Heterogeneous catalyst dissolving device

Abstract

The invention relates to a heterogeneous catalyst dissolving device, which comprises: a tank body provided with a tank body inlet and a tank body outlet; the stirring structure is arranged in the tank body and comprises at least three stirrers which are arranged differently; the stirrers are used for stirring a solution in the tank body in sections to form different flow fields to promote stirring and dissolving of a catalyst in the tank body; the guide plate is connected to the inner wall of the tank body; the solution stirred and rotated by the stirring structure collides with the guide plate and then flows downwards, so that the catalyst in the tank body is stirred, mixed and dissolved again; the filtering structure comprises a first filtering structure and a second filtering structure, and the first filtering structure is arranged in the tank body; the second filtering structure is arranged on the outer side of the tank body. The flow guide plate and the segmented stirrer are matched, so that backflow of a solution in the tank body is enhanced, and mixing is more uniform; indissolvable or catalyst coarse particles can be screened out through double filtration inside and outside the tank body; according to the invention, the requirement of uniform and efficient solubility in the catalyst dissolving process can be met.

Description

Technical Field

[0001] This invention relates to the field of pretreatment equipment technology, and more particularly to a heterogeneous catalyst dissolution device. Background Technology

[0002] Polyolefin elastomers, abbreviated as POE, refer to random copolymer elastomers polymerized from ethylene and high-carbon α-olefins using metallocene catalysts. These elastomers exhibit a certain degree of crystallinity, a narrow molecular weight range, and a relatively low density. POE typically refers to ethylene-octene copolymer elastomers with an octene mass fraction greater than 20%. These elastomers have good compatibility with polyolefins and offer high cost-effectiveness, thus they are widely used in automotive, footwear, wire and cable, packaging, polymer modification, and medical fields.

[0003] In the small-scale or pilot-scale polymerization of POE using the olefin solution method, the catalyst needs to be prepared in a certain proportion before the polymerization reaction. It is then dissolved in a solvent in a dissolving device. Through forced optimization of dissolution, the concentration of the catalyst solution is made uniform, thereby ensuring that the concentration of the catalyst entering the reactor is balanced and maintaining the stability of the polymerization reaction.

[0004] Existing technology 1: A chemical solution premixing tank includes a mixing tank mechanism, a mixing scale mechanism, and a discharge mechanism. This design optimizes the design of the mixing blade, making the contact area with the solution larger during the mixing process. However, it does not further optimize other components of the equipment. The solubility of the raw materials under the action of the mixing blade is limited, and the amount of solubility cannot be further increased.

[0005] Existing technology 2: A solvent pretreatment tank includes a box body and a container installed inside the box body. Inside the box body, a first partition and a second partition are fixedly installed sequentially from top to bottom. A top cover is fixedly installed on the top of the box body, and a feed hopper is fixedly installed on top of the top cover. A first filter screen is fixedly installed inside the feed hopper. A discharge pipe is fixedly installed at the bottom of the container, and a second filter screen is fixedly installed inside the box body below the second partition. The drawback of this technology is that it is not conducive to discharge when there are too many impurities in the solution.

[0006] Existing technology 3: A whitening agent dissolving device, which includes a tank, a pre-dissolving cylinder, a feeding mechanism and a stirring mechanism. The defects of this technology are: there is no clear stirring device, temperature control system, and feeding and discharging issues, which is quite different from industrial production equipment and cannot reflect the true activity of the catalyst.

[0007] Therefore, based on years of experience and practice in related industries, the inventor proposes a heterogeneous catalyst dissolution device to overcome the shortcomings of existing technologies. Summary of the Invention

[0008] The purpose of this invention is to provide a heterogeneous catalyst dissolution device that solves the problems existing in the prior art. The guide plate and segmented stirrer set in this invention can enhance the reflux of the solution in the tank and make the mixing more uniform. The dual filtration inside and outside the tank can remove insoluble or coarse catalyst particles. This invention can meet the requirements of uniform and efficient solubility in the catalyst dissolution process, and has important significance for the design of solution polymerization process and the development of heterogeneous catalysts.

[0009] The object of this invention is achieved as follows: a heterogeneous catalyst dissolution device, comprising:

[0010] A tank that provides space for the dissolution of a heterogeneous catalyst, the tank having a tank inlet and a tank outlet;

[0011] A stirring structure is provided inside the tank, including at least three stirrers arranged at different intervals along the axial direction of the tank; each stirrer is used to stir the solution inside the tank in stages to form different flow fields to promote the stirring and dissolution of the catalyst inside the tank.

