A construction waste sorting method

Abstract

The application discloses a construction waste sorting method, comprising the following steps: step 1, uniformly conveying the construction and decoration waste to a primary sorting section; step 2, in the primary sorting section, the material enters a disc wind sorting screen, the undersize material enters a subsequent roller screening system, and the oversize material enters a comprehensive wind sorting area; in the comprehensive wind sorting area, light combustible material is obtained at a light material outlet, and large heavy material is obtained at a heavy material outlet; step 3, the undersize material enters the roller screening system, fine residual soil with a particle size less than a roller screen hole is collected, and large-particle undersize material is sent to a secondary wind sorting system; step 4, in the secondary wind sorting system, light combustible material is obtained at a light material collection end, and heavy small-particle aggregate is obtained at a heavy material collection end; and the large block material in step 2 is subjected to magnetic separation. The construction waste sorting method can reliably separate the construction waste, and the magnetic separator can further recycle metal materials in the construction waste.

Description

Technical Field

[0001] This invention relates to the field of construction waste sorting, and more specifically, to a method for sorting construction waste. Background Technology

[0002] Construction and renovation waste differs from simple engineering spoil or construction waste. Its sources are complex, primarily originating from the renovation and remodeling of residential and commercial properties. Its composition is extremely diverse, typically including: discarded concrete blocks, red bricks, ceramics, plasterboard, mortar, and other inorganic hard materials; discarded wood panels, plastic pipes, packaging foam, wallpaper, textiles, rubber, and other organic lightweight materials; and scrap metal materials such as wire, nails, aluminum alloy frames, and metal fittings. In addition, it also contains a large amount of fine particles such as slag and dust. This mixture of materials of various materials, shapes, densities, and particle sizes presents significant challenges to subsequent resource utilization.

[0003] With the advancement of "zero-waste city" construction and circular economy policies, the use of mechanized sorting methods for the resource recycling of construction and renovation waste has become a development trend. However, existing construction and renovation waste sorting technologies are unable to perform detailed classification and screening of construction waste.

[0004] Construction and renovation waste contains a considerable amount of scrap metal, which has high economic value for recycling. However, in conventional sorting processes, material separation often relies solely on screening or air separation without specifically screening for metals. This results in small iron parts, screws, and other small items being mixed into the aggregate or slag and lost, wasting resources, reducing the purity of aggregate products, and potentially damaging subsequent crushing and screening equipment.

[0005] Lightweight materials in construction and renovation waste, such as plastics, paper, wood blocks, and textiles, have significant density differences and are often mixed with heavy materials. Existing technologies mostly use single-stage air separation or simple gravity separation, which is insufficient to fully separate materials with vastly different weights. This results in a significant amount of heavy small particles, such as small stones and broken glass, being mixed into the lightweight materials, leading to a decrease in the calorific value of lightweight materials as alternative fuels. At the same time, some lightweight impurities may remain in the heavy aggregates, affecting their quality as building material raw materials. Summary of the Invention

[0006] The purpose of this invention is to provide a method for sorting construction waste. This method can reliably separate construction waste containing different components, and the use of a magnetic separator can also recover metal materials from the construction waste, thereby improving the economic benefits of construction waste recycling.

[0007] To achieve the above objectives, the present invention provides a method for sorting construction waste, comprising the following steps: Step 1: Evenly transport the construction and renovation waste to the primary sorting section; Step 2: In the primary sorting section, the material enters the disc air classifier and is classified according to particle size by the disc screen to obtain undersize material with a particle size smaller than the disc gap and oversize material with a particle size larger than the disc gap. The undersize material enters the subsequent drum screening system, and the oversize material enters the comprehensive air classification area. Within the integrated air separation zone, the oversize material, under the controllable airflow, becomes light combustible material at the light material outlet and large pieces of heavy material at the heavy material outlet. Step 3: The undersize material enters the drum screening system for screening, and fine slag with a particle size smaller than the drum screen openings is collected; Large particles with a diameter greater than that of the drum screen are fed into the secondary air separation system. Step 4: Under the action of the inclined airflow from bottom to top in the secondary air separation system, light combustibles in the large particle undersize are obtained at the light material collection end, and heavy small particle aggregates in the large particle undersize are obtained at the heavy material collection end. In step 2, after step 2, the large pieces of material falling from the heavy material outlet in step 2 are subjected to magnetic separation to separate and recycle the large metal objects.

[0008] Preferably, in step 2, a magnetic separator for recovering metals is installed above the material conveyor.

[0009] Preferably, in steps 2 and 4, the wind field parameters of the integrated wind separation zone and the secondary wind separation system are set to be adjustable. After the fan is turned on, the wind separation parameters are adjusted by the wind separation parameter adjustment method.

[0010] Preferably, the fan parameters of the secondary air separation system in step 4 are set as follows: fan frequency is set to 25-45Hz, air volume is set to 28000-35000m³ / h, and air speed is about 15-20m / s.

