Integrated screening system for recycled plastics and screening method of integrated screening system

Abstract

The invention relates to an integrated screening system for recycled plastics and a screening method of the integrated screening system. The screening method comprises the steps that raw materials to be screened are conveyed to a rotary cutting device through a conveying device to be cut; the rotary cutting device is used for cutting the raw materials to be screened in a rotating state to form fragment raw materials with different sizes, and the fragment raw materials naturally fall to the screening device; the screening device is used for screening the fragment raw materials of different sizes formed by cutting so as to screen out mixed impurities, and impurity-free fragment raw materials are formed; and any one or more sorting air draft devices are started, the plastic fragments of the corresponding size are extracted at the sorting channel, and screening of the recycled plastic is completed. The device is high in automation degree and production efficiency, excellent in operation environment and low in production cost, and plastic films of different sizes can be drawn out at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection, and in particular to a screening system and a screening method for recycled plastics. Background Art

[0002] With the rapid development of the petroleum industry, the application scope of plastic products is becoming increasingly wide. In some occasions, they can even replace metal, wood, paper, etc. in large quantities, thus bringing great convenience to people's lives.

[0003] However, as the consumption of plastic products continues to increase, waste plastics are also increasing. Many waste plastic products can be recycled. When recycling plastics, the collected waste plastics are often mixed with a large amount of impurities such as mud and sand, and often appear in a disorderly tangled mass. Therefore, they need to be crushed and screened before recycling to facilitate their reuse in production.

[0004] Among the collected waste plastics, plastic bags wrapped in domestic garbage account for a large proportion. When recycling these plastics, existing equipment is difficult to separate these plastic bags from domestic garbage smoothly. The plastic bags need to be manually scraped first, which is not only time-consuming and labor-intensive, but also poses a great threat to the health of the operators.

[0005] Therefore, providing an integrated screening system and screening method that is simple to operate and can crush and screen recycled plastics in a closed environment has become an issue that urgently needs to be solved in the industry. Summary of the Invention

[0006] In response to the above problems, one of the objectives of the present invention is to provide a screening system and screening method for recycled plastics, which can crush and screen recycled plastics in a closed environment with fast crushing and screening speeds and high screening efficiency.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] The first object of the present invention is to provide an integrated screening system for recycling plastics, which comprises: an integrated box, a conveying device provided at one end of the integrated box, a rotating dividing device and a screening device provided inside the integrated box, and a sorting device provided outside the integrated box and connected to the inner cavity of the integrated box, wherein:

[0009] The conveying device is connected to the rotary dividing device and is used to convey the raw materials to be screened to the rotary dividing device;

[0010] The rotary dividing device is arranged above the interior of the integrated box and is used to divide the raw materials to be screened;

[0011] The screening device is provided at the lower part of the integrated box body and is used to screen the divided raw materials to remove mixed impurities;

[0012] The sorting device includes several sorting sub-devices, each of which includes a sorting port opened on the wall of the integrated box and a sorting channel connected to the sorting port. Each of the sorting channels is provided with a sorting exhaust device, and the height of each of the sorting ports is respectively between the rotating dividing device and the screening device.

[0013] In some embodiments, several layers of screens are provided between the rotary segmentation device and the screening device to screen out plastics of a set size.

[0014] In some embodiments, the mesh size of the sieve is set to 5 to 10 cm. When the mesh size of the sieve is less than 5 cm, it is difficult to screen out large-sized impurities. When the mesh size of the sieve is greater than 10 cm, the screening efficiency is reduced and there is no practical screening effect.

[0015] In some embodiments, the mesh shape of the sieve is set to be circular, elliptical, rectangular or diamond-shaped.

[0016] In some embodiments, the screening device is configured as a first-stage flat plate vibrating screen.

[0017] In some embodiments, the screening device is configured as a two-stage flat plate vibrating screen.

[0018] In some embodiments, the screening device is configured as a multi-stage flat plate vibrating screen, specifically including but not limited to a three-stage flat plate vibrating screen, a four-stage flat plate vibrating screen, a five-stage flat plate vibrating screen, a six-stage flat plate vibrating screen, and the like.

[0019] In some embodiments, the rotary dividing device includes: a main shaft, a plurality of knife row bases mounted on the main shaft, a plurality of fixed slats parallel to the main shaft and axially fixedly connected to the outer edge of each knife row base, a plurality of knife seats evenly distributed longitudinally on each of the fixed slats, and a plurality of cutting knives detachably connected to the knife seats.

[0020] In some embodiments, the cutter is trapezoidal or triangular.

[0021] In some embodiments, depending on the scale of the factory and the processing scale, the diameter of the main shaft is set to 600mm to 2000mm, including but not limited to 600mm, 700mm, 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, 1500mm, 1600mm, 1700mm, 1800mm, 1900mm or 2000mm.