[0012] A guide plate is connected to the inner wall of the tank; the solution, stirred and rotated by the stirring structure, flows downward after colliding with the guide plate, so that the catalyst in the tank is stirred, mixed and dissolved again;

[0013] The filtration structure includes a first filtration structure and a second filtration structure for filtering solid particles (catalysts, impurities, etc. that cannot be dissolved in the solvent) in the solution. The first filtration structure is disposed inside the tank and above the stirring structure. The second filtration structure is disposed outside the tank and connected to the outlet of the tank.

[0014] In a preferred embodiment of the present invention, the three agitators include a propeller-type impeller agitator, a frame agitator, and a straight-blade disc turbine agitator that can rotate synchronously; the propeller-type impeller agitator is disposed below the first filter structure and is used to eliminate air bubbles on the surface of the solution in the tank and to form a downward vortex in the solution; the frame agitator is disposed below the propeller-type impeller agitator and is used to rotate the solution to form an axial liquid flow; the straight-blade disc turbine agitator is located at the bottom end of the tank and is used for liquid-solid suspension of the solution.

[0015] In a preferred embodiment of the present invention, the stirring structure includes a stirring shaft that rotates from the top of the tank and is sealed inside it, the stirring shaft being located at the center of the tank; the propeller-type paddle stirrer, the frame-type stirrer, and the straight-blade disc turbine stirrer are all connected to the stirring shaft.

[0016] In a preferred embodiment of the present invention, a stirring motor is provided at the top of the tank, and the stirring motor is connected to the top of the stirring shaft to drive the stirring shaft to rotate.

[0017] In a preferred embodiment of the present invention, the outer diameter of the propeller-type impeller agitator is 1 / 3 to 2 / 3 of the inner diameter of the tank; the propeller-type impeller agitator includes a plurality of first impellers, the first impellers being of a folded blade structure.

[0018] In a preferred embodiment of the present invention, the outer diameter of the frame agitator is 1 / 3 to 2 / 3 of the inner diameter of the tank; the frame agitator includes a plurality of second blades, the second blades being of a vertical structure.

[0019] In a preferred embodiment of the present invention, the first filter structure is connected to the stirring shaft; the first filter structure includes a detachable multi-layer screen and an external jacket.

[0020] In a preferred embodiment of the present invention, the tank inlet is located at the top of the tank and is connected to a feed valve. The feed valve is connected to a sealing insertion tube that penetrates into the tank. The insertion tube is used to input a catalyst or a solvent for dissolving into the tank.

[0021] In a preferred embodiment of the present invention, the top of the tank is provided with a spare port that can be opened and closed.

[0022] In a preferred embodiment of the present invention, a pressure regulating valve is connected to the top of the tank, and the pressure regulating valve controls the opening degree according to the real-time pressure to maintain the pressure of the tank.

[0023] In a preferred embodiment of the present invention, the tank outlet includes a solution outlet disposed at the bottom end of the tank, the solution outlet is connected to a discharge line, and the discharge line is connected to the second filter structure.

[0024] In a preferred embodiment of the present invention, the pressure resistance range of the tank is 1.5 to 5 MPa; the temperature resistance range of the tank is -10 to 200°C.

[0025] As described above, the heterogeneous catalyst dissolution device of the present invention has the following beneficial effects:

[0026] In the heterogeneous catalyst dissolution device of the present invention, a guide plate is provided inside the tank. After the solution inside the tank rotates, it collides with the guide plate. The guide plate exerts a counterforce on the rotating solution, causing the solution in the upper part of the tank to flow downward. The solution at the edge of the tank and the solution in the middle are further stirred more thoroughly, resulting in a more uniform mixture. Different types of stirrers are used in different sections of the tank to create different flow fields in the solution, which more effectively promotes the dissolution of the catalyst and increases the amount dissolved. The combination of the guide plate and the segmented stirrers can enhance the reflux of the solution inside the tank, resulting in a more uniform mixture.

[0027] The present invention has a first filter structure and a second filter structure respectively provided inside and outside the tank. Through dual filtration, insoluble or coarse catalyst particles can be screened out to prevent uneven feed concentration.

