Solution-method polyethylene preparation device with low-temperature area

Abstract

The utility model discloses a solution method polyethylene preparation device with a low-temperature area, which comprises a kettle body, a stirring shaft, a stirring paddle and a driving device, the stirring shaft penetrates out of the kettle body and is connected with the driving device, and the stirring paddle is arranged on the stirring shaft; the pre-polymerization barrel is fixedly arranged at the lower end of the kettle body and is communicated with the kettle body, and a feeding hole is formed in the pre-polymerization barrel; a premixing area is formed in the prepolymerization barrel, and a reaction area is formed in the kettle body. According to the utility model, the prepolymerization barrel is arranged, so that a sufficient distance is formed between the feeding hole and the high-temperature reaction area in the kettle body, and a low-temperature premixing area is formed, so that reaction raw materials and a metallocene catalyst are preliminarily mixed in a low-temperature environment before reaction; the problem that a metallocene catalyst enters a high-temperature reaction zone and is inactivated before being fully mixed with raw materials is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of reactors, in particular to a solution method polyethylene preparation device with a low temperature zone. Background Art

[0002] Stirred reactors are widely used in chemical production processes such as polymerization, esterification, and oxidation, and are indispensable equipment in the industry. A metallocene catalyst is a catalytic system composed of a complex of a Group IVB transition metal (such as Ti, Zr, or Hf) as the main catalyst and an alkylaluminoxane or organoboron compound (such as B(C6F5)3) as a co-catalyst. Metallocene catalysts exhibit high catalytic activity and can significantly increase the rate of chemical reactions. Metallocene catalysts can modify the composition and structure of their ligands to regulate the molecular weight distribution, stereoregularity, and degree of branching of the product, facilitating the efficient production of products such as polyolefins. Consequently, they are commonly used in the production of polyethylene. The rapid polymerization reaction in polyethylene production is often accompanied by the release of significant amounts of reaction heat. High temperatures significantly reduce or even deactivate the metallocene catalysts used in polyethylene production, severely impacting product quality and production efficiency. Utility Model Content

[0003] The utility model provides a solution process polyethylene preparation device with a low temperature zone to solve the above technical problems.

[0004] In order to achieve the above purpose, the technical solution of the utility model is:

[0005] A solution-process polyethylene preparation device with a low-temperature zone comprises: a kettle body, a stirring shaft, a stirring paddle and a driving device, wherein the stirring shaft passes through the kettle body and is connected to the driving device, and the stirring paddle is installed on the stirring shaft; the device also comprises a prepolymerization barrel, which is fixedly arranged at the lower end of the kettle body and connected to the kettle body, and a feed port is opened on the prepolymerization barrel; a premixing zone is formed in the prepolymerization barrel, and a reaction zone is formed in the kettle body.

[0006] Preferably, the kettle body includes a cylindrical kettle body and a spherical head, the upper end of the prepolymerization barrel is fixed on the spherical head, and the prepolymerization barrel is coaxially arranged with the cylindrical kettle body.

[0007] Preferably, the lower end of the stirring shaft extends into the prepolymerization barrel and is rotatably connected to the barrel bottom of the prepolymerization barrel.

[0008] Preferably, the stirring paddle comprises two large blades arranged at 180°.

[0009] Preferably, the stirring paddle comprises two small blades symmetrically arranged about the axis of the stirring shaft, and the small blades are fixed on the large blade through a plurality of support plates.

[0010] Preferably, the small blade is parallel to the large blade.

[0011] Preferably, the small blade is in the shape of a right-angled trapezoid, with the oblique waist of the right-angled trapezoid facing the inner wall of the kettle body and the lower bottom of the right-angled trapezoid facing the prepolymerization barrel.

[0012] Preferably, the axis of the stirring shaft is perpendicular to the plate surface of the support plate.

[0013] Preferably, a guide plate arranged along the axial direction of the stirring shaft is provided on the inner wall of the kettle body.

[0014] Preferably, the guide plate is inclined along the rotation direction of the stirring paddle.

