Household garbage comprehensive treatment system and method based on multistage sorting and recycling

Abstract

The invention relates to the technical field of garbage treatment, in particular to a household garbage comprehensive treatment system and method based on multistage sorting and recycling. The pre-sorting unit is used for identifying metal impurities; the fragment treatment unit is arranged at the downstream of the pre-sorting unit and is used for crushing the mixed garbage; the multi-stage sorting unit is arranged at the downstream of the fragment treatment unit and is used for carrying out multi-class screening treatment on the crushed garbage; the regeneration treatment unit is arranged at the downstream of the multi-stage sorting unit and is used for respectively carrying out regeneration treatment on different types of garbage; and the waste treatment unit is arranged at the downstream of the regeneration treatment unit and is used for correspondingly treating the waste gas and the waste water. On the whole, through multi-stage sorting and regeneration treatment, the system can convert different components in the garbage into valuable resources, such as regenerated plastics, building aggregates, biomass fuels and organic fertilizers. Therefore, high-value utilization of the garbage is realized, and the utilization rate of resources is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste treatment, and particularly relates to a comprehensive domestic waste treatment system and method based on multi-stage sorting and resource utilization. Background Art

[0002] In traditional waste treatment, landfilling and incineration are mainly used, and the resource utilization rate is less than 60%. Recyclable components such as plastics, metals, and bricks are not fully separated and utilized, resulting in waste of resources. For example, PET, PE, and PP plastics in mixed waste are difficult to be directly used in the production of high-end products due to insufficient sorting accuracy (usually less than 85%), and the added value of recycled plastics is limited. The leachate of landfills pollutes soil and groundwater, and harmful gases such as dioxins are generated during the incineration process. The effluent COD of traditional wastewater treatment (such as a single precipitation process) is > 300 mg / L and cannot be reused; the deodorization efficiency of waste gas treatment (such as a spray tower) is less than 60%, which is difficult to meet environmental protection requirements. Each unit of the existing waste treatment system (crushing, sorting, recycling) is mostly independently designed, lacking overall process optimization. For example, the crushing particle size does not match the sorting equipment, resulting in low screening efficiency; the recycling treatment is not differentially designed according to different waste characteristics (such as the moisture content of kitchen waste and the type of plastics), and the added value of products is limited. Traditional equipment is difficult to handle complex waste components (such as kitchen waste with a water content > 50% and entangled plastic bags), and problems such as blockage and corrosion are likely to occur during the treatment process. The lack of modular design makes it difficult for the system to be expanded or migrated, restricting its application in small and medium-sized cities and post-disaster emergency scenarios. Summary of the Invention

[0003] The present invention provides a comprehensive domestic waste treatment system and method based on multi-stage sorting and resource utilization to solve the technical problems of limited treatment of complex waste components and low resource utilization rate in the prior art.

[0004] To solve the above problems, the following technical solutions are adopted for a comprehensive domestic waste treatment system and method based on multi-stage sorting and resource utilization provided by the present invention: A comprehensive domestic waste treatment system based on multi-stage sorting and resource utilization includes a pre-sorting unit for identifying metal impurities; a debris treatment unit provided downstream of the pre-sorting unit and used for crushing mixed waste; a multi-stage sorting unit provided downstream of the debris treatment unit and performing multi-category screening on the crushed waste; a recycling treatment unit provided downstream of the multi-stage sorting unit and used for respectively recycling different types of waste; and a waste treatment unit provided downstream of the recycling treatment unit and used for correspondingly treating waste gas and wastewater.

[0005] Further, the debris treatment unit includes an anti-winding double-shaft shredder, the cutter surface of the anti-winding double-shaft shredder is coated with a tungsten carbide wear-resistant layer, and the rotation speed of the cutter is 20 - 30 rpm.

[0006] Integrated treatment method for domestic waste based on multi-stage sorting and resource utilization, comprising the following steps: S1. Identify and sort out metal impurities in the waste mixture through a pre-sorting unit; S2. Crush the metal impurities and the mixed waste containing plastic bags respectively through different crushing devices in the shredding unit; S3. The waste crushed by the multi-stage sorting unit is subjected to multi-category screening through different screening methods; S4. Different types of waste are respectively subjected to different regeneration treatments through the regeneration treatment unit, facilitating recycling and reuse; S5. The waste gas and waste water generated during the recycling process are subjected to corresponding treatments through the waste treatment unit.

[0007] Furthermore, in S1, metal impurities are specifically identified and sorted out through a metal detector.