[0011] Preferably, the fan parameters for the integrated air selection zone in step 2 are set as follows: fan frequency is set to 15-50Hz, air volume is set to 20000-48000m³ / h, and wind speed is approximately 12-22m / s.

[0012] Preferably, the method for adjusting the air separation parameters of the integrated air separation zone and the secondary air separation system is set to be the same.

[0013] Preferably, the method for adjusting the wind separation parameters includes: S1. Start the secondary air separation system fan according to the set start-up parameters; S2. Check whether the material blown out at the light material outlet 21 or the light material collection end 41 contains non-combustible substances, and check whether the material collected at the heavy material outlet 22 or the heavy material collection end 42 contains light combustible substances. S3. If the material collected at the lightweight material outlet 21 or the lightweight material collection end 41 contains non-combustible materials, then perform at least one of the following actions: reduce the fan frequency by 3Hz, reduce the opening of the inlet and outlet valves by 5%, or adjust the outlet angle downward by 3°. S4. Repeat step S3 until qualified light combustible material is collected at the light material outlet 21 or the light material collection end 41. S5. If the material collected at the heavy material outlet 22 or the heavy material collection end 42 contains light combustibles, then perform at least one of the following actions: increase the fan frequency by 3Hz, increase the opening of the inlet and outlet valves by 5%, or adjust the outlet angle upward by 3°. S6. Repeat step S5 until qualified heavy small-particle aggregate is collected at the heavy material outlet 22 or the heavy material collection end 42.

[0014] Preferably, the power-on parameters include baseline power-on parameters and parameters from the previous operation; The baseline start-up parameters are set as follows: fan frequency 30Hz, inlet and outlet damper 70% opening, outlet angle 40° upwards. The parameters for the last operation were set to the air selection parameters before the last shutdown.

[0015] Preferably, the disc air classifier is equipped with a stepped structure with a height difference to drive the material to tumble and achieve reliable dispersion of the material.

[0016] Preferably, the disc separation gap of the disc air classifier is adjustable within the range of 15-60mm.

[0017] According to the above technical solution, this invention first uses a disc air classifier to preliminarily screen construction waste according to particle size. The larger particles on the screen then enter a comprehensive air classification zone for further air classification, resulting in both larger-sized lightweight fuels and larger-sized heavy materials. In the comprehensive air classification zone, due to the significant difference in weight and density between large lightweight materials (such as plastic buckets, packaging bags, and foam blocks) and large heavy materials (such as concrete blocks and bricks), their trajectories differ considerably under controlled airflow. Lightweight materials are easily blown away, while heavy materials fall vertically. Therefore, in the comprehensive air classification zone, due to the large weight difference between light and heavy materials, the pass rate of air classification is very high, easily separating lightweight combustible materials and achieving efficient and low-energy-consumption primary sorting.

[0018] Furthermore, the smaller-diameter undersize material is sent to a drum screen system for a second screening. Fine soil particles smaller than the drum screen's apertures, approximately 10mm in diameter, are separated first. Because fine soil particles are small, have a high specific gravity, and high moisture content, if they enter the secondary air separation system, the upward airflow will easily blow them up, mixing them with lightweight combustibles. This would increase the ash content and decrease the calorific value of the alternative fuel, affecting fuel quality. Therefore, pre-separating the fine soil in the drum screen system 3 effectively prevents it from being blown up and forming dust in the subsequent secondary air separation system, preventing it from being collected as lightweight fuel along with other lightweight materials, thus ensuring the combustion efficiency and quality of the lightweight fuel.

[0019] Meanwhile, after the fine slag is separated by the drum screening system, the material entering the secondary air classification system is granular material with a relatively uniform particle size, greater than 10mm, and free of a large amount of dust. This allows the secondary air classification system to perform precise secondary gravity separation of small-particle lightweight combustible aggregates in a relatively clean environment, further improving the purity of aggregate products and the quality of lightweight fuels.

[0020] Therefore, this invention, through a stepped process design—first disc screening and grading, then direct air separation of large pieces, and finally, secondary air separation after removing slag and soil from small pieces—fully leverages the advantages of each sorting unit: primary air separation utilizes the large density difference between large materials to achieve efficient separation, while drum screening removes easily dusty fine slag and soil in advance, creating favorable conditions for secondary air separation. Using this construction waste sorting method, reliable separation of construction waste containing different components can be achieved, and the use of magnetic separators can also recover metal materials from construction waste, improving the economic benefits of construction waste recycling.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a construction waste sorting method; Figure 2 This is a schematic diagram of a disc air classifier. Figure 3 This is a schematic diagram of a magnetic separator.

