Household garbage pretreatment process

Abstract

The invention relates to the technical field of solid waste treatment, in particular to a household garbage pretreatment process. The technology comprises the steps that S1, household garbage is sorted, flexible materials are separated from other materials, and the flexible materials and other recoverable materials are obtained; s2, the sorted flexible materials are compressed into blocks with certain shapes and sizes; s3, the compressed flexible material is cut into fragments of a certain size; and S4, the slit flexible material is subjected to drying treatment, so that the moisture in the flexible material is reduced to a certain degree. According to the process, the flexible materials in the household garbage are sorted out through the sorting equipment, the problem that the equipment is damaged due to the fact that part of cotton, hemp and other easily-entangled objects are entangled on the subsequent treatment equipment is solved, meanwhile, primary separation of the high-calorific-value materials in the household garbage is achieved, the labor intensity is reduced, and the treatment efficiency is improved; and the pyrolysis or combustion efficiency of the rear-end material is improved.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste treatment, and in particular to a process for pre-treating domestic waste. Background Art

[0002] The current treatment methods for flexible materials of domestic waste include landfill, incineration or pyrolysis. Converting flexible materials of domestic waste into high calorific value biochar is a resource treatment method. In the process of resource treatment, the classification and separation of flexible materials of domestic waste can not only improve the resource efficiency of flexible materials of domestic waste, but also reduce the pollution to the environment and achieve the reduction of volume and amount of flexible materials of domestic waste. The output of flexible materials of domestic waste increases year by year, among which flexible materials such as paper, plastic, rubber, cotton and linen cloth account for a large proportion. Effective pretreatment of flexible materials in flexible materials of domestic waste can reduce their impact on the environment and equipment.

[0003] In the prior art, the pretreatment of flexible materials in domestic waste mainly adopts manual sorting, crushing and other methods. In the process of waste sorting, the sorting workload is large and the process is simple and repetitive. Manual sorting not only faces problems such as pungent odor and poor working environment, but also has the possibility of harmful substances harming human health. It is not difficult to imagine that this method takes a long time to process, has high processing costs, low efficiency, high labor intensity, serious environmental pollution, and high subsequent drying energy consumption.

[0004] Therefore, a new type of domestic waste pretreatment process is urgently needed to improve separation efficiency, reduce environmental pollution, and reduce drying energy consumption. Summary of the invention

[0005] The purpose of the present invention is to provide a domestic waste pretreatment process to solve the technical problems existing in the prior art of using manual sorting, crushing and other methods to treat flexible materials in domestic waste, which results in long time consumption, high treatment cost, low efficiency, high labor intensity, serious environmental pollution and high subsequent drying energy consumption.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A domestic waste pretreatment process, comprising:

[0008] S1: sorting domestic waste through sorting equipment, separating flexible materials from other materials, and obtaining flexible materials and other recyclable materials;

[0009] S2: compressing the sorted flexible materials into blocks of certain shape and size;

[0010] S3: cutting the compressed flexible material into pieces of a certain size;

[0011] S4: Drying the cut flexible material to reduce the moisture in the flexible material to a certain level.

[0012] Furthermore, the step of sorting the domestic waste by a sorting device comprises:

[0013] Identify flexible materials from household waste by visual identification and / or air flow separation;

[0014] Magnetic metals, non-magnetic metals, glass, bulk organic matter and sand and gravel are identified from domestic waste through a comprehensive identification method of magnetic separation, vortex separation, color separation and X-ray separation.

[0015] Furthermore, the visual recognition method includes: using CCD vision technology, laser vision technology and near-infrared vision technology to couple and comprehensively judge the external characteristics and internal characteristics of the target material.

[0016] Furthermore, the air flow separation method includes: raw materials containing small-particle flexible materials enter the air flow separator through the feed port, and the materials are separated by the air flow generated by the high-pressure fan. The small-particle flexible materials are lifted by the air flow and discharged through the discharge port, and the remaining materials of different volumes are graded and separated.

