A salt-forming method isocyanate synthesis device and method

Abstract

The application provides a salt-forming isocyanate synthesis device and method, which comprises a floor; a synthesis tank and a trapping tower are fixedly connected to the top surface of the floor respectively; a gas injection assembly is installed in the inner cavity of the synthesis tank; a reflux assembly is connected to the bottom of the synthesis tank; a filter screen is fixedly connected to the bottom of the inner cavity of the synthesis tank; a stirring assembly is installed in the middle of the inner cavity of the synthesis tank; a heat preservation layer is fixedly connected to the outer surface of the synthesis tank; a heating assembly is connected to the outer surface of the heat preservation layer; a preheating assembly is connected to the outer surface of the heat preservation layer; a dosing opening is fixedly connected to the top surface of the synthesis tank; a valve is installed in the inner cavity of the dosing opening; a maintenance opening is fixedly connected to the top surface of the synthesis tank; and a sealing cover is fixedly connected to the top surface of the maintenance opening through bolts. The synthesis tank, the gas injection assembly, the reflux assembly, the stirring assembly and the heating assembly are cooperated with each other, so that the synthesis of isocyanate is realized.

Description

Technical Field

[0001] This invention relates to the field of isocyanate synthesis technology, specifically to a salt-forming method for isocyanate synthesis apparatus and method. Background Technology

[0002] Isocyanates are a general term for various esters of isocyanate, used in industries such as home appliances, automobiles, construction, footwear, furniture, and adhesives. Classified by the number of -NCO groups, they include monoisocyanates (R-N=C=O), diisocyanates (O=C=N-R-N=C=O), and polyisocyanates, etc.

[0003] Currently, isocyanate synthesis involves the following four steps: First, amine and hydrogen chloride are mixed in an inert solvent to prepare amine hydrochloride. Second, the amine hydrochloride is preheated. Third, a preheated high-speed inert gas stream is introduced into the photochemical reactor through an atomizing nozzle, followed by the addition of the preheated amine hydrochloride. The amine hydrochloride is atomized by the inert gas stream and reacts with preheated carbonyl chloride entering the reactor to obtain isocyanate. Fourth, after leaving the photochemical reactor, the isocyanate is captured by a solvent in a trapping tower to obtain the isocyanate reaction solution. However, the above steps present the following problems in actual production and processing:

[0004] During the production of amine hydrochloride, a certain amount of hydrogen chloride gas needs to be injected into the synthesis tank. The traditional injection method is to inject hydrogen chloride gas into the synthesis tank through a gas injection pipe, and then mix the hydrogen chloride gas with the solution by stirring the solution inside the synthesis tank. However, this fusion method is not only inefficient, but also easily causes the hydrogen chloride gas in the upper part of the synthesis tank to fail to mix with the solution, resulting in a waste of resources.

[0005] Therefore, there is a need for a salt-forming isocyanate synthesis apparatus that can improve fusion efficiency and save costs. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a salt-forming method and apparatus for isocyanate synthesis, which solves the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] A salt-forming isocyanate synthesis apparatus includes a floor; a synthesis tank and a trapping tower are fixedly connected to the top surface of the floor; an injection assembly is installed inside the synthesis tank; a reflux assembly is connected to the bottom of the synthesis tank; a filter screen is fixedly connected to the bottom of the synthesis tank; a stirring assembly is installed in the middle of the synthesis tank; an insulation layer is fixedly connected to the outer surface of the synthesis tank; a heating assembly and a preheating assembly are connected to the outer surface of the insulation layer; a dosing port is fixedly connected to the top surface of the synthesis tank; a valve is installed inside the dosing port; a maintenance port is fixedly connected to the top surface of the synthesis tank; and a sealing cap is fixedly connected to the top surface of the maintenance port by bolts. The stirring assembly includes a motor frame. The motor frame is fixedly connected to the center of the top surface of the synthesis tank. A drive motor is fixedly connected to the top surface of the motor frame. A stirring shaft is fixedly connected to the output shaft end of the drive motor. One end of the stirring shaft passes through the top surface of the synthesis tank and is rotatably connected to the inner cavity of the synthesis tank. A first ring is fixedly connected to the lower part of the outer surface of the stirring shaft. A first mounting groove is provided at equal intervals on the circumference of the first ring. A first stirring rod is rotatably connected to the inner cavity of the first mounting groove through a pin. A scraper is rotatably connected to one side of the first stirring rod through a pin. The bottom of the first stirring rod is in contact with the top surface of the filter screen, and one side of the scraper is in contact with the inner wall of the synthesis tank.

[0009] Furthermore, the stirring assembly also includes a second ring, which is slidably connected to the outer surface of the stirring shaft. The second ring has second mounting grooves evenly spaced on its circumference. The inner cavity of the second mounting groove is rotatably connected to a second stirring rod via a pin. A scraper is rotatably connected to one side of the second stirring rod via a pin. A return spring is fixedly connected to the bottom of the second ring and between the bottom and top surface of the first ring. A return spring is sleeved on the outside of the stirring shaft.

[0010] Furthermore, the gas injection assembly includes a vacuum pump and a placement rack. The vacuum pump and the placement rack are fixedly connected to the top surface of the floor. The input end of the vacuum pump is connected to a three-way pipe. A three-way pipe is fixedly connected inside the placement rack. The two ends of the three-way pipe are connected to a first connecting valve head and a second connecting valve head, respectively. The output end of the vacuum pump is connected to a first annular nozzle through a hose. Air nozzles are fixedly connected at equal intervals on the inner circumference of the first annular nozzle. One end of the hose passes through the top of the synthesis tank and is fixedly connected to the synthesis tank.