[0008] Furthermore, in S2, the mixed waste containing plastic bags is input into an anti-winding double-shaft shredder for crushing treatment, and fragments with a particle size ≤ 50 mm are output.

[0009] Furthermore, in S3, the screening methods are specifically as follows: separating metal through magnetic separation; separating non-metal through eddy current separation; classifying by particle size through a vibrating screen, separating light plastics and paper through air separation; sorting different types of plastics through infrared optical sorting.

[0010] Furthermore, when sorting different types of plastics through infrared optical sorting, they are specifically classified according to the types of PET, PE, and PP, and the sorting accuracy ≥ 95%.

[0011] Furthermore, in S4, the regeneration treatment methods include Treatment of masonry materials: The selected bricks and stones are crushed to particles ≤ 10 mm through a jaw crusher, and after washing to remove impurities, they are used as building recycled aggregates; Plastic regeneration treatment: The single-type plastics after sorting are melted, extruded, filtered, and pelletized to form recycled plastic pellets; Treatment of wood materials: The sorted wood fragments are dried to a moisture content ≤ 15% and then compressed into biomass fuel pellets; Treatment of kitchen waste: Through high-temperature aerobic fermentation, adding a compound bacterial agent, and the fermentation products are screened and packaged as organic fertilizers.

[0012] Furthermore, when treating kitchen waste, high-temperature aerobic fermentation is carried out in a closed reactor, the temperature is controlled at 55 - 65 °C, and the fermentation period is 15 - 20 days.

[0013] Further, in S5, when the waste gas and waste water pass through the waste treatment unit, specifically, the waste gas is deodorized through a biological filter tower; the waste water is recycled after sedimentation and activated carbon adsorption treatment.

[0014] The beneficial effects of the integrated domestic waste treatment system and method based on multi-stage sorting and resource utilization provided by the present invention are as follows: In the present invention, through multi-stage sorting, the separation efficiency of waste components is ≥90%, the purity of recycled plastics reaches 98%, the impurity content of construction aggregates is ≤2%, the energy consumption of the whole process is reduced by 30%, and the resource utilization rate is increased to more than 85%. Overall, through multi-stage sorting and recycling treatment, the system can convert different components in waste into valuable resources, such as recycled plastics, construction aggregates, biomass fuels, and organic fertilizers, etc. This realizes the high-value utilization of waste and improves the resource utilization rate.

[0015] Through the optimization of the whole process of "pre-sorting - crushing - multi-stage sorting - recycling treatment - waste treatment", the present invention realizes the efficient, clean and high-value utilization of domestic waste. It is applicable to small and medium-sized cities with a daily treatment capacity of 50 - 200 tons. The modular design is convenient for expansion to meet different scale requirements. In addition, it can be quickly deployed to disaster areas to realize the harmless treatment and resource utilization of waste and ensure the environmental safety after the disaster. Description of the Drawings

[0016] By referring to the following detailed description with reference to the drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 is a block diagram of the integrated domestic waste treatment system based on multi-stage sorting and resource utilization of the present invention.

[0017] Description of the Reference Numerals: 1. Pre-sorting unit; 2. Fragment processing unit; 3. Multi-stage sorting unit; 4. Recycling treatment unit; 5. Waste treatment unit. Detailed Embodiments

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] The number of any element in the drawings is for illustration rather than limitation, and any naming is only for distinction without any limiting meaning.

[0020] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments of the present invention.

[0021] An embodiment of the integrated domestic waste treatment system based on multi-stage sorting and resource utilization provided by the present invention: As Figure 1 shown, It includes a pre-sorting unit 1 for identifying metal impurities; a debris treatment unit 2, disposed downstream of the pre-sorting unit 1 and used for crushing the mixed waste; a multi-stage sorting unit 3, disposed downstream of the debris treatment unit 2 and performing multi-category screening on the crushed waste; a regeneration treatment unit 4, disposed downstream of the multi-stage sorting unit 3 and used for respectively performing regeneration treatment on different types of waste; and a waste treatment unit 5, disposed downstream of the regeneration treatment unit 4 and used for correspondingly treating waste gas and waste water.

[0022] In this embodiment, the debris treatment unit 2 includes an anti-winding double-shaft shredder, the surface of the cutter of the anti-winding double-shaft shredder is coated with a tungsten carbide wear-resistant layer, and the rotation speed of the cutter is 20 - 30 rpm.

[0023] Specifically, the thickness of the tungsten carbide wear-resistant layer is 0.3 mm, the wear resistance is increased by 3 times, and the downtime for maintenance is reduced by 80%. The output debris particle size is ≤50 mm, and the plastic bag crushing rate is ≥99%, preventing plastic from winding around the cutter.