[0015] Beneficial effects:

[0016] The present application discloses a solution-based polyethylene preparation device with a low-temperature zone. By setting a prepolymerization barrel, a sufficient distance is set between the feed port and the high-temperature reaction zone in the kettle body, thereby forming a low-temperature premixing zone. The reaction raw materials and the metallocene catalyst are placed in a low-temperature environment for preliminary mixing before the reaction, thereby solving the problem of the metallocene catalyst being deactivated when it enters the high-temperature reaction zone before being fully mixed with the raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 This is a schematic structural diagram of a solution-process polyethylene preparation device with a low-temperature zone disclosed in the present utility model;

[0019] Figure 2 for Figure 1 Cross-sectional view of AA;

[0020] Figure 3 for Figure 1 Cross-sectional view of the middle BB;

[0021] Figure 4 for Figure 3 Cross-sectional view of CC.

[0022] 1. Kettle body; 11. Cylindrical kettle body; 12. Spherical head; 2. Stirring shaft; 3. Stirring paddle; 31. Large paddle; 32. Small paddle; 33. Support plate; 4. Prepolymerization barrel; 5. Guide plate. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0024] A solution-process polyethylene preparation device with a low-temperature zone, combined with Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, the reactor comprises: a kettle body 1, an agitator shaft 2, an agitator paddle 3, and a drive device. The agitator shaft 2 extends through the kettle body 1 and connects to the drive device, and the agitator paddle 3 is mounted on the agitator shaft 2. It also comprises a prepolymerization barrel 4, which is fixedly mounted at the lower end of the kettle body 1 and communicates with the kettle body 1. The prepolymerization barrel 4 is provided with a feed port. A premixing zone is formed within the prepolymerization barrel 4, and a reaction zone is formed within the kettle body 1. By adding the prepolymerization barrel 4 at the lower end of the kettle body 1, a sufficient distance is provided between the feed port and the high-temperature reaction zone within the kettle body 1, thereby forming a low-temperature premixing zone. This allows the reaction raw materials and the metallocene catalyst to remain in the prepolymerization barrel 4 for a short time, undergoing preliminary mixing in a low-temperature environment to form a high-temperature-resistant prepolymer monomer. Subsequently, the monomer enters the reaction zone under the action of the feed port pressure to participate in the subsequent polymerization reaction. The setting of the prepolymerization barrel 4 does not affect the "overall plug flow and local full mixing flow" of the fluid in the kettle body 1, effectively improving the utilization rate of the catalyst, the efficiency of the reaction and the quality of the product, reducing the loss of the catalyst, and solving the problem of the metallocene catalyst being deactivated when it enters the high-temperature reaction zone before being fully mixed with the raw materials, thereby greatly reducing the production cost.

[0025] Preferably, the kettle body 1 includes a cylindrical kettle body 11 and a spherical head 12 , the upper end of the prepolymerization barrel 4 is fixed on the spherical head 12 , and the prepolymerization barrel 4 is coaxially arranged with the cylindrical kettle body 11 .

[0026] Specifically, the prepolymerization barrel 4 includes a cylindrical barrel body and a spherical barrel bottom. The inner diameter of the cylindrical barrel body is 410 mm, the height is 400 mm, and the wall thickness is 15 mm.

[0027] Specifically, a discharge port is provided on the cylindrical kettle body 11, and two feed ports are provided on the spherical barrel bottom, and the two feed ports are symmetrically arranged about the axis of the cylindrical barrel body.

[0028] Specifically, the driving device includes a motor, a reducer and a coupling, thereby driving the stirring shaft 2 to rotate.

[0029] Preferably, the lower end of the stirring shaft 2 extends into the prepolymerization barrel 4 and is rotatably connected to the barrel bottom of the prepolymerization barrel 4, so as to realize the support of the upper and lower ends of the stirring shaft 2 and ensure the reliable rotation of the stirring shaft 2.

[0030] Preferably, the stirring paddle 3 comprises two large paddles 31 arranged at 180°. The large paddles 31 can meet the stirring of raw materials with large viscosity, so that the raw materials are fully mixed in the reaction zone, and the generation of flow dead zones is reduced.

[0031] Preferably, the stirring paddle 3 comprises two small paddles 32 arranged in the center of the axis of the stirring shaft 2 in a central symmetry, and the small paddles 32 are fixed on the large paddles 31 by a plurality of support plates 33. The small paddles 32 are parallel to the large paddles 31. The small paddles 32 are right-angled trapezoids, the oblique sides of the right-angled trapezoids are directed to the inner wall of the kettle body 1, and the lower bases of the right-angled trapezoids are directed to the prepolymer barrel 4. The small paddles 32 are added to form a fully mixed flow in the reaction zone, and the generation of flow dead zones is reduced.

