A method and system for sorting municipal solid waste

Abstract

This invention relates to the field of waste sorting technology, and discloses a method and system for sorting household waste. The method includes the following steps: breaking open bags, dispersing, and screening household waste to remove particulate waste; dispersing the household waste and conveying it to a first conveyor belt to remove iron-containing waste; using a first image recognition module to identify regularly shaped recyclable waste on the first conveyor belt, and using several first robotic arms to sort the identified recyclable waste; conveying the household waste to a second conveyor belt, heating the second conveyor belt to thermally deform plastic waste; using a second image recognition module to identify the thermally deformed plastic waste on the second conveyor belt, and simultaneously using several second robotic arms to sort the identified thermally deformed plastic waste. This invention has good recognition effect and high separation efficiency; in addition to sorting out well-shaped plastic products, it also has a good separation effect on plastic waste with damaged shapes.

Description

Technical Field

[0001] This invention relates to the field of waste sorting technology, and in particular to a method and system for sorting household waste. Background Technology

[0002] Household waste refers to solid waste generated by people in their daily lives or in activities that provide services for daily life, as well as solid waste that is considered household waste according to laws and administrative regulations. It mainly includes residential waste, market and commercial waste, public place waste, street cleaning waste, and waste from enterprises and institutions.

[0003] The treatment of municipal solid waste is shifting from incineration to resource utilization, the latter offering advantages such as reduced carbon emissions, lower processing subsidies, and reduced pollution. Currently, there is increased focus on low-value recyclables. However, the sorting of recyclables at the residential level is ineffective, relying mainly on manual sorting by scavengers to extract some higher-value components, which is done in poor working conditions and at a slow pace. While machine sorting is used, it struggles to identify deformed or severely damaged plastic waste, resulting in low sorting efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a method for sorting household waste and a system for implementing the method. The method for sorting household waste has good identification effect and high separation efficiency. In addition to sorting out plastic products with intact shapes, it also has a good separation effect on plastic waste with damaged shapes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for sorting household waste is provided, including the following steps:

[0007] S10. Break open bags, break up, and screen household waste to remove particulate waste;

[0008] S20. The household waste with granular waste removed is dispersed and then transferred to the first conveyor belt to remove iron-containing waste;

[0009] S30. Use the first image recognition module to identify recyclable waste with regular shape on the first conveyor belt, and use several first robotic arms to sort out the identified recyclable waste.

[0010] S40. Continue to transport the household waste to the second conveyor belt, heat the second conveyor belt to cause the plastic waste to deform due to heat; use the second image recognition module to identify the plastic waste that has undergone heat deformation on the second conveyor belt, and use several second robotic arms to sort out the identified heat-deformed plastic waste.

[0011] As a further solution to the household waste sorting method, the heating temperature of the second conveyor belt is 70℃-90℃.

[0012] As a further option for the sorting method of municipal solid waste, the municipal solid waste is cooled before and after the heating zone of the second conveyor belt, along the conveying direction of the second conveyor belt.

[0013] As a further solution to the municipal solid waste sorting method, the heating treatment of the second conveyor belt specifically refers to: heating the second conveyor belt so that the second conveyor belt has three heating zones spaced apart. Along the conveying direction of the second conveyor belt, the temperatures of the three heating zones are 70℃-90℃, 90℃-125℃, and 125℃-150℃, respectively, and each heating zone corresponds to several second robotic arms.

[0014] As a further option for the sorting method of household waste, the temperatures of the three heating zones along the conveying direction of the second conveyor belt are 80℃, 120℃, and 140℃, respectively.

[0015] As a further option for the sorting method of municipal solid waste, the municipal solid waste is cooled before and after each heating zone along the conveying direction of the second conveyor belt.

[0016] On the other hand, a household waste sorting system is provided to implement the household waste sorting method, including a drum, a first vibrating feeder, a first conveyor belt, a second vibrating feeder and a second conveyor belt arranged sequentially along the household waste conveying direction, and also including an iron removal mechanism, a first image recognition module, a plurality of first robotic arms, a heating mechanism, a second image recognition module and a plurality of second robotic arms.

