Multi-stage and multi-section stirring device, optimization method of stirring blades and sulfuric acid alkylation reactor

Abstract

The invention relates to the technical field of chemical equipment, in particular to a multi-stage and multi-section stirring device and a sulfuric acid alkylation reactor, the multi-stage and multi-section stirring device comprises a stirring shaft, push type stirring blades and a motor, at least one section is arranged at the end of the stirring shaft, and the section comprises a first shaft section, a second shaft section and a shaft sleeve; a polygonal bulge structure and a wedge-shaped key body structure are arranged at the end part of the first shaft section, and the size of the wedge-shaped key body structure is larger than that of the outer circular surface of the first shaft section; a polygonal groove structure and a first wedge-shaped groove are formed in the end part of the second shaft section; the shaft sleeve comprises a second wedge-shaped groove; the polygonal protruding structure is inserted into the polygonal groove structure, one part of the wedge-shaped key body structure is inserted into the first wedge-shaped groove, the other part of the wedge-shaped key body structure is inserted into the second wedge-shaped groove, a first locking piece is arranged between the shaft sleeve and the second shaft section, the wedge-shaped key body part is embedded into the two sets of wedge-shaped grooves, wedge-shaped self-locking matching is formed, and self-locking linkage is achieved through natural resistance. Stress concentration is effectively reduced, and operation stability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical equipment, and particularly relates to a multi-stage and multi-section stirring device and a sulfuric acid alkylation reactor. Background Art

[0002] The sulfuric acid alkylation reactor is a key equipment in petrochemical and fine chemical production, and is widely used in the alkylation reaction process. The core part of this reactor is the stirring device, whose main function is to improve the reaction efficiency through mechanical stirring to ensure the full contact between reactants and catalysts. Since the sulfuric acid alkylation reaction process is usually carried out under high temperature, high pressure and strong corrosive conditions, the stirring shaft of the stirring device needs to bear huge mechanical stress and chemical corrosion. Therefore, the structure and design of the stirring shaft are crucial for the stable operation of the reactor.

[0003] However, the current stirring devices generally adopt an integral single stirring shaft. During long-term operation, due to uneven stress distribution and corrosion, the stirring shaft is prone to fatigue fracture or serious wear, which directly affects the stability of the equipment and production efficiency. Especially at the hydraulic head rotating shaft of the stirring shaft, due to stress concentration, fracture often occurs, resulting in frequent equipment failures and shutdowns, thus increasing production costs.

[0004] The information disclosed in this background art section is only intended to deepen the understanding of the overall background art of the present invention, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0005] The present invention provides a multi-stage and multi-section stirring device and a sulfuric acid alkylation reactor, thereby effectively solving the problems pointed out in the background art.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A multi-stage and multi-section stirring device, comprising: a stirring shaft, a propeller stirring blade and a motor, the propeller stirring blade is arranged on the stirring shaft, and the motor drives the stirring shaft to rotate; At least one segment is provided at the end of the stirring shaft, the segment includes a first shaft segment, a second shaft segment and a shaft sleeve, the end of the first shaft segment forms a polygonal convex structure with an axis distribution, a wedge key structure is arranged at the intersection of every two faces of the polygonal convex structure, and the size of the wedge key structure is larger than the outer circular surface of the first shaft segment; the end of the second shaft segment is provided with a polygonal groove structure, and a first wedge groove is arranged at the intersection of every two faces of the polygonal groove structure; The shaft sleeve includes a hollow body and an annular reinforcing rib arranged at one end of the body, and a second wedge groove is arranged between the two annular reinforcing ribs; The polygonal convex structure is inserted into the polygonal groove structure, a part of the wedge key structure is inserted into the first wedge groove, and another part is inserted into the second wedge groove, and a first locking member is provided between the shaft sleeve and the second shaft section.

[0007] Further, an end cover is provided at one end of the shaft sleeve close to the segment for restricting the axial movement of the first shaft section along the stirring shaft; The end cover includes an annular side wall and a bottom wall provided at the bottom of the side wall. The bottom wall abuts against the end face of the part of the protruding wedge key structure. A step surface is provided on the shaft sleeve close to the side of the end cover. The side wall is sleeved on the step surface and fixed with a second locking member.

