A domestic waste landfill excavation, screening, washing and granulation system and its working method

Abstract

The present invention provides a municipal solid waste landfill excavation, screening, water washing and granulation system and its operating method. The excavated, screened, water-washed and granulated municipal solid waste landfill is recycled as plastic granules, which, compared to the previous method of directly burning in an incinerator, not only reduces carbon emissions, but also generates economic value from the sale of plastic granules, which can be used to offset the cost of excavation and screening. The screening system includes a primary drum screen, a plastic separator, an oversize magnetic separator, an air separator, an undersize magnetic separator, a secondary drum screen, a ferrous metal buffer silo, a humus buffer silo, a humus conveyor, an aggregate buffer silo, and a lightweight material buffer silo; the water washing system includes a No. 1 cleaning tank, a No. 1 scooping machine, a crusher, a No. 2 cleaning tank, a No. 2 scooping machine, a strong washer, a No. 3 cleaning tank, a baler, a sedimentation and clear water tank, a sewage tank, a centrifugal dehydrator, and a sludge plate and frame filter press; and the hot melt granulation system includes a storage yard, a receiving machine, a stranding machine, a cooling water tank, a pelletizer, and a bagging machine.

Description

Technical Field

[0001] The invention relates to a domestic garbage landfill excavation, screening, washing and granulation system and a working method thereof. Background Art

[0002] Before the construction of waste incineration power plants, most cities used landfills to dispose of garbage, which also led to the long operation of landfills in most cities. Since the landfills were built at an early time, the technical level, construction level, and material quality were relatively backward. In recent years, hazardous incidents such as odor, groundwater pollution, and landslides caused by the aging of landfills have occurred frequently.

[0003] With the continuous improvement of the construction of waste incineration power plants, all domestic waste generated in cities can be consumed in waste incineration plants and no longer need to be sent to landfills. Therefore, more and more landfills will be idle.

[0004] To prevent problems before they occur, a large number of landfills are gradually being excavated, managed and ecologically restored.

[0005] Landfills with severe leakage require complete excavation. Most landfills, after excavation, use screening to separate the light material above the sieve, packaging it for incineration. However, this light material above the sieve contains a large amount of plastic. Direct incineration not only incurs incineration costs, increases the incinerator's flue gas treatment pressure, and increases carbon emissions.

[0006] According to statistics, there are approximately 1,960 domestic waste landfills in China, with a total waste stock of 8 billion tons and covering an area of ​​550 million square meters. The various materials in the landfills are complex. The following table shows the composition of several landfills in China:

[0007]

[0008] Of this, rubber and plastics account for approximately 15%-28%, with an average of about 20%. If these could be utilized, the total would be as much as 1.6 billion tons. Summary of the Invention

[0009] The purpose of the present invention is to overcome the above-mentioned shortcomings in the prior art and to provide a domestic waste landfill excavation, screening, washing and granulation system with a rational structural design and its working method, so that the domestic waste landfill excavation, screening, washing and granulation can be recycled as plastic particles, which are directly sent to the incineration plant for combustion in the past. This not only reduces carbon emissions, but also the economic value generated by the sale of plastic particles can be used to offset the cost of excavation and screening.

[0010] The technical solution adopted by the present invention to solve the above problems is: a domestic waste landfill excavation, screening, washing and granulation system, characterized by comprising an excavation system, a screening system, a washing system and a hot melt granulation system;

[0011] The screening system includes a material distribution conveyor, a first-stage drum screen, a plastic separator, an oversize conveyor, a plastic feed conveyor, an oversize magnetic separator, an air separator, an undersize conveyor, an undersize magnetic separator, a second-stage drum screen, a ferrous metal buffer silo, a ferromagnetic metal collection conveyor, a humus buffer silo, a humus conveyor, an aggregate collection conveyor, an aggregate buffer silo, a lightweight material collection conveyor, and a lightweight material buffer silo; the water washing system includes a No. 1 cleaning tank, a No. 1 scooping machine, a crusher, a No. 2 cleaning tank, a No. 2 scooping machine, a strong washer, a No. 3 cleaning tank, a baler, a sedimentation and clear water tank, a sewage tank, a centrifugal dewatering machine, and a sludge plate and frame filter press; the hot-melt granulation system includes a storage yard, a receiving machine, a screw feeder, a stranding machine, a cooling water tank, a pelletizer, and a bagger;

