Post-treatment device for purifying and homogenizing polyolefin powder

Abstract

The utility model relates to a polyolefin powder purifying and homogenizing post-processing device which comprises a vibration screening and premixing unit and a homogenizing unit, and the vibration screening and premixing unit is communicated with the homogenizing unit through a powder conveying mechanism. The vibration screening and premixing unit comprises a premixing hopper and a plurality of vibration screens, and a first iron remover is arranged between a discharge port of each vibration screen and a feed port of the premixing hopper; the homogenizing unit comprises a stock bin, a mixer, a filter and a second iron remover, the filter is arranged at the top of the stock bin and is communicated with the interior of the stock bin, the mixer is arranged at the lower end of the stock bin and is communicated with the interior of the stock bin, and the second iron remover is arranged at the lower part of the mixer and is communicated with the interior of the mixer. Compared with the prior art, the device has the advantages that the polyolefin powder is highly purified and homogenized, the materials are uniformly mixed and dispersed, and the cleanliness of products is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of polyolefin production, and specifically relates to a polyolefin powder purification and homogenization post-treatment device. BACKGROUND

[0002] Polyolefin is a general term for a class of thermoplastic resins obtained by polymerization or copolymerization of alpha-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and certain cyclic olefins. Among them, polyethylene shows excellent wear resistance, impact strength, self-lubricating performance, and low-temperature resistance, and is widely used in industry. The polyolefin production process mainly includes solution method, slurry method, and gas phase method, among which the slurry method is relatively mature and the product quality is relatively stable. In the production of polyolefin by the slurry method, after the polymerization reaction is completed, the reaction slurry is transferred to a flash tank for product separation, and the separated solid-phase polymer is sent to a degassing and drying unit. The dried polymer powder is sieved and homogenized to obtain the finished product. The sieving and homogenization operations play an important role in obtaining qualified products. In addition, polyolefin also needs to be mixed with other additives to improve its performance.

[0003] Most of the existing mixing and homogenization treatment devices use stirring or gravity mixing, which has various problems. Patent CN221291915U discloses a polyethylene mixing device, which quickly mixes the polyethylene material at the bottom with other materials by fixedly connecting a plurality of stirring rods to the spiral blades at the lower part of the connecting rod. This device uses mechanical stirring to mix the materials, which has problems such as material layering, wall sticking, mechanical stirring heating, and material agglomeration.

[0004] The existing technology also discloses air flow mixing machine equipment. For example, patent CN212188890U discloses a pulse air flow mixing machine, which includes a bin, a mixer, a discharge valve, and a filter. The opening and closing of the air blowing nozzle are controlled by a solenoid valve to achieve pulse blowing of the air blowing nozzle. The high-pressure and high-speed airflow blown by the air blowing nozzle realizes the stirring and mixing of the materials. Patent CN113559756A discloses a positive pressure pulse air flow mixing machine, which uses a combination of a spray disc device and a middle blowing device to improve the mixing uniformity and reduce the damage to the material particles. The container does not have lifting or rotating movements.

[0005] However, the existing air flow mixing machine cannot be directly applied to the polyolefin powder homogenization process. This is because the polyolefin powder produced by the slurry method (such as high molecular weight polyethylene) has fine particles (D50 particle size of 100-120 μm), the powder is sticky due to the poor resin morphology and the formation of oligomers and residual gas impurities on the surface, the flowability is poor, and the powder is prone to agglomeration and adhesion to the bin wall. The straight-up and straight-down pulse air supply method has the problem of uneven homogenization.

[0006] In addition, downstream manufacturers also put forward higher and higher requirements for the cleanliness of polyolefin powder, for example, in the production of lithium battery diaphragm, if the content of metal impurities such as iron in the raw material is high, it is not conducive to the puncture strength of the battery diaphragm, so it is necessary to effectively remove the metal impurities in the powder. In the medical field, such as medical filter material, artificial joint and the like, higher requirements are put forward for the purity of polyolefin raw materials. The existing treatment equipment is difficult to achieve higher purification treatment standards. Utility model content

[0007] The utility model discloses a kind of polyolefin powder purification homogenization post-processing device to solve the above problems.

