Triphosgene feeding device
By designing a triple phosgene feeding device including a stirring tank, metering pump, circulation pump and solid dissolver, the problems of blockage of existing devices, poor feeding accuracy, large safety risks and high energy consumption are solved, and the accurate and stable addition of triple phosgene solution is achieved.
Patent Information
- Application Number
- CN202510224102.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2025-04-25
AI Technical Summary
The existing triple phosgene feeding device has defects such as blockage problems, poor feeding accuracy, high safety risks, and high energy consumption, making it difficult to achieve accurate and stable addition of triple phosgene solution.
A tripophosgene feeding device including a stirring tank, a metering pump, a circulation pump, a connecting pipe and a solid dissolver is designed. Through the cooperation of an inert gas replacement, a circulation pump and a feeding inlet control valve, the uniform dissolution and accurate feeding of the tripophosgene solid are achieved.
The device can prevent pipeline blockage, improve feeding accuracy, reduce safety risks, reduce energy consumption, and achieve stable and accurate addition of three phosgen solution.
Smart Images
Figure CN119869353A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of chemical equipment, and in particular to a triphosgene feeding device applied in the chemical field. Background Art
[0002] Triphosgene, commonly known as solid phosgene, also known as bis(trichloromethyl) carbonate or BTC, is a stable solid compound that can be stored in a sealed container at room temperature. Even when boiling, it only decomposes into trace amounts of phosgene and liquid phosgene.
[0003] Solid phosgene is a highly reactive substance and can completely replace the highly toxic phosgene and diphosgene in chemical reactions. The main types of reactions it can participate in include: chloromethylation, carbonation, ureidation, isocyanation, chlorination, isonitrilation, cyclization, α-chlorochloroformylation of aldehydes, etc.
[0004] At present, the acylation reaction in the production process of imidazole fungicide prochloraz is to first put solid phosgene into toluene, then heat up to dissolve all the solid phosgene, and then drop the solid phosgene toluene solution into the acylation reactor to react with the amine salt. However, there are the following problems:
[0005] (1) Toluene storage bulge: If new toluene is used to dissolve solid phosgene each time, the toluene in the production process will increase and cause storage bulge; in addition, the excess toluene can only be sold at a low price, which greatly increases the cost.
[0006] (2) High safety risk: If recycled toluene is used to dissolve solid phosgene, the trace amount of alkaline substances (triethylamine, n-propylamine, etc.) in the recycled toluene will easily cause the solid phosgene to decompose rapidly, thus causing a greater safety risk.
[0007] (3) High energy consumption: Solid phosgene must be heated and dissolved before it can be added dropwise, which not only increases energy consumption, but also causes solid phosgene toluene solution to precipitate solid phosgene at low temperatures, causing pipeline blockage.
[0008] (4) Poor accuracy of adding materials: Manual addition of triphosgene solution has the disadvantages of poor accuracy of adding materials, high labor intensity and large reaction fluctuations.
[0009] Therefore, a triphosgene feeding device is needed to overcome one or more of the above-mentioned drawbacks. Summary of the invention
[0010] The object of the present invention is to provide a triphosgene feeding device which can ensure that a triphosgene solution is accurately and stably added to a reaction system, so as to solve the problems of easy clogging and poor feeding accuracy of existing triphosgene feeding equipment.
[0011] To achieve the above-mentioned purpose, the triphosgene feeding device of the present invention comprises a stirring kettle, a metering pump, a circulating pump, a first connecting pipe, a second connecting pipe, a third connecting pipe and a solid dissolver for adding triphosgene solid therein. The stirring kettle is provided with a gas inlet end, a liquid inlet end and a liquid outlet end, the liquid outlet end is respectively connected to the inlet ends of the metering pump and the circulating pump through the first connecting pipe, and the first connecting pipe is provided with a feeding inlet control valve for controlling the connection and disconnection between the liquid outlet end and the inlet end of the metering pump; the outlet end of the circulating pump is connected to the inlet end of the solid dissolver through the second connecting pipe, and the outlet end of the solid dissolver is connected to the liquid inlet end through the third connecting pipe.
