Equipment and method for sorting plastic films from residual films

Abstract

The invention relates to the field of waste plastic sorting, and discloses equipment and a method for sorting plastic membranes from residual membranes. The equipment comprises a crushing device used for crushing residual film materials; the vibration screening device comprises a plurality of screening plates which are arranged at intervals in the vertical direction, each screening plate is obliquely arranged relative to the horizontal direction, the high end of the screening plate on the uppermost layer forms a feeding end communicated with the discharging port of the crushing device, and the diameters of screening holes of the screening plates are sequentially reduced from top to bottom; the plurality of plastic film separating devices are arranged corresponding to the plurality of sieve plates and are used for separating out plastic films in the materials on the corresponding sieve plates; and the plastic film selecting device is used for separating and purifying the plastic films from the plurality of plastic film separating devices. The equipment and the method can effectively solve the problems of recovery of plastic films from waste plastic film residues and backfilling of lost soil and biomass in the plastic film residues.

Description

Technical Field

[0001] The invention relates to the field of waste plastic sorting, and in particular to a device and a method for sorting plastic film sheets from residual films. Background Art

[0002] A large amount of mulch and greenhouse molds are needed in the planting process of crops such as cotton, but they cannot be completely recycled after use. The unrecycled residual film in the soil tillage layer will not only hinder the movement of water and make the soil's water conductivity worse, but also affect the permeability of air in the soil and the normal activity of soil microorganisms, resulting in difficulties in nutrient transportation, affecting the field emergence rate and the normal growth of crops.

[0003] In order to reduce the residual film content in the soil, residual film is now mostly recycled through residual film recycling machines, but this also leads to the problem of a large amount of arable land soil loss. If the plastic film in the residual film cannot be effectively separated, the disposal of the residual film is also a problem. In addition, plastic itself is a high-quality hydrocarbon resource. Separating the plastic in the residual film and effectively reusing it can also alleviate the country's energy crisis to a certain extent and ensure the country's energy security.

[0004] At present, the sorting technology for recycling plastic from residual film is not mature. CN114474487A provides a residual film processing, sorting and recycling production line, including the following process steps: S1, use a film tearing machine to break the roll and tear it; S2, screen through a vibrating screen; S3, introduce it into the wind selection bin; S4, carry out wind selection, enter the wind selection machine to discharge the cotton stalks and cotton in the residual film mixture, and enter the straw film separation device to extract the film; S5, transport it to the drum screen, the wind selection machine puts the film extracted from the residual film mixture into the drum screen from the discharge port for operation, and the cotton stalks and wood chips with particularly small film surfaces are screened out by rotating and falling in the drum screen. However, this production line uses a vibrating screen to separate small-sized materials and uses a wind selection machine to discharge the cotton stalks and cotton in the residual film mixture. A large number of smaller-sized plastic film pieces will be mixed in materials such as cotton stalks and wood chips, which may be difficult to meet the backfill conditions of lost soil.

[0005] CN207022399U provides a method for separating residual film from impurities, which utilizes the different physical properties of the components of residual film mixed with impurities, and realizes separation and collection of residual film by comprehensive screening method and air selection method. Pour the residual film and impurities into the upper end of the tilted vibrating screen, and set an air selection chamber just above the lower part of the vibrating screen. When the vibrating screen and the air selection chamber work at the same time, the stones and soil blocks with the highest specific gravity leak out from the gaps between the vibrating screen bars, and the large impurities with moderate specific gravity make parabolic motion in the air selection chamber, and finally the flow channel vibrates the lower edge of the screen, and the residual film with the lightest specific gravity and fine impurities will flow into the mesh residual film frame along the air selection chamber. Due to the effect of wind force, the residual film is attached to the mesh residual film frame, and the fine impurities are blown out of the mesh residual film frame, thereby realizing the separation of residual film and impurities. However, this method separates all substances except stones and soil with the help of a wind selection chamber. A large number of plastic film sheets and other impurities gather on the mesh residual film frame. Not only is the impurity content of the collected plastic film high, but the mesh residual film frame needs to be constantly replaced to maintain continuous operation. At the same time, a large amount of airflow mixed with fine debris flows into the air, causing air pollution. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of high impurity content in plastic film sheets recovered from discarded residual film and backfilling of soil and biomass lost in the residual film in the prior art.

