Low temperature catalytic apparatus for isocyanate crosslinkers

Abstract

The utility model discloses a low temperature catalytic device of isocyanate crosslinking agent, include: reation kettle body, second reagent storage tank, high pressure delivery pump group, second reagent distribution ring, nozzle, local mixing mechanism, jet impact board, shunt guide vane array and stirring mechanism, wherein, second reagent distribution ring set up in the inside of reation kettle body, and are connected with second reagent storage tank through high pressure delivery pump group, and multiple nozzles equidistance set up on the outside wall of second reagent distribution ring. The utility model discloses through multiple nozzle radial jet flow and local turbulent flow generating device cooperation, realizes reagent fast dispersion and even mixing, and low shear stirring mechanism ensures system stability. The utility model can solve the problem that the mixing is uneven after adding the catalyst or the second reagent in the low temperature high viscosity system, has the advantages of quick dispersion, even mixing, energy consumption reduction and simple operation, is suitable for low temperature catalytic reaction of isocyanate crosslinking agent.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a low-temperature catalytic device for isocyanate crosslinking agents. Background Technology

[0002] Isocyanates are important chemical raw materials containing highly reactive isocyanate groups (-NCO) in their molecular structure. They can undergo polymerization, chain extension, or cross-linking reactions with compounds containing active hydrogen (such as polyols, water, and amines), making them key raw materials for the preparation of polyurethane foams, elastomers, coatings, adhesives, sealants, and other products. In these reactions, to achieve precise control over the reaction rate, product molecular structure, and final properties, specific catalysts or other reaction components (secondary reagents) are usually added. Effective dispersion of the catalyst and uniform mixing with the reaction system are crucial for avoiding side reactions, improving product consistency, and increasing production efficiency.

[0003] Currently, in industry, the addition of catalysts or secondary reagents is mostly carried out using traditional methods such as direct pouring, manual injection from the side of the vessel, or dispersion using a stirring paddle. These methods rely on macroscopic fluid flow and mechanical shear to achieve mixing, which can meet basic mixing requirements in low- or medium-viscosity reaction systems. However, with the development of high-performance and special-application isocyanate products, many reactions need to be carried out at lower temperatures (such as 0°C to ambient temperature) to suppress side reactions between isocyanate groups and water or themselves, extend the operating life, and meet the processing requirements of heat-sensitive monomers. However, low temperatures lead to a significant increase in system viscosity and a sharp decrease in fluid flowability.

[0004] In such high-viscosity, low-flowability, low-temperature environments, traditional addition and mixing methods exhibit significant shortcomings: the injected catalyst struggles to diffuse rapidly, easily accumulating near the feed inlet and resulting in localized concentrations far exceeding the system average. These localized high catalyst concentrations trigger violent exothermic reactions, promoting isocyanate dimerization, trimerization, and even the formation of byproducts such as isoureates and biuret. This not only affects product color, transparency, and mechanical properties (e.g., increasing brittleness), but may also lead to uneven cross-linking distribution due to uneven reaction, resulting in significant fluctuations in final product performance and poor batch stability. Furthermore, forcibly increasing the stirring speed to improve mixing not only increases energy consumption but also easily introduces excessive mechanical heat and bubbles, contradicting the original intent of the low-temperature process and potentially causing product defects.

[0005] Therefore, in order to address the problems of low mixing efficiency, easy local overheating and by-product formation in high viscosity low temperature isocyanate systems, existing technologies urgently need to develop a new type of low temperature catalytic device. This device should be able to achieve instantaneous, fine dispersion and uniform mixing of the catalyst or the second reagent under low temperature and high viscosity conditions, thereby effectively suppressing local overheating and side reactions, ensuring efficient and stable reaction, and improving the overall performance and batch consistency of the final product. Utility Model Content

[0006] This invention overcomes the shortcomings of the prior art and provides a low-temperature catalytic device for isocyanate crosslinking agents.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is: a low-temperature catalytic device for isocyanate crosslinking agents, comprising: Reactor body; The second reagent storage tank is located outside the main body of the reaction vessel; A high-pressure delivery pump unit is connected to the second reagent storage tank via pipeline; The second reagent distribution ring is disposed inside the reactor body, and the second reagent distribution ring is connected to the outlet of the high-pressure delivery pump group through a pipeline; Multiple nozzles are equidistantly arranged on the outer wall of the second reagent dispensing ring and communicate with the internal flow channel of the second reagent dispensing ring; A local mixing mechanism is disposed on the outer wall of the second reagent dispensing ring, adjacent to the outlet region of each nozzle; and The stirring mechanism is located on the central axis of the reactor body.