[0023] Explanation of reference numerals in the attached figures 1. Disc air classifier; 2. Integrated air classification zone; 3. Drum screening system; 4. Secondary air classification system; 41. Light material collection end; 42. Heavy material collection end; 21. Light material outlet; 22. Heavy material outlet; 5. Conveyor; 6. Magnetic separator; 10. Fan; 11. First disc screening line; 12. Second disc screening line; 61. Permanent magnet core; 62. Waste iron conveyor belt; 63. Belt geared motor; 64. Equipment support frame; 65. Belt conveyor roller; 66. Non-magnetic baffle; 67. Metal collection box; Detailed Implementation The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] In this invention, unless otherwise stated, directional terms included in the terminology represent only the orientation of the term in its normal use or as commonly understood by those skilled in the art, and should not be regarded as a limitation on the term.

[0025] See Figure 1 A method for sorting construction waste includes the following steps: Step 1: Evenly transport the construction and renovation waste to the primary sorting section; This step can be achieved using a variable frequency plate chain feeder, which can transport materials in both horizontal and inclined directions. Construction waste is fed into the horizontal receiving section at the tail of the variable frequency plate chain by a loader, and then lifted up and transported to the subsequent primary sorting section for sorting.

[0026] Step 2: In the primary sorting section, the material enters the disc air classifier 1 and is classified according to particle size by the disc screen to obtain undersize material with a particle size smaller than the disc gap and oversize material with a particle size larger than the disc gap. The undersize material enters the subsequent drum screening system 3, and the oversize material enters the comprehensive air classification zone 2. Within the integrated air separation zone 2, the oversize material, under the controllable airflow, becomes light combustible material at the light material outlet 21 and large pieces of heavy material at the heavy material outlet 22. The conveying surface of the disc air classifier 1 consists of multiple parallel rollers with discs installed alternately on them. The rollers rotate via sprockets or gears, with the rotation direction consistent with the material flow direction. Mixed waste moves forward under the drive of the high-speed rotating discs, being continuously thrown up and bounced during the movement, thus achieving thorough dispersion. Simultaneously, during the forward conveying of material, fine materials smaller than the disc separation gaps fall through the gaps and are collected and conveyed to a drum screen for further processing. Materials larger than the disc gaps remain above the conveying surface and are sent to the integrated air classification zone 2. Therefore, the disc air classifier 1 can achieve preliminary separation of materials according to their diameter. More importantly, within the disc air classifier 1, the materials are continuously dispersed, allowing for reliable separation of light combustible materials from heavy materials, which is beneficial for improving the accuracy of subsequent air classification using a blower.

[0027] Within the integrated air separation zone 2, under the controllable airflow, larger diameter oversize materials such as plastics, white garbage, waste paper, and packaging bags are blown up and sent to the light material outlet 21. Therefore, light combustible materials can be obtained at the light material outlet 21. However, denser heavy materials are difficult to be blown up by the wind and eventually fall into the heavy material outlet 22. Therefore, large pieces of heavy material are obtained at the heavy material outlet 22.

[0028] Lightweight combustibles are collected at the lightweight material outlet 21 and then conveyed to a storage facility for use as alternative fuel or for sale. Meanwhile, large, heavy materials, primarily composed of stone, are vertically dropped through the heavy material outlet 22 onto a lower conveyor for storage and subsequent processing as large aggregate particles.

[0029] Step 3: The undersize material enters the drum screening system for three rows of screening to collect fine slag and soil particles with a diameter smaller than the drum screen openings; Large particles with a diameter greater than the screen openings of the drum screen are fed into the secondary air separation system 4. The undersize material passing through the disc air classifier 1 enters the drum screen system 3 for screening. As the undersize material moves within the drum screen, it is rotated and scattered by the drum. During this process, heavy materials and soil in the undersize material are stripped off through the screen holes and collected as fine soil, then transported by a conveyor to a storage location. Because lightweight combustible materials are typically larger in size and lighter in weight, they are less likely to leak through the drum screen holes. Therefore, these lightweight combustible materials, along with the larger particles of undersize material larger than the drum screen holes, are sent to the secondary air classification system 4 for air classification.

[0030] Preferably, since some fine metals will also fall from the disc screen, a magnetic separator can be added to the conveyor of fine slag. The magnetic field strength of the magnetic separator is about 1000 Gs, so as to separate and store the small metal particles. This avoids damage to downstream equipment and achieves better economic recovery benefits.

[0031] Therefore, in the entire system, large pieces of metal and small pieces of metal are separated by magnetic separators at different process stages, ultimately ensuring that all metals are removed from all materials.