[0028] This invention can meet the requirements of uniform and efficient solubility during catalyst dissolution, and is of great significance for the design of solution polymerization process and the development of heterogeneous catalysts. Attached Figure Description

[0029] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0030] in:

[0031] Figure 1 This is a schematic diagram of the heterogeneous catalyst dissolution device of the present invention.

[0032] Figure 2 This is a schematic diagram of the flow field state formed by the straight-blade disc turbine agitator of the present invention.

[0033] Figure 3 This is a schematic diagram of the straight-blade disc turbine stirrer of the present invention.

[0034] In the picture:

[0035] 1. Spare port;

[0036] 2. Feed valve;

[0037] 3. Agitator motor;

[0038] 4. Pressure regulating valve;

[0039] 5. First filtration structure;

[0040] 6. Deflector plate;

[0041] 7. Propeller-type paddle mixer;

[0042] 8. Frame mixer;

[0043] 9. Straight-blade disc turbine mixer;

[0044] 10. Drain outlet discharge line;

[0045] 11. Second filtration structure;

[0046] 12. Stirring shaft;

[0047] 13. Tank body;

[0048] 14. Insert the bottom tube. Detailed Implementation

[0049] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0050] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0052] like Figure 1 As shown, the present invention provides a heterogeneous catalyst dissolution device, comprising:

[0053] A tank 13 provides space for the dissolution of heterogeneous catalysts, and the tank 13 is provided with a tank inlet and a tank outlet; heterogeneous catalyst dissolution refers to the dissolution of catalysts and reactants in different phases (e.g., the catalyst is a solid while the solvent is a liquid or gas);

[0054] The stirring structure is installed inside the tank 13, including at least three stirrers arranged at different intervals along the axial direction of the tank 13, i.e., stirrers of different types; each stirrer is used to stir the solution (liquid mixture of solvent and catalyst) in the tank 13 in stages to form different flow fields to promote the stirring and dissolution of the catalyst in the tank 13.

[0055] The guide plate 6 is connected to the inner wall of the tank 13; the solution stirred and rotated by the stirring structure collides with the guide plate 6 and flows downward to stir, mix and dissolve the catalyst in the tank 13 again; the guide plate 6 is a metal baffle structure, which can eliminate vortices in the fluid, improve the main circulation and increase the degree of turbulence.

[0056] The filtration structure includes a first filtration structure 5 and a second filtration structure 11 for filtering solid particles in a solution. The first filtration structure 5 is disposed inside the tank 13 and above the stirring structure; the second filtration structure 11 is disposed outside the tank 13 and connected to the tank outlet.

[0057] Polyolefin elastomers (POEs) are thermoplastic elastomers produced through in-situ polymerization of ethylene and α-olefins using metallocene catalysts. The crystalline regions of the polyethylene segments (resin phase) act as physical cross-linking points, exhibiting certain plastic properties. The addition of certain amounts of α-olefins (1-butene, 1-hexene, 1-octene) weakens the crystalline regions of the polyethylene segments. Catalyst feeding is a necessary and crucial step in the production of polyolefin elastomers. Understanding the principles of catalyst dissolution and solvent interaction is essential for understanding catalytic processes. The solubility of the catalyst affects its catalytic efficiency, while the properties of the solvent determine the catalytic reaction environment, thus influencing the reaction rate, selectivity, and product distribution. Improving the efficiency of catalyst and solvent dissolution is crucial in the design and optimization of catalytic reactions, especially in heterogeneous catalytic systems where the catalyst and reactants reside in different phases (e.g., the catalyst is solid while the reactants are liquid or gas). The surface area and dispersion of the catalyst affect the catalytic effect. Improving the dissolution efficiency of heterogeneous catalysts and precisely controlling the catalyst feed rate and temperature are critical technical problems that urgently need to be solved.

[0058] In the small-scale or pilot-scale polymerization of POE produced by olefin solution method, the catalyst needs to be dissolved before the polymerization reaction to maintain a stable and uniform feed and increase catalytic efficiency. This method can significantly improve the quality of the product. The increased comonomer insertion rate can increase the rubber phase in the product, resulting in excellent tensile properties.

