Stirrer, reactor and application

Abstract

The invention discloses a stirrer, a reactor and application. The stirrer comprises a stirring shaft, curved-surface blades arranged on the stirring shaft, plane blades arranged on the stirring shaft and supporting rods arranged on the stirring shaft. A cavity is formed in the stirring shaft; the curved-surface blade is provided with a cavity and a gas hole channel. Compared with a traditional anchor stirrer, the stirrer has better overall circulation capacity, sufficient mixing and exchange between materials in the end socket at the bottom of the reactor and materials above the end socket are guaranteed, the mixing time of the materials is shortened, the mixing degree is improved, meanwhile, the stirrer is internally provided with the cavity and the air channel, and the stirring efficiency is improved. Reaction gas and materials can be fully mixed, and a high-index polyolefin product with stable performance can be prepared.

Description

Technical Field

[0001] This invention relates to a stirrer, and more specifically to a stirrer and reactor used in the production process of a high-viscosity polymerization system. Background Technology

[0002] Polyolefin resins are a class of thermoplastic resins obtained by the individual polymerization or copolymerization of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene, as well as certain cyclic olefins. These resins occupy an important position in the modern plastics industry and have a wide range of uses and applications.

[0003] There are many types of polyolefin resins, including polyethylene (PE), polypropylene (PP), polybutene-1 resin (PB), and poly4-methyl-1-pentene. Due to their unique physical and chemical properties, these resins are widely used in packaging, automobiles, home appliances, construction, industrial pipelines, new energy batteries, and medical devices, among other fields.

[0004] For example, polybutene-1 resin is a thermoplastic resin polymerized from 1-butene. It possesses excellent impact resistance, creep resistance, heat resistance, and resistance to boiling water, earning it the reputation of "the gold standard in plastics." Currently, there are two industrial methods for producing polybutene-1 resin: continuous and batch processes. The continuous process uses liquid-phase bulk polymerization, with butene-1 as the solvent in the polymerization system. The polymerization reaction occurs under the action of a catalyst. This process requires a high level of technical expertise in the subsequent devolatilization process. The batch process consists of two stages: prepolymerization and polymerization. During the polymerization stage, the reactants undergo significant viscosity and phase changes. Initially, the reaction is a low-viscosity fluid mixing and reaction process; as the polymerization proceeds, the viscosity gradually increases until it reaches a molten state. The main challenges in implementing the batch process lie in removing the heat of reaction and ensuring the homogenization of the materials with the catalyst. Because the material undergoes a significant phase change during this process, from a low-viscosity liquid to a high-viscosity liquid, and then to a solid-like state, while also considering the discharge process from the reactor after the reaction, optimizing the agitator in the stirred reactor, especially the agitator inside the reactor bottom head, becomes a key factor. Traditional agitators suitable for stirring and mixing high-viscosity fluids or solid-like phases are mostly anchor agitators. These agitators have disadvantages such as a single material flow direction and high power consumption, and are particularly inadequate in ensuring that the material inside the reactor bottom head moves axially to the main reactor area.

[0005] With the continuous development of the polyolefin industry, the demand for copolymerized and high melt index polyolefin products is constantly increasing. Currently, in the production process of copolymerized and high melt index polyolefin products, a single-point feeding method is used to add comonomers or hydrogen to the reactor. However, some olefin monomers are polymerized in the liquid phase, and hydrogen is fed in the gas phase. The solubility of gas-phase feed in liquid-phase olefins is also poor. The gas and liquid phases can only be mixed through pressure difference and backmixing by the agitator. As the viscosity of the polymerization system increases, the backmixing effect is limited, leading to insufficient mixing of the gas-phase feedstock and the olefin liquid phase, resulting in unstable product performance.