[0008] The utility model discloses the purpose by the following technical scheme:

[0009] A kind of polyolefin powder purification homogenization post-processing device, including vibrating screen pre-mixing unit and homogenization unit, the vibrating screen pre-mixing unit is communicated with homogenization unit by powder conveying mechanism;

[0010] The vibrating screen pre-mixing unit includes premixing hopper and multiple vibrating screens, first de-ironer is arranged between the discharge port of vibrating screen and the feed port of premixing hopper;

[0011] The homogenization unit includes bunker, mixer, filter, second de-ironer, the filter is arranged at the top of bunker and is communicated with the inside of bunker, the mixer is arranged at the lower end of bunker and is communicated with the inside of bunker, and the second de-ironer is arranged at the lower part of mixer and is communicated with the inside of mixer.

[0012] As a preferred technical scheme, the premixing hopper is provided with a distributor at the feed port, and the distributor includes at least one conical cover with mesh. The conical cover-shaped distributor helps to preliminarily mix each material entering the hopper, plays a premixing role, and helps to improve the homogenization efficiency.

[0013] As a preferred technical scheme, the vibrating screen pre-mixing unit further includes at least one additive feeding hopper for adding additives, and a metering scale is arranged at the lower end of the additive feeding hopper.

[0014] As a preferred technical scheme, the powder conveying mechanism is a pipe chain conveying mechanism or a vacuum feeding mechanism.

[0015] As a preferred technical scheme, the mixer includes a base, a passage penetrating through the base is arranged in the middle of the base, a cone valve sealing unit is arranged in the passage, and the cone valve sealing unit includes a cone valve spool and a driving mechanism for driving the cone valve spool to lift.

[0016] The gas distribution ring is arranged in the base of the mixer, and the gas distribution ring is annularly arranged in a ring cavity structure around the base.

[0017] In operation, the high-speed airflow blown by the air passages collides with the conical valve core in the middle, and due to the deflection of the center line of the air passage and the conical rebound of the conical valve core, a spiral upward airflow is formed, which drives the powder material to move upward in a spiral manner, avoiding straight upward and downward movement, and improving the mixing effect of the material. The mixed material is removed by the iron remover to remove metal impurities such as iron powder, thereby improving the purity of the product.

[0018] As a preferred technical solution, the conical valve core is a hollow conical structure, the central axis of the conical valve core is collinear with the central axis of the channel, the upper part of the conical valve core is located in the hopper, and the conical valve core and the bottom of the hopper and the channel form an annular discharge channel, and the material is discharged from the hopper through the annular discharge channel.

[0019] As a preferred technical solution, a sealing gasket is arranged on the inner wall of the bottom of the lower end of the channel; and / or, the driving mechanism is a telescopic air cylinder or a telescopic oil cylinder, the telescopic rod of the driving mechanism is fixedly connected with the bottom of the conical valve core, the air inlet end and the air outlet end of the telescopic cylinder are connected with the electromagnetic reversing valve through the air pipe and are in communication with the external air source; the pulse controller realizes the extension and contraction of the telescopic cylinder by controlling the electromagnetic reversing valve; the bottom of the conical valve core is a hollow structure, and the driving mechanism is installed in the hollow structure.

[0020] As a preferred technical solution, the air passages are arranged at equal intervals on the gas distribution ring, the center line of the air passage is arranged at a deflection angle with the axial cross center line of the hopper, and a plurality of air passages are arranged around the conical valve core.

[0021] And / or, the outer side of the gas distribution ring is in communication with the air inlet pipe assembly, and the external high-pressure gas is introduced in a pulse manner through the air inlet pipe assembly. The air inlet pipe assembly comprises a first air inlet pipe and a second air inlet pipe arranged symmetrically, the first air inlet pipe and the second air inlet pipe are connected with a V-shaped adjusting valve and a pneumatic pulse valve respectively, the air inlet ends of the first air inlet pipe and the second air inlet pipe are connected with an air inlet manifold, a pneumatic ball valve is installed on the air inlet manifold, and an external high-pressure gas source is connected.

[0022] As a preferred technical solution, the hopper is a cylindrical structure with a circular upper part and a conical lower part, the hopper comprises a cylindrical part at the upper part and a conical part at the lower part, the upper end of the hopper is provided with a feeding port, and the feeding port is arranged on the side wall of the upper part of the cylindrical part close to the hopper.

[0023] And / or, the filter adopts a bag filter, and is connected with an electromagnetic valve.

[0024] And / or, the base is detachably fixedly connected with the lower end of the silo through a flange assembly, and the channel is matched with the bottom of the silo.

