Screening device, system and method for separating polyolefin powder and block materials

Abstract

The invention discloses a screening device, system and method for separating polyolefin powder and block materials, and the screening device comprises a screening mechanism which is arranged in a waste material box and connected to the lower portion of a discharging pipe; the powder collecting device is connected to the lower portion of the screening mechanism and used for receiving the powder screened out through the screening mechanism; the lump material collecting device is connected with the screening mechanism through a material conveying piece and is used for receiving the lump materials which are not screened by the screening mechanism; the screening mechanism does not need to be driven by external power, and separation of powder materials and block materials is achieved by means of the self weight of the materials. According to the scheme, the screening mechanism which does not need to be driven by external power and works only depending on the dead weight of the materials is adopted, the beneficial effect that extra electric energy or mechanical power is not consumed in the whole separation process is achieved, and the situation that energy consumption and operation cost are increased due to powder recycling is fundamentally avoided.

Description

Technical Field

[0001] This application generally relates to the field of post-processing technology for polyolefin production. More specifically, this application relates to a screening device for separating polyolefin powder from lumps; further, this application also relates to a polyolefin powder-lump separation system; and further still, this application also relates to a method for recovering polyolefin powder. Background Technology

[0002] In the gas-phase fluidized bed production process of polyolefins (such as polyethylene and polypropylene), a certain amount of lumpy material (lumps) will be generated in the reactor and degassing chamber. Currently, the industry generally uses vibrating screens to perform preliminary separation of this material, and the separated lumps fall directly into the waste bin below for disposal as waste material.

[0003] Existing technical solutions have many obvious shortcomings in practical applications, specifically in terms of material utilization, cost control, and operating environment and management. During the vibrating screening process, due to the influence of airflows such as nitrogen backflushing in the system, a large amount of lightweight powder is carried into the waste bin along with the block material. Statistics show that the fallen block material contains a lot of valuable powder. This powder cannot be effectively separated after being mixed with the block material and can only be treated as low-value waste along with the block material, directly resulting in a significant loss of economic benefits.

[0004] In view of this, there is an urgent need to provide a screening device, system and method for separating polyolefin powder and lumps, so as to achieve automatic recovery of powder at the lowest additional cost in the polyolefin post-processing stage and improve the operating environment. Summary of the Invention

[0005] In order to at least solve one or more of the technical problems mentioned above, this application proposes screening devices, systems and methods for separating polyolefin powders and lumps in several aspects.

[0006] In a first aspect, this application provides a screening device for separating polyolefin powder and lumps, comprising: a screening mechanism disposed in a waste bin and connected below a feed pipe; a powder collection device connected below the screening mechanism and used to receive the powder screened by the screening mechanism; and a lumps collection device connected to the screening mechanism via a conveying component and used to receive lumps that have not passed through the screening mechanism; wherein the screening mechanism does not require external power drive and relies on the weight of the material to achieve the separation of powder and lumps.

[0007] In some embodiments, the screening mechanism includes a receiving cavity enclosed by a housing and a screen; the aperture of the screen is configured to intercept lumps larger than a preset particle size.

[0008] In some embodiments, the screen is disposed at an angle within the receiving cavity.

[0009] In some embodiments, a first discharge port is provided at the bottom of the housing, and a second discharge port is provided on the side wall of the housing; the first discharge port is directly connected to the powder collection device, and the second discharge port is connected to the block material collection device through a conveying component.

[0010] In some embodiments, the conveyor is a U-shaped trough having a predetermined length along its extension direction and used to guide the block material to slide down.

[0011] In some embodiments, a protective cover is also included, which surrounds the U-shaped groove and forms a continuous channel.

[0012] In some embodiments, the conveying component is a cylindrical connecting pipe.

[0013] In some embodiments, the powder collection device is a sealed ton bag, and the block material collection device is also a sealed ton bag.

[0014] In a second aspect, this application provides a polyolefin powder-lump separation system, comprising: a vibrating screen for preliminary separation of polyolefin powder and lumps; and a screening device for separating polyolefin powder and lumps as described above, which is connected to the lumps outlet of the vibrating screen via the feed pipe.