[0059] Under normal experimental conditions, the tank of the heterogeneous catalyst dissolution device of the present invention can also serve as a raw material storage tank. Different types of stirrers (with different forms of stirring paddles) are installed inside the tank 13. Stirring increases the amount of catalyst dissolved. Optimizing the design of the catalyst dissolution device is an important part of the production of polyolefin elastomers.

[0060] In the heterogeneous catalyst dissolution device of the present invention, a guide plate 6 is provided inside the tank 13. After the solution inside the tank 13 rotates, it collides with the guide plate 6. The guide plate 6 generates a counterforce on the rotating solution, causing the solution in the upper part of the tank 13 to flow downward. The solution at the edge of the tank 13 and the solution in the middle are further stirred more thoroughly, resulting in more uniform mixing. Different types of stirrers are used in the tank 13 for zoned stirring, forming different flow fields in the solution, which more effectively promotes the dissolution of the catalyst. The combination of the guide plate 6 and the segmented stirrers can enhance the reflux of the solution in the tank, resulting in more uniform mixing. The tank 13 of the present invention is provided with a first filter structure 5 and a second filter structure 11 inside and outside the tank 13, respectively. Through double filtration, insoluble or coarse catalyst particles can be screened out, preventing uneven feed concentration.

[0061] This invention can meet the requirements of uniform and efficient solubility during catalyst dissolution, and is of great significance for the design of solution polymerization process and the development of heterogeneous catalysts.

[0062] Furthermore, the solvents required to dissolve the catalyst include:

[0063] Ⅰ: Hydrocarbon nonpolar solvents and haloalkanes (weakly electrophilic solvents): n-hexane, n-octane, cyclohexane, toluene, benzene, carbon tetrachloride, chloroform, chlorobenzene, carbon disulfide, dichloroethane.

[0064] II: Ethers, aldehydes, ketones, esters, amides and amines (electron-donating solvents): diethyl ether, ethyl acetate, tetrahydrofuran, butyraldehyde, butanone, acetaldehyde, cyclohexanone, acetone, pyridine, dimethylformamide.

[0065] III: Alcohols, phenols, nitro acids, sulfonic acids and carboxylic acids (strong electron-donating or strong hydrogen-bonding solvents): hexanol, n-pentanol, n-butanol, n-propanol, m-cresol, acetonitrile, ethanol, acetic acid, formic acid, methanol, phenol, water.

[0066] like Figure 1 As shown, the three agitators include a propeller-type impeller agitator 7, a frame agitator 8, and a straight-blade disc turbine agitator 9, which can rotate synchronously. The propeller-type impeller agitator 7 is located below the first filter structure 5 and is used to eliminate air bubbles on the surface of the solution in the tank 13 and to make the solution form a downward vortex. The frame agitator 8 is located below the propeller-type impeller agitator 7 and is used to rotate the solution to form an axial liquid flow. The straight-blade disc turbine agitator 9 is located at the bottom of the tank 13 and is used for liquid-solid suspension of the solution.

[0067] Furthermore, such as Figure 1 As shown, the stirring structure includes a stirring shaft 12 that rotates from the top of the tank 13 and is sealed inside it, with the stirring shaft 12 located at the center of the tank 13; a propeller-type paddle stirrer 7, a frame-type stirrer 8, and a straight-blade disc turbine stirrer 9 are all connected to the stirring shaft 12.

[0068] Furthermore, such as Figure 1 As shown, a stirring motor 3 is installed at the top of the tank 13. The stirring motor 3 is connected to the top of the stirring shaft 12 to drive the stirring shaft 12 to rotate. The stirring shaft 12 drives three stirrers to rotate, ensuring that they rotate at the same frequency and speed.

[0069] Furthermore, the stirring motor at the top of the tank 13 is a three-phase AC induction motor, which adopts frequency conversion stirring. The maximum speed is 2000 r / min, the minimum speed is 200 r / min, the power is 300 W, the length of the stirring shaft 12 is 700 mm to 2000 mm, and the diameter of the stirring shaft 12 is 10 to 15 mm.

[0070] Furthermore, such as Figure 1 As shown, the outer diameter of the propeller-type impeller agitator 7 is 1 / 3 to 2 / 3 of the inner diameter of the tank; the propeller-type impeller agitator includes multiple first impellers, and the first impellers have a folded blade structure.

