Equipment for continuously preparing isocyanate
By using a combination of a hollow stirring shaft and a gas disk in the isocyanate reactor, the high-pressure phosgene is refined and the contact area with the reaction solution is increased, and the problem of low conversion rate in the prior art is solved, thereby achieving efficient generation and continuous preparation of isocyanate.
Patent Information
- Application Number
- CN202421885139.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-06
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-08-06
AI Technical Summary
When phosgene is introduced in the existing isocyanate reactor, the contact surface between phosgene and the internal reactants is small, which affects the conversion rate of isocyanate.
A device for continuous preparation of isocyanate is designed, using a combination of a hollow stirring shaft and a gas disk, which is passed into the hollow stirring shaft through high-pressure phosgene, refined into tiny bubbles and released evenly into the reaction solution, significantly increasing the contact area between phosgene and the reaction solution.
It significantly improves the conversion efficiency of isocyanate, ensures efficient production of isocyanate, and realizes the stability of the continuous preparation process of isocyanate through the control mechanism.
Smart Images
Figure CN222855465U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field, and specifically relates to a device for continuously preparing isocyanate. Background Art
[0002] Isocyanate is a general term for various esters of isocyanic acid, which are used in household appliances, automobiles, construction, footwear, furniture, adhesives and other industries. If classified by the number of -NCO groups, it includes monoisocyanate R-N=C=O, diisocyanate O=C=N-R-N=C=O and polyisocyanate.
[0003] Isocyanate, as a vital organic synthetic raw material, plays an indispensable role in the synthesis of polymer materials such as polyurethane and polyamide. In the preparation process of isocyanate, the reactor occupies a pivotal position. Its industrial preparation method first adds amine to a cold phosgene solution, and initially forms a carbamate compound and an amine hydrochloride through reaction. Subsequently, under the condition of gradually increasing the temperature and continuously introducing phosgene, the carbamate compound and the amine hydrochloride are promoted to be converted, and the target product isocyanate is finally generated. However, when phosgene is introduced into the existing isocyanate reactor, direct addition is often adopted, which results in a smaller contact area between phosgene and the internal reactants, thereby affecting the conversion rate of isocyanate. In view of this problem, the utility model proposes an isocyanate preparation device, which aims to increase the contact area between phosgene and the reaction solution, thereby significantly improving the conversion efficiency and ensuring the efficient generation of isocyanate.
[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Utility Model Content
[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: an equipment for continuously preparing isocyanate, comprising a reactor and a control mechanism, the reactor comprising a reactor body and a reactor cover, a stirring mechanism is arranged at the center of the reactor cover, the stirring mechanism comprises a hollow stirring shaft, a gas distribution disk is fixedly connected to the bottom end of the hollow stirring shaft, a stirrer is fixed to the shaft body of the hollow stirring shaft located at the top of the gas distribution disk, a driving assembly is installed at the top of the hollow stirring shaft, the driving assembly comprises a driving motor, bevel gears are fixed to the output end of the driving motor and the shaft body at the top of the hollow stirring shaft, the two bevel gears are meshed and connected, a transmission box is arranged on the outside of the bevel gear, the transmission box body is fixed to the top end face of the reactor cover, a sealing gas hood is fixed at the center of the top of the transmission box, an air inlet is arranged on one side of the sealing gas hood, and the shaft body at the top of the hollow stirring shaft is rotatably connected to the reactor cover and the transmission box respectively.
[0006] As a preferred technical solution of the utility model, the rotating connection between the hollow stirring shaft body, the kettle cover and the transmission box all adopts a magnetic or mechanical dynamic sealing structure.
[0007] As a preferred technical solution of the utility model, a solid inlet is arranged on the surface of the kettle cover, a liquid inlet pipe is connected to one side of the top of the kettle body, and a discharge port is opened at the center of the bottom end of the kettle body.
[0008] As an optimal technical solution of the utility model, the control mechanism includes a controller and a liquid level sensor, control valves are installed at the connection between the liquid inlet pipe and the kettle body and at the discharge port, the liquid level sensor is installed inside the kettle cover, and the controller is electrically connected to the liquid level sensor and the control valve respectively.
[0009] As a preferred technical solution of the utility model, an electric heating layer is arranged on the outside of the kettle body, and a heat preservation layer is arranged on the outside of the electric heating layer.
[0010] As a preferred technical solution of the utility model, the kettle cover and the kettle body are fastened together by a flange.