[0015] In a third aspect, this application provides a method for recovering polyolefin powder, comprising the following steps: pre-screening a mixture containing powder and lumps through a vibrating screen; introducing the pre-screened lumps and the powder they carry into a screening device for separating polyolefin powder and lumps as described above, thereby achieving secondary separation of powder and lumps through the screening device.

[0016] The screening device for separating polyolefin powder and lumps, as described above, utilizes a screening mechanism located within the waste bin and connected to the bottom of the feed pipe. This achieves the beneficial effect of directly introducing the lumps and entrained powder after initial separation by the vibrating screen for automatic and immediate secondary screening, effectively preventing the powder from being discarded along with the lumps. Furthermore, the solution employs a screening mechanism that operates solely by the material's own weight without external power, achieving the beneficial effect of consuming no additional electrical or mechanical power throughout the separation process. This fundamentally avoids the increased energy consumption and operating costs associated with recovering powder. Attached Figure Description

[0017] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, and the same or corresponding reference numerals denote the same or corresponding parts, wherein:

[0018] Figure 1 A screening device for separating polyolefin powder and lumps according to an embodiment of this application is shown.

[0019] In the diagram: 100, a screening device for separating polyolefin powder and lumps; 101. Waste bin; 102. Feed pipe; 103. Screening mechanism; 104. Block material collection device; 105. Powder material collection device; 106. Protective cover. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be understood that the terms "comprising" and "including" used in the specification and claims of this application indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0022] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0023] As used in this specification and claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0024] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0025] like Figure 1 As shown, in some embodiments, this application provides a screening device 100 for separating polyolefin powder and lumps, comprising: a screening mechanism 103 disposed in a waste bin 101 and connected below a feed pipe 102; a powder collection device 105 connected below the screening mechanism 103 and used to receive the powder screened by the screening mechanism 103; and a lumps collection device 104 connected to the screening mechanism 103 via a conveying component and used to receive lumps that have not passed through the screening mechanism 103; wherein the screening mechanism 103 does not require external power drive and relies on the weight of the material to achieve the separation of powder and lumps.

[0026] In this application, the screening device 100 for separating polyolefin powder and lumps aims to separate the polyolefin powder and lumps. Its structure mainly includes three parts: a screening mechanism 103, a powder collection device 105, and a lump collection device 104. The screening mechanism 103 is installed inside the waste bin 101 and directly connected to the lower part of the discharge pipe 102, forming a key node in material flow. The powder collection device 105 is located directly below the screening mechanism 103, and its function is to specifically receive and accommodate the fine powder separated by the screening mechanism 103. The lump collection device 104 is connected to the screening mechanism 103 via a conveyor, and is used to receive and accommodate the larger lumps that failed to pass through the screening mechanism 103 and were separated.

[0027] It is worth noting that the screening mechanism 103 requires no external power during the entire operation. The separation action relies entirely on the gravity of the materials themselves; that is, the mixture of powder and lumps falls from the feed pipe 102 and, when passing through the screening mechanism 103, is automatically screened under its own weight. The powder, due to its smaller particle size, passes through, while the lumps are blocked and guided elsewhere, thus achieving effective separation of the two.

[0028] The solution proposed in this application, through a screening mechanism 103 installed inside the waste bin 101 and connected below the discharge pipe 102, achieves the beneficial effect of directly introducing the lumps and entrained powder materials initially separated by the vibrating screen for automatic and immediate secondary screening, effectively blocking the path of powder materials being discarded along with the lumps. Furthermore, by employing a screening mechanism 103 that operates solely by the weight of the material without external power, the solution achieves the beneficial effect of not consuming additional electrical energy or mechanical power throughout the entire separation process, fundamentally avoiding the increased energy consumption and operating costs associated with recovering powder materials.

[0029] In one specific embodiment, the screening mechanism 103 includes a receiving cavity enclosed by a housing and a screen; the aperture of the screen is configured to intercept lumps larger than a preset particle size. The screen is inclinedly disposed within the receiving cavity.