[0007] In order to achieve the above object, the present invention provides, on one hand, a device for sorting plastic film sheets from residual film, comprising:

[0008] A crushing device, wherein the crushing device is used to crush residual film materials;

[0009] A vibration screening device, the vibration screening device comprising a plurality of sieve plates spaced apart from each other in a vertical direction, each of the sieve plates being arranged obliquely relative to a horizontal direction, a high end of the uppermost sieve plate forming a feed end connected to a discharge port of the crushing device, and sieve apertures of the plurality of sieve plates decreasing in size from top to bottom;

[0010] A plurality of plastic film separation devices, wherein the plurality of plastic film separation devices are arranged corresponding to the plurality of sieve plates, so as to separate the plastic film sheets from the materials on the corresponding sieve plates; and

[0011] A plastic film concentrating device is used to separate and purify plastic film sheets from a plurality of plastic film separating devices.

[0012] The equipment of the present invention can crush the residual film material by setting a crushing device, which can not only facilitate the separation of plastic film sheets from the residual film, but also make the compacted residual film mixture fluffy, which is conducive to the separation of downstream processes; by setting a multi-layer sieve plate to classify the residual film material according to size, and setting a corresponding plastic film separation device to separate the plastic film sheets on each layer of the sieve plate, materials of different sizes and compositions can be separated under differentiated operating conditions, thereby reducing the impurity content in the separated plastic film sheets and the content of plastic film sheets in the impurities; by setting a plastic film selection device, the separated plastic film sheets can be further separated and purified, further reducing the impurity content in the plastic film sheets. Therefore, the equipment of the present invention can effectively solve the problem of recovering plastic film sheets from discarded residual films and backfilling the soil and biomass lost in the residual films.

[0013] In some embodiments, the apparatus further comprises a feed conveying device, and the feed conveying device is used to convey residual film materials to the crushing device.

[0014] In some embodiments, the crushing device is configured to crush the residual film material into an average long side size of 2 cm-10 cm, preferably 3 cm-8 cm.

[0015] In some embodiments, the inclination angle of the sieve plate is 0.01-30°.

[0016] In some embodiments, the sieve holes of the top sieve plate have a diameter of 0.2 cm to 6 cm, and the sieve holes of the remaining sieve plates have a diameter of 0.01 cm to 3 cm.

[0017] In some embodiments, the plastic film separation device comprises a suction or blowing device. Preferably, the gas linear velocity of the suction or blowing device is in the range of 5 m / s-30 m / s.

[0018] In some embodiments, the vibration screening device further includes a first conveying portion disposed at intervals below the plurality of screen plates, the first conveying portion being used to receive and convey outwardly materials screened by the bottommost screen plate.

[0019] In some embodiments, the discharge port of the crushing device is located at the bottom of the crushing device, and the discharge port is arranged opposite to the feed end.

[0020] In some embodiments, the apparatus further comprises a second conveying portion, and the second conveying portion is used to convey the material on the uppermost screen plate back to the crushing device.

[0021] In some embodiments, the device further comprises a third conveying portion, and the third conveying portion is used to convey the materials on each layer of the sieve plate except the uppermost layer of the sieve plate to the outside.

[0022] Another aspect of the present invention provides a method for separating plastic film sheets from residual film, comprising the following steps:

[0023] S1. Crushing the residual film material into an average long side size of 2cm-10cm;

[0024] S2, classifying the broken residual film particles according to their size and performing multi-level screening;

[0025] S3, separating the plastic membrane sheets from the screened multi-level materials respectively;

[0026] S4, separating and purifying the separated plastic membrane again.

[0027] The method of the present invention has the same advantages as the device, which will not be described in detail here.

[0028] In some embodiments, the method further comprises, after step S3, crushing and separating the primary material after separating the plastic film sheets again according to steps S1-S4.

[0029] In some embodiments, the method further comprises, after step S3, a step of discharging the remaining grade materials after the plastic film sheets are separated.

[0030] In some embodiments, in step S1, the residual film material is broken into pieces with an average long side size of 3 cm to 8 cm.

[0031] In some embodiments, in step S3, the plastic film is separated by suction or blowing. Preferably, the linear velocity of the gas for suction or blowing is in the range of 5-30 m / s.

[0032] In some embodiments, the method is performed using the above-mentioned device for sorting plastic film sheets from residual film.

[0033] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 It is a schematic diagram of an embodiment of the device for sorting plastic film sheets from residual film in the present invention.

