It should be noted that the first flow meter 307 is installed at the end of the first pump body 308 away from the liquid filling assembly 301, so that the first flow meter 307 can accurately measure the flow rate of the liquid after it has been pressurized by the first pump body 308, thereby avoiding the problem of inaccurate readings caused by changes in the pressure before the pump.
[0031] Furthermore, the collection component 304 includes a third vessel 30401 and a second pump body 30402. The third vessel 30401 is connected to the second interface 102 through the second pipe 305 and receives all the washed mixture discharged from the distillation vessel 1, including an inorganic acid solution containing dissolved yellow mud-like substances, and waste residue that may not have fully reacted but has detached from the wall of the distillation vessel 1. The second pump body 30402 is installed on the second pipe 305 and provides the necessary power to overcome the pipe resistance, ensuring that the waste liquid can be smoothly transferred from the distillation vessel 1 to the third vessel 30401.
[0032] This embodiment uses a closed pipeline system and a pumping method to better control the extraction of waste liquid, reducing the opportunity for operators to directly contact hazardous substances, thereby improving the safety level.
[0033] Furthermore, the cleaning device 3 also includes a temperature detection element 309. The distillation vessel 1 has a temperature measuring port 103, and the temperature detection element 309 is installed in the temperature measuring port 103 to detect the temperature change in the distillation vessel 1. This temperature change includes the temperature during the cleaning process and the distillation reaction process, which helps the operator or the automated control system to adjust parameters such as heating power and cooling rate according to the actual situation to achieve the best distillation effect and cleaning efficiency.
[0034] Preferably, the temperature detection element 309 includes an infrared thermal imaging device, a fiber optic temperature sensor, a micro / nano temperature sensor, or a temperature detector. The infrared thermal imaging device does not require direct contact with the object being measured, making it suitable for high-temperature environments or hard-to-reach locations; the fiber optic temperature sensor provides highly accurate temperature readings; the micro / nano temperature sensor allows for better dynamic temperature monitoring; and the temperature detector (such as a thermocouple or resistance thermometer) is relatively more cost-effective. This embodiment preferably uses a temperature detector. By placing the temperature detection element 309 inside the distillation vessel 1, especially near the bottom, the actual temperature inside the vessel can be continuously monitored.
[0035] In application, the heating element 2 includes a constant-temperature electric heating mantle, a microwave heating device, or an infrared heating device. A constant-temperature electric heating mantle can provide a relatively uniform heating effect, facilitating better control of temperature stability. A microwave heating device directly heats the interior of the material without transferring heat through the container wall, thus improving heating efficiency; while an infrared heating device can rapidly raise the temperature of the target area. Preferably, in this embodiment, the heating element 2 is a constant-temperature electric heating mantle.
[0036] Furthermore, it also includes a distillation column 4 and a connection port 5, with the distillation column 4 connected to the connection port 5.
[0037] Understandably, the distillation column 4 is filled with packing or trays. These structures increase the gas-liquid contact area, allowing the rising vapor and descending liquid to come into full contact, thereby achieving multiple partial evaporation and condensation processes. The connection port 5 is the interface between the distillation column 4 and the distillation vessel 1, used to ensure effective gas and liquid transfer between them. In this embodiment, the connection port 5 is a column section connection port 5, which also facilitates the flow of strongly oxidizing gas to the distillation column 4 for cleaning during cleaning.
[0038] Furthermore, it also includes a raw material container 6, a third pipeline 7, and a third control valve 8. The raw material container 6 is used to store the raw material to be distilled, which is usually phosphorus trichloride liquid. It is connected to the first interface 101 of the distillation vessel 1 through the third pipeline 7 to ensure that the raw material can flow smoothly from the raw material container 6 to the distillation vessel 1. The third control valve 8 is set at the third pipeline 7 to control the on / off state and flow rate of the raw material. When the raw material is not needed, the pipeline is closed to prevent raw material leakage or unnecessary flow.
[0039] This embodiment also includes a second flow meter 9, installed in the third pipe 7, to measure the flow rate of the raw material passing through the pipe. This ensures that the raw material enters the distillation vessel 1 at a predetermined amount and rate, helping to precisely control the amount of raw material added, thereby maintaining the stability of the distillation process and the consistency of product quality. The third control valve 8, in conjunction with the flow meter data, enables more refined flow management. Furthermore, a third pump body 10 is provided, installed in the third pipe 7, to provide power to pump the raw material from the raw material container 6 into the distillation vessel 1. The second flow meter 9 is installed at the end of the third pump body 10 furthest from the raw material container 6, so that the second flow meter 9 can accurately measure the flow rate of the liquid after it has been pressurized by the third pump body 10, thus avoiding inaccurate readings caused by changes in the pressure before the pump.