[0012] The excavation system cooperates with the material-leveling conveyor;

[0013] The uniform material conveyor is connected to the inlet of the first-stage drum screen; the oversize outlet of the first-stage drum screen is connected to the inlet of the plastic separator, and the light material outlet of the plastic separator is connected to the No. 1 cleaning tank through the plastic conveyor; the undersize outlet of the first-stage drum screen is connected to the inlet of the second-stage drum screen through the undersize belt; the undersize outlet of the second-stage drum screen is connected to the humus soil buffer silo through the humus conveyor; the oversize outlet of the second-stage drum screen is connected to the aggregate buffer silo through the aggregate collection conveyor; the heavy material outlet of the plastic separator is connected to the inlet of the air separator through the oversize conveyor; the heavy material outlet of the air separator is connected to the aggregate buffer silo through the aggregate collection conveyor; the light material outlet of the air separator is connected to the light material buffer silo through the light material collection conveyor; an oversize magnetic separator is provided on the oversize conveyor, and an undersize magnetic separator is provided on the undersize conveyor, and both the oversize magnetic separator and the undersize magnetic separator are connected to the ferrous metal buffer silo through the ferromagnetic metal collection conveyor;

[0014] The No. 1 cleaning tank is connected to the No. 1 scooping machine; the No. 1 scooping machine is connected to the inlet of the crusher, and the outlet of the crusher is connected to the No. 2 cleaning tank; the No. 2 cleaning tank is connected to the No. 2 scooping machine; the No. 2 scooping machine is connected to the inlet of the strong washer; the outlet of the strong washer is connected to the No. 3 cleaning tank; the No. 3 cleaning tank is connected to the baler; the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank are all provided with a cleaning water outlet and a water supply port; the cleaning water outlets of the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank are all connected to the inlet of the sewage tank; the outlet of the sewage tank is connected to the inlet of the centrifugal dehydrator; the water outlet of the centrifugal dehydrator is connected to the inlet of the sedimentation clear water tank; the outlet of the sedimentation clear water tank is connected to the water supply ports of the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank; the sludge outlet of the centrifugal dehydrator is connected to the inlet of the sludge plate and frame filter press;

[0015] The baler cooperates with the stockpile; the receiving machine cooperates with the stockpile; the outlet of the receiving machine is connected to the inlet of the plasticizing mechanism through the screw feeder; the outlet of the plasticizing mechanism is connected to the inlet of the strip drawing machine; the outlet of the strip drawing machine is connected to the inlet of the cooling water trough; the outlet of the cooling water trough is connected to the inlet of the pelletizer; the outlet of the pelletizer is connected to the inlet of the bagging machine.

[0016] The excavation system of the present invention includes a garbage excavator, a loader, a temporary drying and storage shed and a forklift; the garbage excavator cooperates with the loader, the loader cooperates with the temporary drying and storage shed, the forklift cooperates with the temporary drying and storage shed; the forklift cooperates with the material distribution conveyor.

[0017] The bottoms of the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank described in the present invention are all provided with slag discharge devices.

[0018] The water washing system of the present invention further comprises a dosing room, which is connected to the sedimentation and clear water tank.

[0019] The water outlet of the sludge plate-frame filter press of the present invention is connected to the inlet of the sedimentation and clear water tank.

[0020] The hot melt granulation system of the present invention further comprises a fume purification device, which is connected to the plasticizing mechanism.

[0021] The plasticizing mechanism of the present invention comprises a No. 1 plasticizing machine, a No. 2 plasticizing machine and a No. 3 plasticizing machine, and the No. 1 plasticizing machine, the No. 2 plasticizing machine and the No. 3 plasticizing machine are connected in sequence.

[0022] The screening system, water washing system and hot-melt granulation system of the present invention are all arranged in a workshop, and a deodorizing device is provided in the workshop.