[0036] Description of Reference Numerals

[0037] 1-crushing device, 2-vibration screening device, 21-screen plate, 22-first conveying part, 3-plastic film separation device, 4-plastic film selection device. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

[0039] The present invention provides these embodiments to make the present invention thorough and complete, and fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​described in these embodiments should be interpreted as being merely exemplary, rather than as limiting.

[0040] It should be noted that, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0041] In addition, the words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly perpendicular, but is within the tolerance range. "Parallel" is not strictly parallel, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0042] It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0043] All terms used in the present invention have the same meanings as those understood by ordinary technicians in the field to which the present invention belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0044] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0045] In one aspect, the present invention provides a device for separating plastic film sheets from residual film, Figure 1 , the device comprises:

[0046] A crushing device 1, which is used to crush residual film materials (including plastic film, soil, and other impurities such as straw, cotton, etc.);

[0047] A vibration screening device 2, the vibration screening device 2 comprises a plurality of sieve plates 21 arranged at intervals from each other in the vertical direction, each sieve plate 21 is arranged obliquely relative to the horizontal direction, the high end of the uppermost sieve plate 21 forms a feed end connected to the discharge port of the crushing device 1, and the sieve apertures of the plurality of sieve plates 21 decrease in order from top to bottom;

[0048] A plurality of plastic film separation devices 3, wherein the plurality of plastic film separation devices 3 are arranged corresponding to the plurality of sieve plates 21, so as to separate the plastic film sheets from the materials on the corresponding sieve plates 21; and

[0049] The plastic film concentrating device 4 is used to separate and purify the plastic film sheets from the plurality of plastic film separating devices 3 .

[0050] In the above, it should be noted that the sieve plate 21 can vibrate in the vertical direction and / or the horizontal direction. The vibration screening device 2 may also include a driving mechanism (such as a motor) for driving the sieve plate 21 to vibrate. The plastic film separation device 3 can separate the plastic film sheets in the entire range of the sieve plate 21, or it can concentrate on separating the plastic film sheets only at the lower end (i.e., the discharge end) of the sieve plate 21. The corresponding arrangement of multiple plastic film separation devices 3 and multiple sieve plates 21 can be understood as: multiple plastic film separation devices 3 and multiple sieve plates 21 can be arranged one by one, or more than two plastic film separation devices 3 can be arranged corresponding to each sieve plate 21.

[0051] When in use, the residual film material is first sent to the crushing device 1 for crushing, and the crushed material enters the feeding end of the uppermost sieve plate 21 of the vibrating screening device 2 through the discharge port of the crushing device 1. With the vibration of the uppermost sieve plate 21, primary screening is performed, that is, the larger material remains on the uppermost sieve plate 21 and gradually moves to the discharge end of the uppermost sieve plate 21, and the smaller material falls through the sieve holes of the uppermost sieve plate 21 to the lower sieve plate 21 for secondary screening, that is, the larger material remains on the second sieve plate 21. And gradually move to the discharge end of the second sieve plate 21, and the smaller materials fall through the sieve holes of the second sieve plate 21 onto the lower sieve plate 21 for three-stage screening, and so on; then the plastic film separation device 3 corresponding to each sieve plate 21 is used to separate the plastic film sheets in the materials on the corresponding sieve plate 21; finally, the plastic film selection device 4 is used to separate the plastic film sheets separated by multiple plastic film separation devices 3 (at this time, the plastic film sheets still contain some soil particles) again to obtain clean plastic film sheets.

[0052] The equipment of the present invention is provided with a crushing device 1 to crush the residual film material, which can not only facilitate the separation of plastic film sheets from the residual film, but also make the compacted residual film mixture fluffy, which is conducive to the separation of downstream processes; by providing a multi-layer sieve plate 21 to classify the residual film material according to the size, and providing a corresponding plastic film separation device 3 to separate the plastic film sheets of the material on each layer of the sieve plate 21, the materials of different sizes and compositions can be separated under differentiated operating conditions, thereby reducing the impurity content in the separated plastic film sheets and the content of plastic film sheets in the impurities; by providing a plastic film selection device 4, the separated plastic film sheets can be further separated and purified, and the impurity content in the plastic film sheets can be further reduced. Therefore, the equipment of the present invention can effectively solve the problem of recovering plastic film sheets from discarded residual films and backfilling the soil and biomass lost in the residual films.