[0012] Compared with the prior art, a high-purity inert gas (such as nitrogen) is introduced through the gas inlet end of the stirring kettle to replace the interior of the stirring kettle with the desired working environment; with the cooperation of the circulating pump and the feeding inlet control valve, the solvent replaced by the inert gas and added with the metered amount is continuously circulated between the stirring kettle and the solid dissolver through the first connecting pipe, the second connecting pipe and the third connecting pipe, so that the metered triphosgene solid contained in the solid dissolver is gradually and evenly dissolved in the solvent to form a solution with a uniform concentration, thereby preventing the reaction fluctuation caused by the triphosgene solid entering the reaction system; through the cooperation of the metering pump and the feeding inlet control valve, the triphosgene solution is accurately and stably added to the reaction system, thereby preventing the defects of large metering fluctuation, high labor intensity and poor feeding accuracy caused by manual addition. In addition, since the metered triphosgene solid contained in the solid dissolver is gradually and evenly dissolved in the solvent circulated by the circulating pump, the blockage of the first connecting pipe, the second connecting pipe and the third connecting pipe can be prevented.
[0013] Preferably, the solid dissolver comprises a cylinder, a sealing cover, a hollow disperser, an inlet tube body for forming the inlet end of the solid dissolver, an outlet tube body for forming the outlet end of the solid dissolver and a mesh basket for containing triphosgene solid, the disperser is located in the internal space of the cylinder, the inlet end of the disperser is also connected to the inlet tube body in a mating manner, the inlet tube body is sealed and fixedly connected to the cylinder and protrudes outward from the cylinder, the mesh basket is located in the internal space of the cylinder and above the corresponding outlet end of the disperser, the sealing cover is detachably sealed and connected to the cylinder, the sealing cover also seals the opening of the internal space of the cylinder, the outlet tube body is sealed and fixedly connected to the cylinder and protrudes outward from the cylinder, and the outlet tube body is also connected to the internal space of the cylinder.
[0014] Preferably, the outlet end of the disperser is in a cone shape with a larger upper portion and a smaller lower portion, the outlet end of the disperser faces the bottom of the mesh basket, the opening of the inner space of the cylinder is arranged upward, and the sealing cover covers the cylinder from above.
[0015] Preferably, the inlet end of the disperser is seal-welded to the inlet pipe body.
[0016] Preferably, a window structure with a scraper is provided on the side wall of the cylinder, and the scraper is configured to scrape the window structure.
[0017] Preferably, the scraper is made of a polytetrafluoroethylene sheet with a thickness of 2 mm to 5 mm.
[0018] Preferably, the inlet pipe body and the outlet pipe body are arranged to intersect with the side wall of the cylinder, a sewage pipe communicating with the internal space of the cylinder is provided on the bottom of the cylinder, and a sewage control valve is provided on the sewage pipe.
[0019] Preferably, the first connecting pipe is further provided with a kettle outlet control valve adjacent to the liquid outlet end and a pump inlet control valve adjacent to the inlet end of the circulation pump, and the feed inlet control valve is adjacent to the inlet end of the metering pump.
[0020] Preferably, the first connecting pipeline includes a main pipeline and a first branch pipeline and a second branch pipeline branching from the main pipeline, the liquid outlet end is connected to the main pipeline, the inlet end of the metering pump is connected to the first branch pipeline, the inlet end of the circulating pump is connected to the second branch pipeline, and the feeding inlet control valve is arranged on the first branch pipeline.
[0021] Preferably, the second connecting pipeline is provided with a pump outlet control valve adjacent to the outlet end of the circulation pump and a dissolver inlet control valve adjacent to the inlet end of the solid dissolver, and the third connecting pipeline is provided with a dissolver outlet control valve adjacent to the outlet end of the solid dissolver and a kettle inlet control valve adjacent to the liquid inlet end.
[0022] Preferably, the metering pump is a diaphragm metering pump; the outlet end of the metering pump is connected to a feeding pipeline and a feeding outlet control valve arranged on the feeding pipeline.
[0023] Preferably, the liquid outlet is located at the bottom of the stirring tank, and the gas inlet and the liquid inlet are located at both sides of the top of the stirring tank.