[0030] In this application, the screening mechanism 103 includes a receiving cavity enclosed by a shell, and a screen inclinedly disposed inside the receiving cavity. The screen's aperture size is specifically configured to intercept lumps with a particle size greater than or equal to a preset value. Furthermore, the inclined arrangement of the screen in this solution directly affects the material's trajectory and residence time on its surface, which is crucial for the mechanism to achieve effective separation without power and relying on its own weight.

[0031] In one specific implementation, a first discharge port is provided at the bottom of the housing, and a second discharge port is provided on the side wall of the housing; the first discharge port is directly connected to the powder collection device 105, and the second discharge port is connected to the block material collection device 104 through a conveying component.

[0032] In this application, a first discharge port is provided at the bottom of the shell, and a second discharge port is provided on the side wall. This structural design achieves complete separation and directional conveying of powder and lumps after screening. That is, the powder passing through the screen falls naturally under gravity and directly enters the powder collection device 105 connected below through the first discharge port. The lumps intercepted by the screen slide along the inclined screen surface to the side of the shell, pass through the second discharge port, and are guided by a conveying component to finally enter the lumps collection device 104. The design of this dual discharge port and corresponding collection device ensures that the powder and lumps are physically separated and collected separately after leaving the screening mechanism 103, thereby effectively avoiding the re-mixing of materials and providing a structural basis for the separate recovery of powder and the separate disposal of lumps.

[0033] In one specific implementation, the conveyor is a U-shaped channel with a predetermined length along its extension direction, used to guide the block material to slide down. It also includes a protective cover 106, which is disposed around the U-shaped channel above it, forming a continuous channel.

[0034] In the solution of this application, the conveying component is specifically designed as a U-shaped trough with a preset length along its extension direction. The U-shaped trough enables it to stably receive and guide the block material discharged from the screening mechanism 103, allowing it to slide naturally down the trough into the block material collection device 104, effectively preventing the block material from spilling or getting stuck during the conveying process.

[0035] In addition, the screening device also includes a protective cover 106, which surrounds the upper part of the U-shaped trough, together forming a continuous closed or semi-closed channel. The protective cover 106 provided in this application not only places the block material conveying process in a closed space, preventing material spillage and dust emission, but also helps maintain the stability of the local environment of the system, improving the cleanliness and safety of the overall operation.

[0036] In one specific implementation, the conveying component is a cylindrical connecting pipe.

[0037] In this application, the conveying component is not a U-shaped trough, but a cylindrical connecting pipe. This connecting pipe, with its predetermined length and tubular shape, provides a closed conveying channel for the lumps discharged from the screening mechanism 103. Under the influence of gravity, the lumps slide or roll within the pipe and are directly guided to the lumps collection device 104. This cylindrical pipe structure enhances the sealing of the conveying process, more effectively preventing accidental scattering of lumps or escape of dust during transfer.

[0038] In one specific implementation, the powder collection device 105 is a sealed ton bag, and the block material collection device 104 is also a sealed ton bag.

[0039] In this application, both the powder collection device 105 and the lump material collection device 104 are implemented using sealed ton bags. This design means that the powder and lump materials obtained from screening are respectively introduced into two independent, sealed flexible container bags (ton bags) after leaving the screening mechanism 103. Using sealed ton bags not only achieves physical isolation and classified collection of the two materials, but their sealing characteristics also effectively prevent the lightweight powder from scattering during collection, while avoiding environmental pollution from the lump materials. Furthermore, as a standardized container and transportation unit commonly used in the industry, the ton bag allows the collected powder to directly enter the recycling and granulation process, while the lump materials are easily disposed of as waste. This achieves integration and standardization in the collection, storage, and transfer processes, improving operational efficiency and reducing secondary packaging costs.

[0040] In some embodiments, this application provides a polyolefin powder-lump separation system, comprising: a vibrating screen for preliminary separation of polyolefin powder and lumps; and a screening device 100 for separating polyolefin powder and lumps as described above, which is connected to the lumps outlet of the vibrating screen via the feed pipe 102.

[0041] In this application, the polyolefin powder-lump separation system mainly includes a vibrating screen and a screening device as described above. The vibrating screen is used for preliminary separation of materials from the polyolefin production unit, separating most of the powder from the lumps. The lumps separated in this step still carry some powder and are discharged from their lump outlet, then conveyed via the feed pipe 102 to the screening device 100 of this application for separating polyolefin powder and lumps. This screening device is connected to the feed pipe 102 through its inlet and is specifically designed to perform secondary fine screening of the lumps from the vibrating screen, effectively separating the powder they carry.