[0023] A working method of a domestic waste landfill excavation, screening, washing and granulation system, characterized by comprising the following steps:

[0024] (1) Screening process: The waste excavated by the excavation system in the domestic waste landfill is fed to the material conveyor. The screening system finally screens out five categories: plastics, humus, aggregates, lightweight materials, and iron metals. The screening process specifically includes the following steps:

[0025] (1-1) Plastics: The material is fed into the primary drum screen by the material-distributing conveyor, and the material on the screen enters the plastic separator. The plastic separated by the plastic separator is sent to the washing system through the plastic conveyor;

[0026] (1-2) Humus soil: The undersize of the first drum screen enters the second drum screen through the undersize belt, and the undersize of the second drum screen enters the humus soil buffer silo through the humus soil conveyor;

[0027] (1-3) Aggregate: The oversize material from the secondary drum screen enters the aggregate buffer silo via the aggregate collection conveyor; the heavy material separated from the plastic separator enters the winnowing machine via the oversize material conveyor, and the heavy material after winnowing enters the aggregate buffer silo via the aggregate collection conveyor;

[0028] (1-4) Light materials: Light materials selected by the winnowing machine enter the light material buffer silo through the light material collection conveyor;

[0029] (-15) Ferrous metal: The metals separated by the oversize magnetic separator and the undersize magnetic separator are conveyed into the ferrous metal buffer silo via the ferromagnetic metal collection conveyor;

[0030] (2) Washing process: The plastics in the screening system are sent to the No. 1 washing tank through the plastic conveyor. The plastics in the No. 1 washing tank are fished out by the No. 1 scooping machine and sent to the crusher. After being crushed, they enter the No. 2 washing tank. The plastics in the No. 2 washing tank are fished out by the No. 2 scooping machine and sent to the strong washing machine. After the plastics are cleaned, they enter the No. 3 washing tank. After the final washing, the plastics enter the baler.

[0031] After cleaning the No. 1, No. 2, and No. 3 cleaning tanks, the water used in the No. 1, No. 2, and No. 3 cleaning tanks is pumped into the sewage tank, and then initially dehydrated by high-speed rotation in the centrifugal dehydrator. The resulting water enters the sedimentation and clear water tank for flocculation and sedimentation. The treated clear water is then pumped back into the No. 1, No. 2, and No. 3 cleaning tanks for water replenishment. The sludge generated after centrifugal dehydration is further dehydrated and dried by the sludge plate and frame filter press.

[0032] (5) Hot melt granulation process: The plastic is washed and packaged, then transported to the yard for temporary storage. After natural air drying, it is sent to the receiving machine. The receiving machine feeds the material to the plasticizing mechanism through a screw feeder, and finally enters the drawing machine. After the drawing strip is shaped, the material enters the cooling water tank for cooling. After cooling, it enters the bagging machine through the pelletizer and is then transported out.

[0033] After completing the preparatory work of pile shaping, odor control and pile dewatering of the domestic waste landfill, the excavation system starts excavation, and the waste is dried after excavation. After the moisture content of the waste meets the requirements of the screening equipment, the waste is fed to the screening system.

[0034] Compared with the prior art, the present invention has the following advantages and effects:

[0035] 1. The present invention rationally utilizes plastic materials in landfills and increases their economic value for reuse.

[0036] 2. The present invention reduces the transportation costs and processing costs of transporting plastics to incineration plants, as well as the secondary pollution generated after incineration.

[0037] 3. The present invention reduces carbon emissions from the incineration of plastics. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0040] The embodiment of the present invention includes an excavation system A, a screening system B, a water washing system C and a hot melt granulation system D.

[0041] The excavation system A includes a garbage excavator A1, a loader A2, a drying and temporary storage shed A3, and a forklift A4.

[0042] The screening system B includes a material distribution conveyor B1, a first-level drum screen B2, a plastic separator B3, an oversize conveyor B4, a plastic conveying conveyor B5, an oversize magnetic separator B6, an air separator B7, an undersize conveyor B8, an undersize magnetic separator B9, a second-level drum screen B10, a ferrous metal buffer silo B11, a ferromagnetic metal collection conveyor B12, a humus buffer silo B13, a humus conveyor B14, an aggregate collection conveyor B15, an aggregate buffer silo B16, a light material collection conveyor B17 and a light material buffer silo B18.