[0024] By processing waste through the above system, through multi-stage sorting and regeneration treatment, the system can convert different components in the waste into valuable resources, such as recycled plastics, construction aggregates, biomass fuels, and organic fertilizers, etc. This realizes the high-value utilization of waste and improves the resource utilization rate.

[0025] An integrated domestic waste treatment method based on multi-stage sorting and resource utilization includes the following steps: S1. Identify and separate metal impurities in the waste mixture through the pre-sorting unit 1.

[0026] Specifically, metal impurities are identified and separated through a metal detector.

[0027] Specifically, a channel-type metal detector (sensitivity ≥ FeΦ2 mm) can be used, equipped with an automatic sorting robotic arm, the sorting accuracy is ≥98%, and the metal impurity recovery rate is ≥95%.

[0028] S2. Crush the metal impurities and the mixed waste containing plastic bags respectively through different crushing devices in the debris treatment unit 2.

[0029] Among them, the mixed waste containing plastic bags is input into the anti-winding double-shaft shredder for crushing treatment, and debris with a particle size of ≤50 mm is output.

[0030] S3. The garbage broken by the multi-stage sorting unit 3 is subjected to multi-category screening treatment through different screening methods.

[0031] The screening methods are specifically as follows: separating metals by magnetic separation; separating non-metals by eddy current separation; classifying by particle size through a vibrating screen, and separating light plastics and paper by air separation; separating different types of plastics by infrared optical sorting.

[0032] The specific method can adopt the following operations.

[0033] Separate metals by magnetic separation, using a magnetic separator, and the magnetic induction intensity of the permanent magnet drum is ≥8000 Gs to separate ferromagnetic substances (such as iron wires and bottle caps).

[0034] Separate non-metals by eddy current separation, using an eddy current separator (frequency 3000 Hz) to separate non-ferrous metals such as aluminum and copper (such as aluminum cans).

[0035] Vibrating screen (three-layer screen: 50 mm, 20 mm, 5 mm), the grading particle size control accuracy is ±2 mm, separating bricks, stones, plastics, and organic debris.

[0036] Air separator (wind speed 8 - 12 m / s), separating light plastic films and paper.

[0037] Infrared optical sorter (spectral resolution 5 nm), when separating different types of plastics by infrared optical sorting, specifically classify according to the types of PET, PE, and PP, and the sorting accuracy is ≥95%.

[0038] The added value of recycled plastic particles is increased by 30%, and they can be directly used for the production of high-end products.

[0039] S4. The recycling treatment unit 4 conducts different recycling treatments on different categories of garbage respectively to facilitate recycling and reuse.

[0040] The recycling treatment methods include Treatment of bricks and stones: The selected bricks and stones are crushed by a jaw crusher to particles ≤10 mm, and after washing to remove impurities, they are used as building recycled aggregates. Specifically, the strength of the building aggregates reaches the C30 standard and can be used as road base materials.

[0041] Plastic recycling treatment: The sorted single-type plastics are melted, extruded, filtered, and pelletized to form recycled plastic particles.

[0042] Specifically, a twin-screw extruder (temperature control ±2 °C), and the melt index of the recycled particles meets GB / T 12670-2008, and they are made into raw materials for products such as trash cans and pipes.

[0043] Wood material treatment: The selected wood fragments are dried to a moisture content of ≤ 15% and then compressed into biomass fuel pellets.

[0044] Specifically, a biomass granulator (compression ratio 1:8) is used, with a fuel calorific value of ≥ 4000 kcal / kg, replacing coal for heating.

[0045] Food waste treatment: Through high-temperature aerobic fermentation and adding compound bacterial agents, the fermentation products are screened and packaged as organic fertilizers.

[0046] The closed reactor, i.e., the closed fermentation tank (volume 50 m³), has a temperature controlled at 55 - 65 °C and a fermentation cycle of 18 days, and is used for landscaping.

[0047] The system's resource utilization rate reaches 85% (only 60% with traditional methods), and the annual output value of products such as organic fertilizers and recycled aggregates is high.

[0048] S5. The waste gas and wastewater generated during the recycling process are correspondingly treated by the waste treatment unit 5.

[0049] When the waste gas and wastewater pass through the waste treatment unit 5, specifically, the waste gas is deodorized through a biological filter tower; the wastewater is treated by sedimentation and activated carbon adsorption and then recycled.

[0050] Specifically, a biological filter tower (packing height 3 m) has a deodorization efficiency of ≥ 90%. A sedimentation tank (surface load 1.2 m³ / m²·h) + an activated carbon adsorption tank (contact time 30 min), with the effluent COD ≤ 100 mg / L and a recycling rate of ≥ 80%.