[0017] The system includes the following components: a roller for breaking open bags, dispersing, and screening household waste to remove particulate waste, and conveying the waste to the first vibrating feeder; the first vibrating feeder for dispersing the waste and conveying it to the first conveyor belt; an iron removal mechanism for separating iron-containing waste on the first conveyor belt; a first image recognition module and a first robotic arm adjacent to the first conveyor belt, the first image recognition module for identifying regularly shaped recyclable waste on the first conveyor belt, and the first robotic arm for sorting out the identified regularly shaped recyclable waste; a second vibrating feeder for dispersing the iron-containing waste and regularly shaped recyclable waste and conveying them to the second conveyor belt; a heating mechanism adjacent to the lower surface of the upper second conveyor belt for heating the second conveyor belt to deform plastic waste on it; a second image recognition module and a second robotic arm adjacent to the second conveyor belt, the second image recognition module for identifying the deformed plastic waste on the second conveyor belt, and the second robotic arm for sorting out the identified deformed plastic waste.

[0018] As a further embodiment of the municipal solid waste sorting system, it also includes a first cooling mechanism and a second cooling mechanism, which are located adjacent to the lower surface of the second conveyor belt located above. The first cooling mechanism, the heating mechanism, and the second cooling mechanism are arranged sequentially along the conveying direction of the second conveyor belt.

[0019] As a further embodiment of the municipal solid waste sorting system, the heating mechanism includes three heating sections arranged at intervals along the conveying direction of the second conveyor belt, with the heating temperature of the three heating sections increasing sequentially.

[0020] As a further embodiment of the municipal solid waste sorting system, it also includes multiple cooling mechanisms, which are located adjacent to the lower surface of the second conveyor belt located above, with one cooling mechanism provided before and after each heating section.

[0021] Beneficial effects:

[0022] For recyclable waste with regular shapes, including regular-shaped plastic bottles and cardboard boxes, this invention can effectively identify them using a first image recognition module and sort them out using a first robotic arm. However, the first image recognition module struggles to identify other severely damaged or deformed plastic bottles or other plastic products. This invention heats a second conveyor belt, causing the plastic waste on it to deform. Once the second image recognition module detects this deformation, it triggers the sorting action of the second robotic arm, thus separating the heat-deformed plastic products. Compared to existing technologies, this invention's waste sorting method has better identification and separation efficiency for plastic products. Besides separating well-shaped plastic products, it also effectively separates plastic waste with damaged shapes. Attached Figure Description

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the household waste sorting system described in Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram showing the installation of the heating mechanism and cooling mechanism on the second conveyor belt according to Embodiment 1 of the present invention.

[0026] Figure 3 This is a schematic diagram showing the installation of the heating mechanism and cooling mechanism on the second conveyor belt according to Embodiment 2 of the present invention. Detailed Implementation

[0027] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationships shown in the accompanying drawings. They are used solely for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," etc., are merely used for distinction in description and have no special meaning.

[0031] Example 1

[0032] like Figure 1 As shown, the household waste sorting method of this embodiment includes the following steps:

[0033] S10. Break open bags, break up, and screen household waste to remove particulate waste;

[0034] S20. The household waste with granular waste removed is dispersed and then transferred to the first conveyor belt to remove iron-containing waste;

[0035] S30. Use the first image recognition module to identify recyclable waste with regular shape on the first conveyor belt, and use several first robotic arms to sort out the identified recyclable waste.

[0036] S40. Continue to transport the household waste to the second conveyor belt, heat the second conveyor belt to cause the plastic waste to deform due to heat; use the second image recognition module to identify the plastic waste that has undergone heat deformation on the second conveyor belt, and use several second robotic arms to sort out the identified heat-deformed plastic waste.

[0037] The waste sorting method in this embodiment mainly separates plastic products (including some textiles with the same chemical composition, such as polyester) from dry waste. Plastic products have a high calorific value and can be used separately after sorting, such as as raw materials for recycling, or for pyrolysis of gas or oil. Compared with direct incineration, this significantly reduces carbon emissions and pollutant emissions.