[0006] Chinese patent CN212236880U discloses a stirrer for the production of acrylic pressure-sensitive adhesive, comprising: a stirring tank, a support frame, a first motor, a second motor, an outer stirrer, an inner stirrer, and a sealed bearing. The support frame is located at the top center of the stirring tank, with one side connected to the first motor and the top of the support frame connected to the second motor. The outer and inner stirrers are located inside the stirring tank. The upper end of the outer stirrer is connected to the first motor sequentially through the stirring tank and the support frame. The inner stirrer is fitted inside the outer stirrer, with a sealed bearing fitted on its upper part. The inner stirrer is connected to the inner wall of the outer stirrer through the sealed bearing, and its upper end is connected to the second motor through the support frame. The outer stirrer includes: a bevel gear, bevel gear teeth, a sealed rotating shaft, a connecting plate, a stirring cylinder, and an inclined hole. However, this stirrer cannot achieve overall material circulation, particularly in terms of achieving sufficient vertical mixing and exchange between the material inside the bottom head and the material above the head.

[0007] Chinese patent CN202290039U discloses a high-viscosity fluid agitator, including a reaction vessel, a stirring shaft, a drive motor, at least two layers of folding-blade paddle agitators, a three-blade backward-curved agitator, and auxiliary stirring blades. The auxiliary stirring blades, the three-blade backward-curved agitator, and the folding-blade paddle agitator are arranged sequentially from bottom to top along the stirring shaft. The auxiliary stirring blades are located at the bottom of the stirring shaft, and the three-blade backward-curved agitator is positioned above the auxiliary stirring blades. At least two layers of folding-blade paddle agitators are positioned above the three-blade backward-curved agitator. The technical problem addressed is the existence of dead zones in the stirring of high-viscosity fluids within the reaction vessel. However, the agitator provided by this technology can only achieve sufficient mixing in the horizontal direction of the material, making it difficult to achieve mixing in the vertical direction, thus failing to achieve overall material circulation.

[0008] Chinese patent CN206622096U discloses a reactor for the polymerization of polyisobutylene, comprising a sealed reactor body with baffles on the inner wall, a feed inlet at the upper end, a discharge outlet at the lower end, and a vent at the upper end. A stirring shaft is rotatably connected within the reactor body, with one end extending from the upper end and connected to a stirring motor. However, while the stirrer used in this technology can prevent highly viscous materials from adhering to the reactor wall and achieve horizontal mixing, it struggles to achieve vertical mixing, thus hindering overall material circulation.

[0009] Chinese patent CN208553808U discloses a stirrer for high-viscosity materials, including a stirring shaft comprising a drive shaft and a driven shaft, with a universal coupling between them. The drive shaft is connected to a drive device. An upper turbine blade and a lower turbine blade are mounted on the driven shaft, which passes through the center of both blades, connecting them. The outer ends of the upper and lower turbine blades are connected to an upper and a lower fixed ring, respectively. An axial blade is positioned between the upper and lower fixed rings, with its upper end face fixedly connected to the lower end face of the upper fixed ring and its lower end face connected to the upper end face of the lower fixed ring. One side of the axial blade is flat, while the other side is a smoothly convex curved surface. However, this technology can only achieve horizontal mixing of the material, making vertical mixing difficult and failing to achieve uniform and thorough mixing.

[0010] During olefin polymerization, the phase state of the material undergoes a significant transformation, changing from a low-viscosity liquid state to a high-viscosity liquid state, and finally to a near-solid state. Therefore, traditional anchor-type agitators suffer from drawbacks such as unidirectional material flow and high power consumption. Furthermore, the discharge process from the reactor after reaction must also be considered. Thus, optimizing the agitator in a stirred reactor, especially the agitator inside the reactor bottom head, is essential. Additionally, using a single-hole feedstock in olefin polymerization can lead to insufficient and uneven mixing of the gaseous feedstock, resulting in unstable product performance. Therefore, finding a method for uniform gaseous feedstock feeding is of significant guiding importance for controlling the performance of heterogeneous polymerization products. Summary of the Invention

[0011] The technical problem this invention aims to solve is to ensure that high-viscosity fluids or solid-like phases are fully mixed during the production of polyolefins, so as to achieve good mass and heat transfer, while also solving the problem of insufficient mixing of gas-phase raw materials during olefin polymerization, which leads to unstable product quality.