[0017] Furthermore, the step of: sorting domestic waste by means of a sorting device, further comprises: using a sorting robot with a suction cup to suck up the material and throw it into a corresponding recycling bin.

[0018] Furthermore, in step S4, the flexible material is dried by low-temperature drying.

[0019] Furthermore, the low-temperature drying method includes using a heat pump to dry the material, and / or using a solar dryer to air-dry the material.

[0020] Furthermore, in step S4, the flexible material is dried by a multi-stage drying method.

[0021] Furthermore, the sorting equipment in step S1 includes a belt conveyor, an identification system and a sorting robot;

[0022] The belt conveyor transports the domestic waste to the working positions of the identification system and the sorting robot; the identification system is used to identify the types of domestic waste; based on the identification results of the identification system, the sorting robot absorbs the materials and throws them into the corresponding recycling bin to separate the flexible materials from other materials.

[0023] Furthermore, it also includes:

[0024] S5: Pyrolyze and upgrade the cut flexible material to obtain powdered solid fuel.

[0025] Beneficial effects of the present invention:

[0026] The domestic waste pretreatment process provided by the present invention comprises: S1: sorting the domestic waste by sorting equipment, separating the flexible material from other materials, and obtaining the flexible material and other recyclable materials; S2: compressing the sorted flexible material into blocks of a certain shape and size; S3: cutting the compressed flexible material into fragments of a certain size; S4: drying the cut flexible material to reduce the moisture in the flexible material to a certain extent.

[0027] Compared with the prior art method of using manual sorting and crushing to process flexible materials in domestic waste, the domestic waste pretreatment process provided in the present application uses sorting equipment to sort out flexible materials in domestic waste, thereby avoiding the problem of some easily entangled materials such as cotton and linen entangled in subsequent processing equipment and causing equipment damage. At the same time, it realizes the preliminary separation of high calorific value materials in domestic waste (such as paper, plastic products, and cotton and linen fabrics), reduces labor intensity, improves processing efficiency, and improves the pyrolysis or combustion efficiency of back-end materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a flow chart of a domestic waste pretreatment process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the prior art, the pretreatment of flexible materials in domestic waste mainly adopts methods such as manual sorting and crushing. This method takes a long time to process, has high processing costs, low efficiency, high labor intensity, serious environmental pollution, and high energy consumption for subsequent drying.

[0032] Based on this, the embodiment of the present invention provides a domestic waste pretreatment process, referring to Figure 1 , the process includes:

[0033] S1: sorting domestic waste through sorting equipment, separating flexible materials from other materials, and obtaining flexible materials and other recyclable materials;

[0034] S2: compressing the sorted flexible materials into blocks of certain shape and size;

[0035] S3: cutting the compressed flexible material into pieces of a certain size;

[0036] S4: Drying the cut flexible material to reduce the moisture in the flexible material to a certain level.

[0037] As described above, the domestic waste pretreatment process provided in the present application mainly includes a sorting step, a compression step, a cutting step and a drying step. Specifically: first, flexible materials such as paper, plastic film, cotton and linen cloth are sorted out from domestic waste by a sorting device; then the sorted flexible materials are sent to a compression device for compression, and the flexible materials are compressed into blocks; then the block-shaped flexible materials are sent to a cutting device for cutting, and the block-shaped flexible materials are cut into sheets; then the sheet-shaped flexible materials are sent to a drying device for drying, so that the flexible materials form dry materials that can be directly recycled.

[0038] Compared with the prior art method of using manual sorting and crushing to process flexible materials in domestic waste, the domestic waste pretreatment process provided in the present application uses sorting equipment to sort out flexible materials in domestic waste, thereby avoiding the problem of some easily entangled materials such as cotton and linen entangled in subsequent processing equipment and causing equipment damage. At the same time, it realizes the preliminary separation of high calorific value materials in domestic waste (such as paper, plastic products, and cotton and linen fabrics), reduces labor intensity, improves processing efficiency, and improves the pyrolysis or combustion efficiency of back-end materials.