[0038] In this embodiment, recyclable waste with regular shapes includes plastic bottles and cardboard boxes, which can be effectively identified by the first image recognition module and sorted out by the first robotic arm. However, some plastic bottles or other plastic products in the household waste are severely damaged and deformed, making them difficult for the first image recognition module to identify. Therefore, in this embodiment, a second conveyor belt is set downstream of the first conveyor belt, and the second conveyor belt is heated. This causes the plastic products in the household waste on the second conveyor belt to deform upon heating, resulting in a more obvious deformation movement compared to other waste, making them easily identifiable. After the second image recognition module detects the deformation movement of the plastic product, it triggers the sorting action of the second robotic arm to separate the heat-deformed plastic product.

[0039] This embodiment uses the heat deformation of plastic waste to enable the second image recognition module to identify it, which significantly improves the recognition reliability compared to relying solely on vision.

[0040] Compared with the prior art, the household waste sorting method of this embodiment has a better identification effect on plastic products and a higher separation efficiency. In addition to sorting out plastic products with intact shapes, it also has a good separation effect on plastic waste with damaged shapes.

[0041] Furthermore, the heating temperature of the second conveyor belt is 70℃-90℃. By designing the heating temperature of the second conveyor belt to be 70℃-90℃, the plastic waste can undergo thermal deformation, and the thermal deformation movement of the plastic waste can be recognized by the second image recognition module.

[0042] Furthermore, in step S40, the household waste is cooled before and after the heating zone of the second conveyor belt, along the conveying direction of the second conveyor belt. Since the second conveyor belt is made of a heat-conducting material, cooling the household waste before and after the heating zone prevents heat from being transported along the second conveyor belt, prevents plastic waste from being deformed by heat before entering the heating zone and passing through the heat deformation identification, and also prevents plastic waste from continuing to melt after leaving the heating zone. At the same time, heat can be recovered through the cooling process.

[0043] In step S40, after several second robotic arms sort out the identified heat-deformed plastic waste, the remaining waste is conveyed to the next workstation via the second conveyor belt for temporary storage or direct processing.

[0044] This embodiment also provides a household waste sorting system for implementing the household waste sorting method described in the above embodiments. Figure 1As shown, the municipal solid waste sorting system of this embodiment includes a drum, a first vibrating feeder, a first conveyor belt, a second vibrating feeder and a second conveyor belt arranged sequentially along the conveying direction of municipal solid waste, and also includes an iron removal mechanism, a first image recognition module, a plurality of first robotic arms, a heating mechanism, a second image recognition module and a plurality of second robotic arms.

[0045] The system includes the following components: a roller for breaking open bags, dispersing, and screening household waste to remove particulate waste, and conveying the waste to the first vibrating feeder; the first vibrating feeder for dispersing the waste and conveying it to the first conveyor belt; an iron removal mechanism for separating iron-containing waste on the first conveyor belt; a first image recognition module and a first robotic arm adjacent to the first conveyor belt, the first image recognition module for identifying regularly shaped recyclable waste on the first conveyor belt, and the first robotic arm for sorting out the identified regularly shaped recyclable waste; a second vibrating feeder for dispersing the iron-containing waste and regularly shaped recyclable waste and conveying them to the second conveyor belt; a heating mechanism adjacent to the lower surface of the upper second conveyor belt for heating the second conveyor belt to deform plastic waste on it; a second image recognition module and a second robotic arm adjacent to the second conveyor belt, the second image recognition module for identifying the deformed plastic waste on the second conveyor belt, and the second robotic arm for sorting out the identified deformed plastic waste.

[0046] In this embodiment, the dry waste, after being filtered and dehumidified, is first stored in a receiving bin. The household waste in the receiving bin is then conveyed to a drum via a conveyor device. The drum is equipped with blades and a screen. The blades can break up bagged waste and disperse various types of household waste, which helps to spread it evenly onto the first conveyor belt. Heavier small particles, such as broken glass, pebbles, and bones, can be partially removed by screening. The structure of the drum is conventional technology in the art and will not be described in detail.

[0047] The first and second vibrating feeders are used to further disperse the material. By controlling the feeding speed and the corresponding conveyor belt speed, a discrete material distribution can be formed on the downstream conveyor belt, facilitating subsequent identification. Both the first and second vibrating feeders are conventional technologies in this field and will not be described in detail further.