[0011] Furthermore, the gas injection assembly also includes a pneumatic rod, which is fixedly connected to the top surface of the synthesis tank. The pneumatic rod has an L-shaped rod at its output shaft end, one end of which penetrates the top surface of the synthesis tank and is slidably connected to it. A connecting rod is fixedly connected to the bottom surface of the L-shaped rod, one end of which is fixedly connected to a first annular nozzle, and the other end of which is fixedly connected to a pressing cylinder. A pressing cylinder is slidably connected to the outer surface of the stirring shaft.

[0012] Furthermore, the reflux assembly includes a reflux pump, which is fixedly connected to the top surface of the floor. The input end of the reflux pump is connected to the bottom of the inner cavity of the synthesis tank through a water inlet pipe. The output end of the reflux pump is connected to a three-way valve through a drain pipe. One end of the three-way valve is connected to a second annular nozzle through a liquid flow pipe. Atomizing nozzles are fixedly connected at equal intervals to the bottom of the second annular nozzle. The top of the inner cavity of the synthesis tank is fixedly connected to the second annular nozzle. The other end of the three-way valve is connected to the inner cavity of the trapping tower through a discharge pipe.

[0013] Furthermore, the heating assembly includes an electric heating wire heating box, which is fixedly connected to the top surface of the floor. A suction fan is fixedly connected to the top surface of the electric heating wire heating box. The air inlet of the suction fan is connected to the inner cavity of the electric heating wire heating box through an air inlet pipe, and the air outlet of the suction fan is connected to the inner cavity of the insulation layer through an air outlet pipe. One side of the electric heating wire heating box is connected to the lower part of the insulation layer through a return air pipe.

[0014] Furthermore, the preheating component includes a spiral tube, the outer surface of the insulation layer is connected to the spiral tube, a valve is installed at one end of the spiral tube near the insulation layer, and a flexible hose is installed inside the spiral tube.

[0015] A method for synthesizing isocyanates via salt formation, the production method comprising the following steps:

[0016] S1. Preparation of amine hydrochloride:

[0017] S1.1 Add amine solution and inert solvent to the synthesis tank;

[0018] S1.2 Start the drive motor. The drive motor drives the stirring shaft, the second ring, the first stirring rod, and the scraper to rotate as a whole, stirring and mixing the solution.

[0019] S1.3 Activate the pneumatic rod, which will drive the pressing cylinder and the first annular nozzle to move downward. When the pressing cylinder moves downward, it will press the second ring, causing the second ring to move downward and drive the second stirring rod to rotate at a certain angle, and causing the scraper to retract inward, so that the scraper is no longer in contact with the inner wall of the synthesis tank. At the same time, the first annular nozzle will descend to be located outside the scraper and inside the solution.

[0020] S1.4 Connect the hydrogen chloride gas storage tank to the first connecting valve head, and open the valve inside the first connecting valve head;

[0021] Start the vacuum pump, which will inject hydrogen chloride gas into the solution through the three-way pipe, hose, first annular nozzle and jet nozzle;

[0022] S1.5 Adjust the valve in the three-way valve to connect the liquid flow pipe and the drain pipe, start the reflux pump, the reflux pump will draw the solution at the bottom of the synthesis tank into the second annular nozzle through the water inlet pipe, drain pipe and liquid flow pipe, and finally spray it out in the form of water mist through the atomizing nozzle, and mix it evenly with the gas in the upper part of the inner cavity of the synthesis tank.

[0023] S1.6 When the amine hydrochloride is prepared and formed, close the valve inside the first connecting valve head and remove the hydrogen chloride gas storage tank;

[0024] S2. Preheating treatment of amine hydrochloride in the synthesis tank:

[0025] S3. Inject carbonyl chloride into the synthesis tank to generate crude isocyanate:

[0026] S4. Inject nitrogen gas into the synthesis tank to remove excess carbonyl chloride, obtaining the isocyanate product:

[0027] S5, purification of isocyanate products.

[0028] Furthermore, in S3, carbonyl chloride is injected into the synthesis tank to generate crude isocyanate. The specific steps are as follows:

[0029] S3.1 Open the valve inside the spiral tube to allow hot air to enter the insulation layer;

[0030] S3.2 Connect the carbonyl chloride storage tank to the first connecting valve head and open the valve inside the first connecting valve head; start the vacuum pump, which will draw carbonyl chloride into the hose through the three-way pipe, and then heat it through the spiral tube. The heated carbonyl chloride is then sprayed into the amine hydrochloride solution through the jet nozzle; finally, crude isocyanate is obtained.

[0031] Furthermore, in step S4, nitrogen gas is injected into the synthesis tank to remove excess carbonyl chloride, yielding the isocyanate product. The specific method is as follows:

[0032] Connect the nitrogen storage tank to the second connecting valve head, and open the valve inside the second connecting valve head;

[0033] Start the vacuum pump, which will draw nitrogen into the hose through the three-way pipe, and then heat it through the spiral tube. The heated nitrogen is then injected into the crude isocyanate through the nozzle, and finally the finished isocyanate product is obtained.

[0034] This invention provides an apparatus and method for synthesizing isocyanates via a salt-forming process. Compared with existing technologies, it has the following advantages:

[0035] 1. Through the cooperation of the drive motor, stirring shaft, first ring, first stirring rod, scraper, and second stirring rod in the stirring assembly, the solution is stirred, and the inner wall of the synthesis tank and the filter screen are cleaned at the same time. At the same time, through the cooperation of the second ring, second stirring rod, and return spring, the scraper can be retracted to facilitate the entry of the first annular nozzle.