[0043] The water washing system C includes the No. 1 cleaning tank C1, the No. 1 scooping machine C2, the crusher C3, the No. 2 cleaning tank C4, the No. 2 scooping machine C5, the strong washing machine C6, the No. 3 cleaning tank C7, the baler C8, the dosing room C9, the sedimentation and clear water tank C10, the sewage tank C11, the centrifugal dehydrator C12 and the sludge plate and frame filter press C13.

[0044] The hot melt granulation system D includes a storage yard D1, a receiving machine D2, a screw feeder D3, a flue gas purification device D7, a strand drawing machine D8, a cooling water trough D9, a pelletizer D10 and a bagging machine D11.

[0045] The garbage excavator A1 cooperates with the loader A2, the loader A2 cooperates with the drying and temporary storage shed A3, and the forklift A4 cooperates with the drying and temporary storage shed A3.

[0046] Forklift A4 cooperates with material distribution conveyor B1, which is connected to the inlet of the first-stage drum screen B2; the oversize outlet of the first-stage drum screen B2 is connected to the inlet of the plastic separator B3, and the light material outlet of the plastic separator B3 is connected to the inlet of the No. 1 cleaning tank C1 through the plastic conveyor B5; the undersize outlet of the first-stage drum screen B2 is connected to the inlet of the second-stage drum screen B10 through the undersize belt B8; the undersize outlet of the second-stage drum screen B10 is connected to the humus buffer silo B13 through the humus conveyor B14; the oversize outlet of the second-stage drum screen B10 is connected to the aggregate buffer silo through the aggregate collection conveyor B15. The heavy material outlet of the plastic separator B3 is connected to the inlet of the air separator B7 through the oversize conveyor B4; the heavy material outlet of the air separator B7 is connected to the aggregate buffer silo B16 through the aggregate collection conveyor B15; the light material outlet of the air separator B7 is connected to the light material buffer silo B18 through the light material collection conveyor B17; an oversize magnetic separator B6 is provided above the oversize conveyor B4, and an undersize magnetic separator B9 is provided above the undersize conveyor B8, and both the oversize magnetic separator B6 and the undersize magnetic separator B9 are connected to the ferrous metal buffer silo B11 through the ferromagnetic metal collection conveyor B12.

[0047] The No. 1 cleaning tank C1 is connected to the No. 1 scooping machine C2; ​​the No. 1 scooping machine C2 is connected to the inlet of the crusher C3, and the outlet of the crusher C3 is connected to the No. 2 cleaning tank C4; the No. 2 cleaning tank C4 is connected to the No. 2 scooping machine C5; the No. 2 scooping machine C5 is connected to the inlet of the strong washing machine C6; the outlet of the strong washing machine C6 is connected to the No. 3 cleaning tank C7; the No. 3 cleaning tank C7 is connected to the baler C8.

[0048] The bottoms of the No. 1 cleaning pool C1, the No. 2 cleaning pool C4 and the No. 3 cleaning pool C7 are all equipped with slag discharge devices, and the slag is backfilled on site into the landfill after being discharged.

[0049] Cleaning tank No. 1 C1, cleaning tank No. 2 C4 and cleaning tank No. 3 C7 are all provided with cleaning water outlets and water replenishment ports; the cleaning water outlets of cleaning tank No. 1 C1, cleaning tank No. 2 C4 and cleaning tank No. 3 C7 are all connected to the inlet of sewage tank C11; the outlet of sewage tank C11 is connected to the inlet of centrifugal dehydrator C12; the water outlet of centrifugal dehydrator C12 is connected to the inlet of sedimentation water tank C10; the outlet of sedimentation water tank C10 is connected to the water replenishment ports of cleaning tank No. 1 C1, cleaning tank No. 2 C4 and cleaning tank No. 3 C7; the dosing room C9 is connected to the sedimentation water tank C10; the sludge outlet of centrifugal dehydrator C12 is connected to the inlet of sludge plate and frame filter press C13; the water outlet of sludge plate and frame filter press C13 is connected to the inlet of sedimentation water tank C10.