[0025] As a preferred technical scheme, the second iron remover is arranged downstream of the mixer, and the second iron remover comprises an electric iron remover and / or a manual iron remover; the electric iron remover is a rotary iron remover, and the manual iron remover is a drawer-type iron remover; when the product is a medical material or a product with particularly high requirements for impurities, the iron remover can also adopt an electromagnetic iron remover, and the electromagnetic iron remover has a higher magnetic removal depth.

[0026] And / or, an arch breaking ring pipe is arranged on the conical part of the silo or the conical section of the mixer, and the arch breaking ring pipe is a vent pipe capable of introducing a purge gas;

[0027] And / or, the roughness Ra of the inner wall surface of the homogenizing unit is less than 0.4.

[0028] And / or, the inner wall of the homogenizing unit is provided with a PTFE lining.

[0029] As a preferred technical scheme, a pipe chain conveying device is adopted, and a non-metal material such as PTFE is used for the pipe chain scraper, so as to reduce the introduction of metal impurities.

[0030] Compared with the prior art, the utility model has the following beneficial effects:

[0031] The post-processing device of the utility model purifies and homogenizes, first carries out vibration screening of each material through the vibration screening premixing unit, removes large-particle materials, guarantees the particle fineness of the material, and carries out an iron removal step, removes part of metal impurities, enters the premixing hopper to carry out premixing, and is helpful to improve the efficiency of subsequent homogenization. In the subsequent homogenization stage, the polyolefin powder is homogenized through a pulse airflow mixing mode, compared with the traditional mechanical stirring homogenization mode, the problems such as material layering, mechanical stirring heating, material agglomeration and caking and the like are avoided. In view of the problems such as fine polyolefin powder particles, sticky powder, easy agglomeration, easy wall sticking, uneven homogenization, poor flowability and easy bridging, a mixer with improved structure is adopted, the air inlet channel is optimized, a spiral airflow suitable for polyolefin powder is formed, the polyolefin powder is blown up in a spiral shape along the center area of the silo, the homogenization effect is good, and the polyolefin powder is not easy to stick to the wall. In addition, an iron remover is arranged in the pipeline downstream of the mixer, a second iron removal step is carried out on the flowing material, the cleanliness of the powder is greatly improved, and the use requirements of downstream customers are better met. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a whole structure schematic view of the post-processing device shown in the embodiment;

[0033] Figure 2 It is a structure schematic view of the vibration screening premixing unit shown in the embodiment.

[0034] Figure 3 Structure diagram of the homogenizing unit shown in the embodiment;

[0035] Figure 4 Structure diagram of the mixer;

[0036] Figure 5 Structure diagram of the gas flow in the mixer;

[0037] Figure 6 Top view of the connection between the gas inlet pipe assembly and the mixer;

[0038] In the figure:

[0039] 100-vibrating sieve pre-mixing unit; 200-homogenizing unit; 300-powder conveying mechanism;

[0040] 101-pre-mixing hopper; 102-vibrating sieve; 103-first iron remover; 104-additive hopper; 105-metering scale; 106-distributor;

[0041] 201-hopper; 202-mixer; 203-filter; 204-second iron remover; 205-anti-arching ring pipe;

[0042] 2021-base; 20211-channel; 2022-cone valve spool; 2023-driving mechanism; 2024-gas distribution ring; 2026-gas passage; 20251-first gas inlet pipe; 20252-second gas inlet pipe; 20253-V-shaped adjusting valve; 20254-pneumatic pulse valve; 20255-pneumatic ball valve. DETAILED DESCRIPTION

[0043] The utility model will be explained in detail below, and the utility model is not explained in detail, which is a technical scheme disclosed in the art.

