In the process of solid waste treatment such as household waste and construction waste, large waste (such as furniture, mattresses, used household appliance shells, large plastic buckets, etc.) due to their large volume, high hardness, and complex composition, if directly entered into subsequent crushing and sorting equipment, it is easy to cause problems such as clogging, wear, and failure, seriously affecting the efficiency of the production line. As the "first screening checkpoint" in solid waste treatment, the large garbage removal screen accurately separates large impurities in materials through physical screening principles, providing qualified raw materials for subsequent processes. It is the core equipment to ensure the stable, efficient, and safe operation of the production line. Its role runs through the entire process of solid waste treatment, specifically reflected in the following five dimensions:

1. Protect downstream equipment and reduce the risk of failures and losses

The core equipment of the solid waste treatment production line, such as crushers, drum screens, and air separators, have clear feed particle size restrictions. The forced entry of large garbage can cause fatal damage, and the primary function of the removal screen is to "intercept the risk source".

Taking the treatment of household waste as an example, waste sofas, mattresses (usually over 1m ³ in volume), and wooden furniture fragments (over 50cm in length) mixed with ordinary waste, if directly entered into the jaw crusher, will get stuck in the feeding port and cause the equipment to stop, and forcibly starting may burn out the motor; Hard large items (such as concrete blocks and waste iron pots) will collide with the crusher hammer, causing the hammer to crack and the lining plate to wear, greatly shortening the service life of the equipment. According to data from a municipal solid waste treatment plant, without a large waste removal screen, the crusher malfunctions 6-8 times a month due to blockage of large waste, requiring 4-6 hours of downtime for each maintenance, with an annual maintenance cost exceeding 500000 yuan; After installing the removal screen, the number of failures has been reduced to less than once a month, maintenance costs have been reduced by 70%, and the average service life of the equipment has been extended by 30%.

In the construction waste disposal scenario, the hazards of large waste such as discarded door and window frames, reinforced concrete blocks, and large pipes are more prominent. This type of material has high hardness and heavy weight. If it enters the vibrating screen, it will cause the mesh to tear, and if it enters the air separator, it will block the airflow channel. The large garbage removal screen accurately intercepts such large impurities by setting a reasonable sieve hole size (usually 30-50cm), ensuring that the particle size of the materials entering downstream equipment meets the requirements, avoiding equipment overload, blockage, wear and other problems from the root, and ensuring the continuous operation of the production line.

2. Improve the subsequent sorting efficiency and ensure the purity of resource utilization

The core goal of solid waste treatment is "resource recycling", and the mixing of large garbage can seriously interfere with sorting accuracy, reducing the purity and value of renewable resources. The large-scale garbage removal screen uses "early diversion" to clear obstacles for subsequent sorting processes, improve overall processing efficiency and resource recovery rate.

In the household waste sorting line, large pieces of waste (such as discarded furniture and household appliance shells) are often mixed with multiple materials (wood, metal, plastic, fabric). If they enter the sorting system together with ordinary waste, they will entangle the drum screen and block the air sorting machine channel, resulting in the inability to accurately separate lightweight recyclable materials such as plastic and paper. According to data from a certain resource recycling base, equipped with large garbage removal screens, the recovery rate of iron metals by subsequent magnetic separators has increased from 85% to 95%, and the separation purity of plastics by air separators has increased from 82% to 93%. The sales price per ton of recycled plastics has increased by 200-300 yuan. At the same time, the removed large garbage can be dismantled and processed separately: broken wooden furniture can be used as biomass fuel, metal parts can be recycled through magnetic separation, and plastic shells can be classified and regenerated, achieving the "separate resource utilization of large garbage" and improving the overall resource utilization rate of the project.

In the management project of stale garbage, the removal of large garbage (such as discarded mattresses, plastic bag wraps, and worn-out kitchen utensils) is particularly crucial. After long-term landfill, this type of garbage is prone to adhere to soil and humus soil, forming "large clumps of condensed matter". If not removed in advance, it will result in subsequent screening and sorting machines being unable to effectively separate humus soil from recyclables. In a landfill treatment project, the application of large-scale garbage removal screens has increased the screening efficiency of subsequent humus soil by 40%, and the purity of humus soil has reached over 90%. It can be directly used for landscaping and soil improvement, and its resource value has been significantly improved.

3. Optimize the processing flow and reduce overall operating costs

The difficulty of handling large garbage is much higher than that of ordinary garbage. If mixed with ordinary garbage, it will increase the energy consumption and cost of various links such as crushing, sorting, and transportation. The large-scale garbage removal screen optimizes the overall processing flow and reduces comprehensive operating costs through "classification processing and precise diversion".

From the perspective of crushing cost, large garbage has a large volume and complex structure, and crushing requires more energy consumption: the energy consumption of crushing 1 ton of large garbage is about 3-5 times that of ordinary garbage. The large garbage removal screen separates these high-energy consuming materials in advance and uses a dedicated crusher to process them separately, avoiding the overall energy consumption increase caused by mixing and crushing with ordinary garbage. According to data from a certain garbage treatment plant, the unit processing energy consumption of the entire production line decreased from 1.8 kWh/ton to 1.2 kWh/ton after being equipped with a screening system, saving over 300000 yuan in electricity bills annually.