[0036] 2. Through the cooperation of the pneumatic rod, L-shaped rod, first annular nozzle and jet nozzle in the gas injection assembly, nitrogen, hydrogen chloride and carbonyl chloride are injected into the solution, so that the gas and solution can be rapidly mixed; at the same time, the first connecting valve head and the second connecting valve head in the gas injection assembly facilitate subsequent connection with different gas storage tanks.

[0037] 3. Through the cooperation of the reflux pump, water inlet pipe, water outlet pipe, second annular nozzle and atomizing nozzle in the reflux assembly, the solution is atomized, so that the atomized solution can better contact and react with the gas, thus accelerating the overall reaction speed.

[0038] 4. Through the cooperation of the suction fan, air inlet pipe, air outlet pipe, and electric heating wire heating box in the heating assembly, the solution is heated, allowing the solution to mix with the gas.

[0039] 5. By cooperating with the spiral tubes in the preheating component, the injected gas is preheated, making the temperature of the injected gas similar to the temperature of the liquid in the synthesis tank. This allows for better mixing of the liquid and gas, thus accelerating the reaction rate. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram of the overall structure of the present invention is shown;

[0042] Figure 2 This shows a schematic diagram of the overall structure of the invention from another perspective;

[0043] Figure 3 This diagram shows a partial top view of the overall structure of the present invention;

[0044] Figure 4 A schematic diagram of the overall partial cross-sectional structure of the present invention is shown;

[0045] Figure 5The present invention is shown. Figure 4 Enlarged structural diagram of region A in the middle;

[0046] Figure 6 A schematic diagram of the stirring assembly structure of the present invention is shown;

[0047] Figure 7 A schematic diagram of the gas injection assembly structure of the present invention is shown;

[0048] The diagram shows: 1. Floor; 2. Synthesis tank; 3. Capture tower; 4. Gas injection assembly; 41. Vacuum pump; 42. Placement rack; 43. T-connector; 44. First connecting valve head; 45. Second connecting valve head; 46. Hose; 47. First annular nozzle; 48. Air nozzle; 49. Pneumatic rod; 410. L-shaped rod; 411. Connecting rod; 412. Pressing cylinder; 5. Return assembly; 51. Return pump; 52. Water inlet pipe; 53. Drain pipe; 54. T-valve; 55. Liquid flow pipe; 56. Second annular nozzle; 57. Atomizing nozzle; 58. Feed pipe; 6. Filter screen; 7. Stirring assembly; 71. Motor frame; 72. Drive motor; 73. Stirring shaft; 74. First ring; 75. First mounting groove; 76. First stirring rod; 77. Scraper; 78. Second ring; 79. Second mounting groove; 710. Second stirring rod; 711. Return spring; 8. Insulation layer; 9. Heating assembly; 91. Heating wire heating box; 92. Fan; 93. Air inlet pipe; 94. Air outlet pipe; 95. Return air pipe; 10. Preheating assembly; 101. Spiral spiral tube; 11. Dosing port; 12. Maintenance port; 13. Sealing cover. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Example 1

[0051] To address the technical problems in the background art, the following is provided: a salt-forming method for isocyanate synthesis apparatus and method.

[0052] Combination Figures 1-7As shown, the present invention provides an isocyanate synthesis apparatus and method using a salt-forming method, comprising a floor 1; a synthesis tank 2 and a trapping tower 3 are fixedly connected to the top surface of the floor 1 respectively; an injection assembly 4 is installed inside the synthesis tank 2; a reflux assembly 5 is connected to the bottom of the synthesis tank 2; a filter screen 6 is fixedly connected to the bottom of the synthesis tank 2; a stirring assembly 7 is installed in the middle of the synthesis tank 2; a heat insulation layer 8 is fixedly connected to the outer surface of the synthesis tank 2; a heating assembly 9 is connected to the outer surface of the heat insulation layer 8; a preheating assembly 10 is connected to the outer surface of the heat insulation layer 8; a dosing port 11 is fixedly connected to the top surface of the synthesis tank 2; a valve is installed inside the dosing port 11; a maintenance port 12 is fixedly connected to the top surface of the synthesis tank 2; and a sealing cap 13 is fixedly connected to the top surface of the maintenance port 12 by bolts. The stirring assembly 7 includes a motor frame 71. The motor frame 71 is fixedly connected to the middle of the top surface of the synthesis tank 2. A drive motor 72 is fixedly connected to the top surface of the motor frame 71. A stirring shaft 73 is fixedly connected to the output shaft end of the drive motor 72. One end of the stirring shaft 73 passes through the top surface of the synthesis tank 2 and is rotatably connected to the inner cavity of the synthesis tank 2. A first ring 74 is fixedly connected to the lower part of the outer surface of the stirring shaft 73. A first mounting groove 75 is provided at equal intervals on the circumference of the first ring 74. A first stirring rod 76 is rotatably connected to the inner cavity of the first mounting groove 75 through a pin. A scraper 77 is rotatably connected to one side of the first stirring rod 76 through a pin. The bottom of the first stirring rod 76 is in contact with the top surface of the filter screen 6, and one side of the scraper 77 is in contact with the inner wall of the synthesis tank 2.

[0053] The above solution can achieve the following effects:

[0054] 1. Through the coordinated operation of the drive motor 72, stirring shaft 73, first ring 74, first stirring rod 76, scraper 77, and second stirring rod 710 in the stirring assembly 7, the solution is stirred, and the inner wall of the synthesis tank 2 and the filter screen 6 are cleaned simultaneously. At the same time, through the coordinated operation of the second ring 78, second stirring rod 710, and return spring 711, the scraper 77 can be retracted, facilitating the entry of the first annular nozzle 47.