[0044] As shown in Figure 1 A polyolefin powder purification and homogenization post-processing device, which comprises a vibrating sieve pre-mixing unit 100 and a homogenizing unit 200, the vibrating sieve pre-mixing unit 100 and the homogenizing unit 200 are communicated through a powder conveying mechanism 300, the vibrating sieve pre-mixing unit 100 and the homogenizing unit 200 are fixedly installed through a base frame, and the homogenizing unit 200 can be provided with multiple groups as needed, such as two groups in the embodiment. Figure 2As shown in the figure, the vibrating screen pre-mixing unit 100 comprises a pre-mixing hopper 101 and a plurality of vibrating screens 102 (two are shown in the figure), and a first iron remover 103 is arranged between the discharge port of the vibrating screen 102 and the feeding port of the pre-mixing hopper 101, and the first iron remover 103 preferably adopts an automatic rotating iron remover to remove the first metal impurities from the material to be mixed entering the pre-mixing hopper 101. The pre-mixing hopper 101 is provided with a distributor 106 at the feeding port thereof, and the distributor 106 comprises at least one conical cover with mesh (two are shown in the figure), and the conical cover-shaped distributor is helpful to preliminarily mix the materials entering the hopper, plays a pre-mixing role, and is helpful to improve the homogenization efficiency and accelerate the mixing process. As shown in the figure, Figure 2 As shown in the figure, the vibrating screen pre-mixing unit 100 further comprises at least one additive feeding hopper 104 for adding additives, and a metering scale 105 is arranged at the lower end of the additive feeding hopper 104 for metering the amount of additives. As a preferred technical solution, the powder conveying mechanism 300 is a pipe chain conveying mechanism or a vacuum feeding mechanism, and in this embodiment, the pipe chain conveying mechanism is adopted for conveying the pre-mixed material to the homogenization bin.

[0045] Further, as shown in the figure, Figure 3 The homogenization unit 200 specifically comprises a bin 201, a mixer 202, a filter 203 and a second iron remover 204, wherein the bin 201 is a cylindrical structure with an upper circular part and a lower conical part, the upper end of the bin 201 is provided with a feeding port, the feeding port is arranged on the upper side wall of the upper part of the cylindrical part of the bin 201 (not shown in the figure), and the powder conveying mechanism 300 is connected with the feeding port. The filter 203 is arranged at the top of the bin 201 and is connected with the inside of the bin 201. As a preferred technical solution of this embodiment, the filter 203 adopts a bag filter and is connected with a solenoid valve. The mixer 202 is arranged at the lower end of the conical part of the bin 201, and the inside thereof is connected with the bin 201. The second iron remover 204 is arranged at the lower part of the mixer 202 and is connected with the inside of the mixer 202, and the discharge port of the second iron remover 204 is connected with a discharge pipe.

[0046] As shown in the figure, Figure 4 As a preferred embodiment of the utility model, the mixer comprises a base 2021, the base 2021 is detachably fixedly connected with the lower end of the bin 201 through a flange assembly, the middle part of the base 2021 is provided with a channel 20211 penetrating through the upper and lower ends of the base 2021, the channel 20211 is matched with the bottom of the bin 201, so that the material from the bottom of the bin 201 can smoothly pass through the channel 20211 and enter the lower part.

[0047] In this embodiment, a cone valve sealing unit is provided in the channel 20211, including a cone valve core 2022 and a drive mechanism 2023 for driving the cone valve core 2022 to rise and fall. The drive mechanism 2023 is installed in the base 2021. The cone valve core 2022 has a cone-shaped structure, and the central axis of the cone valve core 2022 is collinear with the central axis of the channel 20211. The upper part of the cone valve core 2022 is located in the hopper 201. The cone valve core 2022, the bottom of the hopper 201, and the channel 20211 form an annular discharge channel, through which materials can be discharged from the hopper 201. The lower end of the cone valve core 2022 is located inside the channel 20211. When the drive mechanism 2023 drives the cone valve core 2022 to descend, the lower end of the cone valve core 2022 separates from the channel 20211, opening the discharge channel and allowing material to be discharged. When the drive mechanism 2023 drives the cone valve core 2022 to rise, the lower end of the cone valve core 2022 seals against the channel 20211, closing the discharge channel. Figure 4 (The indicated state is the closed state). As a preferred technical solution, a sealing gasket is provided on the inner wall of the lower end of channel 20211. When the cone valve core 2022 moves upward, the sealing gasket improves the sealing performance of the cone valve core 2022 on the cone channel 20211. As a preferred technical solution, the drive mechanism 2023 is a telescopic cylinder or a telescopic hydraulic cylinder. In this embodiment, the drive mechanism 2023 uses a telescopic cylinder. The telescopic rod of the telescopic cylinder is fixedly connected to the bottom of the cone valve core 2022. Both the inlet and outlet ends of the telescopic cylinder are connected to the solenoid directional valve through air pipes and are connected to an external air source. The pulse controller controls the solenoid directional valve to realize the extension and retraction of the telescopic cylinder. Furthermore, the bottom of the cone valve core 2022 has a hollow structure, and the telescopic cylinder is installed inside the cavity. The telescopic cylinder being located inside the cone valve core 2022 can prevent material accumulation in the telescopic cylinder.