[0022] In some embodiments, the number of the blade row bases is 4 to 10, including but not limited to 4, 5, 6, 7, 8, 9 or 10.

[0023] In some embodiments, the diameter range of the blade row base is set to 800mm to 2400mm, including but not limited to 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, 1500mm, 1600mm, 1700mm, 1800mm, 1900mm, 2000mm, 2100mm, 2200mm, 2300mm or 2400mm.

[0024] In some embodiments, the number of fixed slats is 4 to 10, including but not limited to 4, 5, 6, 7, 8, 9 or 10.

[0025] In some embodiments, the length of the fixed slats is set to 1-3 m, including but not limited to 1 m, 2 m or 3 m.

[0026] A second object of the present invention is to provide a screening method using the integrated screening system for recycled plastics, comprising the following steps:

[0027] (1) Using the conveying device to convey the raw materials to be screened to the rotary dividing device for cutting;

[0028] (2) The rotating dividing device divides the raw material to be screened in a rotating state to form fragments of different sizes, which naturally fall to the screening device;

[0029] (3) the screening device screens the fragmented raw materials of different sizes to remove mixed impurities and form impurity-free fragmented raw materials; and

[0030] (4) Turn on any one of the sorting and exhaust devices to extract plastic fragments of corresponding sizes at the sorting channel to complete the screening of the recycled plastics.

[0031] In some embodiments, in step (2), the rotation speed of the rotary segmentation device is set to be lower than 1000 rpm. When the rotation speed of the rotary segmentation device is lower than 1000 rpm, not only is the efficiency low, but there is also a phenomenon of film sticking to the knife. When the rotation speed of the rotary segmentation device is higher than 2800 rpm, there will be a safety hazard.

[0032] In some embodiments, in step (3), the vibration parameters of the screening device are set to 200 times / min and an amplitude of 10 cm.

[0033] In some embodiments, in step (3), the screening device vibrates and conveys the segmented raw materials forward during operation, so that the raw materials that meet the screening conditions are sucked away by the wind, and the raw materials that do not meet the screening conditions are conveyed out of the integrated box.

[0034] In some embodiments, in step (4), the wind pressure of the sorting and exhausting equipment is set to 0.2-0.5 MPa, including but not limited to 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, 0.4 MPa, 0.45 MPa or 0.5 MPa, wherein when the wind pressure is lower than 0.2 MPa, incomplete material extraction will occur, and when the wind pressure is higher than 0.5 MPa, impurities will be extracted.

[0035] In some embodiments, in step (4), the height of the sorting port of the sorting device is adjusted to accommodate materials of different sizes. When the size of the material to be extracted is large, the height of the sorting port is increased and the amount of suction is reduced; when the size of the material to be extracted is small, the height of the sorting port is decreased and the amount of suction is increased.

[0036] In some embodiments, in step (4), the exhaust pressure of the sorting exhaust device on each of the sorting channels may be the same or different.

[0037] By adopting the above technical solutions, the present invention has achieved at least the following technical effects: (1) a high degree of automation and production efficiency, an excellent operating environment, low production costs, and the ability to simultaneously extract plastic films of different sizes; (2) the distance between the knife seats, the number of cutters, and the density of the cutters can be flexibly adjusted according to actual production needs, thereby achieving a corresponding plastic screening effect of different sizes; (3) the plastic segmentation speed is fast, and the plastic can be quickly cooled by the surrounding air, and the film-like plastic after cutting will not produce a "knife sticking" phenomenon, that is, it will not stick to the rotating segmentation device; (4) the cutting effect is good, and the waste plastic can be cut into recycled plastic fragments with a size of 5mm*5mm to 10mm*10mm; (5) the screening effect is good, and the waste plastic with an impurity content of 70% to 80% can be screened into an impurity content of only 5% to 10%; (6) the screening efficiency is high, and 1 ton to 1.5 tons of waste plastic can be screened in about 1 hour. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic structural diagram showing an uncovered state of the integrated screening system for recycled plastics of the present invention is shown;

[0039] Figure 2 A schematic structural diagram of the rotary splitting device of the present invention is shown;

[0040] Figure 3 A schematic diagram showing the position structure of the screen relative to the rotating dividing device of the present invention is shown;

[0041] Figure 4 A schematic diagram showing the position structure of the screen relative to the screening device of the present invention is shown;

[0042] Figure 5 Shows a schematic structural diagram of the screen of the present invention;

[0043] Figure 6 A schematic diagram showing the steps of the screening method of the integrated screening system for recycled plastics of the present invention is shown;

[0044] Figure 7 A diagram showing the original state of the recycled plastic of the present invention;

[0045] Figure 8 Shown Figure 7 The diagram shown is a schematic diagram of the state of recycled plastics after being screened by the integrated screening system for recycled plastics of the present invention.