[0039] In step S1, the step of sorting domestic waste by sorting equipment includes:

[0040] Identify flexible materials from household waste by visual identification and / or air flow separation;

[0041] Magnetic metals, non-magnetic metals, glass, bulk organic matter and sand and gravel are identified from domestic waste through a comprehensive identification method of magnetic separation, vortex separation, color separation and X-ray separation.

[0042] During the sorting process, the present application obtains magnetic metals, non-magnetic metals, glass, bulk organic matter and sand and gravel respectively through magnetic separation, vortex separation, color separation and X-ray separation, and identifies flexible materials through visual recognition. Furthermore, during the sorting process, auxiliary separation can be performed based on the physical properties (such as density, shape, particle size) of flexible materials (such as plastics, fabrics, etc.) in domestic waste, and combined with airflow separation, a non-contact separation technology, the flexible materials in domestic waste can be separated out. The use of advanced non-contact separation methods can improve separation efficiency and accuracy and reduce equipment loss.

[0043] Furthermore, the visual recognition method includes: using CCD vision technology, laser vision technology and near-infrared vision technology to couple and comprehensively judge the external characteristics and internal characteristics of the target material.

[0044] Among them, CCD vision technology is specifically: using CCD visual positioning system to identify and locate materials, taking pictures of the characteristic positions of target materials through CCD cameras, industrial lenses and light sources, and then collecting image data through image processing, and performing position calculation to determine the actual position of the target material. During identification, first take pictures, that is, use a special CCD camera, industrial lens and light source to take pictures of the characteristic positions on the target material; then perform image processing, that is, collect image data through image processing; then perform position calculation, that is, determine the actual position of the target material through position calculation, and finally set the benchmark, and determine the precise position of the target material by comparing it with the previously set benchmark.

[0045] Laser vision technology is mainly based on the principle of triangulation, that is, when the laser beam is irradiated on the target material, part of the light is reflected, and the reflected laser beam enters the image sensor through the scanning mirror and the optical system. Due to the certain angle between the laser beam emitter and the scanning mirror, the reflected light will produce a small offset. By measuring this offset, the control system can calculate the distance between the laser beam and the target material. By measuring multiple points at different angles, the control system can calculate the three-dimensional coordinates of the target material.

[0046] Infrared vision technology uses a near-infrared light source to emit light and is equipped with a near-infrared sensitive camera to capture reflected or scattered light. It uses image processing algorithms to analyze the images captured by the camera and extract characteristic information of the target material.

[0047] In summary, by coupling CCD vision technology, laser vision technology and near-infrared vision technology, it is possible to comprehensively judge the external characteristics (color, shape, texture, position, etc.) and internal characteristics (material) of the target material, so as to achieve accurate positioning and subdivision of garbage.

[0048] Furthermore, the airflow separation method includes: the raw materials containing small-particle flexible materials enter the airflow separator through the feed port, and the materials are separated by the airflow generated by the high-pressure fan, the small-particle flexible materials are lifted by the airflow and discharged through the discharge port, and the remaining materials of different volumes are graded and separated. Specifically, the airflow separation method is achieved by an airflow separator. An airflow separator is a device that uses the principle of airflow mechanics to sort materials. Its main principle is to use airflow to form a thin layer of airflow with uniform thickness on the screen to grade particulate materials of different volumes; the grading screen allows fine particles except flexible materials to pass through the screen, while coarse particles are intercepted on the screen, thereby achieving material grading and separation.

[0049] When the airflow separator used in the present application is working, the material enters the airflow separator through the feeding device. Due to the airflow generated by the airflow mechanism, the flexible granular material will form a suspended state therein and then be discharged from the discharge port. The remaining material is classified through the screen according to the particle size of the particles.