[0032] Step 4: Under the action of the inclined airflow from bottom to top in the secondary air separation system 4, light combustibles in the large particle undersize are obtained at the light material collection end 41, and heavy small particle aggregates in the large particle undersize are obtained at the heavy material collection end 42. Materials entering the secondary air separation system 4 are moved forward by a belt conveyor within the equipment. A variable frequency fan blows air upwards from the rear of the equipment at an angle. Lighter, combustible materials with lower density move upwards in a parabolic trajectory under the control of the airflow, and are collected after being discharged through the light material collection end 41 for use as alternative fuel. Heavier materials with higher density, which are difficult to blow, fall freely and evenly under their own weight from the discharge port at the end of the equipment via the belt conveyor, and are then conveyed out and stored for later use as small aggregates such as gravel. The airflow of the variable frequency fan can be adjusted according to the composition of the actual incoming materials to ensure that lighter and heavier materials move along the correct paths.

[0033] In step 2, after step 2, the large pieces of material falling from the heavy material outlet 22 in step 2 are subjected to magnetic separation to separate and recycle the large metal objects.

[0034] Since construction waste contains a certain amount of heavy metals, the large pieces of material falling from the heavy material outlet 22 in step 2 will be transported to the storage yard by a conveyor. Consider adding a magnetic separator at the receiving end of the conveyor. The magnetic separator is suspended above the conveyor and provides a magnetic field strength of more than 2000 Gs. The magnetic separator can efficiently separate the iron in the waste and collect the iron, realize resource recycling and increase economic benefits.

[0035] After step 2, the large pieces of material falling from the heavy material outlet 22 in step 2 are subjected to magnetic separation, which can separate and recycle the large pieces of metal.

[0036] In the primary sorting stage, construction waste is sorted according to particle size. Construction waste with smaller diameters is passed through the drum screening system 3 as undersize material, while construction waste with larger diameters is screened in the integrated air separation zone 2, thereby obtaining lightweight combustibles and heavy materials with larger diameters. The undersize material obtained from the primary sorting stage enters the drum screening system 3. Small particles are collected as fine slag, while large particles enter the secondary air separation system. Lighter, combustible materials are collected at the top, and heavier, denser materials are collected at the bottom. A conveyor 5 is installed behind the heavy material outlet 22. Large heavy materials are transported on the conveyor 5. A magnetic separator is installed along the length of the conveyor 5. The magnetic separator can adsorb metal on the conveyor 5.

[0037] Preferably, in step 3, the undersize material entering the drum screening system 3 is subjected to magnetic separation, or large particle undersize material is subjected to magnetic separation.

[0038] This invention first uses a disc air classifier 1 to preliminarily screen construction waste according to particle size. The larger particles on the screen then enter a comprehensive air classification zone 2 for further air separation, resulting in both larger-sized lightweight fuels and larger-sized heavy materials. In the comprehensive air classification zone 2, due to the significant difference in weight and density between large lightweight materials (such as plastic buckets, packaging bags, and foam blocks) and large heavy materials (such as concrete blocks and bricks), their trajectories differ considerably under controlled airflow. Lightweight materials are easily blown away, while heavy materials fall vertically. Therefore, in the comprehensive air classification zone 2, due to the large weight difference between light and heavy materials, the pass rate of air separation is very high, easily separating lightweight combustible materials and achieving efficient and low-energy-consumption primary sorting.

[0039] Furthermore, the smaller-diameter undersize material is sent to the drum screen system 3 for a second screening. Fine soil particles smaller than the drum screen's apertures, approximately 10mm in diameter, are separated first. Because fine soil particles are small, have a high specific gravity, and high moisture content, if they enter the secondary air separation system 4, the upward airflow will easily blow them up, mixing them with lightweight combustibles. This would increase the ash content and decrease the calorific value of the alternative fuel, affecting fuel quality. Therefore, pre-separating the fine soil in the drum screen system 3 effectively prevents it from being blown up and forming dust in the subsequent secondary air separation system 4, preventing it from being collected as lightweight fuel along with other lightweight materials, thus ensuring the combustion efficiency and quality of the lightweight fuel.

[0040] Meanwhile, after the fine slag is separated by the drum screening system 3, the material entering the secondary air classification system 4 is a relatively uniform particle size, larger than 10mm, and free of a large amount of dust. This allows the secondary air classification system 4 to perform precise secondary gravity separation of small-particle lightweight combustible aggregates in a relatively clean environment, further improving the purity of aggregate products and the quality of lightweight fuels.

[0041] Therefore, this invention, through a stepped process design—first disc screening and grading, then direct air separation of large pieces, and finally, secondary air separation after removing slag and soil from small pieces—fully leverages the advantages of each sorting unit: primary air separation utilizes the large density difference between large materials to achieve efficient separation, while drum screening removes easily dusty fine slag and soil in advance, creating favorable conditions for secondary air separation. Using this construction waste sorting method, reliable separation of construction waste containing different components can be achieved, and the use of magnetic separators can also recover metal materials from construction waste, improving the economic benefits of construction waste recycling.

[0042] In this embodiment, preferably, in step 2, a magnetic separator 6 for recovering metal objects is provided above the material conveying line.