[0008] In a preferred embodiment of the present invention, the outer wall of the reactor body is provided with a jacket, and a cooling medium is introduced into the jacket.

[0009] In a preferred embodiment of this invention, the second reagent dispensing ring is located below the reaction liquid surface and close to the middle of the liquid inside the reaction vessel body.

[0010] In a preferred embodiment of this invention, the nozzle outlet direction is perpendicular to the axis of the second reagent dispensing ring and points towards the central region of the reactor body.

[0011] In a preferred embodiment of this invention, the second reagent dispensing ring is an annular pipe structure with a circular or rectangular cross-sectional shape.

[0012] In a preferred embodiment of this invention, the second reagent dispensing ring is fixed to the inner wall of the reactor body by a plurality of adjustable-length support rods, and the support rods, in conjunction with an electric lifting mechanism, enable the vertical movement of the second reagent dispensing ring.

[0013] In a preferred embodiment of this utility model, the partial mixing mechanism includes: Multiple jet impact plates are disposed directly in front of or slightly off-center from the outlet of each nozzle, and the surface of the jet impact plates is set at an inclination angle of 45°-60° with respect to the jet direction. A flow-diverting guide vane array is disposed on the surface of the jet impact plate. The flow-diverting guide vane array consists of multiple guide vanes, each of which has a serrated or wavy edge.

[0014] In a preferred embodiment of this invention, a plurality of jet impact plates are arranged around the nozzle and are arranged in a spiral or staggered manner.

[0015] In a preferred embodiment of this utility model, the stirring mechanism includes: A drive motor is located on the upper part of the reactor body; A drive shaft is disposed inside the reactor body, and the upper end of the drive shaft is connected to the output end of the drive motor. Multiple stirring blades are arranged on the circumferential surface of the drive shaft, and the rotation radius of the stirring blades is smaller than the radius of the second reagent dispensing ring.

[0016] In a preferred embodiment of this invention, the interior of the second reagent dispensing ring is an annular pressure equalization cavity.

[0017] This utility model solves the defects existing in the background technology, and has the following beneficial effects: (1) This utility model provides a low-temperature catalytic device for isocyanate crosslinking agent. By setting a second reagent distribution ring and multiple nozzles evenly distributed around the circumference inside the reaction vessel, combined with a high-pressure delivery pump group, the second reagent is injected into multiple points, under high pressure, and radially, effectively avoiding the problem of excessive local concentration caused by single-point concentrated addition. This structure can form a strong jet in high-viscosity low-temperature fluid, directly penetrating the main fluid and achieving preliminary dispersion. Compared with the traditional mixing method that relies on mechanical stirring, this utility model achieves distributed addition from the injection stage, significantly improving the initial uniformity of mixing and fundamentally suppressing the violent exothermic reaction and side reaction caused by excessive local catalyst.

[0018] (2) This utility model sets a local mixing mechanism in the outlet area of ​​each nozzle, including an inclined jet impact plate and a diversion guide vane array with serrated / wavy edges. Under the action of jet impact, the high-speed fluid is decomposed into multiple fine streams, which greatly enhances the micro-scale shear and turbulence intensity of the fluid. This design can achieve micro-mixing in a very short distance near the nozzle and completely disperse any possible clusters or concentration gradients. Compared with the traditional single mechanical stirring method, this utility model generates a high shear mixing field near the injection point in real time, avoids catalyst accumulation, and further improves dispersion efficiency and reaction uniformity.

[0019] (3) The present invention adopts a vertically adjustable second reagent dispensing ring support structure, which, together with an electric lifting mechanism, can flexibly adjust the immersion depth of the dispensing ring according to the liquid level change, so as to ensure that the nozzle is always in the optimal spraying position in different reaction stages or batches.

[0020] (4) This utility model is equipped with a low-shear stirring mechanism. Its blade rotation radius is smaller than that of the distribution ring, which avoids interference with the distribution ring and the mixing mechanism. At the same time, it operates at a low speed in a low-temperature, high-viscosity system, and only undertakes the global mild mixing function without generating too much heat and bubbles. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the low-temperature catalytic device of this utility model; Figure 2 This is an internal structural diagram of the low-temperature catalytic device of this utility model; Figure 3 This is a schematic diagram of the partial hybrid structure of this utility model.