[0024] Preferably, the stirring tank is further provided with a filling port and a gas outlet port at a position between the top and the bottom thereof. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1It is a plan view of the triphosgene feeding device of the present invention.
[0026] Figure 2 yes Figure 1 A plan view of a stirred tank in the triphosgene feeding device is shown.
[0027] Figure 3 yes Figure 1 A plan view of the metering pump in the triphosgene feeding device is shown.
[0028] Figure 4 yes Figure 1 A plan view of the circulation pump in the triphosgene feeding device is shown.
[0029] Figure 5 yes Figure 1 The plan view of the first connecting pipeline in the triphosgene feeding device and the feeding inlet control valve, kettle outlet control valve and pump inlet control valve thereon is shown.
[0030] Figure 6 yes Figure 1 A plan view of the solid dissolver in the triphosgene feeding device is shown. DETAILED DESCRIPTION
[0031] In order to explain the technical content and structural features of the present invention in detail, further description is given below in combination with the implementation modes and the accompanying drawings.
[0032] See also Figure 1 The triphosgene feeding device 100 of the present invention circulates the solvent so that the triphosgene solid is gradually and evenly dissolved in the solvent, thereby obtaining a triphosgene solution with a consistent concentration, and the triphosgene solution is accurately and stably added to the external reaction system.
[0033] The triphosgene feeding device of the present invention comprises a stirring kettle 10, a metering pump 20, a circulating pump 30, a first connecting pipe 40, a second connecting pipe 50, a third connecting pipe 60 and a solid dissolver 70 (referring to the solid dissolver 70) into which triphosgene solid is added. The stirring kettle 10 is provided with a gas inlet end 11, a liquid inlet end 12 and a liquid outlet end 13. The liquid outlet end 13 is connected to the inlet end 21 of the metering pump 20 and the inlet end 31 of the circulating pump 30 respectively through the first connecting pipe 40. The first connecting pipe 40 is provided with a feeding inlet control valve 41 for controlling the connection and disconnection between the liquid outlet end 13 and the inlet end 21 of the metering pump 20; the outlet end 32 of the circulating pump 30 is connected to the inlet end 71 of the solid dissolver 70 through the second connecting pipe 50, and the outlet end 72 of the solid dissolver 70 is connected to the liquid inlet end 12 through the third connecting pipe 60; therefore, when the feeding inlet control valve 41 cuts off the liquid When the outlet end 13 is connected to the inlet end 21 of the metering pump 20, and under the operation of the circulation pump 30, the solvent added to the stirring tank 10 flows into the solid dissolver 70 along the first connecting pipe 40 and the second connecting pipe 50, and then flows back to the stirring tank 10 along the third connecting pipe 60, thereby achieving the purpose of solvent circulation; when the triphosgene solid in the solid dissolver 70 is completely dissolved in the solvent, at this time, when the connection between the liquid outlet end 13 and the inlet end 21 of the metering pump 20 is opened by the feed inlet control valve 41, the triphosgene solution can be accurately and stably added to the external reaction system by the metering pump 20. More specifically, as follows:
[0034] Combination Figure 6As an example, the solid dissolver 70 includes a cylinder 73, a sealing cover 74, a hollow disperser 75, an inlet pipe body for forming an inlet end 71 of the solid dissolver 70 (i.e., the label 71 also refers to the inlet pipe body), an outlet pipe body for forming an outlet end 72 of the solid dissolver 70 (i.e., the label 72 also refers to the outlet pipe body), and a mesh basket 76 for containing triphosgene solid. The disperser 75 is located in the internal space 731 of the cylinder 73, and the inlet end 751 of the disperser 75 is also connected to the inlet pipe body 71 in a mating manner to meet the need for the solvent to flow directly into the disperser 75 from the inlet pipe body 71; the inlet pipe body 71 and the cylinder 73 are sealed and fixedly connected, that is, the inlet pipe body 71 and the cylinder 73 are fixedly connected, and the mating point between the inlet pipe body 71 and the cylinder 73 is also sealed to prevent the solvent in the cylinder 73 from leaking from the mating point; the inlet pipe body 71 also protrudes outward from the cylinder 73 to facilitate the assembly operation of the inlet pipe body 71 and the second connecting pipe 50. The mesh basket 76 is located in the internal space 731 of the cylinder 73, and the mesh basket 76 is located above the outlet