[0008] Further, angles are provided on both side surfaces of the wedge key structure, so that one end of the wedge key structure away from the polygonal convex structure gradually expands.

[0009] Further, the included angle between both side surfaces of the wedge key structure is 20° to 40°.

[0010] Further, a third groove structure is provided at the center of the polygonal convex structure, a second convex structure is provided at the bottom of the polygonal groove structure, and the second convex structure is inserted into the third groove structure.

[0011] Further, equidistant additional strain sensors are arranged inside the shaft sleeve.

[0012] Further, it further includes small stirring blades arranged behind the propeller stirring blades. At least two of the small stirring blades are arranged in an eight-character shape for preventing blockage at the outlets of the inner circulation sleeve and the outer circulation sleeve of the alkylation reactor.

[0013] Further, it further includes medium stirring blades arranged before the motor and the small stirring blades. Each medium stirring blade includes a first blade segment and a second blade segment arranged perpendicular to each other for increasing the contact area.

[0014] The present invention further includes an optimization method for stirring blades, including performing a hollowing design on the propeller stirring blades on the multi-stage multi-segment stirring device as described above for alleviating the pressure on the end of the stirring shaft by the propeller stirring blades. The steps of the hollowing design include: According to the method of fluent fluid-structure interaction, the pressure of the fluid on the stirring shaft is conducted into the transient stress simulation to calculate the possible deformation of the stirring shaft under different stress conditions; The deformation is fed back into the backflow fluid simulation, and the two-way fluid-structure interaction of the stirring shaft is realized through iterative calculation; A three-dimensional model of a sulfuric acid alkylation reactor was established, and the three-dimensional model was set by DesignModeler to perform fluid domain filling; Set the raw material inlet, reaction cavity circulation temperature of the sulfuric acid alkylation reactor, and relevant parameters of raw materials, catalysts, and agitator shaft materials added to the fluid; Perform a coupled simulation of fluid flow and transient structure, solve the stress nephogram and total deformation, and observe the force distribution of the agitator shaft; According to the stress nephogram and total deformation, perform a hollowing treatment on the corresponding position of the propeller agitator blade.

[0015] The present invention further includes a sulfuric acid alkylation reactor, comprising a shell, a heat exchange tube bundle, a cold water inlet, a cold water outlet, a raw material inlet, an acid liquid inlet, a reactant outlet, and a multi-stage and multi-section stirring device as described above; The shell includes an outer layer and an inner layer arranged in sequence. The heat exchange tube bundle is arranged in the inner layer. The cold water inlet, the cold water outlet, the raw material inlet, the acid liquid inlet, and the reactant outlet are respectively arranged on the shell, and the cold water inlet, the cold water outlet, and the heat exchange tube bundle are connected; The multi-stage and multi-section stirring device is arranged at one end of the shell close to the raw material inlet, and is used to generate negative pressure during stirring, stir the mixed raw materials and acid liquid, and press them into the interlayer between the outer layer and the inner layer for reaction.

[0016] Through the technical solution of the present invention, the following technical effects can be achieved: Introduce a special wedge-shaped structure at the end of the agitator shaft. This structure has significant self-locking characteristics. When the two wedge surfaces are in contact under force, the wedge fit can automatically generate resistance, effectively preventing the loosening of components under load. This structure is particularly suitable for high-vibration or impact load conditions, significantly enhancing the operation safety and structural reliability of the device.

[0017] The design of annular stiffeners is added and fixed and connected through a special shaft sleeve to ensure that the shaft body will not bend or break when subjected to large torques and stresses. At the same time, stress concentration is reduced, and the stress in the agitator shaft is dispersed to each stiffener position to avoid breakage during the operation of the agitator shaft. Due to the deliberate increase in the length of the wedge key structure at the mating part of the agitator shaft to achieve an interference fit, the extra part is mated with the stiffeners to make the three produce a linkage effect, and at the same time, when combined together, multiple effects are achieved. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of a multi-stage and multi-section stirring device; Figure 2 It is a schematic structural diagram of the first shaft section; Figure 3 It is a schematic structural diagram of the second shaft section; Figure 4 It is a schematic structural diagram of the combination of the first shaft section and the second shaft section; Figure 5 It is a schematic structural diagram of the combination of the first shaft section, the second shaft section, and the shaft sleeve; Figure 6 It is a schematic structural diagram of the combination of the first shaft section, the second shaft section, the shaft sleeve, and the end cover; Figure 7 It is a schematic structural diagram of the bottom wall of the end cover abutting against the end of the wedge-shaped key body structure; Figure 8 It is an equivalent stress nephogram of the stirring shaft; Figure 9 It is a schematic structural diagram of the stirring blade; Figure 10 It is a schematic structural diagram of a sulfuric acid alkylation reactor.