[0043] The magnetic separator 6 mainly consists of a high-performance permanent magnet core 61, a scrap iron conveyor belt 62, a belt-driven geared motor 63, an equipment support frame 64, belt conveyor rollers 65, a non-magnetic baffle 66, and a metal collection box 67. The magnetic separator 6 is installed approximately 300mm from the conveyor surface via the equipment support frame. When the mixed material on the conveyor surface passes below the separator, metal objects are attracted to the scrap iron conveyor belt 62 by the permanent magnet core 61. The scrap iron conveyor belt 62 reciprocates between two belt conveyor rollers 65 via the geared motor 63. The width between the two belt conveyor rollers 65 is greater than the width of the permanent magnet core 61. After the material attracted to the scrap iron conveyor belt 62 is removed from the strong magnetic field area, the magnetic force gradually weakens or disappears. Subsequently, the ferrous material moves diagonally downwards under the influence of forward inertia and downward gravity, colliding with the non-magnetic baffle 66, and then falling into the metal collection box 67 for collection.

[0044] By installing a magnetic separator 6 above the material conveying line, large metal objects can be recovered online during the conveying process. This setup does not occupy additional space and can continuously and automatically separate metals without manual intervention, improving the efficiency and purity of metal recovery. Simultaneously, timely removal of metal objects prevents wear or damage to subsequent equipment, extending equipment lifespan and reducing maintenance costs.

[0045] In this embodiment, preferably, in steps 2 and 4, the wind field parameters of the integrated wind separation zone 2 and the secondary wind separation system 4 are set to be adjustable. After the fan is turned on, the wind separation parameters are adjusted by the wind separation parameter adjustment method.

[0046] In both the integrated air separation zone 2 (step 2) and the secondary air separation system 4 (step 4), a variable frequency fan is configured. The fan's frequency, inlet / outlet valve opening, and outlet angle, among other airflow parameters, can be independently adjusted according to the actual material composition changes. This invention sets adjustable airflow parameters for each air separation zone, and after the fan is started, the air separation parameters are dynamically adjusted using a systematic air separation parameter adjustment method.

[0047] The fan frequency in the integrated air separation zone 2 can be adjusted within the range of 15~50Hz, corresponding to an air volume that can vary from 20000~48000m³ / h, and an air velocity that can be adjusted from 12~22m / s. The fan frequency in the secondary air separation system 4 can be adjusted within the range of 25~45Hz, corresponding to an air volume that can vary from 28000~35000m³ / h, and an air velocity that can be adjusted from 15~20m / s. When the composition of the incoming material changes, operators can adjust the fan frequency, valve opening, and outlet angle to change the air volume, air velocity, air pressure, and blowing direction in the air separation zone, based on factors such as the type and content of light substances and the particle size and density of heavy substances, thereby ensuring that materials with different characteristics can achieve the best separation effect.

[0048] By setting the air field parameters of the integrated air separation zone 2 and the secondary air separation system 4 to be adjustable, the adaptability of the separation process to construction and renovation waste with different composition ratios is significantly improved. The composition of construction and renovation waste fluctuates greatly, and a single set of fixed parameters is insufficient to handle all operating conditions. This invention allows operators to flexibly adjust the air separation parameters according to the actual material characteristics, thereby maintaining a stable and efficient separation effect even when the material composition changes.

[0049] In this embodiment, preferably, the parameters of the fan 10 of the secondary air separation system 4 in step 4 are set as follows: the frequency of the fan 10 is set to 25-45Hz, the air volume is set to 28000-35000m³ / h, and the wind speed is about 15-20m / s.

[0050] In step 4, the material entering the secondary air separation system 4 consists of large particles that have passed through primary screening and drum screening. These particles are characterized by relatively small particle size and relatively low content of light combustibles, mainly small plastic pieces, shredded paper, and small wood blocks, while the heavy materials are small aggregates such as small stones and broken glass.

[0051] Unlike the large materials processed in the integrated air separation zone 2, the secondary air separation system 4 processes much finer materials, thus requiring more precise airflow control. The aforementioned parameter range ensures that while effectively blowing away lightweight combustibles, heavy, small aggregate particles are avoided, thereby guaranteeing high purity and low impurity levels in the aggregate collected at the heavy material collection end 42. When the material contains a high amount of lightweight materials, the fan frequency can be adjusted to the upper limit of 45Hz; when the material is predominantly heavy and it is necessary to prevent the mixing of aggregates into the lightweight materials, the fan frequency can be adjusted to the lower limit of 25Hz.

[0052] In this embodiment, preferably, the parameters of the fan 10 in the comprehensive air selection zone 2 in step 2 are set as follows: the frequency of the fan 10 is set to 15-50Hz, the air volume is set to 20000-48000m³ / h, and the wind speed is about 12-22m / s.