[0040] Understandably, if the installation height of the raw material container 6 is higher than the height of the first interface 101, the third pump body 10 may not need to be installed.
[0041] Furthermore, it also includes a double-ended connector 11, which includes a fourth pipe 1101 and a fifth pipe 1102. The fifth pipe 1102 extends outward from the side wall of the fourth pipe 1101. One end of the fourth pipe 1101 is installed at the first interface 101, and the other end of the fourth pipe 1101 is connected to the third pipe 7 for raw material transportation. The port of the fifth pipe 1102 is connected to the first pipe 302 for cleaning fluid transportation.
[0042] This embodiment uses a dual-ended pipe 11 to handle two different fluids. When switching from production mode to cleaning mode, there is no need for complex pipeline reconfiguration and it can ensure that various fluids can enter the distillation vessel 1. The above method reduces the connection points of the distillation vessel 1, avoids setting up independent interfaces for each fluid, simplifies the complexity of the system, saves space and reduces the potential risk of leakage.
[0043] Furthermore, a fourth control valve 12 is included, which is installed at the connection between the fourth pipe 1101 and the first interface 101 to control whether fluid is allowed to enter the distillation vessel 1 from the fourth pipe 1101. When it is not necessary to supply fluid to the distillation vessel 1, the system can be isolated by closing the fourth control valve 12 to prevent unnecessary flow caused by accidental leakage or misoperation.
[0044] Please see Figure 2 The distillation vessel 1 also includes an inlet 104 for introducing gas, so that during the distillation process, an inert gas (such as nitrogen) is introduced through the inlet 104 to replace the air in the vessel, forming a protective atmosphere to prevent phosphorus trichloride from reacting with oxygen in the air.
[0045] The present invention also provides a cleaning method for use in a phosphorus trichloride distillation apparatus as described above. The cleaning method includes the following steps:
[0046] S110. Open the first control valve 303 to deliver 1-50L of inorganic acid solution to the bottom of the distillation vessel 1. When the amount of inorganic acid solution introduced reaches the preset amount, close the first control valve 303. The mass fraction of the inorganic acid solution is 1%-38%.
[0047] This step involves conveying an inorganic acid solution, which reacts with the residues (mainly yellow mud-like substances) in distillation vessel 1, converting these residues into liquid phosphoric acid for discharge from distillation vessel 1, while reducing the adhesion of solid deposits to the equipment.
[0048] S120. Turn on the heating element 2 to heat the liquid in the distillation vessel 1 to 40-200℃ and keep it at this temperature for 2-50 hours to react with the residue in the distillation vessel 1 and convert the residue into liquid phosphoric acid.
[0049] This step creates high-temperature conditions, allowing the inorganic acid solution to fully react with the residue, accelerating the chemical reaction rate, and ensuring the residue is completely converted into liquid phosphoric acid. It should be noted that the holding time can be adjusted according to actual conditions to ensure the reaction is complete.
[0050] S130. After the heat preservation is completed, the temperature inside the distillation vessel 1 is completely cooled to room temperature;
[0051] The cooling process in this step prepares the solution for the next step, avoids the effects of high temperatures on the highly oxidizing solution, and introduces a fresh solution to further treat any unreacted residues.
[0052] S140. Open the first control valve 303 and supply 1-50L of strong oxidizing solution to the bottom of the distillation vessel 1. When the amount of strong oxidizing solution supplied reaches the preset amount, close the first control valve 303. The mass fraction of the strong oxidizing solution is 1%-60%.
[0053] This step involves conveying a strong oxidizing solution, which, when mixed with an inorganic acid solution, releases a strong oxidizing gas. This gas can clean areas that the inorganic acid solution cannot reach, such as the upper section of distillation vessel 1 (e.g., a distillation column 4 with glass packing or other connected devices), and dissolve some solid impurities such as phosphorus (P). These solid impurities (i.e., unreacted residues) react with hydrochloric acid under high conditions and still adhere to the bottom of distillation vessel 1. The gas can oxidize these substances to pentavalent phosphorus and dissolve them. This step helps to thoroughly remove the remaining deposits.
[0054] S150 and distillation vessel 1 are kept at room temperature for 2-30 hours to allow the strong oxidizing solution to mix with the inorganic acid solution, release the strong oxidizing gas, remove unreacted residues, and completely dissolve them.