[0050] The above-mentioned airflow separator can classify and separate powdered materials in domestic waste. The airflow separator can classify the materials into particles of different sizes according to the particle size and density of the materials by adjusting the airflow velocity and the size of the sieve hole. This is very important for materials that need to be classified according to particle size. In addition, the airflow separator can remove dust from the materials. During the material sorting process, the airflow separator separates the finer particles from the materials through the action of the airflow. These fine particles are usually impurities, dust, pollutants, etc. in the materials. By using the airflow separator for dust removal, the materials can be purified and the quality of the rear-end carbon powder can be improved. In addition, the materials can be dried and heated. The airflow separator can dry the materials with high humidity by controlling the feed air volume and the heating air temperature. The materials can be heated by adjusting the heating air temperature to change the properties and form of the materials, reduce moisture, reduce energy consumption for rear-end drying, and meet specific process requirements. At the same time, light and heavy particles are also separated. When separating materials, the airflow separator can separate particles with lower density from particles with higher density through the action of airflow according to the density difference of the materials. It can separate light and flexible materials from heavy materials to improve material separation efficiency.

[0051] Furthermore, in step S1, the step of: sorting domestic waste by means of a sorting device, further comprises: using a sorting robot with a suction cup to suck up the material and throw it into a corresponding recycling bin.

[0052] The sorting robot used in this application is a sorting robot with visual recognition function. Through the built-in algorithm of the sorting robot, the sorting robot uses sensor vision to scan fast-moving materials to identify the category of the materials, and then uses a suction cup to suck the materials from the conveyor belt and throw them into the corresponding flexible material recovery box. Combined with the existing methods at the front end, sample recognition of various categories, shapes, and surface materials can be achieved, greatly reducing time and cost. Through the trajectory optimization algorithm, the robot arm takes the optimal path and significantly improves the sorting rate. At the same time, in conjunction with the development of the robot trajectory tracking algorithm and the grab and release algorithm, automatic sorting of garbage can be achieved, completely replacing manual labor and improving processing efficiency.

[0053] As described above, a sorting robot with visual recognition function can automatically separate flexible materials and other materials in domestic waste. The sorting robot can automatically detect and classify waste through mechanical structure, sensor and visual recognition system, and combine with belt conveyor to realize efficient and automatic separation of materials.

[0054] In a specific embodiment, the sorting equipment in step S1 includes a belt conveyor, an identification system and a sorting robot;

[0055] The belt conveyor transports the domestic waste to the working positions of the identification system and the sorting robot; the identification system is used to identify the types of materials in the domestic waste; based on the identification results of the identification system, the sorting robot absorbs the materials and throws them into the corresponding recycling bin to separate the flexible materials from other materials.

[0056] Furthermore, the above-mentioned identification system includes a magnetic separator, a vortex separator, a color separator and an X-ray separator, and is used to identify magnetic metals, non-magnetic metals, glass, bulk organic matter and sand and gravel respectively, and the identified materials are transferred to the corresponding recycling bin by the sorting robot. The sorting robot has a visual recognition function (in other embodiments, a visual recognition device can also be set separately on the conveyor line), and the flexible materials are automatically identified and sorted by the visual recognition function. The sorting equipment also includes an airflow separator to classify and separate powdered materials in domestic waste.

[0057] In a specific embodiment, the airflow separator, the identification system and the sorting robot are arranged in sequence along the conveying direction of the belt conveyor. During the sorting process, the airflow separator first takes away the fine particles and dust to facilitate the smooth progress of the subsequent identification process; the coarse particles intercepted on the screen are discharged to the conveyor belt through the discharging device and transported to the next process by the conveyor belt.

[0058] Furthermore, in step S4, the flexible material is dried by low temperature drying, which includes drying the material by using a heat pump and / or air drying the material by using a solar dryer.