[0053] Among them, the inventors found through a lot of research that when the residual film material is too large after being crushed, it is impossible to effectively separate the various substances through vibration screening and air selection, and it is necessary to repeat the crushing and vibration separation operations many times, which is costly and has a poor separation effect; when the residual film material is too small after being crushed, the plastic film will be entangled with impurities such as straw and cotton and it is difficult to separate. Therefore, as a preferred embodiment, the crushing device 1 is configured to crush the residual film material to an average long side size of 2cm-10cm (i.e., the average length range of the longest side of the material, that is, the average maximum size range), and more preferably 3cm-8cm.

[0054] In the present invention, the discharge port of the crushing device 1 can be located at the bottom of the crushing device 1, and the discharge port of the crushing device 1 is arranged directly opposite to the feed end of the uppermost screen plate. In this arrangement, the material can freely fall to the vibration screening device 3 under the action of gravity.

[0055] In the present invention, preferably, the inclination angle of the sieve plate 21 is 0.01-30°, that is, the angle between the plate surface of the sieve plate 21 and the horizontal plane is 0.01-30°.

[0056] In the present invention, as a preferred embodiment, the sieve hole diameter of the top sieve plate 21 is 0.2cm-6cm, and the sieve hole diameters of the remaining sieve plates 21 are 0.01cm-3cm. By setting the above sieve hole size and matching the crushed material size of 2cm-10cm, effective separation of plastic film, soil and impurities can be achieved.

[0057] In the present invention, the vibration screening device 2 may further include a first conveying portion 22 disposed at intervals below the plurality of screen plates 21, and the first conveying portion 22 is used to receive and convey outwardly the material screened off by the lowest screen plate 21. It is understandable that the material screened off to the first conveying portion 22 is basically soil particles, and the first conveying portion 22 can output the soil particles to a fixed position to facilitate backfilling of the soil particles.

[0058] The device of the present invention may also include a second conveying part and a third conveying part (not shown in the figure). The second conveying part is used to convey the material on the uppermost sieve plate 21 back to the crushing device 1 for re-crushing; the third conveying part is used to convey the material (basically impurities) on the remaining sieve plates 21 except the uppermost sieve plate 21 to the outside.

[0059] In the present invention, the plastic film separation device 3 can utilize the characteristic that the plastic film is more easily carried by the air flow to separate the plastic film from other substances. For example, the plastic film separation device 3 may include a suction or blowing device. The light plastic film in the material can be separated by utilizing the suction force or blowing force provided by the suction or blowing device. Preferably, the gas linear velocity range of the suction or blowing device is 5m / s-30m / s. It can be understood that in the case of the suction device, the gas linear velocity range at the inlet of the suction device is 5m / s-30m / s; in the case of the blowing device, the gas linear velocity range at the outlet of the blowing device is 5m / s-30m / s, that is, the gas linear velocity range acting on the material to be separated is 5m / s-30m / s.

[0060] The device of the present invention may further include a feed conveying device (not shown in the figure), which is used to convey the residual film material to the crushing device 1. Specifically, the feed conveying device can be used to uniformly and continuously convey the residual film material to the crushing device 1 to achieve continuous sorting operation, thereby improving the separation efficiency. Of course, in other embodiments, the residual film material can be directly poured into the crushing device through the feed port of the crushing device 1, and of course a feed funnel can also be set at the feed port.

[0061] In the present invention, Figure 1As shown, the crushing device 1 can be located at the upper left of the vibration screening device 2, and the plastic film separation device 3 can be located at the upper right of the vibration screening device 2, thereby reducing the occupied space of the equipment and realizing the separation of plastic film sheets in the residual film within a limited space.

[0062] In the present invention, the crushing device 1 can adopt any crushing device in the prior art. The plastic film separation device 3 can adopt any appropriate separation device in the prior art, such as a blower that can generate airflow or an exhaust fan that can generate negative pressure (see CN207022399U for details). The plastic film selection device 4 can separate the plastic film and soil particles by using the difference in density and size between the plastic film and the soil particles, and can adopt any appropriate separation device in the prior art, such as a vibrating screen. The feed conveying device, the first conveying part, the second conveying part, and the third conveying part can adopt any equipment or component with solid conveying function in the prior art, such as a conveyor belt.

[0063] Another aspect of the present invention provides a method for separating plastic film sheets from residual film, comprising the following steps:

[0064] S1. Crushing the residual film material into an average long side size of 2cm-10cm;

[0065] S2, classifying the broken residual film particles according to their size and performing multi-level screening;

[0066] S3, separating the plastic membrane sheets from the screened multi-level materials respectively;

[0067] S4, separating and purifying the separated plastic membrane again.