[0048] In this embodiment, a gas distribution ring 2024 is provided inside the base 2021 of the mixer. The gas distribution ring 2024 surrounds the base 2021 in a ring-shaped cavity structure. Multiple downwardly inclined air passages 2026 are arranged along the inner circumference of the gas distribution ring 2024 and are connected to it. Preferably, the multiple air passages 2026 are evenly spaced on the gas distribution ring 2024, and the center line of the air passage 2026 has a certain deflection angle (30-75°) with the axial cross center line of the hopper. The multiple air passages 2026 are arranged around the cone valve core 2022. Figure 5 As shown, during operation, the high-speed airflow blown out by the air passage 2026 impacts the cone valve core 2022 in the middle. Due to the deflection setting of the center line of the air passage 2026 and the cone-shaped back thrust of the cone valve core, a spiral upward airflow is formed in the central area, which drives the powder material to move spiral upward and improves the material mixing effect.

[0049] Further, the outside of the gas distribution ring 2024 is connected with the gas inlet pipe assembly, through which external high-pressure gas can be introduced in a pulse manner. As shown in Figure 6 As a preferred technical solution, the gas inlet pipe assembly includes symmetrically arranged first gas inlet pipe 20251 and second gas inlet pipe 20252. The symmetrically arranged two gas inlet pipes can better realize the mixing of the material and avoid bridging of the material. The first gas inlet pipe 20251 and the second gas inlet pipe 20252 are respectively connected with a V-type regulating valve 20253 and a pneumatic pulse valve 20254. The gas inlet ends of the first gas inlet pipe 20251 and the second gas inlet pipe 20252 are connected with a gas inlet manifold. A pneumatic ball valve 20255 is installed on the gas inlet manifold, and an external high-pressure gas source (air or inert gas, preferably nitrogen) is connected.

[0050] Further, a second iron remover 204 is arranged downstream of the mixer. The second iron remover 204 includes an electric iron remover and / or a manual iron remover. Preferably, a pneumatic butterfly valve and a rotary valve are installed in the discharge pipeline downstream of the mixer for controlling the amount of material entering the iron remover. Further preferably, an electric iron remover and a manual iron remover are arranged in sequence in the pipeline downstream of the mixer 203 to remove metal impurities from the material flowing therethrough.

[0051] As a further preferred solution, an arch breaking ring pipe 205 is arranged in the conical part of the silo 201 or the conical section of the mixer. The arch breaking ring pipe 205 is a gas pipe through which purge gas can be introduced. During operation, the arch is broken by introducing gas, which helps to prevent material from clumping and agglomerating and prevents bridging in the conical section.

[0052] As a further preferred solution, the roughness Ra of the inner wall surface of the homogenization unit (including the silo 201, the mixer 202, the conical valve core 2022, etc.) is less than 0.4. A smooth surface makes it easier for the gas flow to carry the powder upward in a spiral manner and prevents the material from sticking to the wall. As a further preferred solution, the inner wall surface of the homogenization unit is provided with a PTFE lining to avoid the introduction of metal impurities.

[0053] The working principle of the device is as follows: the polyolefin powders (such as polyethylene) to be mixed are fed into the vibrating screen through the feeding, the required additives are added through the feeding hopper, the large particle materials are removed through the vibrating screen, the small particle materials meeting the requirements are sent to the premixing hopper, and the first metal impurity removal operation is performed through the first iron remover before entering the premixing hopper. When entering the premixing hopper, the materials are preliminarily mixed due to the distributor arranged in the premixing hopper, which plays a premixing role and helps to improve the efficiency of subsequent homogenization. The premixed materials are sent to the homogenization unit through the powder conveying mechanism (such as the pipe chain conveying mechanism). The discharge port of the homogenization unit is closed, the cone valve sealing unit of the mixer is in a sealed state, all the powders are added through the feeding port at the upper part of the bin, after the feeding is completed, the mixer is started, the pulse control valve assembly is controlled by the program to send the pulse gas in an intermittent manner, the gas flow passes through the air duct of the mixing head in a pulse manner, the compressed gas spirally rises along the cone wall of the conical discharge valve, the materials are impacted by the spirally rising compressed gas and spirally rise and expand with the gas, after the compressed air expands to a certain extent, the materials sink downward, and one pulse mixing process is completed. After one pulse ends, it is paused for several seconds and the second pulse mixing starts, and the operation is sequentially repeated. The materials are continuously thrown, dislocated and dropped with the supply and stop of the compressed gas, and after several cycles of pulses, the materials in the mixing bin are fully diffused, and the materials are fully and uniformly mixed in a short time. The whole mixing process is completed in about 1-2 minutes, and the mixed waste gas is discharged from the bin after being treated by the filter. After the mixing is completed, the materials pass through the second iron remover for the second metal impurity, and the qualified products are discharged from the discharge port for packaging.