[0055] This step involves creating a room temperature environment. By reacting at room temperature, the strong oxidizing gas can slowly and evenly come into contact with the residue, thereby more effectively removing the residue and maintaining this environment for a period of time to ensure that the reaction proceeds fully.
[0056] S160. After cleaning, open the second control valve 306 to guide all the liquid at the bottom of the distillation vessel 1 into the collection assembly 304.
[0057] This step involves collecting all the waste liquid and dissolved residue after cleaning for subsequent treatment or disposal, in order to prevent the waste liquid from being directly discharged into the environment.
[0058] Based on the above steps, the entire cleaning process does not require disassembling the equipment, reducing downtime and labor costs, and improving production efficiency. Furthermore, by precisely controlling parameters such as temperature and flow rate, potential safety hazards during the cleaning process are reduced, and centralized collection of waste liquid facilitates subsequent treatment, minimizing environmental impact.
[0059] It should be noted that the replacement of different solutions in step S130 can be achieved by connecting the first pipe 302 to a vessel containing other solutions.
[0060] Furthermore, inorganic acid solutions include hydrochloric acid.
[0061] Understandably, the inorganic acid solution used in step S120 is hydrochloric acid, which will chemically react with most of the yellow mud-like substance, converting it into liquid phosphoric acid. The reaction equation for this chemical reaction is shown below:
[0062] PC l3(l) + 3H2O(l) → H3PO3(l) + 3HCl(l) — Reaction 1
[0063] P2O5(s) + 3H2O(l) → 2H3PO4(l) — Reaction 2
[0064] POC l3(l) + 3H2O(l) → H3PO4(l) + 3HCl(g) — Reaction 3
[0065] 13P₂O₃ + 33H₂O = 4P (red phosphorus) + 18H₃PO₄ + 4PH₃(g) — Reaction 4
[0066] Among them, the hydrolysis reaction of phosphorus trichloride in reaction formula 1 is a reversible reaction. The use of hydrochloric acid as a cleaning agent increases the reaction products, which can reduce the intensity of the reaction and ensure the safety of the cleaning process.
[0067] Furthermore, strong oxidizing solutions include nitric acid solution, hydrogen peroxide solution, sodium chlorate solution, or potassium chlorate solution. The strong oxidizing gas generated by their reaction with inorganic acids can efficiently clean the entire phosphorus trichloride distillation equipment.
[0068] Example 1
[0069] (1) Open the first control valve 303 and the fourth control valve 12. All other control valves (i.e. the second control valve 306 and the third control valve 8) are closed. Then open the first pump body 308. Based on the first flow meter 307 and the calculation of the transportation time, the first pipeline 302 transports 5L of hydrochloric acid (mass fraction of 20%) into the bottom of the distillation kettle 1. After the feeding is completed, close the first control valve 303 and the fourth control valve 12.
[0070] (2) Turn on the constant temperature electric heating mantle to raise the temperature of the liquid in the distillation kettle 1 to 50°C and keep it at this temperature for 3 hours. Some of the yellow mud-like substances reacted and were converted into liquid phosphoric acid.
[0071] (3) After the heat preservation is completed, allow the distillation vessel 1 to cool naturally to room temperature.
[0072] (4) Replace the first container with a reagent bottle containing hydrochloric acid solution and replace it with a second container containing nitric acid solution.
[0073] (5) Open the first control valve 303 and the fourth control valve 12. All other control valves (i.e. the second control valve 306 and the third control valve 8) are closed. Then open the first pump body 308. Based on the calculation of the first flow meter 307 and the transportation time, the first pipeline 302 transports 1L of nitric acid (mass fraction of 5%) into the distillation kettle 1. After the feeding is completed, close the first control valve 303 and the fourth control valve 12.
[0074] (6) After adding nitric acid, do not heat up the room and keep it at room temperature for 2 hours.
[0075] (7) After cleaning, open the second control valve 306 of the second port 102. All other valves (i.e., the first control valve 303, the third control valve 8 and the fourth control valve 12) are closed. Open the second pump body 30402 to pump all the liquid at the bottom of the distillation vessel 1 into the third vessel 30401.
[0076] This cleaning method and equipment can remove most of the yellow mud-like substance adhering to the phosphorus trichloride distillation equipment, restoring the equipment to its near-transparent original state. The entire cleaning process is highly efficient.