[0055] 2. Through the cooperation of the pneumatic rod 49, L-shaped rod 410, first annular nozzle 47 and jet nozzle 48 in the gas injection assembly 4, nitrogen, hydrogen chloride and carbonyl chloride are injected into the solution, so that the gas and solution can be quickly mixed; at the same time, the first connecting valve head 44 and the second connecting valve head 45 in the gas injection assembly 4 facilitate the connection with different gas storage tanks in the later stage.

[0056] 3. Through the cooperation of the reflux pump 51, water inlet pipe 52, water outlet pipe 53, second annular nozzle 56 and atomizing nozzle 57 in the reflux assembly 5, the solution is atomized, so that the atomized solution can better contact and react with the gas, thus accelerating the overall reaction speed.

[0057] 4. The cooperation of the suction fan 92, air inlet pipe 93, air outlet pipe 94, and heating wire heating box 91 in the heating component 9 realizes the heating of the solution, so that the solution can be mixed with the gas.

[0058] 5. Through the cooperation of the spiral tube 101 in the preheating component 10, the injected gas is preheated so that the temperature of the injected gas is similar to the temperature of the liquid in the synthesis tank 2, which can make the liquid and gas react better and accelerate the reaction rate.

[0059] To achieve the aforementioned technical effects, the following design scheme is proposed for the stirring assembly 7:

[0060] In this embodiment, the stirring assembly 7 further includes a second ring 78. The second ring 78 is slidably connected to the outer surface of the stirring shaft 73. The second ring 78 has second mounting grooves 79 evenly spaced on its circumference. The inner cavity of the second mounting groove 79 is rotatably connected to a second stirring rod 710 via a pin. A scraper 77 is rotatably connected to one side of the second stirring rod 710 via a pin. A return spring 711 is fixedly connected to the bottom of the second ring 78 and between the bottom surface of the first ring 74 and the top surface of the stirring shaft 73. The return spring 711 is sleeved on the outside of the stirring shaft 73.

[0061] The second stirring rod 710 and the scraper 77 in the stirring assembly 7 work together to achieve stirring and mixing of the solution and accelerate its reaction.

[0062] Example 2

[0063] like Figures 1-7 As shown, based on the above embodiments, this embodiment further provides the following:

[0064] To achieve the aforementioned technical effects, the following design scheme for the gas injection component 4 is provided:

[0065] The air injection assembly 4 includes an air pump 41 and a placement rack 42. The air pump 41 and the placement rack 42 are fixedly connected to the top surface of the floor 1. The input end of the air pump 41 is connected to a three-way pipe 43. The placement rack 42 is fixedly connected to the inside of the three-way pipe 43. The two ends of the three-way pipe 43 are connected to a first connecting valve head 44 and a second connecting valve head 45, respectively. The output end of the air pump 41 is connected to a first annular nozzle 47 through a hose 46. Air nozzles 48 are fixedly connected at equal intervals on the inner circumference of the first annular nozzle 47. One end of the hose 46 passes through the top of the synthesis tank 2 and is fixedly connected to the synthesis tank 2. The gas injection assembly 4 also includes a pneumatic rod 49. The pneumatic rod 49 is fixedly connected to the top surface of the synthesis tank 2. The output shaft end of the pneumatic rod 49 has an L-shaped rod 410. One end of the L-shaped rod 410 passes through the top surface of the synthesis tank 2 and is slidably connected to the synthesis tank 2. A connecting rod 411 is fixedly connected to the bottom surface of the L-shaped rod 410. One end of the connecting rod 411 is fixedly connected to a first annular nozzle 47. The other end of the connecting rod 411 is fixedly connected to a pressing cylinder 412. The pressing cylinder 412 is slidably connected to the outer surface of the stirring shaft 73.

[0066] The cooperation between the first connecting valve head 44 and the second connecting valve head 45 in the gas injection assembly 4 facilitates quick connection with external gas cylinders in the later stages.

[0067] By cooperating with the pneumatic rod 49, the first annular nozzle 47, and the jet nozzle 48 in the gas injection assembly 4, nitrogen, hydrogen chloride, and carbonyl chloride are injected into the solution, enabling the gas and solution to rapidly mix.

[0068] The following effects can be achieved by pressing the cylinder 412: 1. The cylinder 412 can be used to store the stirring component without affecting its use; 2. While storing the stirring component, the cylinder 412 can allow the first annular nozzle to enter the solution in the synthesis tank 2; 3. The cylinder 412 can be used to deploy the stirring component to clean the residual solution on the inner wall of the synthesis tank, and also to clean the residual solution on the stirring component.

[0069] Example 3

[0070] like Figures 1-7 As shown, based on the above embodiments, this embodiment further provides the following:

[0071] To achieve the aforementioned technical effects, the following design scheme is proposed for the recirculation component 5:

[0072] The reflux assembly 5 includes a reflux pump 51. The reflux pump 51 is fixedly connected to the top surface of the floor 1. The input end of the reflux pump 51 is connected to the bottom of the inner cavity of the synthesis tank 2 through the water inlet pipe 52. The output end of the reflux pump 51 is connected to a three-way valve 54 through the drain pipe 53. One end of the three-way valve 54 is connected to a second annular nozzle 56 through the liquid flow pipe 55. Atomizing nozzles 57 are fixedly connected at equal intervals at the bottom of the second annular nozzle 56. The top of the inner cavity of the synthesis tank 2 is fixedly connected to the second annular nozzle 56. The other end of the three-way valve 54 is connected to the inner cavity of the trapping tower 3 through the discharge pipe 58.