[0059] Among them, the method of using a heat pump to dry the material requires the use of a heat pump drying unit. Among them, the heat pump drying unit is mainly composed of a finned evaporator (outdoor unit), a compressor, a finned condenser (indoor unit) and an expansion valve. The finned condenser is located in the drying room, and the finned evaporator is located outdoors. When working, the refrigerant circulates in the system under the action of the compressor, and the heat in the external low-temperature environment is transferred to the drying room by allowing the refrigerant to continuously complete the thermal cycle process of evaporation (absorbing heat from the outdoor environment) → compression → condensation (releasing heat in the indoor drying room) → throttling → re-evaporation. The refrigerant completes the gaseous pressure-raising and temperature-raising process in the compressor, enters the indoor unit to release high-temperature heat to heat the air in the drying room, and is cooled and converted into liquid at the same time. When it runs to the outdoor unit, it is throttled and depressurized, and the liquid quickly absorbs heat and evaporates and is converted into gas again. At the same time, the temperature can drop to 15℃~-15℃. At this time, the air around the heat absorber will continuously transfer heat to the refrigerant.

[0060] The heating efficiency of the heat pump drying unit is much greater than that of other heating equipment. Using a heat pump drying unit as a drying equipment can save energy, while also reducing the emission of pollutants such as CO2, achieving the effect of energy conservation and emission reduction.

[0061] In addition to using heat pump drying, you can also use a solar dryer to air dry the material. You can choose a natural convection solar dryer or a forced convection dryer. Among them, there is no additional fan in the natural convection solar dryer, and the airflow flows in the drying room due to the temperature difference; according to different structures, you can choose box type, shed type, greenhouse type, rack type and chimney type. When the material layer is thick, the particles are fine, the porosity is small, the airflow resistance is large, and natural convection alone cannot meet the requirements for airflow speed, you can choose a forced convection solar dryer.

[0062] The heat pump drying and solar energy assisted drying methods in this application belong to low-temperature drying methods, that is, the method of evaporating the water in the flexible material by means of an external heat source lower than the ignition point of the flexible material. The temperature of low-temperature drying is usually 60-80°C, which is lower than the ignition point of the flexible material (for example, the volatilization temperature of chain alkanes and aromatic hydrocarbons is 100-300°C; the volatilization temperature of cycloalkanes is mainly 250-300°C; the volatilization temperature of nitrogen-containing compounds, amines, and oximes is mainly 200-300°C; the volatilization temperature of alcohols, ethers, fatty ketones, amides, nitriles, etc. is all above 300°C. In addition, the volatilization temperature of aldehydes and anilines is mainly 150°C, and the volatilization temperature of lipids is 150-250°C). The use of low-temperature drying can fully avoid the volatilization of different types of organic matter in the flexible material and avoid the volatilization of odorous gases. It has the distinctive characteristics of economy, reliability, and environmental protection, and greatly reduces the operating cost of domestic waste treatment.

[0063] Furthermore, in order to save energy, in step S4, the flexible material is dried by a multi-stage drying method. In order to remove the last moisture in the material, the processing temperature is required to be extremely high, resulting in high energy consumption, reduced production capacity and affected product quality. The multi-stage drying method used is used to dry the material multiple times so that the material finally reaches an ideal state.

[0064] On the basis of the above steps, the domestic waste pretreatment process further comprises:

[0065] S5: Pyrolysis and upgrading of the cut flexible materials to obtain powdered solid fuel. Other recyclable materials (such as glass, metal, etc.) are recycled, achieving the reduction, resource utilization and harmless treatment of organic waste including domestic waste.

[0066] In summary, the domestic waste pretreatment process provided by the present application separates the flexible materials in domestic waste and separates other recyclables at the same time, thereby achieving full utilization of the materials, by coupling a mechanical structure, a visual recognition sensor system, and a non-contact separation method based on the properties of the materials. The separated flexible materials are subjected to pretreatment processes such as sorting, compression, cutting, and drying. During drying, a low-temperature drying method such as heat pump drying and solar-assisted drying is adopted, combined with a multi-stage drying method, to achieve the purpose of reducing energy consumption and saving energy. At the same time, it has the advantages of high efficiency, environmental protection, and reduced labor intensity. Finally, the flexible material is pyrolyzed to obtain biochar powder, optimize the fuel properties of the material, and provide multiple directions for the resource utilization of domestic waste.

