Purification and homogenization treatment system for producing pure polyolefin powder

Abstract

The invention relates to a purification and homogenization treatment system for producing pure polyolefin powder, which comprises a vibration screening and premixing unit and a homogenization unit, and the vibration screening and premixing unit is communicated with the homogenization 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, high purification and homogenization treatment on polyolefin powder are realized, the materials are uniformly mixed and dispersed, and the product cleanliness is high.

Description

Technical Field

[0001] The invention relates to the technical field of polyolefin production, and in particular to a purification and homogenization processing system for producing pure polyolefin powder. Background Art

[0002] Polyolefin is a general term for a class of thermoplastic resins obtained by polymerizing or copolymerizing α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and some cycloolefins. Among them, polyethylene exhibits excellent wear resistance, impact strength, self-lubricating properties, 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 them, the slurry method technology is relatively mature and the product quality is relatively stable. In the slurry method of producing polyolefins, after the polymerization reaction is completed, the reaction slurry is moved to a flash tank for product separation, and the separated solid polymer enters the degassing and drying unit. The dried polymer powder is screened and homogenized to obtain the finished product, and the screening and homogenization operations play an important role in finally obtaining qualified products. In addition, polyolefins also need to be mixed with other additives to improve their performance.

[0003] Most existing mixing and homogenizing devices use stirring or gravity blending, which has various problems. Patent CN221291915U discloses a polyethylene mixing device, which quickly mixes the polyethylene material at the bottom with other materials by fixing a spiral sheet at the lower part of the connecting rod and fixing multiple stirring rods. The device uses mechanical stirring to mix the materials, which has problems such as material stratification, wall adhesion, mechanical stirring heat generation, and material agglomeration.

[0004] The prior art also discloses air flow mixer equipment. For example, patent CN212188890U discloses a pulse air flow mixer, the homogenization unit includes a silo, a mixer, a discharge valve and a filter, which controls the opening and closing of the blowing nozzle by a solenoid valve to realize pulse blowing of the blowing nozzle, and the high-pressure and high-speed airflow blown out of the blowing nozzle is used to stir and mix the materials. Patent CN113559756 A discloses a positive pressure pulse air flow mixer, the mixer uses a combination of a spray disc device and a middle spray device to improve the mixing uniformity, reduce the damage to the material particles, and the container does not have lifting, rotating and other movements.

[0005] However, the existing air flow mixer cannot be directly applied to the homogenization process of polyolefin powder. This is because the polyolefin powder (such as high molecular weight polyethylene) produced by the slurry process has fine particles (D50 particle size is 100-120μm), the powder is sticky due to poor resin morphology, oligomers formed on the surface and residual gas impurities, the fluidity becomes poor, it is easy to agglomerate and adhere to the wall of the silo, and the straight up and down pulse air supply method has the problem of uneven homogenization.

[0006] In addition, downstream processing manufacturers have also put forward higher and higher requirements for the cleanliness of polyolefin powder. For example, in the lithium battery separator produced by polyethylene, if the raw material contains high levels of metal impurities such as iron, it is not conducive to the puncture strength of the battery separator. Therefore, it is necessary to effectively remove the metal impurities in the powder. In the medical field, such as medical filter materials and artificial joints, there are higher requirements for the purity of polyolefin raw materials. It is difficult for existing processing equipment to reach higher purification standards. Summary of the invention

[0007] The object of the present invention is to solve the above problems and provide a purification and homogenization system for producing pure polyolefin powder.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A purification and homogenization system for producing pure polyolefin powder, comprising a vibration screening premixing unit and a homogenization unit, wherein the vibration screening premixing unit is connected with the homogenization unit through a powder conveying mechanism;

[0010] The vibrating screening premixing unit comprises a premixing hopper and a plurality of vibrating screens, and a first iron remover is arranged between a discharge port of the vibrating screen and a feed port of the premixing hopper;

[0011] The homogenization unit includes a silo, a mixer, a filter, and a second iron remover. The filter is arranged at the top of the silo and is connected to the interior of the silo. The mixer is arranged at the lower end of the silo and is connected to the interior of the silo. The second iron remover is arranged at the lower part of the mixer and is connected to the interior of the mixer.