[0022] In the diagram: 1. Reactor body; 2. Second reagent storage tank; 3. High-pressure delivery pump set; 4. Second reagent distribution ring; 5. Nozzle; 6. Local mixing mechanism; 7. Jet impact plate; 8. Diverting guide vane array; 9. Stirring mechanism. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0024] like Figure 1 and Figure 2As shown, a low-temperature catalytic device for isocyanate crosslinking agents includes: a reaction vessel body 1, a second reagent storage tank 2, a high-pressure delivery pump group 3, a second reagent distribution ring 4, a nozzle 5, a local mixing mechanism 6, a jet impact plate 7, a flow guide vane array 8, and a stirring mechanism 9. These components, through a reasonable arrangement and connection, jointly achieve rapid dispersion and uniform mixing of the catalyst or second reagent in a low-temperature, high-viscosity system.

[0025] The reactor body 1 is a cylindrical structure with a jacket on its outer wall. A low-temperature cooling medium is circulated within the jacket to maintain the low-temperature environment of the reaction system. The reactor body 1 has a discharge port at the bottom and a feed port and observation window at the top. In actual operation, the reactor body 1 serves as the core load-bearing component of the entire device, used to hold the isocyanate crosslinking agent.

[0026] In this embodiment, the second reagent storage tank 2 is located outside the reaction vessel body 1. It is a sealed tank with a liquid level sensor and a temperature control device inside. The liquid level sensor is used to monitor the remaining amount of reagent in the tank in real time, while the temperature control device controls the temperature inside the tank through built-in heating or cooling elements to ensure that the reagent is under suitable storage conditions. The second reagent storage tank 2 is connected to the inlet end of the high-pressure delivery pump group 3 through a pressure-resistant pipeline. A filter is installed in the pipeline to remove any impurities that may be present, thereby avoiding the influence of impurities on the subsequent fluid delivery and injection process.

[0027] In this embodiment, the high-pressure delivery pump unit 3 uses a high-pressure pump to extract reagents or catalysts from the second reagent storage tank 2 and deliver them through a high-pressure pipeline to the inner cavity of the second reagent distribution ring 4 (the pump is not shown in the figure). A one-way valve is installed at the outlet end of the high-pressure delivery pump unit 3 to prevent fluid backflow. Pressure sensors and flow meters are installed on the high-pressure pipeline to monitor pressure and flow parameters in real time during the delivery process. This monitoring data is fed back to the operating interface through the control system, allowing operators to adjust the operating status of the high-pressure pump according to actual conditions, ensuring the stability and accuracy of the delivery process.

[0028] In this embodiment, the second reagent dispensing ring 4 is an annular pipe structure with a circular or rectangular cross-section. It is installed inside the reactor body 1 and fixed to the inner wall of the reactor body 1 by multiple adjustable-length support rods. The support rods, in conjunction with an electric lifting mechanism (not shown in the figure), enable the vertical movement of the second reagent dispensing ring 4, thereby adapting to the liquid level operation requirements of different batches or different reaction stages. The electric lifting mechanism is located on the upper part of the reactor body 1, with its telescopic rod pointing vertically downwards.

[0029] Furthermore, the second reagent distribution ring 4 is positioned below the reaction liquid surface and close to the middle region of the liquid to ensure that the reagent can be evenly distributed throughout the reaction system. Figure 2As shown, multiple nozzles 5 are evenly distributed on the outer wall of the second reagent dispensing ring 4. The number and angle of the nozzles 5 are optimized according to the size of the reactor body 1 and the viscosity of the fluid. For example, in a reactor body 1 with a diameter of 800 mm, 16 nozzles 5 can be set, with an angular interval of 22.5° between each nozzle 5, to achieve all-round coverage of the fluid.

[0030] It should be noted that the interior of the second reagent distribution ring 4 is designed as an annular pressure equalization chamber, the main function of which is to ensure that the fluid has a uniform pressure distribution throughout the annular chamber before the catalyst or the second reagent enters each nozzle 5.