[0020] Reference numerals: 1, stirring shaft; 11, segments; 111, first shaft section; 111a, polygonal convex structure; 111b, wedge-shaped key body structure; 111c, third groove structure; 112, second shaft section; 112a, polygonal groove structure; 112b, first wedge-shaped groove; 112c, second convex structure; 113, shaft sleeve; 113a, body; 113b, annular reinforcing rib; 113c, second wedge-shaped groove; 113d, step surface; 113e, equally spaced additional strain sensors; 114, end cover; 114a, side wall; 114b, bottom wall; 115, first locking member; 116, second locking member; 2, pusher stirring blade; 21, hollow; 3, small stirring blade; 4, medium stirring blade; 41, first blade segment; 42, second blade segment; 5, motor. 01, multi-stage and multi-section stirring device; 02, outer layer; 021, outer circulation sleeve; 03, inner layer, 031, inner circulation sleeve; 04, heat exchange tube bundle; 05, cold water inlet; 06, cold water outlet; 07, raw material inlet; 08, acid liquid inlet; 09, reactant outlet. Detailed implementation manners

[0021] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] As Figures 1 to 7 shown: A multi-stage and multi-section stirring device includes: a stirring shaft 1, a propeller stirring blade 2, and a motor 5. The propeller stirring blade 2 is arranged on the stirring shaft 1, and the motor 5 drives the stirring shaft 1 to rotate; The stirring shaft 1 is provided with at least one section 11 at the end. The section 11 includes a first shaft section 111, a second shaft section 112, and a shaft sleeve 113. The end of the first shaft section 111 forms a polygonal convex structure 111a with an axial center distribution. A wedge key structure 111b is arranged at the intersection of every two faces of the polygonal convex structure 111a, and the size of the wedge key structure 111b is larger than the outer circular surface of the first shaft section 111; a polygonal groove structure 112a is provided at the end of the second shaft section 112, and a first wedge groove 112b is arranged at the intersection of every two faces of the polygonal groove structure 112a; The shaft sleeve 113 includes a hollow body 113a and an annular reinforcing rib 113b arranged at one end of the body 113a. A second wedge groove 113c is arranged between the two annular reinforcing ribs 113b; The polygonal convex structure 111a is inserted into the polygonal groove structure 112a. A part of the wedge key structure 111b is inserted into the first wedge groove 112b, and the other part is inserted into the second wedge groove 113c. A first locking member 115 is arranged between the shaft sleeve 113 and the second shaft section 112.

[0024] During installation, referring to Figures 2 to 5 , first insert the polygonal convex structure 111a of the first shaft section 111 into the polygonal groove structure 112a of the second shaft section 112. At this time, the wedge key structure 111b is inserted into the second wedge groove 113c. Then install the shaft sleeve 113 at the splicing position, so that the wedge key structure 111b protruding from the outer circular surface of the second shaft section 112 is inserted into the second wedge groove 113c of the shaft sleeve 113. Then, fix the shaft sleeve 113 and the second shaft section 112 through the first locking member 115 to complete the assembly of the stirring shaft 1. Then, install the propeller stirring blade 2 and the motor 5 at both ends of the stirring shaft 1 respectively, asFigure 1 As shown, the installation of the stirring device is completed.