[0073] Through the cooperation of the reflux pump 51, water inlet pipe 52, water outlet pipe 53, second annular nozzle 56 and atomizing nozzle 57 in the reflux assembly 5, the solution is atomized, so that the atomized solution can better contact and react with the gas, thus accelerating the overall reaction speed.

[0074] To achieve the aforementioned technical effects, the heating component 9 is designed as follows:

[0075] In this embodiment, the heating component 9 includes an electric heating wire heating box 91. The electric heating wire heating box 91 is fixedly connected to the top surface of the floor 1. A suction fan 92 is fixedly connected to the top surface of the electric heating wire heating box 91. The air inlet of the suction fan 92 is connected to the inner cavity of the electric heating wire heating box 91 through the air inlet pipe 93. The air outlet of the suction fan 92 is connected to the inner cavity of the insulation layer 8 through the air outlet pipe 94. One side of the electric heating wire heating box 91 is connected to the lower part of the insulation layer 8 through the return air pipe 95.

[0076] To achieve the aforementioned technical effects, the preheating component 10 is designed as follows:

[0077] In this embodiment, the preheating component 10 includes a spiral tube 101, the outer surface of the insulation layer 8 is connected to the spiral tube 101, a valve is installed at one end of the spiral tube 101 and near the insulation layer 8, and a hose 46 is installed in the inner cavity of the spiral tube 101.

[0078] The preheating component 10 uses a spiral tube 101 to heat carbonyl chloride and nitrogen, allowing them to be better fused.

[0079] A method for synthesizing isocyanates via salt formation, the production method comprising the following steps:

[0080] S1. Preparation of amine hydrochloride:

[0081] S1.1 Add amine solution and inert solvent to the synthesis tank;

[0082] S1.2 Start the drive motor. The drive motor drives the stirring shaft, the second ring, the first stirring rod, and the scraper to rotate as a whole, stirring and mixing the solution.

[0083] S1.3 Activate the pneumatic rod, which will drive the pressing cylinder and the first annular nozzle to move downward. When the pressing cylinder moves downward, it will press the second ring, causing the second ring to move downward and drive the second stirring rod to rotate at a certain angle, and causing the scraper to retract inward, so that the scraper is no longer in contact with the inner wall of the synthesis tank. At the same time, the first annular nozzle will descend to be located outside the scraper and inside the solution.

[0084] S1.4 Connect the hydrogen chloride gas storage tank to the first connecting valve head, and open the valve inside the first connecting valve head;

[0085] Start the vacuum pump, which will inject hydrogen chloride gas into the solution through the three-way pipe, hose, first annular nozzle and jet nozzle;

[0086] S1.5 Adjust the valve in the three-way valve to connect the liquid flow pipe and the drain pipe, start the reflux pump, the reflux pump will draw the solution at the bottom of the synthesis tank into the second annular nozzle through the water inlet pipe, drain pipe and liquid flow pipe, and finally spray it out in the form of water mist through the atomizing nozzle, and mix it evenly with the gas in the upper part of the inner cavity of the synthesis tank.

[0087] S1.6 When the amine hydrochloride is prepared and formed, close the valve inside the first connecting valve head and remove the hydrogen chloride gas storage tank;

[0088] S2. Preheating treatment of amine hydrochloride in the synthesis tank:

[0089] S3. Inject carbonyl chloride into the synthesis tank to generate crude isocyanate:

[0090] S4. Inject nitrogen gas into the synthesis tank to remove excess carbonyl chloride, obtaining the isocyanate product:

[0091] S5, purification of isocyanate products.

[0092] S6: Clean Synthesis Tank 2;

[0093] S6.1. Dry the residual slurry to form a relatively dry residue:

[0094] Disconnect the carbonyl chloride storage tank and nitrogen storage tank from the first and second connecting valve heads, and open the valves on the first and second connecting valve heads.

[0095] Start the air pump, and the air pump will draw outside air into the hose through the three-way pipe. At this time, the air in the hose is heated by the spiral tube outside the hose. The heated air will be discharged into the outside of the stirring assembly through the first annular nozzle and the air jet nozzle to start heating the solution adhering to the outside of the stirring assembly.

[0096] The pneumatic rod is activated, and the pneumatic rod drives the first annular nozzle to rise and fall through the L-shaped rod and connecting rod. At this time, different positions of the stirring component can be dried, and the inner wall of the synthesis tank can be dried through the heat insulation layer.

[0097] After drying, the heating and gas injection components can be turned off.

[0098] S6.2 Scrape off any residual material from the inner wall of the synthesis tank:

[0099] Start the pneumatic rod. The pneumatic rod drives the first annular nozzle and the pressing cylinder to move upward through the L-shaped rod and the connecting rod. When the pressing cylinder moves upward, it will disengage from the second ring. At the same time, the first annular nozzle will also disengage from the outside of the scraper. After disengagement, the second ring will be reset under the action of the return spring, so that the second stirring rod contacts the top surface of the filter plate, and at the same time, the scraper contacts the inside of the synthesis tank 2.

[0100] Start the drive motor, which drives the first ring, the first stirring rod and the scraper to rotate through the stirring shaft. The first stirring rod can scrape the top surface of the filter plate, and the scraper can scrape the inner wall of the synthesis tank.