[0053] In step 2, the material entering the comprehensive air separation zone 2 is the oversize material of the disc screen, that is, large pieces of material with a particle size larger than the gap between the discs. This may include a variety of materials such as large plastic buckets, packaging bags, hard plastic pipes, wood blocks, stones, and concrete blocks, with significant differences in weight and density between the materials.

[0054] Given the characteristics of these large and diverse materials, the integrated air separation zone 2 needs to provide a wider range of airflow adjustment and a broader range of air velocity adjustment. When the material contains a large amount of relatively heavy materials such as hard plastics and small wood blocks, the fan frequency can be set at 40~45Hz, with an airflow of approximately 35,000 m³ / h and an air velocity of approximately 19 m / s. When the material contains a large amount of relatively large materials such as white waste and compressed packaging bags, the fan frequency can be set at 25~40Hz, with an airflow of approximately 28,000 m³ / h and an air velocity of approximately 15 m / s. When the material contains a large amount of lighter materials such as waste paper and broken foam, the fan frequency can be set at 10~25Hz, with an airflow of approximately 18,000 m³ / h and an air velocity of approximately 12 m / s. If the material content on site is complex, it is advisable to select a 30Hz frequency, an air volume of 24000m³ / h, and an air speed of about 13m / s as the operating conditions for starting the machine. The frequency can then be adjusted according to the situation of parabolic conveying of lightweight materials.

[0055] In this embodiment, preferably, the air separation parameter adjustment methods for the integrated air separation zone 2 and the secondary air separation system 4 are set to be the same.

[0056] Although the integrated air separation zone 2 and the secondary air separation system 4 process materials with different particle sizes and characteristics, they both use the same set of air separation parameter adjustment methods. Whether adjusting the fan parameters of the integrated air separation zone 2 or the fan parameters of the secondary air separation system 4, the same adjustment logic and adjustment step size are followed.

[0057] This embodiment greatly simplifies operator training and reduces operational difficulty by setting the adjustment methods for the air separation parameters of the integrated air separation zone 2 and the secondary air separation system 4 to be the same. Operators only need to master one adjustment method to apply it to two different air separation sections, reducing the probability of human error. At the same time, the same adjustment logic ensures coordination and consistency in parameter adjustment between the two air separation sections, which is beneficial to the stable operation of the entire sorting system. Furthermore, the unified adjustment method facilitates automated control, laying the foundation for upgrading this method to a fully automatic closed-loop control system, and exhibiting good scalability.

[0058] In this embodiment, preferably, the wind separation parameter adjustment method includes: S1. Start the secondary air separation system 4 fans 10 according to the set start-up parameters; First, start the fan 10 according to the set startup parameters. The startup parameters can be the set baseline startup parameters or the parameters from the last operation. Selecting the last operation parameters can quickly restore the verified operating conditions, which is suitable for situations where the properties of the incoming material are relatively stable; selecting the baseline startup parameters is suitable for situations where the properties of the incoming material have changed significantly or for the first startup.

[0059] S2. Check whether the material blown out at the light material outlet 21 or the light material collection end 41 contains non-combustible substances, and check whether the material collected at the heavy material outlet 22 or the heavy material collection end 42 contains light combustible substances. At the light material outlet 21 or light material collection end 41, check whether the swept material contains non-combustible materials such as small stones, broken glass, and sand. At the same time, at the heavy material outlet 22 or heavy material collection end 42, check whether the collected material contains light combustible materials such as broken plastic pieces and scraps of paper. This inspection can be carried out by manual visual observation or by online detection equipment.

[0060] S3. If the material collected by the lightweight material collection end 41 contains non-combustible materials, then perform at least one of the following actions: reduce the frequency of the fan 10 by 3Hz, reduce the opening of the inlet and outlet valves by 5%, and adjust the outlet angle downward by 3°. If non-combustible materials are found in the material collected at the lightweight material outlet 21 or the lightweight material collection end 41, it indicates that the air separation intensity is too high, blowing aggregates that should fall to the heavy material collection end 42 into the lightweight material as well. In this case, it is necessary to reduce the air separation intensity by performing at least one of the following actions: reducing the frequency of the blower 10 by 3Hz, reducing the opening of the inlet and outlet valves by 5%, and adjusting the outlet angle downward by 3°. These adjustments can be performed independently or in combination to reduce the air volume, air velocity, and air pressure, thereby weakening the airflow and allowing the heavy aggregates to overcome airflow resistance and fall to the heavy material collection end 42.

[0061] S4. Repeat step S3 until qualified light combustibles are collected at the light material collection end 41; Repeat step S3 for adjustment and inspection. After each adjustment, run the material for about one minute and observe the material blowing situation again until the light combustible material collected at the light material collection end 41 no longer contains obvious non-combustible material, which means it meets the qualified standard.