[0046] Description of reference numerals:

[0047] Integrated box 1, screen 2, rotary dividing device 3, main shaft 31, knife row base 32, fixed slats 33, knife seat 34, cutter 35, screening device 4, sorting device 5. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "positive," "negative," "front," "back," and "rear" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the systems or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the use of terms such as "first" and "second" to define components is intended solely to facilitate the distinction between such components. Unless otherwise stated, these terms have no special meanings and should not be construed as indicating or implying relative importance.

[0050] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0051] As a non-limiting embodiment, Figure 1 As shown, the integrated screening system for recycled plastics provided by the present invention includes: an integrated box 1, a conveying device (not shown in the figure), a screen 2, a rotating dividing device 3, a screening device 4 and a sorting device 5.

[0052] The conveying device is located at one end of the integrated box and is connected to the rotary segmentation device 3, thereby conveying the raw materials to be screened to the rotary segmentation device 3. The rotary segmentation device 3 for segmenting the raw materials to be screened is located above the interior of the integrated box 1. The screening device 4 is located inside the integrated box and placed below the rotary segmentation device 3. It is used to screen the segmented raw materials to remove impurities such as mud, sand and gravel mixed therein. The sorting device 5 is located outside the integrated box 1 and is connected to the inner cavity of the integrated box 1.

[0053] Specifically, as shown in Figure 2, the rotary dividing device 3 includes: a main shaft 31, a knife row base 32, a fixed slat 33, a knife seat 34 and a cutter 35, wherein a plurality of knife row bases 32 are sleeved on the main shaft 31, a plurality of fixed slats 33 are parallel to the main shaft 31 and axially fixedly connected to the outer edge of each knife row base 32, and a plurality of knife seats 34 are evenly distributed longitudinally on each fixed slat 33, and the cutter 35 is detachably connected to the knife seat 34.

[0054] Therefore, the number of cutters and the density between the cutters can be flexibly adjusted according to the amount of raw materials to be screened. When the raw materials to be screened are large, the number of cutters can be increased, and when the raw materials to be screened are small, the number of cutters can be reduced. In addition, by adjusting the density of the cutters, not only can the cutting size of the raw materials to be screened be adjusted, but it can also greatly improve the cutting efficiency and cutting force, effectively improving the subsequent screening efficiency.

[0055] In this non-limiting embodiment, the screening device 4 is configured as a primary plate vibrating screen or a secondary plate vibrating screen. During operation, the screening device 4 vibrates and simultaneously conveys the segmented raw materials forward, so that the raw materials that meet the screening conditions are sucked away by the wind, and the raw materials that do not meet the screening conditions are conveyed out of the integrated box.

[0056] As another non-limiting embodiment, Figure 3 and Figure 4 As shown, several layers of screens 6 (such as Figure 5 As shown, the screen 6 can be used to screen out plastic of a predetermined size. In this non-limiting embodiment, the screen 6 has a mesh size of 5 to 10 cm, thereby facilitating the separation of recycled plastic fragments of 5 mm*5 mm to 10 mm*10 mm for subsequent recycling. The mesh size of the screen can be circular, elliptical, rectangular, or diamond-shaped, but is not limited thereto and can be any shape.

[0057] The sorting device 5 includes several sorting sub-devices, each of which includes a sorting port opened on the wall of the integrated box 1 and a sorting channel connected to the sorting port. Each sorting channel is provided with a sorting exhaust device with different exhaust pressures. The height of each sorting port is respectively between the rotating dividing device 3 and the screening device 4.

[0058] In this non-limiting embodiment, the height of the sorting port of the sorting device is adjustable, thereby being suitable for extracting plastic fragments of different size requirements.

[0059] like Figure 6 As shown, the present invention utilizes the above-mentioned integrated screening system for recycled plastics to perform a screening method, comprising the following steps: first, in step S1, a conveying device is used to convey the raw material to be screened to a rotary segmentation device for cutting; then, in step S2, the rotary segmentation device divides the raw material to be screened in a rotating state to form fragmented raw materials of different sizes, which naturally fall to the screening device; then, in step S3, the screening device screens the fragmented raw materials of different sizes formed by the segmentation to remove mixed impurities and form impurity-free fragmented raw materials; finally, in step S4, any one of the sorting and exhaust devices is turned on to extract plastic fragments of corresponding sizes at the sorting channel to complete the screening of the recycled plastics.