[0071] The propeller-type impeller agitator 7 consists of a first impeller, a first connecting key, a first collar, and a first vertical shaft. The outer diameter of the propeller-type impeller agitator 7 is 1 / 3 to 2 / 3 of the inner diameter D of the tank 13. The first impeller has 5 blades, which are folded blades with a folding angle θ = 45°. The dimensions are designed as d / D = 0.4–0.9, b / d = 0.2–0.3, and Bn = 2. Operating conditions: n = 100 r / min–600 r / min, v = 1–6 m / s. Commonly used medium viscosity range: 0–40 Pa / s. Wherein, n is the rotational speed; v is the blade tip velocity; Bn is the number of blades; d is the inner diameter of the agitator; D is the inner diameter of the tank; and θ is the folding angle.

[0072] When the propeller-type impeller agitator 7 is used for mixing, the fluid is drawn in from above the first impeller and discharged in a cylindrical spiral shape from below. The fluid then flows back up the container wall to the top of the first impeller, forming an axial flow. The propeller-type impeller agitator 7 is placed in the upper layer, which can eliminate air bubbles on the liquid surface and form a downward-propelling vortex.

[0073] Furthermore, such as Figure 1 As shown, the outer diameter of the frame mixer 8 is 1 / 3 to 2 / 3 of the inner diameter of the tank 13; the frame mixer 8 includes multiple second blades, which are vertically oriented.

[0074] The frame-type agitator 8 consists of a second impeller, a second connecting key, a second collar, and a second vertical shaft. The outer diameter of the frame-type agitator 8 is 1 / 3 to 2 / 3 of the inner diameter D of the tank 13. The dimensions are designed as d / D = 0.4 to 0.9 and b / d = 0.2 to 0.3. The operating conditions are: n = 100 r / min to 600 r / min, v = 1 to 6 m / s. The commonly used medium viscosity range is 0 to 40 Pa / s. Wherein, n is the rotational speed; v is the blade tip velocity; Bn is the number of blades; d is the inner diameter of the agitator; and D is the inner diameter of the tank.

[0075] The circumferential velocity of the outer edge of the second impeller blade is generally 5–15 m / s, mainly causing axial liquid flow and generating a large circulation volume. The second impeller of the frame agitator 8 can prevent catalyst from adhering to the wall and can create a large turbulence in the tank 13.

[0076] Furthermore, such as Figure 3 As shown, the dimensions of the straight-blade disc turbine agitator 9 are designed as d / D = 0.4–0.9, b / d = 0.2–0.3, and the operating conditions are: n = 100 r / min–600 r / min, v = 1–6 m / s, where n is the rotational speed; v is the blade tip velocity; Bn is the number of blades; d is the inner diameter of the agitator; and D is the inner diameter of the tank. The straight-blade disc turbine agitator 9 is suitable for heterogeneous systems, possesses high shear force and dispersion capability, and is used for liquid-solid suspension operations. The resulting flow field is as follows: Figure 2 As shown.

[0077] Furthermore, such as Figure 1 As shown, the first filter structure 5 is connected to the stirring shaft 12; the first filter structure 5 includes detachable multi-layer screens and an external jacket. The first filter structure 5 can be disassembled and cleaned periodically, and is mainly used to filter impurities and insoluble substances in the catalyst. The screens are arranged in multiple layers according to the degree of catalyst solubility.

[0078] Furthermore, such as Figure 1 As shown, the tank inlet is located at the top of the tank 13 and is connected to the feed valve 2. The feed valve 2 is connected to a sealed bottom tube 14 that penetrates into the tank 13. The bottom tube 14 is used to input the catalyst (solid) or the solvent (liquid) for dissolution into the tank 13.

[0079] Furthermore, such as Figure 1 As shown, the top of the tank 13 is provided with a spare port 1 that can be opened and closed, and the spare port 1 can be used to input gas into the tank 13.

[0080] Furthermore, such as Figure 1 As shown, a pressure regulating valve 4 is connected to the top of the tank 13. The pressure regulating valve 4 controls its opening according to the real-time pressure to maintain the pressure of the tank 13. When the tank 13 is purged with nitrogen, the pressure regulating valve 4 is fully open, and the gas inside the tank 13 is discharged through the pressure regulating valve 4.

[0081] A pressure gauge is connected to the tank 13 to display the pressure value inside the tank 13 in real time, which facilitates pressure monitoring during the dissolution process of the heterogeneous catalyst.