[0050] The baler C8 cooperates with the stockpile D1; the receiving machine D2 cooperates with the stockpile D1; the outlet of the receiving machine D2 is connected to the inlet of the plasticizing mechanism through the screw feeder D3; the outlet of the plasticizing mechanism is connected to the inlet of the drawing machine D8; the outlet of the drawing machine D8 is connected to the inlet of the cooling water trough D9; the outlet of the cooling water trough D9 is connected to the inlet of the pelletizer D10; the outlet of the pelletizer D10 is connected to the inlet of the bagging machine D11; the flue gas purification device D7 is connected to the plasticizing mechanism.

[0051] The plasticizing mechanism includes a No. 1 plasticizing machine D4, a No. 2 plasticizing machine D5 and a No. 3 plasticizing machine D6, and the No. 1 plasticizing machine D4, the No. 2 plasticizing machine D5 and the No. 3 plasticizing machine D6 are connected in sequence.

[0052] The sizes and positions of the excavation system A, screening system B, water washing system C and hot melt granulation system D can be adjusted according to actual conditions.

[0053] The screening system B, water washing system C and hot melt granulation system D are all arranged in the workshop, and a deodorization device E is installed in the workshop to treat the odor in the system and discharge it after meeting the standards.

[0054] The various conveyors of the present invention can be belt conveyors.

[0055] A working method of a domestic waste landfill excavation, screening, washing and granulation system comprises the following steps:

[0056] (1) Overall steps: excavation process → screening process → water washing process → hot melt granulation process.

[0057] (2) Excavation process: After completing the landfill's preparatory work such as pile shaping, odor control, and pile dewatering, the excavator A1 begins excavation. After excavation, the garbage is transported to the drying and temporary storage shed A3 by the loader A2. After the moisture content of the garbage meets the requirements of the screening equipment, the forklift A4 loads the garbage into the screening system.

[0058] (3) Screening process: The garbage from the landfill excavation system is fed to the material distribution conveyor B1 by the forklift A4. The material distribution conveyor B1 can evenly distribute the material to ensure the stable input of the system. The screening system finally screens out five categories: plastics, humus, aggregates, lightweight materials, and iron metals. The screening process specifically includes the following steps:

[0059] (3-1) Plastics: The material is fed by a uniform material conveyor B1 into a first-stage drum screen B2. The mesh size of the drum screen is generally 60mm-100mm. The oversize material larger than 60mm-100mm enters the plastic separator B3. Below the plastic separator B3 is a transfer conveyor. Above the conveyor, a flexible material stripper similar to a circular comb is installed parallel to the conveying direction. The oversize material is transported above the belt. The flexible material stripper removes light materials such as plastic, cloth strips, and bamboo pieces and sends them to the washing system via the plastic conveyor conveyor B5.

[0060] (3-2) Humus: The undersize material of the primary drum screen B2 generally contains humus and smaller aggregates. It can enter the secondary drum screen B10 via the undersize material belt B8. The mesh size of the drum screen is generally 20mm-40mm. After screening, the undersize material with a mesh size smaller than the mesh size is transported to the humus buffer silo B13 via the humus conveyor B14 for external transportation.

[0061] (3-3) Aggregate: Both the primary drum screen B2 and the secondary drum screen B10 produce aggregate. The undersize material from the primary drum screen B2 typically contains humus and smaller aggregates, which are fed via the undersize conveyor B8 to the secondary drum screen B10. The screen openings on this drum screen are typically 20mm-40mm. Oversize material larger than this size is fed via the aggregate collection conveyor B15 to the aggregate buffer silo B16 for shipment. Furthermore, heavy material from the plastic separator B3 and other smaller materials not separated by the light-weight screen are fed via the oversize conveyor B4 to the air separator B7. After the light-weight materials are blown out by the air separator B7, the remaining heavy material (typically stone aggregate) is fed via the aggregate collection conveyor B15 to the aggregate buffer silo B16 for shipment.

[0062] (3-4) Light materials: The material-distributing conveyor B1 feeds the first-stage drum screen B2, and the oversize material enters the plastic separator B3. The heavy materials and other smaller materials not separated by the light-weight screen in the plastic separator B3 pass through the oversize conveyor B4 to the air separator B7. The light materials are then blown out by the air separator B7 and passed through the light material collection conveyor B17 to the light material buffer silo B18 for shipment.