end 752 of the disperser 75 to meet the need of the solvent flowing into the disperser 75 to flush the triphosgene solid contained in the mesh basket 76 after being dispersed. Since the solvent is dispersedly flushed with the triphosgene solid contained in the mesh basket 76 after passing through the disperser 75, the solvent is fully in contact with the triphosgene solid contained in the mesh basket 76. The sealing cover 74 is detachably sealed with the cylinder 73 to meet the need of adding triphosgene solid to the mesh basket 76; the sealing cover 74 also seals the opening 7311 of the internal space 731 of the cylinder 73 to meet the need of forming a sealed space in the internal space 731 of the solid dissolver 70. The outlet tube body 72 is fixedly connected to the cylinder body 73 in a sealed manner, that is, the outlet tube body 72 is fixedly connected to the cylinder body 73, and the fitting part between the outlet tube body 72 and the cylinder body 73 is also sealed to prevent the solvent in the cylinder body 73 from leaking from the fitting part; the outlet tube body 72 protrudes from the cylinder body 73, and the outlet tube body 72 is also connected to the internal space 731 of the cylinder body 73 to meet the need that the solvent after flushing the triphosgene solid contained in the mesh basket 76 first flows into the internal space 731 of the cylinder body 73 and then flows out from the outlet tube body 72. Specifically, at Figure 1 and Figure 6In the embodiment, as an example, the outlet end 752 of the disperser 75 is in the shape of a cone with a larger top and a smaller bottom, and the outlet end 752 of the disperser 75 is directly opposite to the bottom 761 of the mesh basket 76. This design allows the solvent to contact the triphosgene solid contained in the mesh basket 76 more fully; optionally, as an example, the maximum outer diameter of the outlet end 752 of the disperser 75 is the same as the outer diameter of the mesh basket 76, but is not limited to this; in addition, the opening 7311 of the internal space 731 of the cylinder 73 is arranged upward to facilitate the operator to add triphosgene solid to the mesh basket 76 from the top of the cylinder 73; in addition, the sealing cover 74 is covered on the cylinder 73 from above, and the sealing cover 74 can be fixedly connected to the cylinder 73 by means of screws, for example but not limited to these, which is more convenient for the assembly and disassembly operations between the sealing cover 74 and the cylinder 73.
[0035] like Figure 6 As shown in FIG. 1 , as an example, the inlet end 751 of the disperser 75 is sealed and welded to the inlet pipe body 71, so that the fixation and sealing between the disperser 75 and the inlet pipe body 71 are more reliable, so that the disperser 75 is more reliably suspended in the internal space 731 of the cylinder 73. Figure 6 As an example, a window structure 734 with a scraper 733 is provided on the side wall 732 of the cylinder 73. The scraper 733 is configured to scrape the window structure 734. Therefore, with the help of the window structure 734, the dissolution of the triphosgene solid in the mesh basket 76 can be observed in time. With the help of the scraper 733, the material that affects the line of sight in the window structure 734 can be scraped off at any time to facilitate observation. Optionally, Figure 6 As an example, the scraper 733 is a polytetrafluoroethylene sheet with a thickness of 2 mm to 5 mm, so that the scraper 733 has the advantages of low friction coefficient, corrosion resistance, high temperature resistance and insulation; obviously, according to actual needs, the scraper 733 can also be a sheet of other materials, so it is not limited to Figure 6 Limits shown.
[0036] Another example Figure 6 As shown, as an example, the inlet pipe body 71 and the outlet pipe body 72 are arranged to intersect with the side wall 731 of the cylinder 73. Optionally, as an example, the inlet pipe body 71 and the outlet pipe body 72 are each perpendicularly intersected with the side wall 731 of the cylinder 73, which is more convenient for the fixed connection of the side wall 731 of the cylinder 73 with the inlet pipe body 71 and the outlet pipe body 72 respectively; a sewage pipe 736 connected to the internal space 731 of the cylinder 73 is provided on the bottom 735 of the cylinder 73, and a sewage control valve 737 is provided on the sewage pipe 736. With the help of the cooperation of the sewage pipe 736 and the sewage control valve 737, the sewage control valve 737 can be opened when sewage discharge is required, and the sewage control valve 737 can be closed when sewage discharge is not required. In addition, since the sewage pipe 736 is located at the bottom 735 of the cylinder 73, sewage discharge is more thorough.
