With the acceleration of urbanization and the improvement of residents' living standards, the amount of urban waste generated is increasing. As a key link in waste disposal, waste sorting is of great significance for achieving waste reduction, resource utilization and harmless treatment. Among many waste sorting equipment, the trommel screen has become an indispensable equipment for waste sorting due to its high efficiency, stability and strong adaptability, and is widely used in various waste disposal scenarios.

Working principle and structural characteristics of trommel screen

Trommel Screen

The main structure of the trommel screen is a cylindrical drum made of screen mesh. The drum is driven by transmission devices such as motors, reducers, couplings, etc., and rotates around its own axis at a certain speed. The waste enters from one end of the trommel screen. During the rotation of the drum, due to the guide plate or lifting bar on the inner wall of the drum, the waste is lifted to a certain height under the action of friction and gravity, and then slides and rolls. waste particles with a particle size smaller than the sieve hole size pass through the sieve during the movement and become the underscreen material; waste with a particle size larger than the sieve hole size remains in the screen drum and is discharged from the other end of the drum as the drum rotates, becoming the overscreen material, thereby realizing the screening of waste.

The screen of the trommel screen can be made of different materials and screen hole sizes according to actual needs. Common materials include stainless steel, manganese steel, etc., and the screen hole shapes include round, square, strip, etc. It has a simple structure, stable operation, easy maintenance, and high screening efficiency, and can adapt to waste materials of different properties and particle sizes. In addition, the trommel screen can also flexibly control the screening effect by adjusting the parameters such as the speed and inclination of the drum.

Application scenarios of trommel screen in waste sorting

Trommel Screen

1. Domestic waste sorting

In the field of domestic waste treatment, the trommel screen is one of the important equipment for front-end sorting. The composition of urban domestic waste is complex, including kitchen waste, waste paper, plastic, metal, glass, fabric, bricks, tiles and stones. The trommel screen can perform preliminary screening on the collected raw domestic waste, and separate the smaller-sized kitchen waste, ash and other screened materials, which can be further composted or anaerobic fermented to produce biogas; the screened materials are mainly larger-sized plastics, paper, fabrics and other recyclables, as well as inert materials such as bricks, tiles and stones, which are convenient for further sorting through magnetic separation, wind separation and other equipment to achieve resource recovery and separate treatment of inert materials.

2. Construction waste sorting

Construction waste mainly includes waste concrete, bricks, stones, wood, metals, etc. The trommel screen can be used to remove fine particles such as soil and dust in the construction waste sorting, and at the same time classify the construction waste according to particle size. The fine particles under the sieve can be further processed and utilized as raw materials for recycled aggregates. The larger-sized discarded concrete blocks, bricks and tiles on the sieve can be crushed and screened again through the trommel screen to produce recycled aggregates of different specifications for road bases, non-load-bearing structures of buildings, etc., to achieve resource recycling of construction waste, reduce dependence on natural sand and gravel, and reduce environmental pollution.

3. Industrial waste sorting

The nature of industrial waste in different industries varies greatly, but the trommel screen can play a certain role. For example, in the waste generated by the food processing industry, the trommel screen can screen out fine organic matter such as peels and vegetable leaves for composting; in the waste generated by the mechanical processing industry, the trommel screen can separate metal debris and non-metallic impurities, which is convenient for metal recycling and the rational disposal of non-metallic waste. In addition, in the waste treatment of chemical, papermaking and other industries, the trommel screen can also be used as a pretreatment equipment to perform preliminary screening of the waste, providing convenience for subsequent treatment processes.

The key role of trommel screen in waste sorting

Trommel Screen

1. Improve the efficiency of waste sorting

The trommel screen can screen waste continuously and stably, and its processing capacity is large, which can process a large amount of waste materials in a short time. Compared with manual sorting, the trommel screen is not affected by factors such as physical strength and emotions of personnel, and can maintain a high working efficiency, which greatly shortens the time of waste sorting and improves the overall efficiency of waste treatment. At the same time, the trommel screen can be used in conjunction with other sorting equipment (such as magnetic separators, air separators, etc.) to form a complete set of waste sorting production lines, realize multi-level and precise sorting of waste, and further improve the sorting efficiency.

2. Realize effective classification of waste

By reasonably selecting the mesh size of the trommel screen, the waste can be accurately classified according to different particle sizes, which provides convenience for subsequent processing and utilization. For example, in the sorting of domestic waste, the fine kitchen waste under the screen is suitable for biological treatment, and the larger recyclables on the screen are convenient for classified collection and recycling; in the sorting of construction waste, the graded recycled aggregates can be applied to different construction engineering fields according to different particle sizes, which improves the utilization value of construction waste. This effective classification makes waste treatment more refined and scientific, and helps to maximize the resource utilization of waste.

2. Reduce the cost of subsequent treatment

The trommel screen pre-separates impurities in the waste that are not suitable for subsequent treatment processes, reducing the wear and blockage of these impurities on subsequent treatment equipment, extending the service life of the equipment, and reducing the maintenance cost of the equipment. For example, in the anaerobic fermentation treatment of domestic waste, the trommel screen can be used to remove inert substances such as bricks, tiles, and stones, which can avoid damage to the fermentation tank by these substances and ensure the smooth progress of the fermentation process; in the production of recycled aggregates from construction waste, after screening out impurities such as soil, the quality of recycled aggregates can be improved, and the energy consumption and cost in the subsequent processing process can be reduced. In addition, after the initial sorting by the trommel screen, the volume of the waste is reduced to a certain extent, reducing the cost of waste transportation and storage.

Trommel Screen

3. Improve the environmental benefits of waste treatment

The application of the trommel screen helps to achieve the reduction, resource utilization and harmless treatment of waste. By screening, recyclable materials are separated for recycling and reuse, which reduces the waste of resources and the demand for the exploitation of primary resources; the organic waste screened can be converted into fertilizer or energy through biological treatment, which reduces the amount of landfill and reduces the pollution of landfill to soil, groundwater and other environments; the separated inert materials can also be properly disposed of to avoid the damage to the environment caused by their random stacking. Therefore, the application of trommel screens in waste sorting is of great significance to improving the environmental benefits of waste disposal and helps promote the sustainable development of cities.

Trommel screens have a wide range of applications and important roles in waste sorting. With the continuous development of waste disposal technology and the increasing requirements for environmental protection, trommel screens will also continue to innovate technology and optimize and upgrade to better adapt to the sorting needs of different types of waste, play a greater role in the field of waste disposal, and make greater contributions to the efficient disposal of waste and the sustainable use of resources.

Author : Song Ying

Song Ying is a blog column writer. She has more than 8 years of experience in the manufacturing and service of environmental protection machinery. She has a deep understanding of the garbage screening and crushing industry and is happy to share practical industry knowledge and technology.