[0012] To address the problems existing in the prior art, the present invention provides a stirrer, a reactor, and an application, the stirrer being suitable for the thorough mixing of high-viscosity fluids or solid-like materials, such as in the production process of polyolefins.

[0013] The present invention provides a stirrer, which includes: a stirring shaft, curved blades disposed on the stirring shaft, flat blades disposed on the stirring shaft, and a support rod disposed on the stirring shaft; the interior of the stirring shaft is a cavity; the curved blades are provided with cavities and gas channels.

[0014] In one embodiment, the planar blade is also provided with a cavity and gas channels.

[0015] In one embodiment, the planar blade has 3-6 gas channels, and the gas channels are connected to the cavity of the stirring shaft.

[0016] In one embodiment, the support rod is also provided with a cavity and a gas channel.

[0017] In one embodiment, the curved blade has 10-20 gas channels, which are connected to the cavity of the stirring shaft.

[0018] In one embodiment, the gas channel is provided with a cap, the cap opening in the opposite direction to the stirring direction. The cap effectively prevents the polymer slurry from entering the gas channel after aeration is stopped, thus preventing blockage of the biogas channel.

[0019] In one embodiment, the diameter of the gas channel is 3-5 mm.

[0020] In one embodiment, one end of the planar blade is used to fix the curved blade; one end of the curved blade is fixed to the stirring shaft by welding, and there are two curved blades in total, and the axis of the stirring shaft is centrally symmetrical.

[0021] In one embodiment, the support rod is a cylindrical rod, and one end of the support rod is fixed to the stirring shaft by welding, and the other end is fixed to the curved blade by welding.

[0022] In one embodiment, the support rods are arranged in a staggered 90° configuration to support the curved blade.

[0023] In one embodiment, the cavity of the stirring shaft is a feed passage for gaseous raw materials, and the cavity is through. The gaseous raw materials include at least one of ethylene, propylene, and hydrogen.

[0024] In one embodiment, the diameter of the cavity of the stirring shaft is 0.25-0.5 times the diameter of the stirring shaft.

[0025] In one embodiment, the curved blade is in the form of a spatial curved surface.

[0026] The present invention also provides a reactor comprising a stirrer.

[0027] In one embodiment, the stirrer extends vertically into the reactor from the top.

[0028] In one embodiment, the bottom of the reactor is an ellipsoidal or spherical head; the working area of ​​the agitator is the head.

[0029] In one embodiment, the stirring shaft is collinear or concentric with the axis of the reactor.

[0030] In one embodiment, the maximum projected diameter of the curved blade in the vertical direction is 0.85 to 0.97 times the long diameter of the head.

[0031] In one embodiment, the height of the curved blade is 0.05 to 0.1 times the long diameter of the head.

[0032] In one embodiment, the curved blade is integrally formed with the inner surface of the head, that is, the edge of the curved blade and the inner surface of the head maintain a constant distance, which can minimize the flow dead zone as much as possible; the integral forming of the inner surface causes the edge of the curved blade to form a helix with a variable diameter, and the pitch of the helix is ​​0.25-1 times the long diameter of the head.

[0033] In one embodiment, the shape of the planar blade follows the shape of the spherical cap of the head, and the height of the planar blade is 0.03 to 0.1 times the long diameter of the head.

[0034] The present invention also provides an application of the above-described stirrer or reactor in olefin polymerization reactions.

[0035] The olefins include, but are not limited to, at least one of butene-1, hexene-1, and octene-1.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] (1) The agitator provided by the present invention has better overall circulation capacity than the traditional anchor agitator, which is conducive to ensuring the full mixing and exchange between the material in the bottom head of the reactor and the material above the head, thereby shortening the mixing time and improving the mixing degree. At the same time, the agitator is equipped with a cavity and air passage, which is conducive to the full mixing of reaction gas and material, and can prepare high-index polyolefin products with stable performance, and improve the flexibility (nominal strain at break) of polyolefin products.