[0077] Example 2
[0078] (1) Open the first control valve 303 and the fourth control valve 12, and keep all other control valves closed. Then open the first pump body 308. Based on the calculation of the first flow meter 307 and the transportation time, the first pipeline 302 transports 5L of hydrochloric acid (mass fraction of 10%) into the bottom of the distillation kettle 1. After the feeding is completed, close the first control valve 303 and the fourth control valve 12.
[0079] (2) Turn on the constant temperature electric heating mantle to raise the temperature of the liquid in the distillation kettle 1 to 40°C and keep it at this temperature for 10 hours. Some yellow mud-like substances were reacted and converted into liquid phosphoric acid.
[0080] (3) After the heat preservation is completed, allow the distillation vessel 1 to cool naturally to room temperature.
[0081] (4) Replace the first container with a reagent bottle containing hydrochloric acid solution and replace it with a second container containing nitric acid solution.
[0082] (5) Open the first control valve 303 and the fourth control valve 12, while all other control valves are closed. Then, turn on the first pump body 308. Based on the first flow meter 307 and the calculation of the transportation time, the first pipeline 302 transports 2L of nitric acid (mass fraction of 2.5%) into the distillation kettle 1. After the feeding is completed, close the first control valve 303 and the fourth control valve 12.
[0083] (6) After adding nitric acid, do not heat up the room and keep it at room temperature for 5 hours.
[0084] (7) After cleaning, open the second control valve 306 of the second interface 102, while all other valves are closed. Open the second pump body 30402 to pump all the liquid at the bottom of the distillation vessel 1 into the third vessel 30401.
[0085] The cleaning method and equipment can remove most of the yellow mud-like substance adhering to the phosphorus trichloride distillation equipment, restoring the equipment to its near-transparent original state. The entire cleaning process is slightly more efficient, but the cleaning effect is slightly worse than that of Example 1.
[0086] Example 3
[0087] (1) Open the first control valve 303 and the fourth control valve 12, and keep all other control valves closed. Then open the first pump body 308. Based on the calculation of the first flow meter 307 and the transportation time, the first pipeline 302 transports 5L of hydrochloric acid (mass fraction of 20%) into the bottom of the distillation kettle 1. After the feeding is completed, close the first control valve 303 and the fourth control valve 12.
[0088] (2) Turn on the constant temperature electric heating mantle to raise the temperature of the liquid in the distillation kettle 1 to 50°C and keep it at this temperature for 5 hours. Some yellow mud-like substances were reacted and converted into liquid phosphoric acid.
[0089] (3) After the heat preservation is completed, allow the distillation vessel 1 to cool naturally to room temperature.
[0090] (4) Replace the first container with a reagent bottle containing hydrochloric acid solution and replace it with a second container containing hydrogen peroxide solution.
[0091] (5) Open the first control valve 303 and the fourth control valve 12, while all other control valves are closed. Then, turn on the first pump body 308. Based on the calculation of the first flow meter 307 and the transportation time, the first pipeline 302 transports 1L of hydrogen peroxide (mass fraction of 5%) into the distillation kettle 1. After the feeding is completed, close the first control valve 303 and the fourth control valve 12.
[0092] (6) After adding hydrogen peroxide solution, do not heat up the room and keep it at room temperature for 2 hours.
[0093] (7) After cleaning, open the second control valve 306 of the second interface 102, while all other valves are closed. Open the second pump body 30402 to pump all the liquid at the bottom of the distillation vessel 1 into the third vessel 30401.
[0094] The cleaning method and equipment can remove most of the yellow mud-like substance adhering to the phosphorus trichloride distillation equipment, restoring the equipment to its near-transparent original state. The entire cleaning process is relatively efficient, and the cleaning effect is slightly worse than that of Example 1, but slightly better than that of Example 2.
[0095] In summary, the embodiments of the present invention provide a phosphorus trichloride distillation equipment and cleaning method, which does not require disassembling the entire device for cleaning and avoids increasing cleaning dead spots; the added cleaning agent can reduce the intensity of the reaction between phosphorus trichloride and water, achieving the cleaning effect while ensuring cleaning safety, and all inlet and outlet materials are transported by pipeline, minimizing the entry of air and reducing safety hazards during the cleaning process.
[0096] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.