[0101] After scraping is complete, turn off the drive motor;

[0102] S6.3 Shake off any residual material on the mixing components:

[0103] Activate the pneumatic rod to rapidly reciprocate. As the pneumatic rod rapidly extends and retracts, it causes the pressing cylinder to quickly impact the second ring and then quickly detach from it. When the second ring is impacted, the second stirring rod and scraper begin to retract. As the pneumatic rod retracts, the second ring rapidly unfolds under the action of the return spring. When the second ring unfolds, the second stirring rod impacts the filter screen, and after the impact, the residual material on the second stirring rod, scraper, and first stirring rod is shaken off onto the filter screen.

[0104] After the residual material is cleaned up, turn off the pneumatic rod;

[0105] S6.4 Manually clean the residual material accumulated on the filter plate;

[0106] After removing the bolts on the sealing cover and opening the maintenance port, staff can enter the synthesis tank through the maintenance port to clean the residual material on the filter plates.

[0107] As an improvement to the above technical solution, in S3, the specific steps for injecting carbonyl chloride into the synthesis tank to generate crude isocyanate are as follows:

[0108] S3.1 Open the valve inside the spiral tube to allow hot air to enter the insulation layer;

[0109] S3.2 Connect the carbonyl chloride storage tank to the first connecting valve head and open the valve inside the first connecting valve head; start the vacuum pump, which will draw carbonyl chloride into the hose through the three-way pipe, and then heat it through the spiral tube. The heated carbonyl chloride is then sprayed into the amine hydrochloride solution through the jet nozzle; finally, crude isocyanate is obtained.

[0110] As an improvement to the above technical solution, in step S4, nitrogen gas is injected into the synthesis tank to remove excess carbonyl chloride, and the specific method for obtaining the isocyanate product is as follows:

[0111] Connect the nitrogen storage tank to the second connecting valve head, and open the valve inside the second connecting valve head;

[0112] Start the vacuum pump, which will draw nitrogen into the hose through the three-way pipe, and then heat it through the spiral tube. The heated nitrogen is then injected into the crude isocyanate through the nozzle, and finally the finished isocyanate product is obtained.

[0113] Working principle and usage process of this invention:

[0114] In use:

[0115] Step 1: Preparation of amine hydrochloride;

[0116] First, open the valve inside the dosing port 11, and then inject a certain amount of amine solution and inert solvent into the synthesis tank 2. The inert solvent can be one of xylene, chlorobenzene, diethyl phthalate, dimethyl isophthalate, etc. After the amine solution and inert solvent are added, start the drive motor 72 through an external power source. The drive motor 72 drives the stirring shaft 73 to rotate. When the stirring shaft 73 rotates, it will drive the first ring 74 to rotate. When the first ring 74 rotates, it will drive the first stirring rod 76 and the scraper 77 to rotate. As the first stirring rod 76 and the scraper 77 rotate, the amine solution and inert solvent begin to be mixed evenly.

[0117] After mixing, the pneumatic rod 49 is activated. As the pneumatic rod 49 retracts, it moves the L-shaped rod 410 downwards. This downward movement of the L-shaped rod 410 moves the connecting rod 411 downwards. This downward movement of the connecting rod 411 moves the pressing cylinder 412 and the first annular nozzle 47 downwards. As the pressing cylinder 412 moves downwards, it comes into contact with the upper part of the second ring 78, causing the second ring 78 to move downwards. This downward movement of the second ring 78 compresses the return spring 711. The movement will cause the second stirring rod 710 to rotate at a certain angle. As the second stirring rod 710 rotates, it will drive the scraper 77 to move to a certain position. As the scraper 77 moves, it will no longer be in contact with the inner wall of the synthesis tank 2. As the scraper 77 moves, it will also drive the first stirring rod 76 to rotate at a certain angle. As the scraper 77 separates from the inner wall of the synthesis tank 2, the first annular nozzle 47 will be located on one side of the scraper 77 and will also be located in the solution. When the first annular nozzle 47 is completely immersed in the solution, the operation of the pneumatic rod 49 will stop.

[0118] When the first annular nozzle 47 is immersed in the solution, the canister containing hydrogen chloride gas is first connected to the first connecting valve head 44. After connection, the valve inside the first connecting valve head 44 is opened. After opening, the vacuum pump 41 is started by an external power source. The vacuum pump 41 injects gas into the first annular nozzle 47 through the three-way pipe 43 and the hose 46. After injection, the first annular nozzle 47 sprays the gas evenly into the solution through the nozzle 48, so that the hydrogen chloride gas and the solution are evenly mixed.

[0119] As hydrogen chloride gas is injected, the operator first adjusts the valve in the three-way valve 54 to connect the drain pipe 53 and the liquid flow pipe 55. After connection, the reflux pump 51 is started by an external power source. When the reflux pump 51 is working, it draws the solution at the bottom of the inner cavity of the synthesis tank 2 into the second annular nozzle 56 through the water inlet pipe 52 and the drain pipe 53. Finally, it is sprayed out through the atomizing nozzle 57 on the second annular nozzle 56. The sprayed solution forms a mist. After the solution is sprayed out, it will come into contact with the hydrogen chloride gas in the upper part of the inner cavity of the synthesis tank 2, realizing the mutual dissolution of the solution and hydrogen chloride gas. At the same time, the mixing effect of the solution and gas is better through stirring. After the hydrogen chloride gas is injected, the valve in the first connecting valve head 44 is closed.

[0120] Step 2: Preheat amine hydrochloride;

[0121] First, the heating element heating box 91 and the suction fan 92 are started by an external power source. When the heating element heating box 91 starts working, it heats the cold air outside. When the suction fan 92 starts working, it exhausts the hot air into the insulation layer 8 through the air inlet pipe 93 and the air outlet pipe 94. Then, through the principle of heat conduction, the heat is transferred to the amine hydrochloride solution inside the synthesis tank 2. At the same time, through the cooperation of the stirring component 7 and the reflux component 5, the amine hydrochloride solution is uniformly preheated.