From the perspective of transportation costs, large garbage has a large volume and low density, occupying a large amount of transportation space and resulting in low transportation efficiency. For example, a 10 ton garbage transport vehicle can only load 3-4 tons of garbage without removing large items (due to the space occupied by large items); After removing large items, the loading capacity can reach 8-9 tons, the transportation efficiency is increased by more than twice, and the annual transportation cost is reduced by 40%. At the same time, the removed large garbage can be transported to a specialized dismantling center, avoiding the repetitive labor of "mixed transportation secondary sorting" and further reducing labor costs.

From the perspective of labor costs, when a screening screen is not equipped, a dedicated person needs to be arranged at the front end of the production line for manual sorting. Each person can only process 5-8 tons of garbage per day, which results in high labor costs and low efficiency; After installing the removal screen, the manual sorting position can be reduced by 60% -80%, requiring only 1-2 people to inspect and clean up the large garbage removed, significantly reducing manpower investment.

4. Ensure production safety and comply with environmental compliance requirements

Large scale garbage often contains safety hazards (such as sharp metal parts, flammable and explosive materials), which may cause safety accidents if they enter the production line; At the same time, failure to timely remove large garbage can lead to non-standard processing procedures that do not comply with environmental policy requirements. The large-scale garbage removal screen plays a key role in "safety assurance" and "compliant operation".

In terms of security, if large waste (such as used knives, broken glass products, and concrete blocks with exposed steel bars) enters the production line, it may scratch operators, puncture equipment conveyor belts, and even cause fires (such as flammable and explosive materials remaining in large waste). A certain garbage treatment plant was once shut down for rectification due to the leakage of unreleased waste liquefied gas cylinders into the crusher, causing the tank to rupture and pose an explosion hazard; After being equipped with a large garbage removal screen, these high-risk large items are intercepted in advance, and the incidence of safety accidents is reduced to zero. In addition, the design of protective barriers and sealing covers for screening can prevent materials from splashing and injuring people, further ensuring the personal safety of operators.

In terms of environmental compliance, China's "Technical Standards for Domestic Waste Treatment" clearly require that "large waste should be collected, transported, and processed separately." Failure to equip large waste removal screens will result in processing procedures that do not meet standards and face penalties from environmental protection departments. At the same time, if large garbage is directly buried, it will occupy a large amount of landfill space and be difficult to degrade, polluting soil and groundwater; After being screened and separated, large garbage can be dismantled, recycled, or treated harmlessly, meeting the environmental requirements of "reduction, resource utilization, and harmlessness". A garbage treatment plant in a certain city was ordered by the environmental protection department to rectify due to the lack of screening equipment. After rectification, a large garbage screening equipment was installed, which not only passed the compliance inspection, but also received environmental subsidies for improving resource utilization.

5. Adapt to complex working conditions and achieve flexible application in multiple scenarios

The large-scale garbage removal screen has strong adaptability and can be customized according to different types of solid waste, processing scales, and site conditions to meet the processing needs of multiple scenarios such as household waste, construction waste, and stale waste. It has become a "universal front-end equipment" for solid waste treatment projects.

In the scenario of household waste disposal, the removal screen often adopts a "drum type" structure, with a sieve hole size set at 30-40cm, suitable for large items such as furniture, mattresses, and household appliance shells commonly found in household waste; Equipped with anti entanglement devices to prevent plastic bags, fabrics, and other materials from entangling the sieve body, suitable for the complex composition and entanglement of household waste.

In the construction waste disposal scenario, the screening screen is selected with a "vibrating" or "grid" structure, with a mesh size of 40-50cm and made of high manganese steel wear-resistant lining plate to resist the impact of hard materials such as concrete blocks and steel bars, adapting to the characteristics of "high hardness and heavy weight" of construction waste.

In the scenario of treating stale garbage, the removal screen adopts a combination design of "crawler conveyor+grid screening", which can adapt to the muddy and complex working environment of landfills. Through adjustable screen holes, it can meet the separation needs of "large condensates" in stale garbage.

In addition, the large garbage removal screen can be flexibly configured according to the processing scale: small processing plants use a single small removal screen (processing capacity of 50-100 tons/day), while large projects adopt multiple parallel or multi-stage screening designs (processing capacity of 500-1000 tons/day). At the same time, it can be linked with equipment such as loaders and conveyors to achieve automated feeding, screening, and discharging, adapting to the production capacity requirements of different projects.

As the "front-end defense line" of the solid waste treatment production line, the large garbage removal screen plays a role that runs through the five core dimensions of "equipment protection, efficiency improvement, cost optimization, safety compliance, and scene adaptation". It can not only avoid downstream equipment damage and reduce operating costs, but also improve resource recovery rate and ensure production safety. It is an indispensable key equipment for modern solid waste treatment projects. With the construction of "zero waste cities" and the promotion of circular economy policies, the importance of large-scale garbage removal screens will be further highlighted, and their design will be upgraded to "intelligent, high wear resistance, and high adaptability", providing stronger support for the efficient and green development of the solid waste treatment industry.