[0011] Compared with the prior art, the utility model has the following beneficial effects: the utility model designs the stirring shaft in the reactor as a hollow structure and equips the bottom end with a gas distribution plate. During operation, high-pressure phosgene is introduced into the hollow stirring shaft, and the phosgene is refined into tiny bubbles by the gas distribution plate and evenly released into the hydrochloride solution of the carbamate compound and the amine in the reactor. This significantly increases the contact area between phosgene and the reaction solution, thereby promoting the conversion efficiency between the carbamate compound and the hydrochloride of the amine, ensuring that the target product isocyanate can be efficiently generated in the end. In addition, the design is also equipped with a control mechanism to accurately control the feeding and discharging process to ensure that the continuous preparation process of isocyanate can be carried out stably. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:
[0013] Figure 1 It is a structural schematic diagram of the utility model;
[0014] Figure 2 It is a schematic diagram of the structure of the utility model;
[0015] In the figure: 1. kettle body; 2. kettle cover; 3. hollow stirring shaft; 4. air distribution plate; 5. stirrer; 6. drive motor; 7. bevel gear; 8. transmission box; 9. sealed air hood; 10. air inlet; 11. solid inlet; 12. liquid inlet pipe; 13. discharge port; 14. insulation layer; 15. liquid level sensor; 16. control valve; 17. electric heating layer. DETAILED DESCRIPTION
[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0017] Example
[0018] See also Figure 1 -, the utility model provides the following technical solutions: a device for continuously preparing isocyanate, comprising a reactor and a control mechanism, wherein the detailed structure of the main body of the reactor comprises a reactor body 1 and a reactor cover 2. A stirring mechanism is arranged at the central part of the reactor cover 2, and the stirring mechanism comprises a hollow stirring shaft 3. The bottom of the hollow stirring shaft 3 is firmly connected to a gas distribution plate 4, which is used to ensure the uniform release of phosgene in the reactor body 1. Above the gas distribution plate 4, a stirrer 5 is fixed to the shaft body of the hollow stirring shaft 3 to further promote the mixing and reaction of the reactants. In order to drive the operation of the stirring mechanism, the reactor is equipped with a driving assembly at the top of the hollow stirring shaft 3. The core of this driving assembly is a driving motor 6, whose output end and the top shaft body of the hollow stirring shaft 3 are both equipped with a bevel gear 7, and the two bevel gears 7 are meshed and connected, and the power of the driving motor 6 can be transmitted to the hollow stirring shaft 3. In order to ensure the stability and sealing of the structure, a transmission box 8 is arranged outside the bevel gear 7, and the transmission box 8 box body is firmly fixed to the top end face of the reactor cover 2. A sealed air hood 9 is provided at the top center of the transmission box 8 to ensure the sealing and safety after the introduction of phosgene. An air inlet 10 is provided on one side of the sealed air hood 9 for the introduction of phosgene. The top shaft of the hollow stirring shaft 3 is connected to the kettle cover 2 and the transmission box 8 in a rotating manner to ensure smooth and stable operation of the hollow stirring shaft 3 during the stirring process.
[0019] In order to ensure the sealing of the rotating connection of the hollow stirring shaft 3, in this embodiment, as a preferred technical solution of the utility model, the rotating connection of the hollow stirring shaft 3, the kettle cover 2 and the transmission box 8 all adopt a magnetic or mechanical dynamic sealing structure.
[0020] In order to facilitate the feeding of solid and liquid materials into the kettle body 1, in this embodiment, as a preferred technical solution of the utility model, a solid inlet 11 is provided on the surface of the kettle cover 2, a liquid inlet pipe 12 is connected to one side of the top of the kettle body 1, and a discharge port 13 is opened at the center of the bottom end of the kettle body 1.
[0021] In order to facilitate the preparation of automatic feeding connection, in this embodiment, as a preferred technical solution of the utility model, the control mechanism includes a controller and a liquid level sensor 15, and a control valve 16 is installed at the connection between the liquid inlet pipe 12 and the kettle body 1 and at the discharge port 13. The liquid level sensor 15 is installed inside the kettle cover 2, and the controller is electrically connected to the liquid level sensor 15 and the control valve 16 respectively.
[0022] In order to provide high-temperature reaction conditions, in this embodiment, as a preferred technical solution of the utility model, an electric heating layer 17 is provided on the outside of the kettle body 1, and an insulation layer 14 is provided on the outside of the electric heating layer 17.