[0054] Application Example 1

[0055] The polyethylene powder mixing experiment is carried out by using the above device.

[0056] The bin volume is 4m 3 ; the bin cone angle is 55°; and the bin diameter is 1.7m.

[0057] One pulse gas supply mixing time: 3 seconds; pulse interval time: 1 minute; batch mixing pulse: 3 pulses / batch; and the high-pressure gas flow pressure is 0.45-0.6MPa.

[0058] The uniformity of mixing is tested by taking A and B samples from the upper and lower parts of the bin, respectively. The material information of the two polyethylene powders is shown in Table 1, and the experimental results are shown in Table 2.

[0059] Table 1

[0060] Mixture material Mass Melt index Particle size D10 / um Particle size D50 / um Particle size D90 / um Polyethylene raw material one 535 kg 0.16 70 113 184 Polyethylene raw material two 390.5 kg 0.30 72 110 187

[0061] Table 2

[0062]

[0063]

[0064] From Table 2, it can be seen that in the first batch (pulse number 3 times), the melt index and particle size of the mixed material reach stable values, indicating that the two polyethylene raw materials have been mixed uniformly.

[0065] Application Example 2

[0066] The volume of the silo is about 12m 3 ; the silo cone angle is 60°. Raw material 1 to raw material 6 are mixed through the above device, and after 6 pulses, the material is discharged (pulse air pressure is 0.6-0.8 MPa). During the discharging process, 6 samples are randomly taken for testing. The experimental data of raw material 1 to raw material 6 and sample 1 to sample 6 are shown in Table 3. From Table 3, it can be seen that after mixing by the device, the D10 particle size, D50 particle size, D90 particle size and melt index of sample 1 to sample 6 are basically the same, indicating that the material has been mixed uniformly.

[0067] Table 3

[0068]

[0069] Product cleanliness detection: According to ISO 16232, the cleanliness of the treated material is analyzed and tested. The results show that according to 1000g sample preparation, microscopic analysis shows that the number of metal particles larger than 400μm in the filter membrane is 0; the number of metal particles between 200-400μm is 1; the number of metal particles between 150-200μm is 0; the number of metal particles between 100-150μm is 0; the number of metal particles between 50-100μm is 7. The results show that after treatment by the device, the larger size metal impurities in the material have been removed, the product cleanliness is high, and meets the demand of downstream manufacturers for high cleanliness of the product. For example, in the preparation of lithium battery separators, the puncture strength of the separator is ensured.

[0070] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the utility model. Those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described herein to other embodiments without having to go through creative labor. Therefore, the utility model is not limited to the above embodiments, and those skilled in the art can make improvements and modifications within the scope of the utility model without departing from the scope of the utility model.

Claims

1. A polyolefin powder purification homogenization post-treatment apparatus, characterized by, The application relates to a premixing and homogenizing device, which comprises a vibrating screening premixing unit (100) and a homogenizing unit (200), wherein the vibrating screening premixing unit (100) is communicated with the homogenizing unit (200) through a powder conveying mechanism (300). The vibrating screening premixing unit (100) comprises a premixing hopper (101) and a plurality of vibrating screens (102), and a first iron remover (103) is arranged between the discharge port of the vibrating screen (102) and the feeding port of the premixing hopper (101). The homogenizing unit (200) comprises a bin (201), a mixer (202), a filter (203) and a second iron remover (204), wherein the filter (203) is arranged at the top of the bin (201) and communicated with the inside of the bin (201), the mixer (202) is arranged at the lower end of the bin (201) and communicated with the inside of the bin (201), and the second iron remover (204) is arranged at the lower part of the mixer (202) and communicated with the inside of the mixer (202).