[0037] like Figure 1 and Figure 2 As shown, as an example, the liquid outlet 13 is located at the bottom 14 of the stirring tank 10, so that the solvent (solution) can flow out more completely; the gas inlet 11 and the liquid inlet 12 are located on both sides of the top 15 of the stirring tank 10, so that the stirring tank 10 can provide additional stirring for the solvent in the process of the solvent flowing from the liquid inlet 12 to the liquid outlet 13, thereby further improving the solvent's dissolving capacity. Figure 1 and Figure 2 As an example, the stirring tank 10 is further provided with a filling port 16 and a gas outlet port 17 at a position between the top 15 and the bottom 14 thereof, so that the operator can add the solvent into the stirring tank 10 with the help of the filling port 16, and the inert gas (such as but not limited to high-purity nitrogen) entering the stirring tank 10 from the gas inlet port 11 and then being discharged from the gas outlet port 17 can be realized with the help of the gas outlet port 17.
[0038] like Figure 1 and Figure 5 As shown, as an example, the first connecting pipe 40 is also provided with a kettle outlet control valve 42 adjacent to the liquid outlet end 13 and a pump inlet control valve 43 adjacent to the inlet end 31 of the circulation pump 30, and the feed inlet control valve 41 is adjacent to the inlet end 21 of the metering pump 20; with the aid of the kettle outlet control valve 42, during the process of introducing high-purity nitrogen replacement into the stirred kettle 10, the kettle outlet control valve 42 cuts off the connection between the liquid outlet end 13 and the first connecting pipe 40; with the aid of the pump inlet control valve 43, during the process of adding the triphosgene solution to the external reaction system by the metering pump 20, the pump inlet control valve 43 is in a disconnected state to prevent the triphosgene solution from entering the circulation pump 30. Specifically, Figure 1 and Figure 5 As an example, the first connecting pipeline 40 includes a main pipeline 40a and a first branch pipeline 40b and a second branch pipeline 40c branched from the main pipeline 40a, the liquid outlet end 13 is connected to the main pipeline 40a, the first branch pipeline 40b is connected to the inlet end 21 of the metering pump 20, the second branch pipeline 40c is connected to the inlet end 31 of the circulation pump 30, and the feed inlet control valve 41 is arranged on the first branch pipeline 40b; therefore, by the design of "the first connecting pipeline 40 includes the main pipeline 40a and the first branch pipeline 40b and the second branch pipeline 40c branched from the main pipeline 40a", on the one hand, the first connecting pipeline 40 has a three-way function, and on the other hand, it is simplified that the first connecting pipeline 40 is connected to the liquid outlet end 13, the inlet end 21 of the metering pump 20 and the inlet end 31 of the circulation pump 30 respectively.
[0039] like Figure 1As shown, as an example, the second connecting pipeline 50 is provided with a pump outlet control valve 51 adjacent to the outlet end 32 of the circulation pump 30 and a dissolver inlet control valve 52 adjacent to the inlet end 71 of the solid dissolver 70; the third connecting pipeline 60 is provided with a dissolver outlet control valve 61 adjacent to the outlet end 72 of the solid dissolver 70 and a kettle inlet control valve 62 adjacent to the liquid inlet end 12, so that with the aid of the kettle inlet control valve 62, during the process of introducing high-purity nitrogen replacement into the stirred kettle 10, the connection between the liquid inlet end 12 and the third connecting pipeline 60 is cut off by the kettle inlet control valve 62.
[0040] like Figure 1 and Figure 3 As shown, as an example, the metering pump 20 is a diaphragm metering pump to improve its life, corrosion resistance and metering accuracy. In addition, the outlet end 22 of the metering pump 20 is connected to a feed pipe 23 and a feed outlet control valve 24 arranged on the feed pipe 23.