[0025] Through the polygonal protrusion structure 111a and the polygonal groove structure 112a, a larger contact area is provided, thereby improving the torque transmission efficiency and enhancing the anti-slip ability. The multi-angle contact surfaces can effectively disperse the lateral force, reduce the risk of stress concentration, and decrease the possibility of shaft bending or misalignment. The wedge-shaped key body structure 111b is located between the first shaft section 111 and the second shaft section 112, forming a wedge-shaped self-locking fit, which can generate natural resistance during operation. The first wedge-shaped groove 112b and the second wedge-shaped groove 113c work together to ensure that the wedge-shaped key body structure 111b achieves the self-locking linkage effect.

[0026] By splitting a long shaft into multiple smaller shaft sections, the stirring shaft 1 can significantly reduce the weight of a single shaft section, thus facilitating transportation and on-site installation. For large alkylation reactors or installation environments with limited space, the structure of the stirring shaft 1 is particularly applicable, enabling rapid assembly and connection on-site.

[0027] In addition, since the segmented structure 11 consists of multiple shaft sections, once a certain shaft section is damaged or needs to be replaced, only the corresponding section needs to be replaced, without the need to replace the entire stirring shaft 1 as a whole. This significantly simplifies the maintenance operation and reduces the maintenance cost and downtime.

[0028] In an environment with high vibration or high impact load, the structure of the stirring shaft 1 can also effectively absorb and disperse external loads, reducing system failures caused by the overall excessive length of the shaft or material mismatch. By reasonably designing the connection structure and support method between each section, it helps to reduce the stress concentration phenomenon and improve the overall operation stability.

[0029] In addition, a special wedge-shaped structure is introduced at the end of the stirring shaft 1, which has significant self-locking characteristics. When the two wedge-shaped surfaces are in contact under force, the wedge-shaped fit can automatically generate resistance, effectively preventing the loosening of components under load. This structure is particularly suitable for working conditions with high vibration or impact load, significantly enhancing the operation safety and structural reliability of the device.

[0030] The design of the annular reinforcing rib 113b is increased and fixedly connected through a special shaft sleeve 113 to ensure that the shaft body will not bend or break under large torque and stress. At the same time, stress concentration is reduced, and the stress in the stirring shaft 1 is dispersed to each reinforcing rib position, avoiding fracture during the operation of the stirring shaft 1. Due to the intentional increase in the length of the wedge-shaped key body structure 111b at the mating part of the stirring shaft 1 to achieve an interference fit, the extra part is mated with the reinforcing rib to make the three produce a linkage effect, and at the same time, they work together to achieve multiple effects.

[0031] The stirring shaft 1 of the present invention is designed with a multi-stage bushing 113 support structure. The connection of the stirring shaft 1 is fixed by the bushing 113, and at the same time, its annular reinforcing rib 113b is combined with it to achieve multiple effects, which can not only fix but also strengthen the fastening. Small annular reinforcing ribs 113b are designed outside the circumference of the bushing 113 to improve the support strength and reduce the weight for easy matching. Each bushing 113 is reasonably spaced, which can effectively disperse the load during the reaction process, reduce the axial and radial pressures on the shaft body, and avoid excessive wear of a single shaft. The bushing 113 is made of corrosion-resistant alloy material and can maintain a long service life in a harsh reaction environment.

[0032] In this embodiment, the stirring shaft 1 is divided into two positions, namely the end and the middle, where two stirring shafts 1 are provided. Different numbers of sub-shaft segments are set according to current requirements, and all are within the protection scope of this application.

[0033] Since vibration is likely to occur during the rotation of the rotating shaft, an interference fit is provided between the inner wall of the annular reinforcing rib 113b and the first shaft segment 111, which can prevent the first shaft segment 111 from falling off along the axial direction of the stirring shaft 1. However, there is still a risk of loosening of the first shaft segment 111. Therefore, the following improvements are made: As a preference of the above embodiment, as Figures 6 to 7 shown, one end of the bushing 113 close to the segment 11 is provided with an end cover 114 for restricting the axial movement of the first shaft segment 111 along the stirring shaft 1; The end cover 114 includes an annular side wall 114a and a bottom wall 114b provided at the bottom of the side wall 114a. The bottom wall 114b abuts against the end face of a partially protruding wedge-shaped key body structure 111b. One side of the bushing 113 close to the end cover 114 is provided with a step surface 113d. The side wall 114a is sleeved on the step surface 113d and fixed with a second locking member 116. Specifically, the end cover 114 is fixed on the bushing 113, the bushing 113 is fixed on the second shaft segment 112, and the bottom wall 114b of the end cover 114 abuts against the side of the partially protruding wedge-shaped key body structure 111b on the first shaft segment 111, restricting the axial movement of the first shaft segment 111 along the stirring shaft 1, preventing the risk of loosening in the circumferential direction of the first shaft segment 111 during long-term use, and improving the stability.