[0062] S5. If the material collected at the heavy material outlet 22 or the heavy material collection end 42 contains light combustibles, then perform at least one of the following actions: increase the frequency of the fan 10 by 3Hz, increase the opening of the inlet and outlet valves by 5%, or adjust the outlet angle upward by 3°. If the material collected at the heavy material collection end 42 is found to contain light combustibles, it indicates that the air separation is insufficient, and some light materials have not been blown away by the airflow and have mixed with the heavy materials. In this case, it is necessary to increase the air separation intensity by performing at least one of the following actions: increasing the frequency of the blower 10 by 3Hz, increasing the opening of the inlet and outlet valves by 5%, and adjusting the outlet angle upwards by 3°. These adjustments can independently or in combination increase the airflow, air velocity, and air pressure, enabling the airflow to effectively blow away the light materials.

[0063] S6. Repeat step S5 until qualified heavy small-particle aggregate is collected at the lightweight material collection end 41.

[0064] Repeat step S5 for adjustment and inspection until the heavy aggregate collected at the heavy material collection end 42 no longer contains obvious light combustibles, which means it meets the qualified standard.

[0065] In this embodiment, preferably, the power-on parameters include baseline power-on parameters and previous running parameters; The baseline start-up parameters are set as follows: fan 10 frequency 30Hz, inlet and outlet damper 70% opening, outlet angle 40° upwards. The parameters for the last operation were set to the air selection parameters before the last shutdown.

[0066] In step S11, there are two options for the startup parameters used to start the fan 10: baseline startup parameters or last operating parameters.

[0067] The baseline start-up parameters are universally applicable initial parameters that have been verified through extensive testing. Specifically, they are set as follows: fan 10 frequency 30Hz, inlet and outlet damper 70% opening, and outlet angle 40° upwards. Under these parameters, the air volume is approximately 24,000 m³ / h, the air velocity is approximately 13 m / s, and the air pressure is approximately 2900 Pa. These baseline parameters are suitable for sorting most conventional construction and renovation waste. When the properties of the incoming material are unclear or during the initial start-up, using these baseline start-up parameters can ensure basic separation performance. During production, the air separation parameters can be fine-tuned based on these start-up parameters.

[0068] The previous operating parameters refer to the air separation parameters that were determined and saved after optimization using the air separation parameter adjustment method of this invention before the last shutdown. When the factory operates continuously and the source of incoming materials is relatively stable, the optimized parameters confirmed before the last shutdown are likely still applicable to this startup. Therefore, directly calling the previous operating parameters as the startup parameters can quickly restore the verified optimal operating conditions, eliminating the need for gradual adjustments from the baseline parameters and improving production efficiency.

[0069] In practice, operators can flexibly choose to use either the baseline startup parameters or the previous operating parameters based on their assessment of changes in the properties of the incoming materials. If the properties of the incoming materials have not changed significantly compared to the last production run, the previous operating parameters should be used first. If the properties of the incoming materials have changed significantly, or if the equipment has been restarted after a long period of downtime, the baseline startup parameters should be used first.

[0070] In this embodiment, preferably, the disc air classifier 1 is provided with a stepped structure with a height difference to drive the material to tumble and achieve reliable dispersion of the material.

[0071] The rollers of the disc air classifier 1 rotate via a sprocket or gear drive, with the rotation direction consistent with the material flow direction. Discs are mounted on the rollers; the mixed waste moves forward under the high-speed rotation of the discs, constantly being thrown up and jumping, thus achieving thorough dispersion. Fine materials with a diameter smaller than the disc separation gap fall through the gaps between the discs and are conveyed to the drum screen for further processing. Materials with a diameter larger than the disc gaps enter the integrated air classification zone 2.

[0072] The disc air classifier 1 adopts a two-stage stepped structure with a height difference. There is a height difference between the first disc screening line 11 and the second disc screening line 12. The height difference is designed so that the material will tumble when it passes through the stepped drop formed by the height difference, so that the different components in the material can be effectively separated during the tumbling and throwing process, which is more conducive to subsequent screening.

[0073] Construction and renovation waste often contains flexible materials such as plastic film, cloth strips, and paper. These materials easily entangle with rigid materials or stick together, forming agglomerates. If the materials cannot be sufficiently dispersed, subsequent air separation cannot effectively separate lightweight materials from heavy materials because the lightweight materials in the agglomerates are trapped by the heavy materials and cannot be blown away by the airflow. By setting up a stepped structure to promote the tumbling and scattering of materials, the materials that were originally stuck together or trapped can be dispersed, making the disc screen screening efficiency higher. At the same time, the materials entering the integrated air separation zone 2 are more uniform and dispersed, which is conducive to the precise capture of lightweight materials by the air separation airflow.

[0074] Therefore, by setting a stepped structure with height difference in the disc air classifier 1, forced tumbling and dispersion of materials are achieved, solving the technical problem of flexible materials in construction and decoration waste easily entangled and sticking together. Moreover, after being fully dispersed, the lightweight components in the material are more easily separated by the airflow.