[0067] Compared with the prior art, the technical advantages of this application are reflected in the following aspects:

[0068] 1. The belt conveyor and the sorting robot with visual recognition sensor system are combined to achieve efficient and automatic separation of flexible materials in domestic waste;

[0069] 2. Based on the physical characteristics of flexible materials in domestic waste, the flexible materials are sorted by combining visual recognition and non-contact separation such as airflow separation to improve separation efficiency and accuracy and reduce equipment loss;

[0070] 3. Pre-treating the flexible materials in domestic waste by steps such as sorting, compression, cutting and drying can effectively improve the processing efficiency and reduce environmental pollution;

[0071] 4. Optimize energy efficiency through energy-saving and low-temperature drying methods (such as heat pump drying and solar-assisted drying); achieve low-energy drying of domestic waste through a combination of low-temperature drying and multi-stage drying, save energy, and help reduce sewage and waste gas generated during waste treatment.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for pretreatment of domestic waste, characterized in that: include: S1: sorting domestic waste through sorting equipment, separating flexible materials from other materials, and obtaining flexible materials and other recyclable materials; S2: compressing the sorted flexible materials into blocks of certain shape and size; S3: cutting the compressed flexible material into pieces of a certain size; S4: Drying the cut flexible material to reduce the moisture in the flexible material to a certain level.

2. The process for pretreatment of domestic waste according to claim 1, characterized in that: The step of sorting domestic waste by sorting equipment includes: Identify flexible materials from household waste by visual identification and / or air flow separation; Magnetic metals, non-magnetic metals, glass, bulk organic matter and sand and gravel are identified from domestic waste through a comprehensive identification method of magnetic separation, vortex separation, color separation and X-ray separation.

3. The process for pretreatment of domestic waste according to claim 2, characterized in that: The visual recognition method includes: using CCD vision technology, laser vision technology and near-infrared vision technology to couple and comprehensively judge the external characteristics and internal characteristics of the target material.

4. The process for pretreatment of domestic waste according to claim 2, characterized in that: The air flow separation method includes: raw materials containing small-particle flexible materials enter the air flow separator through the feed port, and the materials are separated by the air flow generated by the high-pressure fan. The small-particle flexible materials are lifted by the air flow and discharged through the discharge port, and the remaining materials of different volumes are graded and separated.

5. The process for pretreatment of domestic waste according to claim 1, characterized in that: The step of sorting domestic waste by sorting equipment also includes: using a sorting robot with a suction cup to suck up the material and throw it into a corresponding recycling bin.

6. The process for pretreatment of domestic waste according to claim 1, characterized in that: In the step S4, the flexible material is dried by low temperature drying.

7. The process for pretreatment of domestic waste according to claim 6, characterized in that: The low-temperature drying method includes using a heat pump to dry the material, and / or using a solar dryer to air-dry the material.

8. The process for pretreatment of domestic waste according to claim 1, characterized in that: In the step S4, the flexible material is dried in a multi-stage drying manner.

9. The process for pretreatment of domestic waste according to any one of claims 1 to 8, characterized in that: The sorting equipment in step S1 includes a belt conveyor, an identification system and a sorting robot; The belt conveyor conveys the domestic waste to the working position of the identification system and the sorting robot; the identification system is used to identify the type of materials in the domestic waste; According to the recognition result of the recognition system, the sorting robot sucks the material and throws it into the corresponding recycling box to separate the flexible material from other materials.

10. The process for pretreatment of domestic waste according to any one of claims 1 to 8, characterized in that: Also includes: S5: Pyrolyze and upgrade the cut flexible material to obtain powdered solid fuel.

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