[0032] Preferably, the axis of the stirring shaft 2 is perpendicular to the plate surface of the support plate 33, so as to reduce the resistance generated when the support plate 33 rotates.

[0033] Specifically, the plurality of support plates 33 are arranged in parallel and at intervals along the axial direction of the stirring shaft 2, and the support plates 33 are fixed between the large paddles 31 and the small paddles 32 by welding.

[0034] Preferably, the inner wall of the kettle body 1 is provided with a flow guide plate 5 arranged along the axial direction of the stirring shaft 2.

[0035] Specifically, four flow guide plates 5 are uniformly distributed on the inner wall of the kettle body 1, and the flow guide plates 5 are inclined along the rotation direction of the stirring paddle 3 to prevent vortexes from being generated in the stirring process.

[0036] Working principle of the device:

[0037] The raw materials and the metallocene catalyst are added to the prepolymer barrel 4 through the feed port, the raw materials and the metallocene catalyst stay in the relatively low-temperature prepolymer barrel 4 for a while, the raw materials and the metallocene catalyst are pre-mixed to form a high-temperature-resistant prepolymer monomer, and then the raw materials and the metallocene catalyst enter the reaction zone under the action of the pressure of the feed port to participate in subsequent polymerization reaction, and the product after reaction is output through the discharge port.

[0038] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A solution-process polyethylene production device with a low-temperature zone, comprising: A kettle body (1), a stirring shaft (2), a stirring paddle (3) and a driving device, wherein the stirring shaft (2) passes through the kettle body (1) and is connected to the driving device, and the stirring paddle (3) is installed on the stirring shaft (2); it is characterized in that it also includes a prepolymerization barrel (4), the prepolymerization barrel (4) is fixed at the lower end of the kettle body (1) and is connected to the kettle body (1), and a feed port is opened on the prepolymerization barrel (4); a premixing zone is formed in the prepolymerization barrel (4), and a reaction zone is formed in the kettle body (1).

2. The solution-process polyethylene production device with a low-temperature zone according to claim 1, characterized in that: The kettle body (1) comprises a cylindrical kettle body (11) and a spherical head (12); the upper end of the prepolymerization barrel (4) is fixed on the spherical head (12); and the prepolymerization barrel (4) is coaxially arranged with the cylindrical kettle body (11).

3. The solution-process polyethylene production device with a low-temperature zone according to claim 2, characterized in that: The lower end of the stirring shaft (2) extends into the prepolymerization barrel (4) and is rotatably connected to the barrel bottom of the prepolymerization barrel (4).

4. The solution-process polyethylene production device with a low-temperature zone according to claim 1, characterized in that: The stirring paddle (3) comprises two large blades (31) arranged at 180 degrees.

5. The solution-process polyethylene production device with a low-temperature zone according to claim 4, characterized in that: The stirring paddle (3) comprises two small blades (32) symmetrically arranged about the axis of the stirring shaft (2); the small blades (32) are fixed on the large blade (31) via a plurality of support plates (33).

6. The solution-process polyethylene production device with a low-temperature zone according to claim 5, characterized in that: The small blade (32) is parallel to the large blade (31).

7. The solution-process polyethylene production device with a low-temperature zone according to claim 6, characterized in that: The small blade (32) is a right-angled trapezoid, the oblique waist of the right-angled trapezoid faces the inner wall of the kettle body (1), and the lower bottom of the right-angled trapezoid faces the prepolymerization barrel (4).

8. The solution-process polyethylene production device with a low-temperature zone according to claim 5, characterized in that: The axis of the stirring shaft (2) is perpendicular to the plate surface of the support plate (33).

9. The solution-process polyethylene production device with a low-temperature zone according to claim 1, characterized in that: A guide plate (5) is provided on the inner wall of the kettle body (1) and is arranged along the axial direction of the stirring shaft (2).

10. The solution-process polyethylene production device with a low-temperature zone according to claim 9, characterized in that: The guide plate (5) is inclined along the rotation direction of the stirring paddle (3).

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