[0075] In this embodiment, preferably, the disc separation gap of the disc air classifier 1 is adjustable within the range of 15-60mm.

[0076] In this embodiment, the disc separation gap is set to be adjustable from 15 to 60 mm. The disc separation gap of the disc air classifier 1 can be adjusted by adjusting the thickness and number of discs used in the disc air classifier 1.

[0077] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0078] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0079] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for sorting construction waste, characterized in that, Includes the following steps: Step 1: Evenly transport the construction and renovation waste to the primary sorting section; Step 2: In the primary sorting section, the material enters the disc air classifier (1) and is classified by particle size through the disc screen to obtain undersize material with a particle size smaller than the disc gap and oversize material with a particle size larger than the disc gap. The undersize material enters the subsequent drum screening system (3) and the oversize material enters the comprehensive air classifier (2). Within the integrated air separation zone (2), the oversize material is subjected to controlled airflow, resulting in light combustible material at the light material outlet (21) and large pieces of heavy material at the heavy material outlet (22). Step 3: The undersize material enters the drum screening system (3) for screening, and fine slag with a particle size smaller than the drum screen hole is collected; Large particles larger than the sieve openings of the drum screen are fed into the secondary air separation system (4). Step 4: Under the action of the inclined airflow from bottom to top in the secondary air separation system (4), the light combustible material in the large particle undersize is obtained at the light material collection end (41), and the heavy small particle aggregate in the large particle undersize is obtained at the heavy material collection end (42). In step 2, after step 2, the large pieces of material falling from the heavy material outlet (22) in step 2 are magnetically separated to separate and recycle the large pieces of metal.

2. The construction waste sorting method according to claim 1, characterized in that, In step 2, a magnetic separator (6) for recycling metals is installed above the material conveyor.

3. The construction waste sorting method according to claim 1, characterized in that, In steps 2 and 4, the wind field parameters of the integrated wind separation zone (2) and the secondary wind separation system (4) are respectively set to be adjustable. After the fan is turned on, the wind separation parameters are adjusted by the wind separation parameter adjustment method.

4. The construction waste sorting method according to claim 3, characterized in that, The parameters of the fan (10) of the secondary air separation system (4) in step 4 are set as follows: the frequency of the fan (10) is set to 25-45Hz, the air volume is set to 28000-35000m³ / h, and the wind speed is 15-20m / s.

5. The construction waste sorting method according to claim 3, characterized in that, The parameters of the fan (10) in the comprehensive air selection zone (2) in step 2 are set as follows: the frequency of the fan (10) is set to 15-50Hz, the air volume is set to 20000-48000m³ / h, and the wind speed is about 12-22m / s.

6. The construction waste sorting method according to claim 3, characterized in that, The method for adjusting the air separation parameters of the integrated air separation zone (2) and the secondary air separation system (4) is the same.

7. The construction waste sorting method according to claim 6, characterized in that, The method for adjusting the wind separation parameters includes: S1. Start the secondary air separation system (4) fan (10) according to the set start-up parameters. S2. Check whether the material blown out contains non-combustible substances at the light material outlet (21) or light material collection end (41), and check whether the collected material contains light combustible substances at the heavy material outlet (22) or heavy material collection end (42). S3. If the material collected at the lightweight material outlet (21) or the lightweight material collection end (41) contains non-combustible materials, then perform at least one of the following actions: reduce the frequency of the fan (10) by 3 Hz, reduce the opening of the inlet and outlet valves by 5%, or adjust the outlet angle downward by 3°. S4. Repeat step S3 until qualified light combustibles are collected at the light material outlet (21) or the light material collection end (41); S5. If the material collected at the heavy material outlet (22) or the heavy material collection end (42) contains light combustibles, then perform at least one of the following actions: increase the frequency of the fan (10) by 3 Hz, increase the opening of the inlet and outlet valves by 5%, or adjust the outlet angle upward by 3°. S6. Repeat step S5 until qualified heavy small-particle aggregate is collected at the heavy material outlet (22) or heavy material collection end (42).

8. The construction waste sorting method according to claim 7, characterized in that, The startup parameters include the baseline startup parameters and the parameters from the last operation. The baseline start-up parameters are set as follows: fan (10) frequency 30Hz, inlet and outlet damper 70% opening, outlet angle 40° upward; The parameters for the last operation were set to the air selection parameters before the last shutdown.

9. The construction waste sorting method according to claim 1, characterized in that, The disc air classifier (1) is equipped with a stepped structure with a height difference, which is used to drive the material to roll and achieve reliable dispersion of the material.

10. The construction waste sorting method according to claim 9, characterized in that, The disc separation gap of the disc air classifier (1) is adjustable within 15-60mm.

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