[0060] Specifically, first, Figure 7The raw material to be screened, which contains a large amount of impurities, is conveyed by a conveyor to a rotary segmentation device within the integrated housing. All cutting and screening operations are performed within the integrated housing, reducing pollution to the surrounding environment and improving the working environment for operators. The rotary segmentation device then rotates at a high speed of 1000 to 2800 rpm. In practice, the operator can flexibly and specifically adjust the number and spacing of the cutters based on the quantity and properties of the material to be screened. The heat generated by the cutters during high-speed rotation is quickly cooled by the surrounding air, preventing "knife sticking" of the film-like plastic after the cutting process. After cutting, the cut material and impurities naturally fall under the action of gravity onto a screen with a pre-set aperture size, and then onto a sieving device, which sieves the fragments of different sizes formed by the segmentation, removing mixed impurities and forming a pure fragmented material. The screening device vibrates while conveying these fragmented materials forward. After the sorting and exhaust equipment is started, the fragmented materials that meet the screening conditions are sucked away by the wind, and the fragmented materials that do not meet the screening conditions are conveyed out of the integrated box. The operator can adjust the height of the sorting port of the sorting device according to the required screening size. When the size of the material to be extracted is large, the height of the sorting port is increased and the suction volume is reduced. When the size of the material to be extracted is small, the height of the sorting port is lowered and the suction volume is increased. The plastic fragments of the corresponding size are extracted at the sorting channel to complete the screening of the recycled plastics, and finally obtain the following Figure 8 Plastic fragments after sieving are shown.

[0061] After testing, it was found that the waste plastics screened by the integrated screening system for recycled plastics of the present invention can screen waste plastics with an impurity content of 70% to 80% into waste plastics with an impurity content of only 5% to 10%, and the screening efficiency is high, and 1 ton to 1.5 tons of waste plastics can be screened in about 1 hour.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An integrated screening system for recycling plastics, characterized in that: include: An integrated box, a conveying device provided at one end of the integrated box, a rotating dividing device and a screening device provided inside the integrated box, and a sorting device provided outside the integrated box and connected to the inner cavity of the integrated box, wherein: The conveying device is connected to the rotary dividing device and is used to convey the raw materials to be screened to the rotary dividing device; The rotary dividing device is arranged above the interior of the integrated box and is used to divide the raw materials to be screened; The screening device is provided at the lower part of the integrated box body and is used to screen the divided raw materials to remove mixed impurities; The sorting device includes several sorting sub-devices, each of which includes a sorting port opened on the wall of the integrated box and a sorting channel connected to the sorting port. Each of the sorting channels is provided with a sorting exhaust device, and the height of each of the sorting ports is respectively between the rotating dividing device and the screening device.

2. The integrated screening system for recycled plastics according to claim 1, characterized in that: Several layers of screens are provided between the rotary dividing device and the screening device to screen out plastics of set sizes.

3. The integrated screening system for recycled plastics according to claim 2, characterized in that: The mesh size of the sieve is set to 5 to 10 cm.

4. The integrated screening system for recycled plastics according to claim 1, characterized in that: The mesh shape of the screen is set to be circular, elliptical, rectangular or diamond.

5. The integrated screening system for recycled plastics according to any one of claims 1 to 4, characterized in that: The screening device is configured as a first-stage flat plate vibrating screen or a second-stage flat plate vibrating screen.

6. The integrated screening system for recycled plastics according to claim 1, characterized in that: The rotary dividing device includes: a main shaft, a plurality of knife row bases sleeved on the main shaft, a plurality of fixed slats parallel to the main shaft and axially fixedly connected to the outer edge of each knife row base, a plurality of knife seats evenly distributed longitudinally on each of the fixed slats, and a plurality of cutting knives detachably connected to the knife seats.

7. A screening method using the integrated screening system for recycled plastics according to any one of claims 1 to 6, characterized in that: The steps include: (1) Using the conveying device to convey the raw materials to be screened to the rotary dividing device for cutting; (2) The rotating dividing device divides the raw material to be screened in a rotating state to form fragments of different sizes, which naturally fall to the screening device; (3) The screening device screens the fragmented raw materials of different sizes to remove mixed impurities and form impurity-free fragmented raw materials; as well as (4) Turn on any one or more of the sorting and exhaust devices to extract plastic fragments of corresponding sizes at the sorting channel to complete the screening of the recycled plastics.

8. The screening method according to claim 7, characterized in that: In step (2), the rotation speed of the rotary splitting device is set to 1000 to 2800 rpm.

9. The screening method according to claim 7, characterized in that: In step (3), the vibration parameters of the screening device are set to 200 times / min and an amplitude of 10 cm.

10. The screening method according to claim 7, characterized in that: In step (4), the wind pressure of the sorting and exhausting equipment is set to 0.2-0.5 MPa.

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