[0038] (2) The stirrer of the present invention can effectively realize mass and heat transfer during the reaction process, thereby improving the polymerization reaction efficiency.

[0039] (3) The stirrer of the present invention has a ventilation function, and the curved blades are provided with cavities and gas channels to directly introduce gaseous raw materials into the liquid polymerization system during the polymerization process, which increases the contact area between the gaseous raw materials and the liquid polymerization system, ensures the full mixing of the gaseous raw materials and the liquid polymerization system, and guarantees the quality stability of the polymerized product.

[0040] (4) The stirrer of the present invention can not only be applied to the various phase states and flowability of olefin polymerization at different reaction stages, as well as the discharge requirements after the reaction, but also facilitates the full mixing of gas phase raw materials and liquid phase polymerization system and ensures stable control of the quality of polymerization products. Attached Figure Description

[0041] Figure 1 This is an isometric view of the stirrer of the present invention when it is installed in the reactor.

[0042] Figure 2 This is a front view of the stirrer of the present invention when it is installed in the reactor.

[0043] Figure 3 This is a vector diagram showing the material flow within the head at the bottom of the reactor of the present invention.

[0044] Figure 4 This is a diagram showing the macroscopic flow trend of materials inside and near the head of the reactor of the present invention.

[0045] In the attached figures, the following labels are used:

[0046] Head 1

[0047] Stirring shaft cavity 2

[0048] Curved blade 3

[0049] Planar blade 4

[0050] Support rod 5

[0051] 6 stirring shafts

[0052] Gas channel 7 Detailed Implementation

[0053] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0054] The stirrer of the present invention includes: a stirring shaft 6, curved blades 3 disposed on the stirring shaft 6, flat blades 4 disposed on the stirring shaft 6, and a support rod 5 disposed on the stirring shaft 6; the interior of the stirring shaft 6 is a cavity; the curved blades 3 are provided with cavities and gas channels 7.

[0055] In one embodiment, the planar blade 4 is also provided with a cavity and a gas channel 7.

[0056] In one embodiment, the number of gas channels 7 on the planar blade 4 is 3-6, and the gas channels 7 are connected to the cavity of the stirring shaft 6.

[0057] In one embodiment, the support rod 5 is also provided with a cavity and a gas channel 7.

[0058] In one embodiment, the curved blade 3 has 10-20 gas channels 7, and the gas channels 7 are connected to the cavity of the stirring shaft 6.

[0059] In one embodiment, the gas channel 7 is provided with a cap, the opening direction of which is opposite to the stirring direction. The cap can effectively prevent the polymer slurry from entering the gas channel after aeration is stopped, thus preventing blockage of the biogas channel.

[0060] In one embodiment, the diameter of the gas channel 7 is 3-5 mm.

[0061] In one embodiment, one end of the planar blade 4 is used to fix the curved blade 3; one end of the curved blade 3 is fixed to the stirring shaft 6 by welding, and there are two curved blades 3 in total, and the axis of the stirring shaft 6 is symmetrical.

[0062] In one embodiment, the support rod 5 is a cylindrical rod, and one end of the support rod 5 is fixed to the stirring shaft 6 by welding, and the other end is fixed to the curved blade 3 by welding.

[0063] In one embodiment, the support rods 5 are arranged in a staggered 90° manner to support the curved blades 3.

[0064] In one embodiment, the cavity of the stirring shaft 6 is a feed passage for gaseous raw materials, and the cavity is through. The gaseous raw materials include at least one of ethylene, propylene, and hydrogen.

[0065] In one embodiment, the diameter of the cavity of the stirring shaft 6 is 0.25-0.5 times the diameter of the stirring shaft 6.

[0066] In one embodiment, the curved blade 3 is in the form of a spatial curved surface.

[0067] The present invention also provides a reactor, which includes a stirrer.