[0034] In this embodiment, continue to refer to Figure 2 , the two side surfaces of the wedge-shaped key body structure 111b are provided with angles, so that one end of the wedge-shaped key body structure 111b away from the polygonal convex structure 111a gradually expands. On the one hand, the angle design of the two side surfaces of the wedge-shaped key body structure 111b enables the wedge-shaped structure to generate a stronger self-locking effect when subjected to a load, ensuring the fastening between the shaft segments, preventing loosening and detachment, and improving the stability and safety of the stirring device; on the other hand, the gradually expanding structure of the wedge-shaped key can effectively disperse the pressure applied to its surface, reduce the fatigue accumulation at a single contact point, and extend the service life of the stirring device.

[0035] Among them, the included angle between the two side surfaces of the wedge-shaped key body structure 111b is 20° to 40°, which effectively enhances the self-locking effect of the wedge-shaped fit, improves the fastening between shaft segments, prevents loosening caused by vibration or impact, and ensures the stable operation of the device under high load.

[0036] As a preference of the above embodiment, continue to refer to Figure 2 and Figure 3 , a third groove structure 111c is provided at the center of the polygonal protrusion structure 111a, and a second protrusion structure 112c is provided at the bottom of the polygonal groove structure 112a. The second protrusion structure 112c is inserted into the third groove structure 111c, which can effectively improve the torque transmission efficiency and ensure the uniform transmission of torque between each shaft segment, thereby enhancing the transmission performance of the entire stirring device.

[0037] In this embodiment, the cross-sections of the third groove structure 111c and the second protrusion structure 112c are regular hexagram structures, and can also be other polygonal shapes. The regular hexagram structure composed of twelve faces increases the contact area, effectively disperses the stress, reduces the local stress concentration phenomenon, thereby reducing the fatigue accumulation of the shaft segment and improving the service life of the device.

[0038] Among them, the cross-sections of the polygonal protrusion structure 111a and the polygonal groove structure 112a are regular polygonal structures. Specifically, the design of the regular polygonal cross-section provides a more uniform contact surface, evenly distributes the applied force between the contact surfaces, improves the torque transmission efficiency, and avoids the slip problems that may be caused by traditional circular or irregular-shaped contact surfaces, thereby enhancing the overall power transmission performance.

[0039] In this embodiment, the polygonal protrusion structure 111a and the polygonal groove structure 112a are regular hexagon structures. In this embodiment, at least the stirring shaft 1 is designed at the end. Through the combination of the designed polygonal protrusion structure 111a, polygonal groove structure 112a, wedge-shaped structure, first wedge-shaped groove 112b, and second wedge-shaped groove 113c, as an alternative embodiment, the regular hexagon structure is selected, and other polygonal structures are also within the protection scope of this application. The regular hexagon structure can provide a larger contact surface for the multi-shaft fit design, ensure no sliding occurs during torque transmission, has a larger contact area, higher torque transmission efficiency, is suitable for high-load transmission, and due to its multi-angle contact surface, the contact between the shaft and the connecting component is more uniform, can effectively disperse the lateral force acting on the shaft, prevent deviation or bending, and enhance the stability of the overall structure.

[0040] Among them, refer to Figure 6, an equidistant additional strain sensor 113e is arranged inside the shaft sleeve 113. The stress received by each section is detected through the strain sensor to predict the fracture of the stirring shaft 1 in advance, ensure that the temperature of the stirring shaft 1 is within a safe range, avoid material fatigue and fracture caused by overheating, and finally make the sensor and the shaft sleeve 113 produce a linkage effect.

