Ultrahigh-purity polymer circulating homogenization demagnetizing system

Abstract

The utility model relates to an ultra-pure polymer circulating, homogenizing and demagnetizing system which comprises a homogenizing stock bin, and a discharge port of the homogenizing stock bin is connected with a feed end of an automatic demagnetizing device through a pipeline; the discharging end of the automatic demagnetizing device is provided with two branch pipes, and the branch pipes comprise a qualified material output branch and a finished product collecting unit, and the circulating branch is communicated with the homogenizing stock bin through a material returning pipeline and is used for returning the substandard materials to the homogenizing stock bin for secondary homogenizing and demagnetizing treatment. Compared with the prior art, the system has the advantages that the automatic demagnetizing device and the circulating branch are arranged in the system, so that efficient, continuous and clean industrial production is realized, and the system is particularly suitable for large-scale production of high-end polyolefin products such as ultra-clean high-purity polyethylene.

Description

Technical Field

[0001] This utility model belongs to the field of ultra-high purity polymers, specifically relating to an ultra-high purity polymer cyclic homogenization and demagnetization system. Background Technology

[0002] Ultra-high purity polymers are crucial basic materials, belonging to a class of materials with extremely high purity and characteristics such as ultra-low metal ion content and low non-volatile residues. Taking polyethylene as an example, ultra-high purity polyethylene can serve as a key basic material in the semiconductor industry chain. It is a core raw material for applications such as ultrapure water filtration, ultrapure reagent delivery pipelines, and storage containers in semiconductor manufacturing, directly determining the stability and service life of ultrapure water systems. It plays an irreplaceable role in ensuring the yield of chip manufacturing in the semiconductor industry. Actively promoting technological breakthroughs in ultra-high purity polymers and achieving leapfrog development in production technology is of great significance for industrial upgrading in new energy, semiconductor, and medical materials and other new productivity fields.

[0003] Polyethylene and other high molecular weight polymers are obtained through polymerization reactions. Polyethylene is generally produced by catalytic polymerization using Ziegler-Natta catalysts, metallocene catalysts, post-transition metal catalysts, or chromium-based catalysts. These catalysts all contain metal elements, which inevitably remain in the product. In large-scale continuous production, the production equipment used is mostly made of metal, and many moving parts are involved. Wear and tear on the metal parts of the production equipment generates a large number of metal impurity particles that can contaminate the product, making it difficult to obtain ultra-high purity polymers with low metal content. Higher ash and metal impurity content means lower product purity and poor cleanliness, which adversely affects the performance of the final product. For fields such as medical applications (e.g., medical filter materials, artificial joints) and semiconductor applications (e.g., high-purity water filter materials), even higher requirements are placed on polymer purity. Therefore, how to prepare ultra-clean, high-purity polymer products is an urgent problem to be solved. Utility Model Content

[0004] The purpose of this invention is to provide an ultra-high purity polymer circulating homogenization and demagnetization system to solve the above problems.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A circulating homogenization and demagnetization system for ultra-high purity polymer includes a homogenization silo, the outlet of which is connected to the inlet of an automatic demagnetizer via a pipeline.

[0007] The automatic demagnetizer has two branch pipes at its discharge end, including:

[0008] The qualified material output branch connects at its end to the finished product collection unit (such as a packaging warehouse); and

[0009] The circulation branch is connected to the homogenization silo via the return pipeline, and is used to return substandard materials to the homogenization silo for further homogenization and demagnetization.

[0010] As a preferred technical solution of this utility model, a dust collector is installed on the top of the homogenizing silo, and the dust collector is connected to the interior of the homogenizing silo;

[0011] The homogenizing silo is provided with an inlet pipe at the top and an outlet pipe at the bottom. The outlet pipe of the homogenizing silo is equipped with a rotary valve, and the automatic demagnetizer is connected downstream of the rotary valve.

[0012] A reversing valve is installed downstream of the automatic demagnetizer. The first outlet of the reversing valve is connected to the qualified material output branch, and the second outlet is connected to the circulation branch.

[0013] As a preferred technical solution of this utility model, the automatic demagnetizer includes:

[0014] The cavity is divided into a demagnetization zone and a cleaning zone, with a clean material cavity and a slag material cavity corresponding to the bottom.

[0015] A multi-layer movable drawer, each drawer including an outer panel, an inner panel and a magnetic rod extending into the cavity, the magnetic rod being disposed between the outer panel and the inner panel;

[0016] A drive unit is symmetrically arranged on both sides of the drawer's travel direction to drive the movable drawer to move;

[0017] The scraper is fixedly installed on the inner wall of the cavity in the demagnetizing zone.