[0023] In order to facilitate the disassembly and assembly of the kettle cover 2 and the kettle body 1, in this embodiment, as a preferred technical solution of the utility model, the kettle cover 2 and the kettle body 1 are fastened together by a flange.
[0024] In summary, through the technical solution adopted by the utility model, in practical application, phosgene is pressurized through the pump body, and then the high-pressure phosgene is introduced into the sealed gas cover 9 from the air inlet 10, and the high-pressure phosgene is passed into the gas distribution disk 4 through the hollow stirring shaft 3, so that the phosgene is refined into small bubbles through the gas distribution disk 4, wherein the gas distribution disk 4 is a container with a hollow structure, and small air holes are evenly opened on its lower surface for the discharge of phosgene, so that the phosgene is evenly released into the kettle body 1 solution containing the carbamate compound and the hydrochloride of the amine. At the same time, the driving motor 6 drives the hollow stirring shaft 3 to rotate through the bevel gear 7, driving the stirrer 5 at the bottom thereof to rotate synchronously, effectively stirring and mixing the substances inside the kettle body 1, significantly increasing the contact surface between the phosgene and the reactant, thereby accelerating the conversion rate of the carbamate compound and the hydrochloride of the amine into isocyanate, and the kettle body 1 is provided with a control valve 16 at the liquid inlet pipe 12 and the discharge port 13, which can realize the continuous addition of raw materials and the continuous discharge of products. The liquid level sensor 15 is used to detect the liquid level in the reactor body 1 to ensure the stability of the liquid level in the reactor and avoid overflow or empty reactor.
[0025] Finally, it should be noted that in the present utility model, unless otherwise clearly stipulated and limited, terms such as "installation", "setting", "connection", "fixation", and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.
[0026] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.
Claims
1. An apparatus for continuously preparing isocyanate, comprising a reaction kettle and a control mechanism, wherein the reaction kettle comprises a kettle body (1) and a kettle cover (2), and is characterized in that: A stirring mechanism is arranged at the center of the kettle cover (2), the stirring mechanism comprising a hollow stirring shaft (3), the bottom end of the hollow stirring shaft (3) being fixedly connected to an air distribution plate (4), the shaft body of the hollow stirring shaft (3) located at the top of the air distribution plate (4) being fixed with a stirrer (5), the top end of the hollow stirring shaft (3) being provided with a driving assembly, the driving assembly comprising a driving motor (6), the output end of the driving motor (6) and the shaft body at the top of the hollow stirring shaft (3) being fixed with a bevel gear (7), the two bevel gears (7) being meshingly connected, a transmission box (8) being arranged outside the bevel gear (7), the housing of the transmission box (8) being fixed to the top end surface of the kettle cover (2), a sealing air hood (9) being fixed at the top center of the transmission box (8), an air inlet (10) being arranged on one side of the sealing air hood (9), the shaft body at the top of the hollow stirring shaft (3) being rotatably connected to the kettle cover (2) and the transmission box (8) respectively.
2. The device for continuously preparing isocyanate according to claim 1, characterized in that: The rotating connection between the shaft body of the hollow stirring shaft (3), the kettle cover (2) and the transmission box (8) all adopt a magnetic or mechanical dynamic sealing structure.
3. The device for continuously preparing isocyanate according to claim 1, characterized in that: The surface of the kettle cover (2) is provided with a solid inlet (11), one side of the top of the kettle body (1) is connected with a liquid inlet pipe (12), and a discharge port (13) is opened at the center of the bottom end of the kettle body (1).
4. The device for continuously preparing isocyanate according to claim 3, characterized in that: The control mechanism comprises a controller and a liquid level sensor (15); a control valve (16) is installed at the connection between the liquid inlet pipe (12) and the kettle body (1) and at the discharge port (13); the liquid level sensor (15) is installed inside the kettle cover (2); and the controller is electrically connected to the liquid level sensor (15) and the control valve (16), respectively.
5. The device for continuously preparing isocyanate according to claim 1, characterized in that: An electric heating layer (17) is arranged on the outside of the kettle body (1), and a heat-insulating layer (14) is arranged on the outside of the electric heating layer (17).
6. The device for continuously preparing isocyanate according to claim 1, characterized in that: The kettle cover (2) and the kettle body (1) are fastened together via a flange.