[0082] Furthermore, the tank outlet includes a solution outlet located at the bottom of the tank 13. The solution outlet is controlled by a 1 / 4 ball valve to control the catalyst solution (a mixed liquid formed by the catalyst dissolved in a solvent) to enter the next system.

[0083] like Figure 1 As shown, the solution outlet is connected to the discharge line 10, and a second filter structure 11 is connected to the discharge line 10. The inner diameter of the discharge line 10 is 40-50 mm, preferably 45 mm, and it is used to discharge the dissolved catalyst solution. The second filter structure 11 removes insoluble catalyst particles.

[0084] The solution outlet can be located at the center of the bottom of the tank 13, or at other locations that facilitate solution discharge.

[0085] Furthermore, the pressure resistance range of the tank body 13 is 1.5 to 5 MPa, preferably 4.5 MPa; the temperature resistance range of the tank body 13 is -10 to 200℃, preferably 150℃.

[0086] Example 1

[0087] The tank body 13 is cylindrical and is a closed tank. The tank body 13 is made of high-temperature resistant stainless steel, which can be made of SUS304 or SUS310L material. The volume is 10,000 to 50,000 ml, preferably 40,000 ml. The seal is a sanitary mechanical seal.

[0088] The tank body 13 includes an outer shell and an inner liner. The outer shell has a wall thickness of 12–30 mm, preferably 15 mm, and a height of 1000–2500 mm, preferably 1500 mm. The length-to-diameter ratio of the tank body 13 is 5–12.5, preferably 8. The inner liner of the tank body undergoes high-precision polishing to reduce its surface roughness, with a polishing degree of 0.4–0.6 μm, preferably 0.5 μm.

[0089] Example 2

[0090] When using the heterogeneous catalyst dissolution apparatus of the present invention to dissolve the catalyst, the following operating steps are included:

[0091] Step a: Introduce high-pressure nitrogen into tank 13 through spare port 1 until the pressure gauge on tank 13 shows 0.5 MPa. Open pressure regulating valve 4 to release the gas. Repeat the above operation 3 times. Release the gas until the pressure gauge shows 0 MPa on the last time.

[0092] Step b: Stop feeding high-pressure nitrogen into tank 13, close the backup port 1, and adjust the opening of the pressure regulating valve 4 to maintain the pressure in tank 13; open the feed valve 2 and introduce the weighed catalyst (solid particles). After the catalyst is introduced, introduce the dissolving solvent to rinse and establish the liquid level. At the same time, turn on the stirring motor 3 to make the propeller-type impeller stirrer 7, frame stirrer 8, and straight-blade disc turbine stirrer 9 rotate and stir the catalyst and solvent in tank 13. The initial speed is 300 r / min.

[0093] Step c: Inject solvent to the set concentration, increase the speed of stirring motor 3 to 1000 r / min, and use the propeller-type impeller stirrer 7, frame stirrer 8, and straight-blade disc turbine stirrer 9 to segmentally stir the solution in tank 13, enhancing the reflux of the catalyst and solvent mixture in tank 13 and further homogenizing the mixture. After the solution in tank 13 rotates, it collides with the guide plate 6. The guide plate 6 exerts a counter-force on the liquid, causing the liquid in the upper part of tank 13 to flow downwards, further fully stirring the liquid at the edge and in the middle of tank 13, resulting in a more uniform mixture.

[0094] Step d: Stirring time is 10-20 hours. Open the solution outlet. The solution formed after the catalyst is dissolved (catalyst solution) is filtered through the second filter structure 11 and enters the subsequent reaction vessel (existing technology) for polymerization reaction.

[0095] As described above, the heterogeneous catalyst dissolution device of the present invention has the following beneficial effects:

[0096] In the heterogeneous catalyst dissolution device of the present invention, a guide plate is provided inside the tank. After the solution inside the tank rotates, it collides with the guide plate. The guide plate exerts a counterforce on the rotating solution, causing the solution in the upper part of the tank to flow downward. The solution at the edge of the tank and the solution in the middle are further stirred more thoroughly, resulting in a more uniform mixture. Different types of stirrers are used in different sections of the tank to create different flow fields in the solution, which more effectively promotes the dissolution of the catalyst and increases the amount dissolved. The combination of the guide plate and the segmented stirrers can enhance the reflux of the solution inside the tank, resulting in a more uniform mixture.