[0068] In one embodiment, the stirrer extends vertically into the reactor from the top.

[0069] In one embodiment, the bottom of the reactor is an ellipsoidal or spherical head 1; the working area of ​​the agitator is the head 1.

[0070] In one embodiment, the stirring shaft 6 is collinear or concentric with the axis of the reactor.

[0071] In one embodiment, the maximum projected diameter of the curved blade 3 in the vertical direction is 0.85 to 0.97 times the long diameter of the head 1.

[0072] In one embodiment, the height of the curved blade 3 is 0.05 to 0.1 times the long diameter of the end cap 1.

[0073] In one embodiment, the curved blade 3 and the inner surface of the head 1 are formed conformally, that is, the edge of the curved blade 3 and the inner surface of the head 1 maintain a constant distance and a parallel relationship, which can minimize the flow dead zone as much as possible; the conformal forming of the inner surface makes the edge of the curved blade 3 form a helix with a variable diameter, and the pitch of the helix is ​​0.25-1 times the long diameter of the head 1.

[0074] In one embodiment, the shape of the planar blade 4 follows the shape of the spherical cap of the head 1, and the height of the planar blade 4 is 0.03 to 0.1 times the long diameter of the head 1.

[0075] The present invention also provides an application of the above-described stirrer or reactor in olefin polymerization reactions.

[0076] To better understand the present invention, preferred embodiments are described below. It should be noted that these embodiments are not intended to limit the present invention.

[0077] Example 1

[0078] Figure 1 This is an isometric view of the stirrer of the present invention installed in the reactor. Figure 2This is a front view of the stirrer of the present invention installed in the reactor. In this embodiment, the reactor consists of a bottom end cap 1, a stirring shaft cavity 2, curved blades 3, flat blades 4, a support rod 5, a stirring shaft 6, and a gas channel 7. The curved blades 3, flat blades 4, and support rod 5 all have cavities. The stirring shaft cavity 2, curved blades 3, flat blades 4, support rod 5, stirring shaft 6, and gas channel 7 constitute the stirrer. During implementation, the stirring shaft 6 extends vertically downwards into the end cap 1. The curved blades 3 are connected and fixed to the stirring shaft 6 via the support rod 5 and the flat blades 4. The support rods 5 support the curved blades 3 using a staggered 90° arrangement. In the above-mentioned structure, the stirring shaft 6 plays the role of transmitting power, the curved blades 3 play the role of macroscopic material flow and mixing, the flat blades 4 play the role of promoting material movement and discharge at the bottom of the end cap, the support rod 5 plays the role of fixing and connecting the blades, and also has some material mixing capacity. The stirring shaft cavity 2 is concentric with the stirring shaft 6 and plays the role of conveying gaseous raw materials. The gas channels 7 are evenly distributed on the curved blades 3 and the flat blades 4 and are connected to the stirring shaft cavity 2. The gaseous raw materials come into contact with the liquid phase through the gas channels 7, which plays the role of increasing the contact area and uniform mixing.

[0079] The reactor bottom end cap 1 is a standard ellipsoidal end cap. Two curved blades 3 are mounted symmetrically to the axis of the stirring shaft 6. The maximum projected diameter of the curved blades 3 in the vertical direction is 0.9 times the long diameter of the end cap 1, the height is 0.1 times the long diameter of the end cap 1, and the pitch is 0.25 times the long diameter of the end cap 1. The outer contour curve of the curved blades 3 follows the shape of the inner surface of the bottom end cap, and the spacing is 0.05 times the long diameter of the end cap 1. Two flat blades 4 are mounted symmetrically to the stirring shaft 6. Their height is 0.05 times the long diameter of the end cap 1. Their bottom contour follows the shape of the inner surface of the end cap 1, and the spacing between them is 0.05 times the long diameter of the end cap 1. The diameter of the stirring shaft cavity 2 is 0.5 times the diameter of the stirring shaft 6. The curved blade 3 has 10 gas channels 7 with a diameter of 3 mm, and the flat blade has 3 channels with a diameter of 3 mm. Each channel is equipped with a cap, which is opposite to the stirring direction.