[0042] This solution upgrades the traditional single vibrating screen section into a complete system consisting of preliminary separation and non-powered secondary screening in series. With almost no increase in energy consumption, it maximizes the recovery of powder from the material, significantly reduces material loss, and forms a highly efficient and energy-saving closed-loop process for powder and lumps separation.

[0043] In some embodiments, this application provides a method for recovering polyolefin powder, comprising the following steps: pre-screening a mixture containing powder and lumps through a vibrating screen; introducing the pre-screened lumps and the powder they carry into a screening device 100 for separating polyolefin powder and lumps as described above, thereby achieving secondary separation of powder and lumps through the screening device.

[0044] In this application, the polyolefin powder recovery method aims to systematically solve the material loss problem caused by the waste of powder along with bulk materials during the production process. The method mainly includes two key steps: First, the mixture of powder and bulk materials from the reaction system is initially screened through a vibrating screen to achieve initial separation between the two; then, the bulk materials still carrying powder after the initial screening are introduced into a specially designed non-powered screening device through the feed pipe 102, where secondary fine separation of the entrained powder is achieved by relying on the weight of the material and the action of the screening mechanism 103.

[0045] This solution utilizes a series process to efficiently recover powder materials before waste disposal without significantly increasing energy consumption. This directly overcomes the shortcomings of existing technologies that result in large amounts of powder loss, allowing previously discarded powder materials to be returned to the granulation process. This creates an economical, energy-saving, and efficient closed-loop powder recovery process.

[0046] While numerous embodiments of this application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will arise for those skilled in the art without departing from the spirit and intent of this application. It should be understood that various alternatives to the embodiments of this application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A screening device (100) for separating polyolefin powder and lumps, characterized in that, include: A screening mechanism (103) is disposed inside a waste bin (101) and connected below a discharge pipe (102); A powder collection device (105), connected below the screening mechanism (103), is used to receive the powder screened out by the screening mechanism (103); and A block material collection device (104) is connected to the screening mechanism (103) via a conveying component and is used to receive block materials that have not passed through the screening mechanism (103). The screening mechanism (103) does not require external power and relies on the weight of the material to separate powder and lumps.

2. The screening device according to claim 1, characterized in that, The screening mechanism (103) includes a receiving cavity enclosed by a shell and a screen; the aperture of the screen is configured to intercept block materials larger than a preset particle size.

3. The screening device according to claim 2, characterized in that, The screen is installed at an angle inside the receiving cavity.

4. The screening device according to claim 2, characterized in that, A first discharge port is provided at the bottom of the housing, and a second discharge port is provided on the side wall of the housing; the first discharge port is directly connected to the powder collection device (105), and the second discharge port is connected to the block material collection device (104) through a conveying component.

5. The screening device according to any one of claims 1-4, characterized in that, The conveying component is a U-shaped trough with a preset length along its extension direction, used to guide the block material to slide down.

6. The screening device according to claim 5, characterized in that, It also includes a protective cover (106) which surrounds the U-shaped groove above and forms a continuous channel.

7. The screening device according to any one of claims 1-4, characterized in that, The conveying component is a cylindrical connecting pipe.

8. The screening device according to claim 1, characterized in that, The powder collection device (105) is a sealed ton bag, and the block material collection device (104) is also a sealed ton bag.

9. A polyolefin powder separation system, characterized in that, include: Vibrating screens are used for the initial separation of polyolefin powders and lumps; as well as The screening device (100) for separating polyolefin powder and lumps as described in any one of claims 1 to 8 is connected to the lumps outlet of the vibrating screen via the feed pipe (102).

10. A method for recycling polyolefin powder, characterized in that, Includes the following steps: The mixture containing powder and lumps is initially screened using a vibrating screen; The pre-screened lumps and the accompanying powder are introduced into the screening device (100) for separating polyolefin powder and lumps as described in any one of claims 1 to 8, and the secondary separation of powder and lumps is achieved through the screening device.

Images