[0041] In conjunction with the accompanying drawings, the working principle of the triphosgene feeding device of the present invention is described:
[0042] First, high-purity nitrogen is introduced to replace the internal environment of the stirring tank 10. Before the replacement, the tank outlet control valve 42 and the tank inlet control valve 62 need to be closed.
[0043] Next, add the measured triphosgene solid into the mesh basket 76 of the solid dissolver 70, and then seal the solid dissolver 70; add the measured solvent into the stirred tank 10; open the tank outlet control valve 42, the pump inlet control valve 43, the pump outlet control valve 51, the dissolver inlet control valve 52, the dissolver outlet control valve 61 and the tank inlet control valve 62, so that the circulation pump 30, the solid dissolver 70 and the stirred tank 10 form a passage.
[0044] Then, the circulation pump 30 is started to allow the solvent to enter the solid dissolver 70 through the circulation pump 30, contact with the triphosgene solid and dissolve, and obtain the triphosgene solution through continuous circulation and dissolution; wherein, in the solid dissolver 70, the dissolution of the triphosgene solid can be observed through the window structure 734; when the triphosgene solid is completely dissolved, the circulation pump 30, the pump inlet control valve 43, the pump outlet control valve 51, the dissolver inlet control valve 52, the dissolver outlet control valve 61 and the kettle inlet control valve 62 are closed to complete the dissolution process.
[0045] When it is necessary to add triphosgene solution, the feed inlet control valve 41 and the feed outlet control valve 24 are opened, and the triphosgene solution is accurately added to the external reaction system by the metering pump 20 .
[0046] Compared with the prior art, a high-purity inert gas (such as nitrogen) is introduced through the gas inlet end 11 of the stirring kettle 10 to replace the interior of the stirring kettle 10 with the desired working environment; with the cooperation of the circulating pump 30 and the feeding inlet control valve 41, the solvent replaced by the inert gas and added with a measured amount is continuously circulated between the stirring kettle 10 and the solid dissolver 70 through the first connecting pipe 40, the second connecting pipe 50 and the third connecting pipe 60, so that the measured triphosgene solid contained in the solid dissolver 70 is gradually and evenly dissolved in the solvent to form a solution with a uniform concentration, thereby preventing reaction fluctuations caused by the triphosgene solid entering the reaction system; through the cooperation of the metering pump 20 and the feeding inlet control valve 41, the triphosgene solution is accurately and stably added to the reaction system, thereby preventing the defects of large metering fluctuations, high labor intensity and poor feeding accuracy caused by manual addition. In addition, since the measured triphosgene solid contained in the solid dissolver 70 is gradually and evenly dissolved in the solvent circulated by the circulation pump 30, the blockage of the first connecting pipe 40, the second connecting pipe 50 and the third connecting pipe 60 can be prevented.
[0047] It is worth noting that since the triphosgene feeding device 100 of the present invention works in a corrosive environment, which is well known in the art, the material of the triphosgene feeding device 100 of the present invention is selected to be corrosion-resistant material, for example, the stirring tank 10, the metering pump 20, the circulating pump 30, the first connecting pipe 40, the second connecting pipe 50, the third connecting pipe 60, the solid dissolver 70, the feeding inlet control valve 41, the feeding pipe 23, the feeding outlet control valve 24, the tank outlet control valve 42, the pump inlet control valve 43, the pump outlet control valve 51, the dissolver inlet control valve 52, the dissolver outlet control valve 61, the tank inlet control valve 62 and the drain valve 737 are selected to be stainless steel, preferably 316 series stainless steel. In addition, the gas inlet end 11 is connected to the gas pipe 80 with a control valve 81. In addition, the stirred tank 10 can be selected as a stainless steel stirred reactor with a jacket and heat transfer capability, the feed inlet control valve 41, the feed outlet control valve 24, the tank outlet control valve 42, the pump inlet control valve 43, the pump outlet control valve 51, the dissolver inlet control valve 52, the dissolver outlet control valve 61, the tank inlet control valve 62 and the drain valve 737 can each be selected as a stop valve, and the mesh basket 76 can be selected as a flat-mouthed stainless steel mesh basket.
[0048] The above disclosure is only a preferred embodiment of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope of the present invention.