[0080] Figure 3 This is a vector diagram of the material flow within the head of the reactor at the bottom of the present invention. It illustrates the flow field during the stirring and mixing of high-viscosity materials within the head of a reactor with a diameter of 500 mm in this embodiment. From... Figure 3 As can be seen in this embodiment, the material in the head 1 rises upwards from the vessel wall under the action of this embodiment. As it rises along the wall, the material near the stirring shaft 6 also moves downwards along the shaft, replenishing the original material location, thereby completing the circulation within the head 1. Its macroscopic circulation route is as follows: Figure 4 As shown. Compared to traditional anchor-type agitators, this agitator has better overall circulation capability, which helps to ensure sufficient mixing and exchange between the material inside end cap 1 and the material above end cap 1, thereby shortening the mixing time and improving the mixing degree. In this embodiment, when the viscosity of the material is 10000 cP, under the same power consumption conditions, the mixing time of this agitator is reduced by an average of 20%-30% compared to the mixing time of a traditional anchor-type impeller in the bottom end cap.

[0081] Simultaneously, this stirrer was used to prepare high-index polybutene-1 products. The specific steps of this preparation process are as follows:

[0082] A raw material consisting of a liquid-phase mixture of butene-1 monomer and polyalphaolefin (PAO) is introduced into a reactor. The raw material contains butene-1 monomer, polyethylene, and polypropylene, with the butene-1 monomer concentration at 75 wt%. The polymerization reaction temperature is 70°C, the hydrogen addition rate is n(hydrogen / butene-1) = 1:50, the reaction pressure is 1.60 MPa, and the stirrer speed is 200 r / min. Under the action of a catalyst, the polymerization reaction proceeds to obtain a polybutene-1 solution. The obtained polybutene-1 solution is discharged from the reactor and sent to a subsequent stage for flash evaporation and granulation to remove unreacted butene-1 monomer, yielding the polybutene-1 product. Testing showed that the polybutene-1 product produced in this embodiment has a melt index of 22.4 g / 10 min and a nominal strain at break of 280 °C.

[0083] Example 2

[0084] The stirrer and reactor used differ from those in Example 1 in that the bottom of the reactor is a spherical head 1, the number of gas channels 7 on the planar blades 4 is 6, the diameter of the gas channels 7 is 4 mm, the number of gas channels 7 on the curved blades 3 is 20, the diameter of the gas channels 7 is 4 mm, the diameter of the stirring shaft cavity 2 is 0.4 times the diameter of the stirring shaft 6, the maximum projected diameter of the curved blades 3 in the vertical direction is 0.85 times the long diameter of the head 1, the height of the curved blades 3 is 0.05 times the long diameter of the head 1, the pitch of the helix is ​​0.6 times the long diameter of the head 1, and the height of the planar blades 4 is 0.03 times the long diameter of the head 1.

[0085] The high-index polybutene-1 product was prepared using this stirrer. The difference from Example 1 is that the amount of hydrogen added was n(hydrogen / butene-1) = 1:30, the melt index of the polymerized polybutene-1 product was 36.9 g / 10 min, and the nominal strain at break was 300.

[0086] Example 3

[0087] The agitator and reactor used differ from those in Example 1 in that the number of gas channels on the planar blade 4 is 4, the diameter of the gas channel 7 is 5 mm, the number of gas channels 7 on the curved blade 3 is 15, the diameter of the gas channel 7 is 5 mm, the diameter of the agitator shaft cavity 2 is 0.25 times the diameter of the agitator shaft 6, the maximum projected diameter of the curved blade 3 in the vertical direction is 0.97 times the long diameter of the end cap 1, the height of the curved blade 3 is 0.08 times the long diameter of the end cap 1, the pitch of the helix is ​​1 times the long diameter of the end cap 1, and the height of the planar blade 4 is 0.1 times the long diameter of the end cap 1.