[0041] In this embodiment, referring to Figure 1 , it further includes small stirring blades 3 arranged behind the propeller stirring blade 2. At least two small stirring blades 3 are arranged in a V shape to prevent blockage at the outlets of the inner circulation sleeve 031 and the outer circulation sleeve 021 of the alkylation reactor. This is due to the special structure inside the alkylation reactor. Its reaction mechanism is that the paddle at the end of the stirring shaft 1 stirs to play the role of a circulation pump, so that the emulsion combined with the internal sulfuric acid catalyst inlet and the raw material inlet can be sucked into the external circulation sleeve, thereby realizing the circulation of the alkylation reaction.

[0042] As a preference of the above embodiment, it further includes medium stirring blades 4 arranged before the motor 5 and the small stirring blades 3. Each medium stirring blade 4 includes a first blade segment 41 and a second blade segment 42 arranged perpendicular to each other, which are used to increase the contact area and the stirring efficiency. The purpose of the medium stirring blade 4 is to enable the reactants sucked out from the inner layer 03 to be fully mixed before entering the outer layer 02 for circulation, avoid the reactants being unevenly stirred at the external circulation sleeve and unable to fully complete the alkylation reaction, and cause waste by flowing out from the waste acid outlet before being fully reacted.

[0043] The present invention further includes an optimization method for stirring blades, which includes performing a hollowing 21 design on the propeller stirring blade 2 of the multi-stage and multi-section stirring device 01 as described above to relieve the pressure on the end of the stirring shaft 1 by the propeller stirring blade 2. The steps of the hollowing 21 design include: S10: According to the method of fluid-solid coupling of fluent, the pressure of the fluid on the stirring shaft 1 is conducted into the transient stress simulation to calculate the possible deformation of the stirring shaft 1 under different stress conditions; S20: Feed back the deformation to the fluid simulation, and realize the two-way fluid-solid coupling of the stirring shaft 1 through iterative calculation; S30: Establish a three-dimensional model of the sulfuric acid alkylation reactor, and set the three-dimensional model through DesignModeler to perform fluid domain filling; and set and name the inlet and outlet; in order to simulate the overlap of the internal fluid domain and the solid domain, perform a Boolean operation on it, and at the same time suppress the shell area to reduce the calculation time; name each part such as the shaft body, the stirring paddle, and the bearing respectively to facilitate the subsequent processing of the dynamic mesh of the stirring shaft 1; S40: Set the relevant parameters of the raw material inlet 07 of the sulfuric acid alkylation reactor, the circulating temperature of the reaction inner cavity, as well as the raw materials, catalyst, and the material of the stirring shaft 1 added to the fluid; S50: Conduct a coupled simulation of fluid flow (Fluent) and transient structure, solve the stress nephogram and total deformation, and observe the stress distribution of the stirring shaft 1; S60: Perform a hollowing 21 treatment on the corresponding position of the propeller stirring blade 2 according to the stress nephogram and total deformation.

[0044] As Figure 8 shown, it can be observed that the stress concentration on the outer side of the stirring paddle blade is too high. By appropriately adjusting the structural design of the parameters, the stress concentration and gravity of the stirring paddle blade can be reduced, thereby preventing the fracture of the stirring shaft 1. By combining fluid-solid coupling simulation and fluid dynamics analysis, the rationality and feasibility of the hollowing design can be ensured. For the stirring paddle blade, the best positions for the hollowing design are usually the middle and end of the blade. These positions are relatively suitable for weight reduction, and since the bending stress is not concentrated, the impact on the bearing capacity during hollowing is small. The stress on these areas is small. After hollowing, not only the weight can be reduced, but also the performance of the blade will not be significantly affected. Careful design should be carried out in the root area to avoid excessive hollowing to prevent affecting the bearing capacity and stability of the blade, as Figure 9 .

[0045] Through the Fluent fluid-solid coupling simulation, the pressure of the fluid on the stirring shaft 1 can be accurately analyzed and transmitted to the transient stress simulation, ensuring that the deformation under different stress conditions is fully calculated and optimized, providing a scientific basis for the hollowing 21 design of the propeller stirring blade 2. Through the iterative calculation of two-way fluid-solid coupling, the mutual influence between the deformation of the stirring blade and the fluid is finely adjusted, making the design of the stirring blade more efficient and stable, improving the uniformity of the stirring process, and further enhancing the reaction efficiency. Through the iterative calculation of two-way fluid-solid coupling, the mutual influence between the deformation of the stirring blade and the fluid is finely adjusted, making the design of the stirring blade more efficient and stable, improving the uniformity of the stirring process, and further enhancing the reaction efficiency. By optimizing the hollowing 21 design of the stirring blade and reducing its load, the service life of the stirring device is extended under the conditions of high load and long-term operation, and the maintenance frequency and downtime are reduced.