[0012] As a preferred technical solution, the premixing hopper is provided with a distributor at its feed inlet, and the distributor includes at least one conical cover with meshes. The conical cover-shaped distributor helps to preliminarily mix the materials entering the hopper, plays a role of premixing, and helps to improve the efficiency of homogenization.

[0013] As a preferred technical solution, the vibration screening premixing unit further includes at least one additive hopper for adding additives, and a metering scale is provided at the lower end of the additive hopper.

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

[0015] As a preferred technical solution, the mixer includes a base, a channel penetrating the base is provided in the middle of the base, a cone valve sealing unit is provided in the channel, including a cone valve core and a driving mechanism for driving the cone valve core to rise and fall;

[0016] A gas distribution ring is arranged in the base of the mixer, and the gas distribution ring surrounds the base to form an annular cavity structure. The gas distribution ring is provided with a plurality of downwardly inclined air passages connected to the gas distribution ring along its inner circumference, and the outlets of the air passages are arranged opposite to the conical surface of the cone valve core.

[0017] During operation, the high-speed airflow blown out of the airway collides with the cone valve core in the middle. Due to the deflection setting of the airway centerline and the conical recoil effect of the cone valve core, a spiral upward airflow is formed, which drives the powder material to move upward in a spiral, avoiding straight up and down, thereby improving the material mixing effect; the mixed material is removed from metal impurities such as iron powder by the iron remover to improve the purity of the product.

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

[0019] As a preferred technical solution, a sealing gasket is provided 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 to the bottom of the cone valve core, the air inlet and air outlet of the telescopic cylinder are connected to the electromagnetic reversing valve through an air pipe, and are connected to an external air source; the pulse controller realizes the extension and retraction of the telescopic cylinder by controlling the electromagnetic reversing valve; the bottom of the cone valve core is a cavity structure, and the driving mechanism is installed in the cavity.

[0020] As a preferred technical solution, the gas channels are arranged at equal intervals on the gas distribution ring, the center line of the gas channel is arranged at a deflection angle with the axial cross center line of the silo, and a plurality of gas channels are arranged around the cone valve core;

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

[0022] As a preferred technical solution, the silo is a cylindrical structure with a round upper part and a conical lower part, including an upper cylindrical part and a lower conical part. A feed port is provided at the upper end of the silo, and the feed port is provided on the upper side wall of the cylindrical part close to the silo.

[0023] And / or, the filter is a bag filter and is connected to a solenoid valve;

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

[0025] As a preferred technical solution, the second iron remover is arranged downstream of the mixer, and the second iron remover includes an electric iron remover and / or a manual iron remover, including an electric iron remover that is a rotary iron remover and a manual iron remover that is a drawer-type iron remover. When the product is a medical material or other product with particularly high requirements on impurities, the iron remover can also be an electromagnetic iron remover, and the demagnetization depth of the electromagnetic iron remover will be higher.

[0026] And / or, the cone portion of the silo or the cone section of the mixer is provided with an arch-breaking annular pipe, and the arch-breaking annular 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 solution, if a pipe chain conveying device is used, the pipe chain scraper is made of non-metallic material, such as PTFE, to reduce the introduction of metal impurities.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The purification and homogenization treatment system of the present invention first performs vibration screening on each material through a vibration screening premixing unit to remove large particles of material, ensure the particle fineness of the material, and perform an iron removal step to remove some metal impurities, and enter the premixing hopper for premixing, which helps to improve the efficiency of subsequent homogenization. In the subsequent homogenization stage, the polyolefin powder is homogenized by a pulse airflow mixing method, which avoids the problems of material stratification, mechanical stirring heating, material agglomeration and agglomeration compared with the traditional mechanical stirring homogenization method. In view of the problems of fine particles of polyolefin powder, sticky powder, easy agglomeration, easy wall adhesion, uneven homogenization, poor fluidity and easy bridging, a structurally improved mixer is used to optimize the air inlet channel to form a spiral airflow suitable for polyolefin powder, and the polyolefin powder is blown up in a spiral along the central area of ​​the silo, with good homogenization effect and not easy to stick to the wall. In addition, an iron remover is set in the downstream pipeline of the mixer to remove ash such as metal impurities in the second pass of the material flowing through, which greatly improves the cleanliness of the powder and better meets the use needs of downstream customers. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the processing system shown in the embodiment;

[0033] Figure 2 It is a structural schematic diagram of a vibration screening premixing unit shown in an embodiment;