[0068] The method may further include, after step S3, crushing and separating the primary material (corresponding to the material on the uppermost sieve plate) after the plastic film is separated according to steps S1-S4 again.

[0069] The method may further include the step of discharging the remaining material after the plastic film is separated (ie, the material on the remaining sieve plates except the upper sieve plate) after step S3.

[0070] Preferably, in step S1, the residual film material is broken into pieces with an average long side size of 3 cm to 8 cm. In step S3, the plastic film is separated by suction or blowing, and preferably, the linear velocity of the suction or blowing gas is in the range of 5 to 30 m / s.

[0071] The above method of the present invention can be carried out by using the above device for separating plastic film sheets from residual film. The above method of the present invention has the corresponding advantages of the above device, which will not be described in detail here.

[0072] In the present invention, the inventors have found through extensive research that by controlling the size of the crushed material, the size of the sieve holes of each layer of the sieve plate, and the gas linear velocity of the plastic film separation device, the effective separation of the plastic film can be achieved while reducing the separation cost. Specifically, the average long side size of the crushed material is 2cm-10cm, the sieve hole diameter of the top sieve plate 21 is 0.2cm-6cm, the sieve hole diameter of the remaining layers of the sieve plate 21 is 0.01cm-3cm, and the gas linear velocity range of the plastic film separation device is 5m / s-30m / s, which can make the impurity content in the plastic film less than 10%, and the content of plastic film in other impurities less than 1%, and can achieve the backfilling of soil and biomass lost in the residual film.

[0073] The following is further described with reference to the embodiments.

[0074] Example

[0075] The residual film after cotton planting is used as raw material for sorting plastic film. After sorting, other impurities and plastic film are collected to measure the impurity content.

[0076] The method for measuring the impurity content is as follows: first weigh the material to obtain the mass m0, and then dry it at 60℃ for 8h and weigh it again to obtain the mass m 10 . Wash the material, remove surface impurities and weigh it again to get the material mass m 20 . Then the impurity content of the material is (m 20 -m 10 ) / m0*100%.

[0077] Example 1

[0078] Test method: Take 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and crush the material through the crushing device 1. The average long side size of the material after crushing is 6cm. The vibration screening device includes two layers of sieve plates, the sieve hole size of the upper sieve plate is 2cm, and the sieve hole size of the lower sieve plate is 0.1cm. The gas linear velocity of the plastic film separation device is 12m / s. After separation, the content of impurities (mainly soil particles) in the plastic film is 9.6%, the content of plastic film in other impurities is 0.3%, and the content of plastic film in soil particles is <0.1%.

[0079] Comparative Example 1

[0080] Test method: 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and the equipment and method described in Example 1 are used. The only difference from Example 1 is that the average long side size of the material after crushing is 12cm. After separation, the content of impurities in plastic film is 12.7%, the content of plastic film in other impurities is 0.8%, and the content of plastic film in soil particles is <0.1%.

[0081] Comparative Example 2

[0082] Test method: 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and the equipment and method described in Example 1 are used. The only difference from Example 1 is that the average long side size of the material after crushing is 1cm. After separation, the content of impurities in plastic film is 20.8%, the content of plastic film in other impurities is 1.7%, and the content of plastic film in soil particles is 0.2%.

[0083] Comparative Example 3

[0084] Test method: 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and the equipment and method described in Example 1 are used. The only difference from Example 1 is that the vibration screening device has only one layer of sieve plate, and its sieve hole size is 10mm. After separation, the content of impurities in plastic film is 10.8%, the content of plastic film in other impurities is 0.7%, and the content of plastic film in soil particles is 1.2%.

[0085] Comparative Example 4

[0086] Test method: 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and the equipment and method described in Example 1 are used. The difference from Example 1 is that the vibration screening device has only one layer of sieve plate, the sieve hole size is 10mm; and there is no plastic film selection device. After separation, the content of impurities in plastic film is 39.4%, the content of plastic film in other impurities is 0.7%, and the content of plastic film in soil particles is 1.3%.

[0087] Comparative Example 5

[0088] Test method: 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and the equipment and method described in Example 1 are used. The only difference from Example 1 is that the gas linear velocity of the plastic film separation device is 32m / s. After separation, the content of impurities in the plastic film is 15.1%, the content of plastic film in other impurities is 0.2%, and the content of plastic film in soil particles is <0.1%.