Claims
1. A phosphorus trichloride distillation apparatus, characterized in that, The device includes a distillation kettle, a heating element, and a cleaning device. The cleaning device includes a liquid loading assembly for providing an inorganic acid solution or a strong oxidizing solution, a first pipe, a first control valve, a collection assembly for collecting cleaning waste, a second pipe, and a second control valve. The distillation kettle is disposed within the heating element. The liquid loading assembly is connected to a first interface of the distillation kettle via the first pipe to introduce the inorganic acid solution or strong oxidizing solution into the distillation kettle. The first control valve is disposed within the first pipe. The collection assembly is connected to a second interface of the distillation kettle via the second pipe. The second control valve is disposed within the second pipe.
2. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, The liquid loading assembly includes a first vessel for providing an inorganic acid solution and a second vessel for providing a strong oxidizing solution. The first vessel is detachably connected to the first pipe and is used to introduce the inorganic acid solution into the distillation vessel for cleaning. The second vessel is detachably connected to the first pipe so that after the inorganic acid solution is introduced into the distillation vessel for cleaning, the strong oxidizing solution is introduced into the distillation vessel to mix with the inorganic acid solution and release a strong oxidizing gas to remove residues.
3. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, The cleaning device further includes a first pump body and a first flow meter, the first pump body and the first flow meter are installed on the first pipeline, and the first flow meter is installed at the end of the first pump body away from the liquid loading assembly.
4. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, The collection assembly includes a third vessel and a second pump body. The third vessel is connected to the second interface through the second pipe, and the second pump body is installed in the second pipe.
5. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, The cleaning device also includes a temperature detection element. The distillation vessel has a temperature measuring port, and the temperature detection element is installed at the temperature measuring port to detect temperature changes in the distillation vessel.
6. The phosphorus trichloride distillation apparatus according to claim 5, characterized in that, The temperature detection device includes an infrared thermal imaging device, a fiber optic temperature sensor, a micro / nano temperature sensor, or a temperature detector.
7. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, The heating element includes a constant temperature electric heating mantle, a microwave heating device, or an infrared heating device.
8. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, It also includes a distillation column and a connection port, the distillation column being connected to the distillation column through the connection port.
9. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, It also includes a raw material vessel, a third pipeline, a third pump body, a second flow meter, and a third control valve. The raw material vessel is connected to the first interface of the distillation vessel through the third pipeline. The third control valve is located at the third pipeline. The third pump body and the second flow meter are installed on the third pipeline, and the second flow meter is installed at the end of the third pump body away from the raw material vessel.
10. The phosphorus trichloride distillation apparatus according to claim 9, characterized in that, It also includes a double-ended connector, which includes a fourth pipe and a fifth pipe. The fifth pipe extends outward from the side wall of the fourth pipe. One end of the fourth pipe is installed at the first interface, and the other end of the fourth pipe is connected to the third pipe. The opening of the fifth pipe is connected to the first pipe.
11. The phosphorus trichloride distillation apparatus according to claim 10, characterized in that, It also includes a fourth control valve, which is installed at the connection between the fourth pipe and the first interface.
12. The phosphorus trichloride distillation apparatus according to claim 1, characterized in that, The distillation vessel also includes an inlet for introducing gas.
13. A cleaning method, characterized in that, The cleaning method, applied to the phosphorus trichloride distillation equipment as described in any one of claims 1-12, comprises the following steps: Open the first control valve to supply 1-50L of inorganic acid solution to the bottom of the distillation vessel. When the amount of inorganic acid solution supplied reaches the preset amount, close the first control valve. The mass fraction of the inorganic acid solution is 1%-38%. Turn on the heating element to raise the temperature of the liquid in the distillation vessel to 40-200℃ and keep it at this temperature for 2-50 hours to react with the residue in the distillation vessel and convert the residue into liquid phosphoric acid; After the heat preservation is completed, the temperature inside the distillation vessel is completely cooled to room temperature; Open the first control valve and supply 1-50L of the strong oxidizing solution to the bottom of the distillation vessel. When the amount of the strong oxidizing solution supplied reaches the preset amount, close the first control valve. The mass fraction of the strong oxidizing solution is 1%-60%. The distillation vessel is kept at room temperature for 2-30 hours to allow the strong oxidizing solution to mix with the inorganic acid solution, releasing a strong oxidizing gas to remove unreacted residues and completely dissolve them. After cleaning, the second control valve is opened to direct all the liquid at the bottom of the distillation vessel into the collection assembly.
14. The cleaning method according to claim 13, characterized in that, The inorganic acid solution includes hydrochloric acid.
15. The cleaning method according to claim 13, characterized in that, The strong oxidizing solution includes nitric acid solution, hydrogen peroxide solution, sodium chlorate solution, or potassium chlorate solution.