[0018] As a preferred technical solution of this utility model, the automatic demagnetizer adopts a vibration-type pneumatic scraper iron remover;

[0019] The drive component includes a cylinder, and the extension rod of the cylinder is connected to the outer panel.

[0020] As a preferred technical solution of this utility model, the cavity of the automatic demagnetizer is provided with a vibrator, which is fixedly installed on the side wall of the cavity of the cleaning area.

[0021] As a preferred technical solution of this utility model, the magnetic rods are arranged in layers with increasing magnetic intensity from top to bottom, the difference in magnetic field intensity between adjacent layers is controlled at 200-500Gs, the magnetic rods in adjacent layers are arranged alternately, and each layer of magnetic rods is installed between the inner panel and the outer panel through bearings.

[0022] As a preferred technical solution of this utility model, the number of homogenizing silos is 2 to 10, and the feed pipes of multiple homogenizing silos are connected in parallel to the upstream conveying system, and the discharge pipes are connected in parallel to the downstream conveying system.

[0023] As a preferred technical solution of this utility model, the homogenizing silo is a gravity homogenizing silo;

[0024] The bottom is provided with a mixing cone, the mixing cone comprising:

[0025] The central feed pipe is vertically positioned at the center of the inner cavity of the mixing bottom cone;

[0026] Dividers are radially distributed around the central feed pipe, forming multiple independent flow channels;

[0027] A conical shell is connected to the bottom of the homogenization silo and forms an external channel between it and the outer wall of the homogenization silo.

[0028] As a preferred technical solution of this utility model, a sampling port or an online magnetic induction detector is provided on the circulation branch; or, a sampling port or an online magnetic induction detector is provided on the discharge end pipe of the automatic demagnetizer. For example, when a Jomesa cleanliness detector is used to test the content of metal foreign matter, if the measured magnetic content of the material is >0.8ppm, the PLC controls the reversing valve to switch to the circulation branch.

[0029] As a preferred technical solution of this utility model, the system conveys materials through a pneumatic conveying system or a pneumatic conveying unit. The working pressure of the pneumatic conveying system is 0.3-0.6 bar (g), and the conveying wind speed is 18-25 m / s.

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

[0031] This utility model provides a circulating homogenization and demagnetization system that improves the homogenization effect (enhancing consistency and batch stability) and magnetic impurity removal efficiency of polyolefin powder through system structural improvements. An automatic demagnetizer continuously demagnetizes the product during the circulating homogenization process until it reaches ultra-clean, high-purity standards. The automatic demagnetizer eliminates the need for manual intervention, effectively removing impurities from the magnetic rods through automated drive, improving efficiency and meeting the demands of continuous large-scale production. The multi-layered magnetic rod assembly, with its rotating rods and gradient arrangement, ensures excellent demagnetization and high efficiency. Furthermore, the homogenization silo uses a gravity-fed design with a mixing cone at the bottom, creating a complex flow channel that facilitates material mixing and homogenization. Gravity mixing ensures homogenization and quality stability of the polyolefin product, improving overall product quality.

[0032] Specifically, the advantages of this utility model include:

[0033] (1) Through the design of automatic demagnetizer and circulation branch, the material circulates multiple times between the homogenization silo and the demagnetizer, and magnetic metal impurities are adsorbed and removed step by step, finally achieving the ultra-clean high purity standard. The automatic demagnetizer adopts a multi-layer movable magnetic rod assembly, combined with gradient enhanced magnetic force distribution and staggered arrangement design, to adapt to the characteristic of decreasing impurity content in material flow, avoid premature adsorption saturation of magnetic rods, significantly improve demagnetization efficiency, and increase the impurity removal rate by more than 30% in a single treatment.

[0034] (2) The automatic demagnetizer automatically cleans impurities adsorbed on the surface of the magnetic rods by driving the drawer-type magnetic rod assembly to move horizontally, in conjunction with the fixed scraper component. It also uses a vibrator to help shake off residual materials, achieving unattended operation throughout the process, reducing downtime for cleaning, and meeting the needs of large-scale continuous production. The magnetic rods are mounted with bearings and can roll freely, uniformly adsorbing impurities during the material falling process, avoiding local accumulation and blockage, and extending the service life of the magnetic rods.

[0035] (3) A mixing cone is set at the bottom of the homogenization silo. The multi-channel structure formed by its radial partition plate and the external channel design allow the material to enter the mixing zone from different heights and directions at different flow rates. It achieves full mixing by gravity. Compared with the airflow homogenization mode, it has lower energy consumption, and the homogenization efficiency is 40% higher than that of the traditional airflow homogenization. Moreover, the residual amount of the discharged material is less than 0.1%, which solves the problem of grade switching and silo cleaning caused by the residue in the traditional airflow homogenization silo.