[0097] The present invention has a first filter structure and a second filter structure respectively provided inside and outside the tank. Through dual filtration, insoluble or coarse catalyst particles can be screened out to prevent uneven feed concentration.

[0098] This invention can meet the requirements of uniform and efficient solubility during catalyst dissolution, and is of great significance for the design of solution polymerization process and the development of heterogeneous catalysts.

[0099] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A heterogeneous catalyst dissolution device, characterized in that, include: A tank that provides space for the dissolution of a heterogeneous catalyst, the tank having a tank inlet and a tank outlet; A stirring structure is provided inside the tank, including at least three stirrers arranged at different intervals along the axial direction of the tank; each stirrer is used to stir the solution inside the tank in stages to form different flow fields to promote the stirring and dissolution of the catalyst inside the tank. A baffle plate is attached to the inner wall of the tank. The solution, stirred and rotated by the stirring structure, flows downwards after colliding with the guide plate, thereby causing the catalyst in the tank to be stirred, mixed, and dissolved again. The filtration structure includes a first filtration structure and a second filtration structure for filtering solid particles in a solution. The first filtration structure is disposed inside the tank and above the stirring structure. The second filtration structure is disposed outside the tank and connected to the outlet of the tank.

2. The heterogeneous catalyst dissolution apparatus as described in claim 1, characterized in that, The three agitators include a propeller-type impeller agitator, a frame agitator, and a straight-blade disc turbine agitator that can rotate synchronously; the propeller-type impeller agitator is located below the first filter structure and is used to eliminate air bubbles on the surface of the solution in the tank and to create a downward vortex in the solution; the frame agitator is located below the propeller-type impeller agitator and is used to rotate the solution to form an axial liquid flow; the straight-blade disc turbine agitator is located at the bottom of the tank and is used for liquid-solid suspension of the solution.

3. The heterogeneous catalyst dissolution apparatus as described in claim 2, characterized in that, The stirring structure includes a stirring shaft that rotates from the top of the tank and is sealed inside it, with the stirring shaft located at the center of the tank; the propeller-type paddle stirrer, the frame-type stirrer, and the straight-blade disc turbine stirrer are all connected to the stirring shaft.

4. The heterogeneous catalyst dissolution apparatus as described in claim 3, characterized in that, A stirring motor is installed at the top of the tank, and the stirring motor is connected to the top of the stirring shaft to drive the stirring shaft to rotate.

5. The heterogeneous catalyst dissolution apparatus as described in claim 3, characterized in that, The outer diameter of the propeller-type impeller agitator is 1 / 3 to 2 / 3 of the inner diameter of the tank; the propeller-type impeller agitator includes a plurality of first impeller blades, the first impeller blades being of a folded blade structure.

6. The heterogeneous catalyst dissolution apparatus as described in claim 3, characterized in that, The outer diameter of the frame agitator is 1 / 3 to 2 / 3 of the inner diameter of the tank; the frame agitator includes multiple second blades, which are vertically oriented.

7. The heterogeneous catalyst dissolution apparatus as described in claim 3, characterized in that, The first filter structure is connected to the stirring shaft; the first filter structure includes a detachable multi-layer screen and an external jacket.

8. The heterogeneous catalyst dissolution apparatus as described in claim 1, characterized in that, The tank inlet is located at the top of the tank and is connected to a feed valve. The feed valve is connected to a sealed insertion tube that penetrates into the tank. The insertion tube is used to input a catalyst or a solvent for dissolving into the tank.

9. The heterogeneous catalyst dissolution apparatus as described in claim 1, characterized in that, The top of the tank is equipped with a spare opening that can be opened and closed.

10. The heterogeneous catalyst dissolution apparatus as described in claim 1, characterized in that, The top of the tank is connected to a pressure regulating valve, which controls the opening degree according to the real-time pressure to maintain the pressure of the tank.

11. The heterogeneous catalyst dissolution apparatus as described in claim 1, characterized in that, The tank outlet includes a solution outlet located at the bottom of the tank, the solution outlet being connected to a discharge line, and the discharge line being connected to the second filter structure.

12. The heterogeneous catalyst dissolution apparatus as described in claim 1, characterized in that, The pressure resistance range of the tank is 1.5 to 5 MPa; the temperature resistance range of the tank is -10 to 200℃.

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