[0031] Furthermore, the outlet direction of nozzle 5 is perpendicular to the axis of the second reagent dispensing ring 4 and points towards the central region of the reactor body 1. The internal channel of nozzle 5 is designed with a tapering structure, with an inlet diameter of 3 mm and an outlet diameter of 1 mm, which can reduce energy loss while increasing the fluid injection speed. Nozzle 5 is fixed to the outer wall of the second reagent dispensing ring 4 by a threaded connection, which facilitates disassembly and maintenance.

[0032] like Figure 3 As shown, the local mixing mechanism 6 surrounds the spray area of ​​the nozzle 5 and is fixed to the outer wall of the second reagent dispensing ring 4 by bolts or welding. It generates high-intensity local shear force and turbulence in the radial jet spray area to promote the instantaneous micro-mixing of the jet fluid and the bulk high-viscosity fluid.

[0033] The local mixing mechanism 6 consists of multiple jet impact plates 7 and a flow-diverting guide vane array 8. The jet impact plates 7 are positioned directly in front of or slightly off-center from the outlet of each nozzle 5, with their surfaces inclined at a 45°-60° angle to the jet direction. When the high-speed jet impacts this plate surface, the jet's kinetic energy is rapidly and efficiently converted into powerful shear force, forcing the fluid to undergo drastic changes in direction and velocity gradients over a very short distance. This impact effect induces the formation of a strong local shear layer and vortices, thereby achieving initial, efficient mixing of the catalyst and the bulk high-viscosity fluid at the micrometer scale. To further enhance the shear effect and mixing surface area, the surface of the jet impact plates 7 is provided with a flow-diverting guide vane array 8, which consists of multiple guide vanes, each with serrated or wavy edges, increasing the complexity and interface disturbance during fluid passage.

[0034] Furthermore, multiple jet impact plates 7 are arranged around the nozzle in a spiral or staggered manner. The jet impact plates 7, in conjunction with the flow guide vane array 8, divide the impacted jet or the directly ejected jet into multiple micro-fluids and guide these micro-fluids to contact the main fluid at a specific angle (such as a micro-tangential angle of 15°-30°) and mix spirally. This can increase the contact area and mixing path of the fluid, and generate effective stratification and remixing in high-viscosity fluids, thereby further improving the mixing uniformity.

[0035] In this embodiment, the stirring mechanism 9 is installed on the central axis of the reactor body 1 and includes a drive motor, a transmission shaft, and stirring blades. The drive motor is connected to the transmission shaft via a reducer, and the transmission shaft is fixed to the top of the reactor body 1 via a bearing housing. The stirring blades cover the entire height of the reaction liquid surface and are designed with low shear to avoid excessive foaming or localized overheating under low temperature and high viscosity conditions. The rotation radius of the stirring blades is smaller than the radius of the second reagent distribution ring 4 to prevent the stirring blades from colliding with the second reagent distribution ring 4 and the local mixing mechanism 6, thus avoiding damage to the device.

[0036] When a catalyst or second reagent needs to be added, the operator starts the high-pressure delivery pump unit 3 via the control system to extract the reagent from the second reagent storage tank 2 and send it into the inner cavity of the second reagent distribution ring 4. Under the action of the high-pressure delivery pump unit 3, the reagent enters the inner cavity of the second reagent distribution ring 4 at a set pressure, and is then sprayed at high pressure through multiple nozzles 5 into the isocyanate crosslinking agent within the reactor body 1. The high-speed fluid jet generated during the spraying process creates strong shear force in the outlet region of the nozzles 5, while the local mixing mechanism 6 further enhances the turbulence intensity in the spraying region, promoting immediate mixing of the catalyst and the main reactants. Subsequently, the stirring mechanism 9 operates at a lower speed, diffusing the uniformly mixed region formed in the spraying region throughout the entire reaction system, thereby maintaining the overall homogeneity of the system.