[0046] The present invention also includes a sulfuric acid alkylation reactor, as Figure 10 shown, which includes a shell, a heat exchange tube bundle 04, a cold water inlet 05, a cold water outlet 06, a raw material inlet 07, an acid liquid inlet 08, a reactant outlet 09, and the multi-stage and multi-section stirring device 01 as described above; The housing includes an outer layer 02 and an inner layer 03 arranged in sequence. The heat exchange tube bundle 04 is arranged in the inner layer 03. A cold water inlet 05, a cold water outlet 06, a raw material inlet 07, an acid solution inlet 08, and a reactant outlet 09 are respectively arranged on the housing, and the cold water inlet 05, the cold water outlet 06, and the heat exchange tube bundle 04 are communicated with each other; A multi-stage and multi-section stirring device 01 is arranged at one end of the housing close to the raw material inlet 07, and is used for generating negative pressure during the stirring process to stir and press the mixed raw materials and acid solution into the interlayer between the outer layer 02 and the inner layer 03 for reaction.

[0047] Through the design of the multi-stage and multi-section stirring device 01, the raw materials and the acid solution can be effectively mixed, and negative pressure can be generated, so that the reactants can be more fully stirred and pressed into the interlayer between the inner layer 03 and the outer layer 02 of the housing for reaction, thereby significantly improving the reaction efficiency and accelerating the chemical reaction process. Through the design of the multi-stage and multi-section stirring device 01, the raw materials and the acid solution can be effectively mixed, and negative pressure can be generated, so that the reactants can be more fully stirred and pressed into the interlayer between the inner layer 03 and the outer layer 02 of the housing for reaction, thereby significantly improving the reaction efficiency and accelerating the chemical reaction process; the energy consumption is reduced, and the overall energy utilization efficiency is improved.

[0048] The optimized structural design of the present invention significantly improves the reliability and durability of the stirring shaft 1 in a harsh reaction environment. By improving the reaction efficiency, reducing the equipment failure rate and maintenance cost, the present invention shows a broad application prospect. This design not only optimizes the reaction efficiency, reduces the energy consumption, and prolongs the service life of the equipment, but also enhances the safety. In addition, the optimized structure reduces the equipment weight, saves materials, and improves the working efficiency.

[0049] Through the optimized design, the reliability of the equipment is improved, the maintenance cost is reduced, and the service life of the equipment is prolonged. It is especially suitable for high-load and high-strength mechanical equipment. This technology can be widely applied to the alkylation reaction process in industries such as chemical industry and oil refining, and has significant economic and social benefits.

[0050] The present invention optimizes the characteristics of unidirectional bending and high-cycle low-stress fatigue fracture caused by stress concentration during the operation of the alkylation reactor, and provides a more stable working environment for the alkylation reaction. Through the combination of various linkage designs, the present invention maximally improves the performance and stability of the reactor. It not only enhances the strength and durability of the stirring shaft 1, but also improves the safety and efficiency of the system through real-time monitoring and adjustment.

[0051] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A multi-stage and multi-section stirring device, characterized in that, It includes a stirring shaft, a propeller stirring blade and a motor. The propeller stirring blade is arranged on the stirring shaft, and the motor drives the stirring shaft to rotate; At least one section is arranged at the end of the stirring shaft. The section includes a first shaft section, a second shaft section and a shaft sleeve. The end of the first shaft section forms a polygonal convex structure with an axial center distribution. A wedge key body structure is arranged at the intersection of every two faces of the polygonal convex structure, and the size of the wedge key body structure is larger than the outer circular surface of the first shaft section; A polygonal groove structure is arranged at the end of the second shaft section, and a first wedge groove is arranged at the intersection of every two faces of the polygonal groove structure; The shaft sleeve includes a hollow body and an annular reinforcing rib arranged at one end of the body. A second wedge groove is arranged between the two annular reinforcing ribs; The polygonal convex structure is inserted into the polygonal groove structure. A part of the wedge key body structure is inserted into the first wedge groove, and the other part is inserted into the second wedge groove. A first locking part is arranged between the shaft sleeve and the second shaft section.