[0036] (4) The parallel design of multiple homogenization silos supports independent or collaborative work of each silo, which not only expands the system's processing capacity and ensures continuous operation of subsequent packaging, but also enables cross-mixing of different batches of materials, further improving the uniformity and consistency of the product. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the cyclic homogenization and demagnetization system of this utility model;

[0038] Figure 2 This is a schematic diagram of the main structure of an automatic demagnetizer.

[0039] Figure 3 This is a side view of the automatic demagnetizer.

[0040] Figure 4 This is a schematic diagram of the gravity homogenization silo structure;

[0041] Figure 5 A schematic diagram of a mixed-base cone structure;

[0042] Figure 6 This is a schematic diagram illustrating the principle of material blending.

[0043] In the diagram: 100-Homogeneous material bin; 101-Blending bottom cone; 1011-Central discharge pipe; 1012-Flow channel; 1013-Conical shell; 200-Automatic demagnetizer; 201-Cavity; 202-Cylinder; 203-Clean material chamber; 204-Slag material chamber; 205-Outer panel; 206-Magnetic rod; 300-Rotary valve; 400-Dust collector; 500-Reversing valve. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings. Any aspects of the present invention not described in detail are technical solutions already disclosed in the field.

[0045] Reference Figure 1 This is a schematic diagram of a circulating homogenization and demagnetization system according to the present invention. The system includes a homogenization silo 100. The upper part of the homogenization silo 100 is connected to a feed pipe, and the lower part of the homogenization silo 100 is connected to a discharge pipe. The homogenization silo 100 receives feed from the upper part and discharges from the lower part. Polyolefin powder from the upstream (excluding hydrocarbon solvents such as hexane) enters the homogenization silo for homogenization treatment.

[0046] The homogenization silo of this system is equipped with a rotary valve 300 at its outlet. Downstream of the rotary valve 300 is an automatic demagnetizer 200, and downstream of the automatic demagnetizer 200 is a reversing valve 500. The reversing valve 500 has two branch pipes: a qualified material output branch and a circulation branch. During operation, polyolefin powder from upstream enters the homogenization silo via a pneumatic conveying system or air conveying unit (such as nitrogen positive pressure conveying) for homogenization. The homogenized material is then demagnetized by the automatic demagnetizer 200. Based on cleanliness requirements, the reversing valve 500 controls material circulation, allowing the material to continuously circulate between the homogenization silo and the circulation branch, undergoing further demagnetization by the automatic demagnetizer 200. A dust collector 400 is installed at the top of the homogenization silo 100. The pneumatically conveyed gas is filtered by the dust collector 400 before being discharged from the homogenization silo (nitrogen enters from the bottom of the circulation pipeline, is separated by the dust collector, and then circulates within the nitrogen system). After several cycles, the powder homogenization is completed. Simultaneously, the magnetic metal impurities in the powder undergo multiple demagnetization processes to reach ultra-clean standards (sampling ports or online magnetic induction detectors are installed on the circulation branch, or on the discharge pipe of the automatic demagnetizer. When the measured magnetic content of the material fails to meet the standard, the PLC controls the reversing valve to switch to the circulation branch until the product meets the standard). After homogenization and demagnetization are completed, the circulation branch is closed by controlling the reversing valve 500, and the qualified material output branch is opened. Qualified products are discharged and sent to the finished product collection unit or packaging unit.

[0047] In a preferred embodiment of this utility model, the system consists of multiple sets of homogenizing silos connected in parallel, for example, 2 to 10 sets, depending on actual needs, and selectively activated during operation. For example, see attached... Figure 1The diagram shows a circulating homogenization and demagnetization system consisting of six sets of homogenization silos arranged in parallel. The parallel arrangement of the homogenization silos provides a sufficiently large buffer space to increase the system's processing capacity. Furthermore, by transferring materials between silos, the system can achieve material mixing between them, improving flexibility and increasing the uniformity of the materials.