[0037] In specific applications, this invention can be used for the industrial production of low-temperature, high-viscosity isocyanate crosslinking agents. For example, in a chemical plant, the device of this invention is used for catalyst addition and mixing. First, the isocyanate crosslinking agent is injected into the reactor body 1, and the temperature of the reaction system is maintained at 5°C by a low-temperature cooling medium in the jacket. Then, the catalyst is injected into the second reagent storage tank 2, and the operating parameters of the high-pressure delivery pump group 3 are set by the control system. After the high-pressure delivery pump group 3 is started, the catalyst is delivered to the inner cavity of the second reagent distribution ring 4 through a high-pressure pipeline, and sprayed into the isocyanate crosslinking agent in the reactor body 1 in a high-pressure form through multiple tiny radial nozzles 5. During the spraying process, the local mixing mechanism 6 enhances the turbulence intensity of the spraying area, promoting the instantaneous mixing of the catalyst and the main reactants. Finally, the stirring mechanism 9 is started to diffuse the uniform mixing area formed in the spraying area into the entire reaction system, ensuring the overall uniformity of the system. Through the operation of this device, the catalyst achieves rapid dispersion and uniform mixing in a short time, significantly improving reaction efficiency and product quality.

[0038] Through the above steps, the catalyst achieves rapid dispersion and uniform mixing in a short time. The tapered channel design of nozzle 5 increases the fluid injection velocity and reduces energy loss; the local mixing mechanism 6 enhances turbulence intensity through the synergistic effect of the jet impact plate 7 and the flow-dividing guide vane array 8, enabling the catalyst to be uniformly dispersed throughout the reaction system in a short time; the stirring mechanism 9 operates at a low speed, spreading the uniform mixing area formed in the injection zone throughout the entire reaction system, ensuring the overall homogeneity of the system. Ultimately, the catalyst distribution in the reaction system is more uniform, the probability of side reactions is significantly reduced, catalytic efficiency is improved, and product quality is enhanced.

[0039] Based on the preferred embodiments of this utility model described above, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A low temperature catalytic device for isocyanate crosslinkers, characterized by, include: Reactor body (1); The second reagent storage tank (2) is located outside the reaction vessel body (1); The high-pressure delivery pump unit (3) is connected to the second reagent storage tank (2) through a pipeline; The second reagent distribution ring (4) is located inside the reactor body (1), and the second reagent distribution ring (4) is connected to the outlet of the high-pressure delivery pump group (3) through a pipeline; Multiple nozzles (5) are equidistantly arranged on the outer wall of the second reagent dispensing ring (4) and communicate with the internal flow channel of the second reagent dispensing ring (4); A local mixing mechanism (6) is disposed on the outer wall of the second reagent dispensing ring (4) and adjacent to the outlet area of ​​each of the nozzles (5); as well as The stirring mechanism (9) is located on the central axis of the reactor body (1).

2. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The outer wall of the reactor body (1) is provided with a jacket, and a cooling medium is introduced into the jacket.

3. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The second reagent distribution ring (4) is located below the reaction liquid surface and close to the middle of the liquid inside the reaction vessel body (1).

4. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The nozzle (5) has an outlet direction perpendicular to the axis of the second reagent dispensing ring (4) and points towards the central region of the reactor body (1).

5. The low-temperature catalytic device for an isocyanate crosslinking agent according to claim 1, characterized in that: The second reagent dispensing ring (4) is a ring-shaped pipe structure with a circular or rectangular cross-section.

6. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The second reagent dispensing ring (4) is fixed to the inner wall of the reactor body (1) by multiple adjustable length support rods. The support rods, in conjunction with the electric lifting mechanism, enable the vertical movement of the second reagent dispensing ring (4).

7. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The local mixing mechanism (6) includes: Multiple jet impact plates (7) are disposed directly in front of or slightly off-center from the outlet of each nozzle (5), and the surface of the jet impact plate (7) is set at an angle of 45°-60° to the jet direction; A flow divider array (8) is disposed on the surface of the jet impact plate (7). The flow divider array (8) consists of multiple flow divider blades, each of which has a serrated or wavy edge.

8. A low temperature catalyst device for isocyanate crosslinkers according to claim 7, characterized in that: Multiple jet impact plates (7) are arranged around the nozzle in a spiral or staggered manner.

9. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The stirring mechanism (9) includes: A drive motor is located on the upper part of the reactor body (1); A drive shaft is disposed inside the reactor body (1), and the upper end of the drive shaft is connected to the output end of the drive motor; Multiple stirring blades are arranged on the circumferential surface of the drive shaft, and the rotation radius of the stirring blades is smaller than the radius of the second reagent dispensing ring (4).

10. The low temperature catalyst device for isocyanate crosslinker according to claim 1, characterized in that: The interior of the second reagent distribution ring (4) is an annular pressure equalization chamber.

Images