[0051] The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization realizes the efficient, clean, and high-value utilization of domestic waste through the optimization of the whole process of "pre-sorting - crushing - multi-stage sorting - regeneration treatment - waste treatment". It is applicable to small and medium-sized cities with a daily treatment capacity of 50 - 200 tons. The modular design is convenient for expansion to meet different scale requirements. In addition, it can be quickly deployed to disaster areas to achieve the harmless treatment and resource utilization of garbage and ensure the post-disaster environmental safety.

[0052] According to the above description of this specification, those skilled in the art can also understand the following terms used, such as the terms indicating orientation or position relationship, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings of this specification. It is only for the purpose of facilitating the elaboration of the solution of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operate in the specific orientation. Therefore, the above orientation or position relationship terms cannot be understood or interpreted as a limitation to the solution of the present invention.

[0053] In addition, in the description of this specification, the meaning of "a plurality of" is at least two, such as two, three or more, etc., unless otherwise specifically defined.

Claims

1. A comprehensive domestic waste treatment system based on multi-stage sorting and resource utilization, characterized in that, It includes a pre-sorting unit (1) for identifying metal impurities; a debris treatment unit (2) provided downstream of the pre-sorting unit (1) and used for crushing mixed garbage; a multi-stage sorting unit (3) provided downstream of the debris treatment unit (2) and performing multi-category screening on the crushed garbage; a recycling treatment unit (4) provided downstream of the multi-stage sorting unit (3) and used for respectively recycling different types of garbage; and a waste treatment unit (5) provided downstream of the recycling treatment unit (4) and used for correspondingly treating waste gas and waste water.

2. The integrated domestic waste treatment system based on multi-stage sorting and resource utilization according to claim 1, characterized in that, The debris treatment unit (2) includes an anti-winding double-shaft shredder, the tool surface of the anti-winding double-shaft shredder is coated with a tungsten carbide wear-resistant layer, and the rotation speed of the tool is 20 - 30 rpm.

3. The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization according to any one of claims 1 - 2 includes the following steps: S1. Identify and separate metal impurities in the garbage mixture through the pre-sorting unit (1); S2. Respectively crush the metal impurities and the mixed garbage containing plastic bags through different crushing devices in the debris treatment unit (2); S3. Perform multi-category screening on the crushed garbage through different screening methods by the multi-stage sorting unit (3); S4. Respectively perform different recycling treatments on different categories of garbage through the recycling treatment unit (4) for convenient recycling and reuse; S5. Correspondingly treat the waste gas and waste water generated during the recycling process through the waste treatment unit (5).

4. The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization according to claim 3, in S1, specifically identify and separate metal impurities through a metal detector.

5. The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization according to claim 3, in S2, input the mixed garbage containing plastic bags into the anti-winding double-shaft shredder for crushing treatment, and output debris with a particle size ≤ 50 mm.

6. The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization according to claim 3, in S3, the screening method is specifically as follows: separate metal through magnetic separation; separate non-metal through eddy current separation; classify by particle size, separate light plastics and paper through a vibrating screen; and separate different types of plastics through infrared optical sorting.

7. The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization according to claim 6, when separating different types of plastics through infrared optical sorting, specifically classify according to the types of PET, PE, and PP, and the sorting accuracy ≥ 95%.

8. The comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization according to claim 3, in S4, the recycling treatment methods include Treatment of masonry materials: The selected bricks and stones are crushed to particles ≤ 10 mm by a jaw crusher, and after washing to remove impurities, they are used as building recycled aggregates; Plastic recycling treatment: The sorted single-type plastics are melted, extruded, filtered, and granulated to form recycled plastic particles; Treatment of wood materials: The sorted wood fragments are dried to a moisture content ≤ 15% and then compressed into biomass fuel particles. Food waste treatment: Through high-temperature aerobic fermentation, adding a composite microbial agent, and screening the fermentation products and packaging them as organic fertilizers.

9. According to the comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization described in claim 8, when treating food waste, the high-temperature aerobic fermentation uses a closed reactor, the temperature is controlled at 55-65 °C, and the fermentation cycle is 15-20 days.

10. According to the comprehensive domestic waste treatment method based on multi-stage sorting and resource utilization described in claim 3, in S5, when the waste gas and waste water pass through the waste treatment unit (5), specifically, the waste gas is deodorized through a biological filter tower; the waste water is recycled after sedimentation and activated carbon adsorption treatment.

Images