[0048] As a preferred embodiment of this utility model, the automatic demagnetizer 200 adopts a vibration-type pneumatic scraper iron remover, the structural schematic diagram of which is shown below. Figure 2 , Figure 3 As shown, the automatic demagnetizer 200 includes a cavity 201. The cavity has multiple movable drawers arranged from top to bottom. Each drawer includes an outer panel 205 located outside the cavity 201 and an inner panel (not shown) located inside the cavity 201. Several magnetic rods 206 extending into the cavity 201 are evenly and horizontally arranged on the outer panel 205, with the ends of the magnetic rods 206 fixed to the inner panel. From top to bottom, the cavity 201 is divided into a demagnetizing zone and a cleaning zone. Correspondingly, a clean material chamber 203 and a slag chamber 204, communicating with the demagnetizing zone and cleaning zone respectively, are provided in the lower part of the cavity 201, discharging clean material and slag material respectively.

[0049] Furthermore, the outer panel 205 is connected to the driving component. In a preferred embodiment, a cylinder 202 can be used, with its extension rod connected to the outer panel 205. The cylinder 202 is symmetrically installed on both sides of the outer panel 205. Driven by the cylinder, the outer panel 205, along with the magnetic rod assembly, moves outward. The automatic demagnetizer 200 works as follows: upstream material enters the cleaning zone of the cavity 201 through the feed inlet. As the material falls, it passes through each magnetic rod 206, where metallic magnetic impurities are intercepted and adsorbed. The clean material falls into the clean material chamber 203 of the cavity 201 and is discharged. A scraper is installed on the inner wall of the cavity 201 in the demagnetization zone. The scraper passes through each magnetic rod 206. When a magnetic rod 206 is pushed out, the scraper cleans the metallic magnetic impurities adsorbed on its surface. The metallic magnetic impurities fall into the demagnetization zone of the cavity 201, achieving automatic cleaning. The metallic magnetic impurities are then discharged through the slag chamber 204.

[0050] In a preferred embodiment, the cavity is provided with 2 to 10 movable drawers from top to bottom; more preferably, it is provided with 4 to 10 movable drawers. Figure 2 A schematic diagram of a four-layer movable drawer is shown, with adjacent magnetic rods 206 staggered for better demagnetization. In a further preferred embodiment, the magnetic rods 206 are mounted to the inner and outer panels via bearings, allowing them to roll. As materials fall, the surface of the rolling magnetic rods 206 uniformly adsorbs magnetic materials, resulting in greater adsorption of metallic magnetic impurities.

[0051] In a preferred embodiment, the magnetism of each layer of magnetic rods increases sequentially from top to bottom, forming a gradient. This gradient arrangement of magnetic rods improves the demagnetization effect because the content of magnetic impurities in the material decreases sequentially along the material flow direction. To better demagnetize and ensure the uniform application of each magnetic rod, avoiding material blockage caused by saturation or excessive adsorption of impurities on the upper rods, the upper rods can have weaker magnetism, while the lower rods progressively strengthen, thus achieving a better demagnetization effect. For example, in a preferred embodiment of this invention, four layers of magnetic rods are arranged sequentially, with the first layer having a surface magnetism of 9000–10000 GS, the second layer 10000–11000 GS, the third layer 11000–12000 GS, and the fourth layer 12000–13000 GS. Each layer of magnetic rods independently performs a cleaning action, achieving large-scale continuous online cleaning.

[0052] As a preferred embodiment, the automatic demagnetizer 200 is equipped with a vibrator. When each layer of magnetic rods performs the cleaning action, the vibrator vibrates to shake off the material accumulated on the surface of the magnetic rods or adsorbed by the magnetic rods. The material is then automatically cleaned by the scraper assembly. In addition, the vibration also helps to prevent powder from bridging and clogging in the equipment.

[0053] This utility model's homogenizing silo is an important piece of equipment for achieving material homogenization and mixing. As a preferred technical solution, this utility model's homogenizing silo adopts a gravity homogenizing design, relying on gravity mixing to homogenize the performance and stabilize the quality of the polyolefin powder product. That is, while the powder flows out under gravity, the automatic mixing and homogenization of powders from different layers is achieved simultaneously. A schematic diagram of the gravity homogenizing silo used in this utility model is shown below. Figure 4 , Figure 5 The homogenizing silo 100 has a mixing cone 101 at its bottom, which can be detachably installed with the homogenizing silo 100. The mixing cone 101 includes a shell, with a central discharge pipe 1011 at the center of the shell cavity. A partition plate is provided outside the central discharge pipe 1011, dividing it into independent flow channels 1012. The lower part of the shell is a conical shell 1013, which forms an external channel with the homogenizing silo. This special flow channel form helps to homogenize and mix materials uniformly by gravity. It is very suitable for the physical properties of polyethylene powder, and achieves uniform mixing and homogenization by utilizing the full-flow form of the material in the silo and relying on gravity flow. The special flow channel form in this mixing cone structure divides the material flow channels of the silo bottom cone, forming multiple flow channels. In each channel, the material flows into the discharge hole at the bottom at different positions and heights with different flow rates. Materials at different heights in the silo enter the multiple channels of the mixing bottom cone through feed holes at different heights and orientations within the silo during discharge (see reference). Figure 6The product is uniformly mixed in the mixing chamber at the bottom, and then passes through the automatic demagnetizer 200 and external material circulation to achieve material homogenization and purification.