[0034] Figure 3 It is a structural schematic diagram of a homogenizing unit shown in an embodiment;

[0035] Figure 4 is a schematic diagram of the structure of the mixer;

[0036] Figure 5 This is a schematic diagram of gas flow in the mixer;

[0037] Figure 6 A top view of the connection between the intake pipe assembly and the mixer;

[0038] In the figure:

[0039] 100-vibration screening premixing unit; 200-homogenization unit; 300-powder conveying mechanism;

[0040] 101-premixing hopper; 102-vibrating screen; 103-first iron remover; 104-additive adding hopper; 105-weighing scale; 106-distributor;

[0041] 201- silo; 202- mixer; 203- filter; 204- second iron remover; 205- arch breaking ring pipe;

[0042] 2021-base; 20211-channel; 2022-cone valve core; 2023-driving mechanism; 2024-gas distribution ring; 2026-air duct; 20251-first air inlet pipe; 20252-second air inlet pipe; 20253-V-type regulating valve; 20254-air-controlled pulse valve; 20255-pneumatic ball valve. DETAILED DESCRIPTION

[0043] The present invention is described in detail below. All matters not described in detail in the present invention are technical solutions already disclosed in the art.

[0044] like Figure 1 As shown, a purification and homogenization system for producing pure polyolefin powder includes a vibration screening premixing unit 100 and a homogenization unit 200. The vibration screening premixing unit 100 is connected to the homogenization unit 200 through a powder conveying mechanism 300. The vibration screening premixing unit 100 and the homogenization unit 200 are fixedly installed through a basic frame. Multiple groups of homogenization units 200 can be set as needed, such as two groups in this embodiment. Figure 2As shown, the vibration screening premixing unit 100 includes a premixing hopper 101 and a plurality of vibration screens 102 (two are shown in the figure). A first iron remover 103 is arranged between the discharge port of the vibration screen 102 and the feed port of the premixing hopper 101. The first iron remover 103 preferably adopts an automatic rotating iron remover to perform the first metal impurity removal on the material to be mixed entering the premixing hopper 101. The premixing hopper 101 is provided with a distributor 106 at its feed port. The distributor 106 includes at least one conical cover with mesh (two are shown in the figure). The conical cover-shaped distributor helps to preliminarily mix the materials entering the hopper, plays a premixing role, helps to improve the homogenization efficiency, and speeds up the mixing process. Figure 2 As shown, the vibration screening premixing unit 100 also includes at least one additive hopper 104 for adding additives, and a metering scale 105 is provided at the lower end of the additive hopper 104 for metering the amount of additives added. As a preferred technical solution, the powder conveying mechanism 300 is a pipe chain conveying mechanism or a vacuum feeding mechanism. In this embodiment, a pipe chain conveying mechanism is specifically used to convey the premixed material to the homogenization silo.

[0045] Furthermore, if Figure 3 As shown, the homogenization unit 200 specifically includes a silo 201, a mixer 202, a filter 203, and a second iron remover 204, wherein the silo 201 is a cylindrical structure with an upper circle and a lower cone, including an upper barrel and a lower cone, and a feed port is provided at the upper end of the silo 201, and the feed port is arranged on the upper side wall of the barrel near the silo 201 (not shown in the figure), and the powder conveying mechanism 300 is connected to the feed port. The filter 203 is arranged at the top of the silo 201 and is connected to the inside of the silo 201. As a preferred technical solution of this embodiment, the filter 203 adopts a bag filter and is connected to a solenoid valve. The mixer 202 is arranged at the lower end of the cone of the silo 201, and its interior is connected to the silo 201. The second iron remover 204 is arranged at the lower part of the mixer 202, and the interior is connected to the mixer 202, and the discharge port of the second iron remover 204 is connected to the discharge pipe.