2. The multi-stage and multi-section stirring device according to claim 1, wherein An end cover is arranged at one end of the shaft sleeve close to the section to limit the axial movement of the first shaft section along the stirring shaft; The end cover includes an annular side wall and a bottom wall arranged at the bottom of the side wall. The bottom wall abuts against the end face of the partially protruding wedge key body structure. A step surface is arranged on the shaft sleeve close to the end cover side. The side wall is sleeved on the step surface and fixed with a second locking part.

3. The multi-stage and multi-section stirring device according to claim 1, wherein Angles are arranged on both sides of the wedge key body structure, so that one end of the wedge key body structure far from the polygonal convex structure gradually expands.

4. The multi-stage and multi-section stirring device according to claim 3, characterized in that, The included angle between the two side faces of the wedge key body structure is 20° to 40°.

5. The multi-stage and multi-section stirring device according to claim 1, characterized in that, A third groove structure is arranged at the center of the polygonal convex structure, and a second convex structure is arranged at the bottom of the polygonal groove structure. The second convex structure is inserted into the third groove structure.

6. The multi-stage and multi-section stirring device according to claim 1, characterized in that, Equidistant additional strain sensors are arranged in the shaft sleeve.

7. The multi-stage and multi-section stirring device according to claim 1, characterized in that, It also includes small stirring blades arranged behind the propeller stirring blades. At least two of the small stirring blades are arranged in a figure-eight shape to prevent blockage at the outlets of the inner circulation sleeve and the outer circulation sleeve of the alkylation reactor.

8. The multi-stage and multi-section stirring device according to claim 7, characterized in that, It also includes medium stirring blades arranged before the motor and the small stirring blades. Each medium stirring blade includes a first blade section and a second blade section arranged perpendicular to each other to increase the contact area.

9. An optimization method for a stirring blade, characterized in that, It includes a hollowing design for the propeller stirring blade on the multi-stage and multi-section stirring device according to any one of claims 1 to 8, which is used to relieve the pressure of the propeller stirring blade on the end of the stirring shaft. The steps of the hollowing design include: According to the method of fluent fluid-structure coupling, the pressure of the fluid on the stirring shaft is transmitted to the transient stress simulation to calculate the deformation that the stirring shaft may generate under different stress conditions; The deformation is fed back to the backflow fluid simulation, and the two-way fluid-structure coupling of the stirring shaft is realized through iterative calculation; A three-dimensional model of the sulfuric acid alkylation reactor is established, and the three-dimensional model is set through DesignModeler to fill the fluid domain; Set the relevant parameters of the raw material inlet, the reaction cavity circulation temperature of the sulfuric acid alkylation reactor, as well as the raw materials, catalysts and agitator shaft materials added to the fluid; Perform a coupled simulation of fluid flow and transient structure, solve the stress nephogram and total deformation, and observe the force distribution of the agitator shaft; According to the stress nephogram and total deformation, perform a hollowing treatment on the corresponding position of the propeller agitator blade.

10. An alkylation reactor with sulfuric acid, characterized in that, It includes a shell, a heat exchange tube bundle, a cold water inlet, a cold water outlet, a raw material inlet, an acid liquid inlet, a reactant outlet and the multi-stage and multi-section stirring device according to any one of claims 1 to 8; The shell includes an outer layer and an inner layer arranged in sequence, the heat exchange tube bundle is arranged in the inner layer, the cold water inlet, the cold water outlet, the raw material inlet, the acid liquid inlet and the reactant outlet are respectively arranged on the shell, and the cold water inlet, the cold water outlet and the heat exchange tube bundle are communicated; The multi-stage and multi-section stirring device is arranged at one end of the shell close to the raw material inlet, and is used to generate negative pressure during stirring, stir and press the mixed raw materials and acid liquid into the interlayer between the outer layer and the inner layer for reaction.

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