[0122] Step 3: Inject carbonyl chloride;

[0123] First, connect the carbonyl chloride storage tank to the second connecting valve head 45. After connection, open the valve inside the second connecting valve head 45. At this time, the valve on the perforated spiral tube 101 is opened, and the hot air in the insulation layer 8 will enter the spiral tube 101. Then, start the vacuum pump 41 again to draw the carbonyl chloride into the hose 46. When the carbonyl chloride moves to the spiral tube 101, the spiral tube 101 will start to heat the carbonyl chloride in the hose 46. After the carbonyl chloride is heated, it will enter the first annular nozzle 47. Finally, the carbonyl chloride will be evenly sprayed into the amine hydrochloride solution through the nozzle 48 on the first annular nozzle 47. After spraying, the gas will react with the solution. At the same time, through the cooperation of the stirring component 7 and the reflux component 5, the carbonyl chloride and the solution are evenly mixed to obtain isocyanate and partial crystals. After the reaction of the amine hydrochloride solution is completed, close the second connecting valve head 45.

[0124] Step 4: Inject nitrogen gas:

[0125] First, the hydrogen chloride tank connected to the first connecting valve head 44 is disassembled. After disassembly, the nitrogen tank is installed on the first connecting valve head 44, and the first connecting valve head 44 is opened so that nitrogen is injected into the synthesis tank 2 through the vacuum pump 41, the first annular nozzle 47 and the jet nozzle 48 (while the nitrogen is also heated by the spiral tube 101). Excess carbonyl chloride in the synthesis tank 2 is removed. After the carbonyl chloride is removed, the first connecting valve head 44 is closed.

[0126] Step 5: Purification;

[0127] First, adjust the valve in the three-way valve 54. After adjustment, the drain pipe 53 is connected to the feed pipe 58. After connection, the isocyanate solution in the synthesis tank 2 will be discharged into the trapping tower 3 through the water inlet pipe 52 and the liquid outlet pipe 55. The crystals produced by the isocyanate will remain in the synthesis tank 2 under the action of the filter screen 6.

[0128] Step 5: Clean the synthesis tank;

[0129] The nitrogen and carbonyl chloride tanks connected to the first connecting valve head 44 and the second connecting valve head 45 are removed. After removal, the valves on the first connecting valve head 44 and the second connecting valve head 45 are opened. At this time, the outside air will be injected into the synthesis tank 2 by the air pump 41, hose 46, first annular nozzle 47 and jet nozzle 48. As the air is injected, the outside air is heated by the cooperation of the spiral tube 101. With the heating and injection of the outside air, the synthesis tank 2 can be heated and dried by the hot air. After drying, the pneumatic rod 49 starts to drive the first annular nozzle 47 to rise and fall. The rising and falling of the first annular nozzle 47 can achieve uniform drying of the inside of the synthesis tank 2. After drying, the staff can enter the synthesis tank 2 through the maintenance port 12 to process it.

[0130] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for synthesizing isocyanates using a salt-forming method, characterized in that: The system includes a floor; a synthesis tank and a trapping tower are fixedly connected to the top surface of the floor; an injection assembly is installed inside the synthesis tank; a reflux assembly is connected to the bottom of the synthesis tank; a filter screen is fixedly connected to the bottom of the synthesis tank; a stirring assembly is installed in the middle of the synthesis tank; an insulation layer is fixedly connected to the outer surface of the synthesis tank; a heating assembly is connected to the outer surface of the insulation layer; a preheating assembly is connected to the outer surface of the insulation layer; a dosing port is fixedly connected to the top surface of the synthesis tank; a valve is installed inside the dosing port; a maintenance port is fixedly connected to the top surface of the synthesis tank; and a sealing cap is fixedly connected to the top surface of the maintenance port by bolts. The stirring assembly includes a motor frame. The motor frame is fixedly connected to the center of the top surface of the synthesis tank. A drive motor is fixedly connected to the top surface of the motor frame. A stirring shaft is fixedly connected to the output shaft end of the drive motor. One end of the stirring shaft passes through the top surface of the synthesis tank and is rotatably connected to the inner cavity of the synthesis tank. A first ring is fixedly connected to the lower part of the outer surface of the stirring shaft. A first mounting groove is provided at equal intervals on the circumference of the first ring. A first stirring rod is rotatably connected to the inner cavity of the first mounting groove through a pin. A scraper is rotatably connected to one side of the first stirring rod through a pin. The bottom of the first stirring rod is in contact with the top surface of the filter screen, and one side of the scraper is in contact with the inner wall of the synthesis tank. The gas injection assembly includes a vacuum pump and a placement rack. The vacuum pump and the placement rack are fixedly connected to the top surface of the floor. The input end of the vacuum pump is connected to a three-way pipe. The placement rack is fixedly connected to a three-way pipe. The two ends of the three-way pipe are connected to a first connecting valve head and a second connecting valve head, respectively. The output end of the vacuum pump is connected to a first annular nozzle through a hose. Air nozzles are fixedly connected at equal intervals on the inner circumference of the first annular nozzle. One end of the hose passes through the top of the synthesis tank and is fixedly connected to the synthesis tank. The gas injection assembly also includes a pneumatic rod. The pneumatic rod is fixedly connected to the top surface of the synthesis tank. The pneumatic rod has an L-shaped rod at its output shaft end. One end of the L-shaped rod passes through the top surface of the synthesis tank and is slidably connected to the synthesis tank. A connecting rod is fixedly connected to the bottom surface of the L-shaped rod. A first annular nozzle is fixedly connected to one end of the connecting rod. A pressing cylinder is fixedly connected to the other end of the connecting rod. A pressing cylinder is slidably connected to the outer surface of the stirring shaft.