[0046] like Figure 4 As shown, as a preferred embodiment of the present invention, the mixer includes a base 2021, and the base 2021 is detachably fixedly connected to the lower end of the silo 201 through a flange assembly. A channel 20211 is provided in the middle of the base 2021, which runs through the upper and lower ends of the base 2021. The channel 20211 is adapted to the bottom of the silo 201, so that the material from the bottom of the silo 201 can smoothly pass through the channel 20211 into 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 driving mechanism 2023 for driving the cone valve core 2022 to rise and fall, and the driving mechanism 2023 is installed in the base 2021. The cone valve core 2022 is a conical structure, 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 silo 201, and an annular discharge channel is formed between the cone valve core 2022 and the bottom of the silo 201 and the channel 20211, and the material can be discharged from the silo 201 through the annular discharge channel. The lower end of the cone valve core 2022 is located in the channel 20211. When the driving mechanism 2023 drives the cone valve core 2022 to descend, the lower end of the cone valve core 2022 is separated from the channel 20211, and the discharge channel is opened. At this time, the material can be discharged; when the driving mechanism 2023 drives the cone valve core 2022 to rise, the lower end of the cone valve core 2022 is sealed against the channel 20211, and the discharge channel is closed ( Figure 4 The state shown is the closed state). As a preferred technical solution, a sealing gasket is provided on the inner wall at the bottom of the lower end of the channel 20211. When the cone valve core 2022 moves upward, the sealing gasket can improve the sealing of the cone valve core 2022 to the conical channel 20211. As a preferred technical solution, the driving mechanism 2023 is a telescopic cylinder or a telescopic oil cylinder. In the present embodiment, the driving mechanism 2023 adopts a telescopic cylinder. The telescopic rod of the telescopic cylinder is fixedly connected to the bottom of the cone valve core 2022. The air inlet and air outlet of the telescopic cylinder are connected to the electromagnetic reversing valve through the air pipe and are connected to the external air source. The pulse controller realizes the extension and retraction of the telescopic cylinder by controlling the electromagnetic reversing valve. In addition, the bottom of the cone valve core 2022 is a cavity structure, and the telescopic cylinder is installed in the cavity. The telescopic cylinder is arranged inside the cone valve core 2022, which can avoid the accumulation of materials in the telescopic cylinder.

[0048] In this embodiment, a gas distribution ring 2024 is arranged in the base 2021 of the mixer, and the gas distribution ring 2024 surrounds the base 2021 to form an annular cavity structure. The gas distribution ring 2024 is provided with a plurality of downwardly inclined air passages 2026 connected thereto along its inner circumference. Preferably, the plurality of air passages 2026 are arranged at equal intervals on the gas distribution ring 2024, and the center line of the air passage 2026 has a certain deflection angle (30 to 75°) with the axial cross center line of the silo, and the plurality of 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 collides with the middle cone valve core 2022. Due to the deflection setting of the center line of the air passage 2026 and the conical recoil effect of the cone valve core, a spiral upward airflow is formed in the central area, driving the powder material to move spirally upward, thereby improving the material mixing effect.

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

[0050] Further, 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. Preferably, a pneumatic butterfly valve and a rotary valve are installed in the discharge pipeline downstream of the mixer to control the feed amount of the material entering the iron remover. Further preferably, in this embodiment, an electric iron remover and a manual iron remover are arranged in sequence in the downstream pipeline of the mixer 203 to remove metal impurities from the material flowing through.

[0051] As a further preferred solution, an arch-breaking annular pipe 205 is provided in the conical part of the silo 201 or the conical section of the mixer. The arch-breaking annular pipe 205 is a ventilation pipe capable of introducing purge gas. When in operation, the arch is broken by introducing gas, which helps to prevent the material from agglomerating and bridging in the conical section.

[0052] As a further preferred solution, the roughness Ra of the inner wall surface of the homogenizing unit (including the silo 201, the mixer 202, the cone valve core 2022, etc.) is less than 0.4, and the smooth surface makes it easier for the airflow to spirally ascend with the powder, and it is not easy to stick to the wall. As a further preferred solution, a PTFE lining is provided on the inner wall surface of the homogenizing unit to avoid the introduction of metal impurities.