[0089] Comparative Example 6

[0090] Test method: 1000kg of residual film raw material, the plastic film content in the raw material is 5.26%, and the equipment and method described in Example 1 are used. The only difference from Example 1 is that the gas linear velocity of the plastic film separation device is 3.5m / s. After separation, the content of impurities in the plastic film is 10.1%, the content of plastic film in other impurities is 2.3%, and the content of plastic film in soil particles is <0.1%.

[0091] So far, various embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed herein.

[0092] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A device for sorting plastic film sheets from residual film, characterized in that: include: A crushing device (1), wherein the crushing device (1) is used to crush residual film materials; A vibration screening device (2), the vibration screening device (2) comprising a plurality of sieve plates (21) arranged at intervals from each other in a vertical direction, each of the sieve plates (21) being arranged obliquely relative to a horizontal direction, the high end of the uppermost sieve plate (21) forming a feed end connected to a discharge port of the crushing device (1), and the sieve apertures of the plurality of sieve plates (21) decreasing in size from top to bottom; A plurality of plastic film separation devices (3), wherein the plurality of plastic film separation devices (3) are arranged corresponding to the plurality of sieve plates (21) so as to separate plastic film sheets from the material on the corresponding sieve plates (21); as well as A plastic film concentrating device (4) is used to separate and purify plastic film sheets from a plurality of plastic film separating devices (3).

2. The device for separating plastic film sheets from residual film according to claim 1, characterized in that: The device further comprises a feed conveying device, wherein the feed conveying device is used to convey residual film material to the crushing device (1); and / or The crushing device (1) is configured to crush the residual film material into an average long side size of 2 cm-10 cm, preferably 3 cm-8 cm.

3. The device for separating plastic film sheets from residual film according to claim 1, characterized in that: The inclination angle of the sieve plate (21) is 0.01-30°, and / or The sieve holes of the uppermost sieve plate (21) have a diameter of 0.2 cm to 6 cm, and the sieve holes of the remaining sieve plates (21) have a diameter of 0.01 cm to 3 cm.

4. The device for separating plastic film sheets from residual film according to claim 1, characterized in that: The plastic film separation device (3) comprises a suction or blowing device. Preferably, the gas linear velocity of the suction or blowing device is in the range of 5 m / s-30 m / s.

5. The device for separating plastic film sheets from residual film according to claim 1, characterized in that: The vibrating screening device (2) further comprises a first conveying portion (22) arranged at intervals below the plurality of screen plates (21), the first conveying portion (22) being used to receive and convey outwardly materials screened by the bottom screen plate (21); and / or The discharge port of the crushing device (1) is located at the bottom of the crushing device (1), and the discharge port is arranged directly opposite to the feed end.

6. The device for separating plastic film sheets from residual film according to any one of claims 1 to 5, characterized in that: The device further comprises a second conveying part, the second conveying part being used to convey the material on the uppermost screen plate (21) back to the crushing device (1); and / or The device further comprises a third conveying portion, and the third conveying portion is used to convey materials on each layer of the sieve plate (21) except the uppermost layer of the sieve plate (21) to the outside.

7. A method for separating plastic film sheets from residual film, characterized in that: The following steps are involved: S1. Crushing the residual film material into an average long side size of 2cm-10cm; S2, classifying the broken residual film particles according to their size and performing multi-level screening; S3, separating plastic membrane sheets from the screened multi-level materials respectively; S4, separating and purifying the separated plastic membrane again.

8. The method for separating plastic film sheets from residual film according to claim 7, characterized in that: The method further comprises, after step S3, crushing and separating the primary material after separating the plastic film again according to steps S1-S4, and / or The method further comprises the step of discharging the remaining material after the plastic film is separated after the step S3.

9. The method for separating plastic film sheets from residual film according to claim 7, characterized in that: In step S1, the residual film material is crushed to an average long side size of 3 cm to 8 cm, and / or In step S3, the plastic film is separated by suction or blowing. Preferably, the linear velocity of the gas for suction or blowing is in the range of 5-30 m / s.

10. The method for separating plastic film sheets from residual film according to any one of claims 7 to 9, characterized in that: The method is carried out using the device for sorting plastic film sheets from residual film as described in any one of claims 1 to 6.

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