Claims
1. A triphosgene feeding device, characterized in that: The invention comprises a stirring kettle, a metering pump, a circulation pump, a first connecting pipe, a second connecting pipe, a third connecting pipe and a solid dissolver into which triphosgene solid is added. The stirring kettle is provided with a gas inlet end, a liquid inlet end and a liquid outlet end. The liquid outlet end is respectively connected with the inlet ends of the metering pump and the circulation pump through the first connecting pipe. The outlet end of the circulation pump is connected with the inlet end of the solid dissolver through the second connecting pipe. The outlet end of the solid dissolver is connected with the liquid inlet end through the third connecting pipe. The first connecting pipe is provided with a feeding inlet control valve for controlling the connection and disconnection between the liquid outlet end and the inlet end of the metering pump.
2. The triphosgene feeding device according to claim 1, characterized in that: The solid dissolver comprises a cylinder, a sealing cover, a hollow disperser, an inlet tube body for forming the inlet end of the solid dissolver, an outlet tube body for forming the outlet end of the solid dissolver and a mesh basket for containing triphosgene solid. The disperser is located in the internal space of the cylinder, and the inlet end of the disperser is also connected to the inlet tube body in a mating manner. The inlet tube body is sealed and fixedly connected to the cylinder and protrudes from the cylinder. The mesh basket is located in the internal space of the cylinder and above the corresponding outlet end of the disperser. The sealing cover is detachably sealed and connected to the cylinder. The sealing cover also seals the opening of the internal space of the cylinder. The outlet tube body is sealed and fixedly connected to the cylinder and protrudes from the cylinder. The outlet tube body is also connected to the internal space of the cylinder.
3. The triphosgene feeding device according to claim 2, characterized in that: The outlet end of the disperser is in a cone shape with a larger top and a smaller bottom. The outlet end of the disperser faces the bottom of the mesh basket. The opening of the inner space of the cylinder is arranged upward. The sealing cover covers the cylinder from above. The inlet end of the disperser is sealed and welded to the inlet pipe body.
4. The triphosgene feeding device according to claim 2, characterized in that: A window structure with a scraper is provided on the side wall of the cylinder. The scraper is configured to scrape the window structure. The scraper is a polytetrafluoroethylene sheet with a thickness of 2 mm to 5 mm.
5. The triphosgene feeding device according to claim 2, characterized in that: The inlet pipe body and the outlet pipe body are arranged to intersect with the side wall of the cylinder, and a sewage pipe communicating with the internal space of the cylinder is arranged on the bottom of the cylinder, and a sewage control valve is arranged on the sewage pipe.
6. The triphosgene feeding device according to claim 1, characterized in that: The first connecting pipeline is also provided with a kettle outlet control valve adjacent to the liquid outlet end and a pump inlet control valve adjacent to the inlet end of the circulation pump, and the feed inlet control valve is adjacent to the inlet end of the metering pump.
7. The triphosgene feeding device according to claim 6, characterized in that: The first connecting pipeline includes a main pipeline and a first branch pipeline and a second branch pipeline branching from the main pipeline. The liquid outlet end is connected to the main pipeline, the inlet end of the metering pump is connected to the first branch pipeline, the inlet end of the circulating pump is connected to the second branch pipeline, and the feeding inlet control valve is arranged on the first branch pipeline.
8. The triphosgene feeding device according to claim 1, characterized in that: The second connecting pipeline is provided with a pump outlet control valve adjacent to the outlet end of the circulation pump and a dissolver inlet control valve adjacent to the inlet end of the solid dissolver, and the third connecting pipeline is provided with a dissolver outlet control valve adjacent to the outlet end of the solid dissolver and a kettle inlet control valve adjacent to the liquid inlet end.
9. The triphosgene feeding device according to claim 1, characterized in that: The metering pump is a diaphragm metering pump; the outlet end of the metering pump is connected to a feeding pipeline and a feeding outlet control valve arranged on the feeding pipeline.
10. The triphosgene feeding device according to claim 1, characterized in that: The liquid outlet is located at the bottom of the stirring tank, the gas inlet and the liquid inlet are located at both sides of the top of the stirring tank, and the stirring tank is also provided with a filling end and a gas outlet at a position between the top and the bottom.