[0088] The high-index polybutene-1 product was prepared using this stirrer. The difference from Example 1 is that the amount of hydrogen added was n(hydrogen / butene-1) = 1:10, the melt index of the polymerized polybutene-1 product was 95.3 g / 10 min, and the nominal strain at break was 300.

[0089] Comparative Example 1

[0090] The difference from Example 1 is that the curved blade 3, the flat blade 4, and the support rod 5 are not provided with gas channels, and the stirring shaft is not provided with a cavity. Otherwise, they are the same as in Example 1.

[0091] The polymerized polybutene-1 product has a melt index of 4.6 g / 10 min and a nominal fracture strain of 110.

[0092] The results from the examples and comparative examples show that the agitator with a cavity can achieve thorough mixing of hydrogen and butene-1 monomer, increase the dispersion of hydrogen in the reactor, facilitate the chain transfer reaction of hydrogen during the polymerization process, prepare high-index polybutene products, and improve the flexibility (nominal strain at break) of polyolefin products.

[0093] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A stirrer, characterized in that, include: The stirring shaft, curved blades mounted on the stirring shaft, flat blades mounted on the stirring shaft, and a support rod mounted on the stirring shaft; the interior of the stirring shaft is a cavity; The curved blade has cavities and gas channels.

2. The stirrer according to claim 1, characterized in that, The planar blades are also provided with cavities and gas channels; The planar blade has 3-6 gas channels, which are connected to the cavity of the stirring shaft.

3. The stirrer according to claim 1, characterized in that, The support rod is also provided with a cavity and a gas channel; The curved blade has 10-20 gas channels, which are connected to the cavity of the stirring shaft.

4. The stirrer according to any one of claims 1-3, characterized in that, The gas channel is equipped with a cap, and the opening direction of the cap is opposite to the stirring direction; The diameter of the gas channel is 3-5 mm.

5. The stirrer according to claim 1, characterized in that, One end of the planar blade is used to fix the curved blade; one end of the curved blade is fixed to the stirring shaft by welding, and there are two curved blades in total, and the axis of the stirring shaft is symmetrical.

6. The stirrer according to claim 1, characterized in that, The support rod is a cylindrical rod, and one end of the support rod is fixed to the stirring shaft by welding, and the other end is fixed to the curved blade by welding. The support rods are arranged in a staggered 90° pattern to support the curved blades.

7. The stirrer according to claim 1, characterized in that, The cavity of the stirring shaft is a feeding passage for gaseous raw materials, and the cavity is continuous. The gaseous raw materials include at least one of ethylene, propylene, and hydrogen. The diameter of the cavity of the stirring shaft is 0.25-0.5 times the diameter of the stirring shaft; The curved blade is in the form of a spatial curved surface.

8. A reactor, characterized in that, Includes the stirrer according to any one of claims 1-7.

9. The reactor according to claim 8, characterized in that, The stirrer extends vertically into the reactor from the top; The bottom of the reactor is an ellipsoidal or spherical head; the working area of ​​the agitator is the head.

10. The reactor according to claim 8, characterized in that, The stirring shaft is collinear or concentric with the axis of the reactor.

11. The reactor according to claim 8, characterized in that, The maximum projected diameter of the curved blade in the vertical direction is 0.85 to 0.97 times the long diameter of the end cap; The height of the curved blade is 0.05 to 0.1 times the diameter of the end cap; The curved blade and the inner surface of the head are integrally formed; the integral forming of the inner surface causes the edge of the curved blade to form a helix with a variable diameter, and the pitch of the helix is ​​0.25-1 times the long diameter of the head.

12. The reactor according to claim 8, characterized in that, The shape of the planar blade follows the shape of the spherical cap of the head, and the height of the planar blade is 0.03 to 0.1 times the long diameter of the head.

13. The use of a stirrer according to any one of claims 1-7 or a reactor according to any one of claims 8-12 in an olefin polymerization reaction.

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