[0053] The working principle of this processing system is as follows: the various polyolefin powders to be mixed (such as polyethylene) are fed into the vibrating screen, the required additives are added through the feeding hopper, the powder is vibrated to remove large particles, and the small-size materials that meet the requirements are sent to the premixing hopper. Before entering the premixing hopper, the first metal impurity removal operation is performed through the first iron remover to remove some metal impurities. When entering the premixing hopper, due to the distributor set in the premixing hopper, the materials are preliminarily mixed, which plays a premixing role and helps to improve the efficiency of subsequent homogenization. The premixed materials are sent to the homogenization unit through a powder conveying mechanism (such as a pipe chain conveying mechanism). Close the outlet of the homogenization unit, the cone valve sealing unit of the mixer is in a sealed state, and all the powder is added through the feed port on the upper part of the silo. After the feeding is completed, start the mixer, and feed the pulse gas in an intermittent air supply through the pulse control valve assembly controlled by the program. The airflow passes through the airway of the mixing head in a pulsed manner, and the compressed gas spirals up along the cone wall of the conical discharge valve. The material is impacted by the spirally rising compressed gas, and spirally rises and expands with the gas. After the compressed air expands to a certain extent, the material settles down, and a pulse mixing process is completed. After a pulse, pause for a few seconds and start the mixing of the second pulse again. The operation is cyclical in sequence. The material is constantly thrown up, dislocated, and dropped with the supply and stop of compressed gas. After several cycles of pulses, the material in the mixed silo is diffused in all directions, and fully and evenly mixed in a short time. The whole mixing process can be completed in about 1 to 2 minutes, and the mixed exhaust gas is treated by the filter and discharged from the silo. After the mixing is completed, the material passes through the second iron remover for the second metal impurity, and the qualified product is discharged through the outlet for finished product packaging.

[0054] Application Example 1

[0055] The above system was used to carry out polyethylene powder mixing experiments.

[0056] The volume of the silo is 4m 3 ; Silo cone angle 55°; Silo diameter 1.7m.

[0057] Mixing time of one pulse gas supply: 3 seconds; pulse interval time: 1 minute; batch mixing pulse: 3 pulses / batch; high-pressure air flow pressure is 0.45~0.6MPa.

[0058] Two samples A and B were taken from the upper and lower parts of the silo to test the uniformity of the mixture. 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] Mixed materials quality Melt Index Particle size D10 / um Particle size D50 / um Particle size D90 / um Polyethylene raw material 535kg 0.16 70 113 184 Polyethylene raw material 2 390.5kg 0.30 72 110 187

[0061] Table 2

[0062]

[0063]

[0064] It can be seen from Table 2 that in the first batch (pulse number 3 times), the melt index and particle size of the mixed material reached a stable value, indicating that the two polyethylene raw materials have been mixed evenly.

[0065] Application Example 2

[0066] The volume of the silo is about 12m 3 ; The cone angle of the silo is 60°. Raw materials 1 to 6 are mixed by the above device, and the materials are discharged after 6 pulses (the pulse pressure is 0.6-0.8Mpa). During the discharge process, 6 samples are randomly taken for testing. The experimental data of raw materials 1 to 6 and samples 1 to 6 are shown in Table 3. As can be seen from Table 3, after mixing by this device, the D10 particle size, D50 particle size, D90 particle size and melt index of samples 1 to 6 are basically the same, indicating that the materials have been mixed evenly.

[0067] Table 3

[0068]

[0069] Product cleanliness detection: According to ISO 16232, the cleanliness analysis and test of the processed materials are carried out. The results show that according to the sample preparation of 1000g, the microscopic analysis shows that the number of metal particles with a size greater than 400μm in the filter membrane is 0; the number of metal particles with a size of 200-400μm is 1; the number of metal particles with a size of 150-200μm is 0; the number of metal particles with a size of 100-150μm is 0; the number of metal particles with a size of 50-100μm is 7. The results show that after being processed by this system, the larger metal impurities in the material have been removed, and the product has a high cleanliness, which meets the downstream manufacturers' demand for high product cleanliness. For example, when preparing lithium battery separators, the puncture strength of the separator is guaranteed.

[0070] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A purification and homogenization system for producing pure polyolefin powder, characterized in that: It comprises a vibration screening premixing unit (100) and a homogenizing unit (200), wherein the vibration screening premixing unit (100) is connected with the homogenizing unit (200) via a powder conveying mechanism (300); The vibration screening premixing unit (100) comprises a premixing hopper (101) and a plurality of vibration screens (102), and a first iron remover (103) is arranged between a discharge port of the vibration screen (102) and a feed port of the premixing hopper (101); The homogenizing unit (200) comprises a silo (201), a mixer (202), a filter (203), and a second iron remover (204); the filter (203) is arranged at the top of the silo (201) and is connected to the interior of the silo (201); the mixer (202) is arranged at the lower end of the silo (201) and is connected to the interior of the silo (201); and the second iron remover (204) is arranged at the lower part of the mixer (202) and is connected to the interior of the mixer (202).