[0048] The structure and installation position of the iron removal mechanism on the first conveyor belt are conventional techniques in the field. For example, the iron removal mechanism can use a conventional magnetic sorting device, which will not be elaborated further. Both the first and second conveyor belts are designed to meet the requirements of material dispersion and flat conveying, and are resistant to waste corrosion. The operating temperature of the first conveyor belt is room temperature. The first and second image recognition modules, as well as the first and second robotic arms, are also conventional techniques in the field.

[0049] For example, such as Figure 2 As shown, the heating mechanism 10 includes a cylindrical electric heating rod 101 and a bearing 102 sleeved on the outer periphery of the electric heating rod 101. The second conveyor belt 20 includes a belt body 201 and pulleys 202. The electric heating rod 101 is disposed between the two pulleys 202 of the second conveyor belt 20 and between the upper belt body and the lower belt body of the second conveyor belt 20. When the second conveyor belt 20 is working, the bearing 102 rolls in contact with the lower surface of the upper belt body of the second conveyor belt 20. After the electric heating rod 101 is heated, it transfers heat to the second conveyor belt 20 through the bearing 102 to heat the domestic waste on the second conveyor belt 20.

[0050] Furthermore, the municipal solid waste sorting system of this embodiment includes a first cooling mechanism 30 and a second cooling mechanism 40. The first cooling mechanism 30 and the second cooling mechanism 40 are adjacent to the lower surface of the second conveyor belt 20 located above. The first cooling mechanism 30, the heating mechanism 10 and the second cooling mechanism 40 are arranged sequentially along the conveying direction of the second conveyor belt 20.

[0051] Specifically, the first cooling mechanism 30 and the second cooling mechanism 40 can be cooling plates disposed between the upper and lower belts of the second conveyor belt 20, and adjacent to the lower surface of the upper belt of the second conveyor belt 20, that is, adjacent to the lower surface of the upper second conveyor belt 20. The cooling plate has a cavity containing coolant, and the cooling plate is in contact with the lower surface of the upper belt to cool the upper belt and the domestic waste on the upper belt, so that the domestic waste is close to room temperature.

[0052] This embodiment, by setting a first cooling mechanism 30 and a second cooling mechanism 40 before and after the heating mechanism 10 respectively, can prevent household waste from being prematurely heated and deformed, thus making it undetectable. Simultaneously, heat recovery and utilization can be achieved based on the first cooling mechanism 30 and the second cooling mechanism 40.

[0053] In this embodiment, the second conveyor belt 20 can be designed to meet the requirements of material dispersion and flat conveying, be resistant to garbage corrosion, have good thermal conductivity, and be able to withstand heat up to 200℃.

[0054] This embodiment also includes a container (not shown in the figure), and the entire municipal solid waste sorting system is installed inside the container to facilitate ventilation and control odor.

[0055] Example 2

[0056] The waste sorting method in this embodiment is basically the same as that in Embodiment 1 above, except for the specific method of heating the second conveyor belt.

[0057] In this embodiment, the heating treatment of the second conveyor belt specifically refers to heating the second conveyor belt to create three heating zones. Along the conveying direction of the second conveyor belt, the temperatures of the three heating zones are 70℃-90℃, 90℃-125℃, and 125℃-150℃, respectively. Since different types of plastics have different heat distortion temperatures, this embodiment, by setting up multiple heating zones, can further classify and sort plastic waste.

[0058] Preferably, along the conveying direction of the second conveyor belt, the temperatures of the three heating zones are 80°C, 120°C, and 140°C, respectively.

[0059] The municipal solid waste sorting system in this embodiment is basically the same as that in Embodiment 1 above, except that the structure and layout of the heating mechanism and the corresponding mechanical sorting mechanism are different.

[0060] Specifically, such as Figure 3 As shown, the heating mechanism 10 in this embodiment includes a first heating section 11, a second heating section 12, and a third heating section 13 arranged sequentially along the conveying direction of the second conveyor belt 20. The heating temperatures of the first heating section 11, the second heating section 12, and the third heating section 13 increase sequentially. Simultaneously, the second robotic arm is also divided into three groups, corresponding to the three heating sections. After the plastic waste undergoes deformation and is identified by the second image recognition module, it is sorted out to prevent it from entering the next heating section. The three heating sections and three heating zones correspond one-to-one.

[0061] The first heating part 11, the second heating part 12 and the third heating part 13 have the same structure as the heating mechanism 10 in the above embodiment 1, and will not be described in detail here.