2. The isocyanate synthesis apparatus according to claim 1, characterized in that: The stirring assembly further includes a second ring, which is slidably connected to the outer surface of the stirring shaft. The second ring has a second mounting groove evenly spaced on its circumference. The inner cavity of the second mounting groove is rotatably connected to a second stirring rod via a pin. A scraper is rotatably connected to one side of the second stirring rod via a pin. A return spring is fixedly connected to the bottom of the second ring and between the bottom and top surface of the first ring. A return spring is sleeved on the outside of the stirring shaft.

3. The isocyanate synthesis apparatus according to claim 2, characterized in that: The reflux assembly includes a reflux pump, which is fixedly connected to the top surface of the floor. The input end of the reflux pump is connected to the bottom of the inner cavity of the synthesis tank through a water inlet pipe. The output end of the reflux pump is connected to a three-way valve through a drain pipe. One end of the three-way valve is connected to a second annular nozzle through a liquid flow pipe. Atomizing nozzles are fixedly connected at equal intervals to the bottom of the second annular nozzle. The top of the inner cavity of the synthesis tank is fixedly connected to the second annular nozzle. The other end of the three-way valve is connected to the inner cavity of the trapping tower through a discharge pipe.

4. The isocyanate synthesis apparatus according to claim 3, characterized in that: The heating assembly includes an electric heating wire heating box, which is fixedly connected to the top surface of the floor. A suction fan is fixedly connected to the top surface of the electric heating wire heating box. The air inlet of the suction fan is connected to the inner cavity of the electric heating wire heating box through an air inlet pipe, and the air outlet of the suction fan is connected to the inner cavity of the insulation layer through an air outlet pipe. One side of the electric heating wire heating box is connected to the lower part of the insulation layer through a return air pipe.

5. The isocyanate synthesis apparatus according to claim 4, characterized in that: The preheating component includes a spiral tube, the outer surface of the insulation layer is connected to the spiral tube, a valve is installed at one end of the spiral tube near the insulation layer, and a flexible tube is installed inside the spiral tube.

6. A method for synthesizing isocyanates via salt formation, characterized in that: The isocyanate synthesis apparatus according to any one of claims 1-5 is used; the synthesis method comprises the following steps: S1. Preparation of amine hydrochloride: S1.1 Add amine solution and inert solvent to the synthesis tank; S1.2 Start the drive motor. The drive motor drives the stirring shaft, the second ring, the first stirring rod, and the scraper to rotate as a whole, stirring and mixing the solution. S1.3 Activate the pneumatic rod, which will drive the pressing cylinder and the first annular nozzle to move downward. When the pressing cylinder moves downward, it will press the second ring, causing the second ring to move downward and drive the second stirring rod to rotate at a certain angle, and causing the scraper to retract inward, so that the scraper is no longer in contact with the inner wall of the synthesis tank. At the same time, the first annular nozzle will descend to be located outside the scraper and inside the solution. S1.4 Connect the hydrogen chloride gas storage tank to the first connecting valve head, and open the valve inside the first connecting valve head; Start the vacuum pump, which will inject hydrogen chloride gas into the solution through the three-way pipe, hose, first annular nozzle and jet nozzle; S1.5 Adjust the valve in the three-way valve to connect the liquid flow pipe and the drain pipe, start the reflux pump, the reflux pump will draw the solution at the bottom of the synthesis tank into the second annular nozzle through the water inlet pipe, drain pipe and liquid flow pipe, and finally spray it out in the form of water mist through the atomizing nozzle, and mix it evenly with the gas in the upper part of the inner cavity of the synthesis tank. S1.6 When the amine hydrochloride is prepared and formed, close the valve inside the first connecting valve head and remove the hydrogen chloride gas storage tank; S2. Preheating treatment of amine hydrochloride in the synthesis tank: S3. Inject carbonyl chloride into the synthesis tank to generate crude isocyanate: S4. Inject nitrogen gas into the synthesis tank to remove excess carbonyl chloride, obtaining the isocyanate product: S5, purification of isocyanate products.

7. The method for synthesizing isocyanates by salt formation according to claim 6, characterized in that: In S3, the specific steps for injecting carbonyl chloride into the synthesis tank to generate crude isocyanate are as follows: S3.1 Open the valve inside the spiral tube to allow hot air to enter the insulation layer; S3.2 Connect the carbonyl chloride storage tank to the first connecting valve head and open the valve inside the first connecting valve head; start the vacuum pump, which will draw carbonyl chloride into the hose through the three-way pipe, and then heat it through the spiral tube. The heated carbonyl chloride is then sprayed into the amine hydrochloride solution through the jet nozzle; finally, crude isocyanate is obtained.

8. The method for synthesizing isocyanates by salt formation according to claim 7, characterized in that: In step S4, nitrogen gas is injected into the synthesis tank to remove excess carbonyl chloride, yielding the isocyanate product. The specific method is as follows: Connect the nitrogen storage tank to the second connecting valve head, and open the valve inside the second connecting valve head; Start the vacuum pump, which will draw nitrogen into the hose through the three-way pipe, and then heat it through the spiral tube. The heated nitrogen is then injected into the crude isocyanate through the nozzle, and finally the finished isocyanate product is obtained.

Images