2. A polyolefin powder purification homogenization post-treatment device according to claim 1, characterized in that, The premixing hopper (101) is provided with a distributor (106) at the feeding port, and the distributor (106) comprises at least one conical cover with mesh holes.

3. A polyolefin powder purification homogenization post-treatment device according to claim 1, characterized in that, The vibrating screening premixing unit (100) further comprises at least one additive feeding hopper (104) for adding additives, and a metering scale (105) is arranged at the lower end of the additive feeding hopper (104).

4. A polyolefin powder purification homogenization post-treatment apparatus according to claim 1, characterized in that, The powder conveying mechanism (300) is a pipe chain conveying mechanism or a vacuum feeding mechanism.

5. A polyolefin powder purification homogenization post-treatment apparatus according to claim 1, characterized in that, The mixer comprises a base (2021), and a channel (20211) penetrating through the base (2021) is arranged in the middle of the base (2021), a cone valve sealing unit is arranged in the channel (20211), and the cone valve sealing unit comprises a cone valve spool (2022) and a driving mechanism (2023) for driving the cone valve spool (2022) to lift. A gas distribution ring (2024) is arranged in the base (2021) of the mixer, the gas distribution ring (2024) is annularly arranged around the base (2021) in a cavity structure, a plurality of downwardly inclined gas channels (2026) are arranged on the inner side of the gas distribution ring (2024) in a circumferential direction and communicated with the gas distribution ring (2024), and the outlet of the gas channel (2026) is oppositely arranged with the conical surface of the cone valve spool (2022).

6. A polyolefin powder purification homogenization post-treatment apparatus according to claim 5, characterized in that, The cone valve spool (2022) is a hollow conical structure, the central axis of the cone valve spool (2022) is collinear with the central axis of the channel (20211), the upper part of the cone valve spool (2022) is located in the bin (201), and the cone valve spool (2022) forms an annular discharging channel with the bottom of the bin (201) and the channel (20211), and the material is discharged from the bin (201) through the annular discharging channel.

7. A polyolefin powder purification homogenization post-treatment apparatus according to claim 5, characterized in that, A sealing gasket is arranged on the inner wall of the lower end of the channel (20211). And / or, the driving mechanism (2023) is a telescopic air cylinder or a telescopic oil cylinder, a telescopic rod of the driving mechanism (2023) is fixedly connected with a bottom of the spool valve spool (2022), an air inlet end and an air outlet end of the telescopic cylinder are connected with an electromagnetic reversing valve through air pipes and are in communication with an external air source; a pulse controller realizes telescopic operation of the telescopic cylinder by controlling the electromagnetic reversing valve; the bottom of the spool valve spool (2022) is a cavity structure, and the driving mechanism (2023) is installed in the cavity.

8. A polyolefin powder purification homogenization post-treatment apparatus according to claim 5, characterized in that, The air passages (2026) are arranged at equal intervals on the gas distribution ring (2024), and center lines of the air passages (2026) are arranged at a deflection angle with respect to an axial cross center line of the silo; and the plurality of air passages (2026) are arranged around the spool valve spool (2022). And / or, the gas distribution ring (2024) is connected with an air inlet pipe assembly on the outside, and external high-pressure gas is introduced in a pulse mode through the air inlet pipe assembly.

9. A polyolefin powder purification homogenization post-treatment apparatus according to claim 5, characterized in that, The silo (201) is a cylindrical structure with a circular upper part and a conical lower part, including a cylindrical part at the upper part and a conical part at the lower part, and the silo (201) is provided with a feeding port at the upper end; the feeding port is arranged on the sidewall of the upper part of the cylindrical part close to the silo (201); And / or, the filter (203) is a bag filter connected with an electromagnetic valve; And / or, the base (2021) is detachably fixedly connected with the lower end of the silo (201) through a flange assembly, and the passage (20211) is matched with the bottom of the silo (201).

10. A polyolefin powder purification homogenization post-treatment apparatus according to claim 1, characterized in that, The second iron remover (204) is arranged downstream of the mixer, and the second iron remover (204) includes an electric iron remover and / or a manual iron remover; And / or, the conical part of the silo (201) or the conical section of the mixer is provided with an arch breaking ring pipe (205), and the arch breaking ring pipe (205) is a gas pipe through which purge gas can be introduced; And / or, a roughness Ra of an inner wall surface of the homogenizing unit is less than 0.4; And / or, the inner wall of the homogenizing unit is provided with a PTFE lining.

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