[0063] (3-5) Ferrous metal: An oversize magnetic separator B6 and an undersize magnetic separator B9 are installed above the oversize conveyor B4 and the undersize conveyor B8 respectively. The metal after magnetic separation enters the ferrous metal buffer silo B11 through the ferromagnetic metal collection conveyor B12 and is then shipped out of the factory.

[0064] (4) Washing process: Plastics, cloth strips, bamboo pieces and other lightweight materials in the screening system are sent to the No. 1 cleaning pool C1 through the plastic conveyor B5. Three stirring wheels are set above the cleaning pool to stir the water in the pool forward. A slag discharge mechanism is set at the bottom to collect and discharge the impurities after cleaning. The main function of the No. 1 cleaning pool C1 is to perform preliminary cleaning on lightweight materials such as plastics, cloth strips, bamboo pieces, etc. Among them, plastics and bamboo pieces will float. The plastics will be picked out by the No. 1 scooping machine C2 (a plurality of metal rods about 10 cm long are arranged at intervals of about 10 cm above the scooping machine to pick out the plastics, while bamboo pieces will fall into the gaps between the metal rods). The sand and other materials contained in other plastics will sink to the bottom of the pool and be discharged through the slag discharge mechanism in the cleaning pool. The plastic fished out by the No. 1 scoop machine C2 enters the crusher C3 for crushing, and then enters the No. 2 cleaning tank C4. The function of this cleaning tank is to further clean the small amount of sand and soil impurities contained in the crushed plastic. The plastic is then salvaged by the No. 2 scoop machine C5 and enters the strong washer C6. The internal high-pressure water flow basically cleans the plastic and then enters the No. 3 cleaning tank C7. After the final cleaning, the plastic enters the baler C8. The baler C8 is equipped with a compressor to compress out excess water before packaging and transporting it out. The compressed water is collected and recycled.

[0065] The water in the cleaning tanks is replaced daily. The water from cleaning tanks C1, C4, and C7 is pumped into sewage tank C11. It then undergoes high-speed dehydration in centrifugal dehydrators C12, where it undergoes initial dehydration. The resulting water enters the sedimentation tank C10, where it undergoes assisted flocculation and sedimentation in the dosing room C9. The treated water is then pumped back into the cleaning tanks for replenishment. The sludge produced after centrifugal dehydration is further dehydrated and dried in the sludge plate and frame filter press C13, with the sludge cake backfilled on-site. The entire system consumes approximately 300 tons of water for startup, all of which is recycled, with approximately 30 tons of fresh water replenished daily. The primary water losses are natural evaporation, moisture from plastic packaging, and moisture from bottom residue and sludge cake.

[0066] (5) Hot melt granulation process: After washing, the plastic is packaged and transported to the storage yard D1 for temporary storage, and the water contained is naturally air-dried. After air-drying, it is sent to the receiving machine D2 by the loader. The receiving machine D2 evenly feeds the material to the No. 1 plasticizer D4 through the screw feeder D3. After preliminary melting, it enters the No. 2 plasticizer D5. During this period, the waste residue is removed. The remaining material enters the No. 3 plasticizer D6 for further melting and finally enters the drawing machine D8. After the drawing and shaping, the material enters the cooling water tank D9 for cooling. After cooling, it enters the bagging machine D11 through the pelletizer D10 and is then transported out. The polyphenylene material can be sold as fuel. The gas generated by the plasticizer is treated by the flue gas purification device D7 and then discharged.

[0067] According to on-site trial operations, the landfill's volume ratio after excavation is approximately 1.5, with an estimated plastic ratio of 20%. After washing, the plastic has a bulk density of approximately 0.15 t / m³. Polystyrene and other materials are processed and discharged during the granulation process, resulting in an actual utilization rate of approximately 5 / 7. Ultimately, the landfill produces approximately 32.1 kg of pellets per cubic meter of storage capacity, with pellets sold for approximately 3,000 yuan per ton. Based on this calculation, excluding operating expenses such as equipment, electricity, and labor, with a landfill capacity of 130,000 cubic meters, revenue and expenditure are essentially balanced. The larger the storage capacity, the higher the benefits generated. When the landfill's waste capacity exceeds 300,000 cubic meters, the revenue generated can cover over 15% of the landfill's management costs. The larger the waste capacity, the higher the proportion of management costs covered.