2. A purification and homogenization system for producing pure polyolefin powder according to claim 1, characterized in that: The premixing hopper (101) is provided with a distributor (106) at its feed inlet, and the distributor (106) comprises at least one conical cover with mesh holes.

3. A purification and homogenization system for producing pure polyolefin powder according to claim 1, characterized in that: The vibration screening premixing unit (100) further comprises at least one auxiliary agent feeding hopper (104) for adding auxiliary agents, and a metering scale (105) is arranged at the lower end of the auxiliary agent feeding hopper (104).

4. A purification and homogenization system for producing pure polyolefin powder according to claim 1, characterized in that: The powder material conveying mechanism (300) is a tube chain conveying mechanism or a vacuum feeding mechanism.

5. A purification and homogenization system for producing pure polyolefin powder according to claim 1, characterized in that: The mixer comprises a base (2021), a channel (20211) penetrating the base (2021) is provided in the middle of the base (2021), a cone valve sealing unit is provided in the channel (20211), and the cone valve core (2022) and a driving mechanism (2023) for driving the cone valve core (2022) to rise and fall are provided. A gas distribution ring (2024) is arranged inside the base (2021) of the mixer, and the gas distribution ring (2024) surrounds the base (2021) to form an annular cavity structure. The gas distribution ring (2024) is provided with a plurality of downwardly inclined air passages (2026) connected to the gas distribution ring (2024) along its inner circumference, and the outlets of the air passages (2026) are arranged opposite to the conical surface of the cone valve core (2022).

6. A purification and homogenization system for producing pure polyolefin powder according to claim 5, characterized in that: The cone valve core (2022) is a hollow cone-shaped structure. The central axis of the cone valve core (2022) is colinear with the central axis of the channel (20211). The upper part of the cone valve core (2022) is located in the silo (201). An annular discharge channel is formed between the cone valve core (2022), the bottom of the silo (201) and the channel (20211), and the material is discharged from the silo (201) through the annular discharge channel.

7. A purification and homogenization system for producing pure polyolefin powder according to claim 5, characterized in that: A sealing gasket is provided on the inner wall of the bottom of the lower end of the channel (20211); And / or, the driving mechanism (2023) is a telescopic air cylinder or a telescopic oil cylinder, the telescopic rod of the driving mechanism (2023) is fixedly connected to the bottom of the cone valve core (2022), the air inlet end and the air outlet end of the telescopic cylinder are connected to the electromagnetic reversing valve through the air pipe, and are connected to the external air source; the pulse controller realizes the extension and retraction of the telescopic cylinder by controlling the electromagnetic reversing valve; the bottom of the cone valve core (2022) is a cavity structure, and the driving mechanism (2023) is installed in the cavity.

8. A purification and homogenization system for producing pure polyolefin powder according to claim 5, characterized in that: The gas channels (2026) are arranged at equal intervals on the gas distribution ring (2024), the center line of the gas channel (2026) is arranged at a deflection angle with the axial cross center line of the silo, and a plurality of gas channels (2026) are arranged around the cone valve core (2022); And / or, the outer side of the gas distribution ring (2024) is connected to the air intake pipe assembly, and the external high-pressure gas is introduced in a pulsed manner through the air intake pipe assembly.

9. A purification and homogenization system for producing pure polyolefin powder according to claim 5, characterized in that: The silo (201) is a cylindrical structure with a round upper part and a conical lower part, comprising an upper cylindrical part and a lower conical part. The upper end of the silo (201) is provided with a feed inlet, which is arranged on the upper side wall of the cylindrical part close to the silo (201); And / or, the filter (203) is a bag filter and is connected to a solenoid valve; And / or, the base (2021) is detachably fixedly connected to the lower end of the silo (201) via a flange assembly, and the channel (20211) is adapted to the bottom of the silo (201).

10. A purification and homogenization system for producing pure polyolefin powder according to claim 1, characterized in that: The second iron remover (204) is arranged downstream of the mixer, and the second iron remover (204) comprises 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 a broken arch annular pipe (205), and the broken arch annular pipe (205) is a vent pipe capable of introducing a purge gas; And / or, the roughness Ra of the 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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