[0054] Existing homogenization silos for processing polyolefin powders (such as polyethylene powder) mostly adopt airflow homogenization schemes. However, after each discharge, there will be about 0.2-0.3% material residue, which needs to be cleaned. Large-scale grade adjustments require silo cleaning, and the cleaning cycle in confined spaces is long (requiring 2 days). In contrast, this utility model adopts the above-mentioned gravity mixing scheme. There will be no residue when mixing or switching grades between silos, which is conducive to achieving ultra-clean and high-purity materials and product consistency.

[0055] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. A circulating homogenization and demagnetization system for ultra-high purity polymers, characterized in that, Includes a homogenizing silo (100), the outlet of which is connected to the feed end of an automatic demagnetizer (200) via a pipeline; The automatic demagnetizer (200) has two branch pipes at its discharge end, including: The qualified material output branch is connected at its end to the finished product collection unit; and The circulation branch is connected to the homogenization silo (100) through the return pipeline, and is used to return substandard materials to the homogenization silo (100) for further homogenization and demagnetization.

2. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 1, characterized in that, A dust collector (400) is installed on the top of the homogenizing silo (100), and the dust collector (400) is connected to the interior of the homogenizing silo (100). The homogenizing silo (100) is provided with a feed pipe at the top and a discharge pipe at the bottom. The discharge pipe of the homogenizing silo (100) is equipped with a rotary valve (300), and the automatic demagnetizer (200) is connected downstream of the rotary valve (300). Downstream of the automatic demagnetizer (200) is a reversing valve (500), the first outlet of the reversing valve (500) is connected to the qualified material output branch, and the second outlet is connected to the circulation branch.

3. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 1, characterized in that, The automatic demagnetizer (200) includes: The cavity (201) is divided into a demagnetization zone and a cleaning zone, and the bottom is provided with a clean material cavity (203) and a slag material cavity (204); A multi-layer movable drawer, each drawer including an outer panel (205), an inner panel and a magnetic rod (206) extending into the cavity (201), the magnetic rod (206) being disposed between the outer panel (205) and the inner panel; A drive unit is symmetrically arranged on both sides of the drawer's travel direction to drive the drawer to move; The scraper is fixedly installed on the inner wall of the cavity (201) of the demagnetizing zone.

4. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 3, characterized in that, The automatic demagnetizer (200) adopts a vibration-type pneumatic scraper iron remover; The drive component includes a cylinder (202), and the telescopic rod of the cylinder (202) is connected to the outer panel (205).

5. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 4, characterized in that, The automatic demagnetizer (200) has a vibrator installed inside its cavity (201), and the vibrator is fixedly installed on the side wall of the cavity (201) of the cleaning area.

6. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 3, characterized in that, The magnetic rods (206) are arranged in layers with increasing magnetic intensity from top to bottom. Adjacent layers of magnetic rods (206) are staggered, and each layer of magnetic rods (206) is installed between the inner panel and the outer panel (205) by bearings.

7. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 1, characterized in that, The number of homogenizing silos (100) is 2 to 10. The feed pipes of multiple homogenizing silos (100) are connected in parallel to the upstream conveying system, and the discharge pipes are connected in parallel to the downstream conveying system.

8. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 1, characterized in that, The homogenizing silo (100) is a gravity homogenizing silo, with a mixing bottom cone (101) at the bottom, the mixing bottom cone (101) comprising: The central feed pipe (1011) is vertically arranged in the center of the inner cavity of the mixing bottom cone (101); The partition plates are radially distributed around the central feed pipe (1011) to form multiple independent flow channels (1012); A conical shell (1013) is connected to the bottom of the homogenizing silo (100) and forms an outer channel between it and the outer wall of the homogenizing silo (100).

9. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 1, characterized in that, The circulation branch is equipped with a sampling port or an online magnetic induction detector; Alternatively, the automatic demagnetizer (200) may be equipped with a sampling port or an online magnetic induction detector on its discharge end pipeline.

10. The ultra-high purity polymer circulating homogenization and demagnetization system according to claim 1, characterized in that, The system transports materials via a pneumatic conveying system or a pneumatic conveying unit.

Images