[0062] Correspondingly, the municipal solid waste sorting system of this embodiment also includes multiple cooling mechanisms, which are respectively located adjacent to the lower surface of the second conveyor belt 20 located above, and each heating section is provided with a cooling mechanism before and after it.

[0063] Specifically, such as Figure 3 As shown, there are four cooling mechanisms, namely the first cooling mechanism 30, the second cooling mechanism 40, the third cooling mechanism 50 and the fourth cooling mechanism 60. The first cooling mechanism 30, the first heating unit 11, the second cooling mechanism 40, the second heating unit 12, the third cooling mechanism 50, the third heating unit 13 and the fourth cooling mechanism 60 are arranged at intervals along the conveying direction of the second conveyor belt 20.

[0064] In other embodiments, the three heating elements can be selectively activated based on the deformation temperature of the actual plastic waste. Correspondingly, only the cooling mechanisms before and after the corresponding heating elements can be activated, which will not be elaborated further.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for sorting household waste, characterized in that, Includes the following steps: S10. Break open bags, break up, and screen household waste to remove particulate waste; S20. The household waste with granular waste removed is dispersed and then transferred to the first conveyor belt to remove iron-containing waste; S30. Use the first image recognition module to identify recyclable waste with regular shape on the first conveyor belt, and use several first robotic arms to sort out the identified recyclable waste. S40. Continue to transport the domestic waste to the second conveyor belt, and heat the second conveyor belt to cause the plastic waste to deform due to heat. The second image recognition module is used to identify the plastic waste that has undergone thermal deformation on the second conveyor belt, and several second robotic arms are used to sort out the identified thermally deformed plastic waste. Specifically, the heating treatment of the second conveyor belt refers to heating the second conveyor belt so that it has three spaced heating zones. Along the conveying direction of the second conveyor belt, the temperatures of the three heating zones are 70℃-90℃, 90℃-125℃, and 125℃-150℃, respectively. Each heating zone corresponds to several second robotic arms. Along the conveying direction of the second conveyor belt, the domestic waste is cooled before and after each heating zone.

2. A household waste sorting system for implementing the household waste sorting method of claim 1, characterized in that, It includes a roller, a first vibrating feeder, a first conveyor belt, a second vibrating feeder and a second conveyor belt arranged sequentially along the direction of conveying domestic waste, and also includes an iron removal mechanism, a first image recognition module, several first robotic arms, a heating mechanism, a second image recognition module and several second robotic arms. The system includes the following components: a roller for breaking open bags, dispersing, and screening household waste to remove particulate waste, and conveying the waste to the first vibrating feeder; the first vibrating feeder for dispersing the waste and conveying it to the first conveyor belt; an iron removal mechanism for separating iron-containing waste on the first conveyor belt; a first image recognition module and a first robotic arm adjacent to the first conveyor belt, the first image recognition module for identifying regularly shaped recyclable waste on the first conveyor belt, and the first robotic arm for sorting out the identified regularly shaped recyclable waste; a second vibrating feeder for dispersing the iron-containing waste and regularly shaped recyclable waste and conveying them to the second conveyor belt; a heating mechanism adjacent to the lower surface of the upper second conveyor belt for heating the second conveyor belt to deform plastic waste on it; a second image recognition module and a second robotic arm adjacent to the second conveyor belt, the second image recognition module for identifying the deformed plastic waste on the second conveyor belt, and the second robotic arm for sorting out the identified deformed plastic waste.

3. The municipal solid waste sorting system according to claim 2, characterized in that, It also includes a first cooling mechanism and a second cooling mechanism, which are located adjacent to the lower surface of the second conveyor belt located above. The first cooling mechanism, the heating mechanism and the second cooling mechanism are arranged sequentially along the conveying direction of the second conveyor belt.

4. The municipal solid waste sorting system according to claim 2, characterized in that, The heating mechanism includes three heating sections arranged at intervals along the conveying direction of the second conveyor belt, with the heating temperature of the three heating sections increasing sequentially.

5. The municipal solid waste sorting system according to claim 4, characterized in that, It also includes multiple cooling mechanisms, which are located adjacent to the lower surface of the second conveyor belt located above, with one cooling mechanism provided before and after each heating section.

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