[0068] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. Any equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Those skilled in the art of the technology to which the present invention belongs can make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A domestic waste landfill excavation, screening, washing and granulation system, characterized by: It includes excavation system, screening system, water washing system and hot melt granulation system; the screening system includes uniform material conveyor, first-level drum screen, plastic separator, oversize conveyor, plastic conveyor, oversize magnetic separator, air separator, undersize conveyor, undersize magnetic separator, second-level drum screen, ferrous metal buffer silo, ferromagnetic metal summary conveyor, humus buffer silo, humus conveyor, aggregate summary conveyor, aggregate buffer silo, light material summary conveyor and light material buffer silo; the water washing system includes No. 1 cleaning tank, No. 1 scooping machine, crusher, No. 2 cleaning tank, No. 2 scooping machine, strong washing machine, No. 3 cleaning tank, baler, sedimentation water tank, sewage tank, centrifugal dehydrator and sludge plate and frame filter press; the hot melt granulation system includes yard, receiving Feeder, screw feeder, drawing machine, cooling water trough, pelletizer and bagging machine; excavation system cooperates with uniform material conveyor; uniform material conveyor is connected to the inlet of the first drum screen; the oversize outlet of the first drum screen is connected to the inlet of the plastic separator, and the light material outlet of the plastic separator is connected to the No. 1 cleaning pool through the plastic conveyor; the undersize outlet of the first drum screen is connected to the inlet of the second drum screen through the undersize belt; the undersize outlet of the second drum screen is connected to the humus buffer silo through the humus conveyor; the oversize outlet of the second drum screen is connected to the aggregate buffer silo through the aggregate collection conveyor; the heavy material outlet of the plastic separator is connected to the inlet of the air separator through the oversize conveyor; the heavy material outlet of the air separator is connected to the aggregate collection conveyor through the aggregate collection conveyor The machine is connected to the aggregate buffer silo; the light material outlet of the air separator is connected to the light material buffer silo through the light material collection conveyor; an oversize magnetic separator is provided on the oversize conveyor, and an undersize magnetic separator is provided on the undersize conveyor. Both the oversize magnetic separator and the undersize magnetic separator are connected to the ferrous metal buffer silo through the ferromagnetic metal collection conveyor; the No. 1 cleaning tank is connected to the No. 1 scooping machine; the No. 1 scooping machine is connected to the inlet of the crusher, and the outlet of the crusher is connected to the No. 2 cleaning tank; the No. 2 cleaning tank is connected to the No. 2 scooping machine; the No. 2 scooping machine is connected to the inlet of the strong washing machine; the outlet of the strong washing machine is connected to the No. 3 cleaning tank; the No. 3 cleaning tank is connected to the baler; the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank are all provided with a cleaning water outlet and Water inlet; the cleaning water outlets of the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank are all connected to the inlet of the sewage tank; the outlet of the sewage tank is connected to the inlet of the centrifugal dehydrator; the water outlet of the centrifugal dehydrator is connected to the inlet of the sedimentation clear water tank; the outlet of the sedimentation clear water tank is connected to the water inlet of the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank; the sludge outlet of the centrifugal dehydrator is connected to the inlet of the sludge plate and frame filter press; the baler cooperates with the yard; the receiving machine cooperates with the yard; the outlet of the receiving machine is connected to the inlet of the plasticizing mechanism through the screw feeder; the outlet of the plasticizing mechanism is connected to the inlet of the drawing machine; the outlet of the drawing machine is connected to the inlet of the cooling water tank; the outlet of the cooling water tank is connected to the inlet of the pelletizer; the outlet of the pelletizer is connected to the inlet of the bagging machine.

2. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The excavation system includes a garbage excavator, a loader, a temporary drying and storage shed and a forklift; the garbage excavator cooperates with the loader, the loader cooperates with the temporary drying and storage shed, the forklift cooperates with the temporary drying and storage shed; the forklift cooperates with the material distribution conveyor.

3. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The bottoms of the No. 1 cleaning tank, the No. 2 cleaning tank and the No. 3 cleaning tank are all provided with slag discharge devices.

4. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The water washing system further comprises a dosing room, which is connected to the sedimentation and clear water tank.

5. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The water outlet of the sludge plate-frame filter press is connected to the inlet of the sedimentation and clear water tank.

6. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The hot melt granulation system further comprises a fume purification device, which is connected to the plasticizing mechanism.

7. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The plasticizing mechanism comprises a No. 1 plasticizing machine, a No. 2 plasticizing machine and a No. 3 plasticizing machine, and the No. 1 plasticizing machine, the No. 2 plasticizing machine and the No. 3 plasticizing machine are connected in sequence.

8. The domestic waste landfill excavation, screening, washing and granulation system according to claim 1, characterized in that: The screening system, water washing system and hot melt granulation system are all arranged in the workshop, and a deodorizing device is set in the workshop.

9. A method for operating the domestic waste landfill excavation, screening, washing and granulation system according to any one of claims 1 to 8, characterized in that: The steps include: (1) Screening process: The waste excavated by the excavation system in the domestic waste landfill is fed to the material conveyor. The screening system finally screens out five categories: plastics, humus, aggregates, lightweight materials, and iron metals. The screening process specifically includes the following steps: (1-1) Plastics: The material is fed into the primary drum screen by the material-distributing conveyor, and the material on the screen enters the plastic separator. The plastic separated by the plastic separator is sent to the washing system through the plastic conveyor; (1-2) Humus soil: The undersize of the first drum screen enters the second drum screen through the undersize belt, and the undersize of the second drum screen enters the humus soil buffer silo through the humus soil conveyor; (1-3) Aggregate: The oversize material from the secondary drum screen enters the aggregate buffer silo through the aggregate collection conveyor; The heavy materials separated from the plastic separator enter the winnowing machine through the overscreen conveyor, and the heavy materials after winnowing enter the aggregate buffer silo through the aggregate collection conveyor; (1-4) Light materials: Light materials selected by the winnowing machine enter the light material buffer silo through the light material collection conveyor; (1-5) Ferrous metal: The metals separated by the oversize magnetic separator and the undersize magnetic separator are conveyed into the ferrous metal buffer silo via the ferromagnetic metal collection conveyor; (2) Washing process: The plastic in the screening system is sent to the No. 1 washing tank through the plastic conveyor. The plastic in the No. 1 washing tank is fished out by the No. 1 scooping machine and sent to the crusher. After crushing, it enters the No. 2 washing tank. The plastic in the No. 2 washing tank is salvaged by the No. 2 scooping machine and then enters the strong washing machine. After the plastic is cleaned, it enters the No. 3 washing tank. After the final washing, the plastic enters the baler. After cleaning the No. 1, No. 2, and No. 3 cleaning tanks, the water used in the No. 1, No. 2, and No. 3 cleaning tanks is pumped into the sewage tank, and then initially dehydrated by high-speed rotation in the centrifugal dehydrator. The resulting water enters the sedimentation and clear water tank for flocculation and sedimentation. The treated clear water is then pumped back into the No. 1, No. 2, and No. 3 cleaning tanks for water replenishment. The sludge generated after centrifugal dehydration is further dehydrated and dried by the sludge plate and frame filter press. (3) Hot melt granulation process: The plastic is washed and packaged, then transported to the yard for temporary storage. After natural air drying, it is sent to the receiving machine. The receiving machine feeds the material to the plasticizing mechanism through a screw feeder, and finally enters the drawing machine. After the drawing and shaping, the material enters the cooling water tank for cooling. After cooling, it enters the bagging machine through the pelletizer and is then transported out.

10. The operating method of the domestic waste landfill excavation, screening, washing and granulation system according to claim 9, characterized in that: After completing the preparatory work of pile shaping, odor control, and pile dewatering in the domestic waste landfill, the excavation system will start excavation work. After excavation, the garbage will be dried. After the moisture content of the garbage meets the requirements of the screening equipment, it will be loaded into the screening system.

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