A rotary drum screen (also known as a trommel screen) is a screening device widely used across various industries. Here is a detailed introduction to its features and applications.

1. Basic Structure

A rotary drum screen generally consists of a power system, a drum assembly, a support system, a frame, feed/discharge ports, and a sealing cover.

1. Power System
   • Motor: Provides power for the machine. It is connected to the screen body via a coupling and to the reducer via a V-belt. This design is precise, reliable, and easy to install and maintain. The motor drives the rotation of the drum, which moves the material across the screen.
   • Reducer: This is a separate component installed between the motor and the drum. It is composed of gears or worm gears enclosed in a rigid housing. Its purpose is to reduce the motor's high speed to a speed suitable for the screener, while also increasing torque to ensure the drum rotates smoothly and powerfully.
2. Drum Assembly
   • Main Drum: The core component of the screener, it is typically made of stainless or carbon steel. Its surface has screen holes of various sizes to classify the material. The drum can be a single or multi-layer structure, with mesh sizes configured to meet different screening needs.
   • Combined Screen Mesh: Installed and welded onto the main shaft's drum cage, this mesh consists of multiple circular galvanized steel rings. This design is easy to repair and replace, and it effectively separates finished products from return materials.
3. Support System
   • Bearing Housing System: Supports the main shaft of the drum at both ends of the frame. It reduces friction during rotation, ensuring the drum's flexibility and stability. It typically uses high-precision rolling bearings that can withstand significant radial and axial loads.
   • Frame: Welded from high-quality carbon steel plates and channels, the frame is the supporting structure for the entire screener. It has passed rigorous quality certifications and specific process requirements, ensuring the equipment's stability and reliability during operation. It bears the weight of the drum, power system, and the vibration and impact forces generated during screening.
4. Feed and Discharge Ports
   • Feed Port: Located at one end of the drum, it's where the material to be screened is fed in. Its design should ensure that the material enters the drum uniformly and smoothly, preventing blockages or buildup.
   • Discharge Ports: Usually located at the bottom or the other end of the drum. Based on the different mesh sizes and screening results, materials of different particle sizes are discharged separately. The number and location of the discharge ports are designed according to specific screening needs.
   • Sealing Cover: Installed at both ends of the drum and other necessary sealing points, it prevents material from leaking during the screening process. It also reduces dust emissions, protecting the environment and the health of operators.

2. Working Principle

1. Material enters the inclined drum assembly through the feed port. The drum rotates at a specific speed. Under the combined action of centrifugal force, gravity, and the drum's inclination, the material tumbles and rolls along the screen surface.
2. Particles smaller than the screen holes pass through the mesh, becoming the "undersize" product. They fall and are discharged through the outlet at the bottom of the drum. Particles larger than the screen holes continue to move forward and are eventually discharged from the outlet at the end of the drum, becoming the "oversize" product.
3. The equipment is equipped with an automatic plate-type or comb-type screen cleaning mechanism. During screening, this mechanism continuously "combs" the screen with a relative motion, dislodging any material stuck in the holes. This prevents clogging and ensures high screening efficiency.

3. Key Features

1. High Screening Efficiency: The inclusion of a beating or screen cleaning device effectively prevents the mesh from clogging, regardless of how sticky, wet, or contaminated the material is. This significantly improves screening efficiency.
2. Improved Working Environment: The entire screening mechanism is designed within a sealed, dust-proof cover, which completely eliminates dust emissions, creating a better working environment.
3. Low Equipment Noise: The noise from the material and the rotating screen is contained by the sealed dust cover, which reduces operational noise and minimizes the impact on the surrounding environment.
4. Long Service Life: The screen mesh is typically made of several circular flat steel rings. Their large cross-sectional area makes them more robust and durable compared to the screen bars of other separation equipment, resulting in a long service life.
5. Easy Maintenance: The sealed dust cover has observation windows on both sides, allowing staff to monitor the equipment's operation at any time. The end of the cover and the side of the cleaning mechanism have quick-opening doors for easy periodic maintenance without affecting normal operation.
6. Wide Range of Applications: It can screen various types of materials, including wet and easy-to-clog materials like coal, coke, and quicklime. It is also suitable for use in stone quarries, sand pits, and the coal, chemical, and mineral processing industries.

4. Fields of Application

1. Mining Industry: Used for the grading and screening of ores, separating different particle sizes for subsequent processing.
2. Building Materials Industry: Screens sand and gravel to produce aggregates of different specifications for concrete mixing plants and other construction needs.
3. Coal Industry: Separates lump coal from coal fines and grades materials during coal washing, improving the quality and utilization rate of coal.
4. Chemical Industry: Screens chemical raw materials to grade large lumps and separate powdered substances, ensuring the material meets the required particle size for production.
5. Waste Management: In municipal solid waste treatment, it can separate different types of waste, such as recyclables, hazardous waste, and kitchen waste, improving the efficiency of waste processing and promoting resource recycling.

5. How to Choose a Rotary Drum Screen

Selecting a rotary drum screen requires a comprehensive assessment of specific production needs, material characteristics, and equipment performance. Here are the key considerations for a precise selection:

1. Understand Material Characteristics
   • Particle Size: This is a crucial factor. Different trommel screens have different screen hole sizes. You need to choose a machine with the right mesh size based on the size distribution of your material to effectively separate the desired particle sizes. For example, the mesh required for screening fine sand is very different from that for large chunks of ore.
   • Moisture and Stickiness: If the material has high moisture content or is sticky, it can easily clog the screen holes. In this case, you should choose a rotary screen with an anti-clogging feature, such as a cleaning device, to prevent material buildup on the screen surface and ensure efficient screening.
   • Hardness and Corrosiveness: The hardness and corrosiveness of the material will also affect equipment selection. For hard materials, you need a machine with a wear-resistant screen mesh, such as high-manganese steel. For corrosive materials, choose a drum screen made of corrosion-resistant materials like stainless steel to extend the equipment's service life.
2. Consider Production Needs
   • Throughput: Determine the machine's processing capacity based on your production scale. The capacity is typically measured in tons per hour. Make sure the selected equipment's capacity matches your needs to avoid bottlenecks or wasted resources.
   • Site Space: The size of your production facility will also limit equipment selection. Rotary screens come in various sizes, so you need to measure the length, width, height, and layout of the installation area to ensure the equipment fits and allows for sufficient space for operation and maintenance.
3. Focus on Equipment Performance
   • Drum Speed: This is a key parameter affecting screening efficiency. A speed that's too high will result in the material staying on the screen for too short a time, leading to inadequate screening. A speed that's too low can cause material to pile up, also reducing efficiency. You should choose a machine with an adjustable or optimal speed for your material's properties and screening requirements.
   • Mesh Material and Structure: The mesh's material and structure directly relate to screening effectiveness and durability. In addition to choosing a material based on its resistance to wear or corrosion, the structure of the mesh (e.g., woven, perforated) is also important. Different structures have different screening accuracies and throughputs, so you need to choose based on your specific needs.
   • Power System: The power system is also a key consideration. The motor's power must match the equipment's processing capacity and drum size to ensure sufficient power and stable operation. You should choose a reliable motor brand with good after-sales service to reduce the chance of equipment failure.
4. Evaluate Equipment Quality and After-Sales Service
   • When choosing, select a drum screen from a reputable manufacturer. Check the manufacturer's qualifications and product quality certifications to ensure the equipment is reliable.
   • You can visit the manufacturer's workshop and see their customer case studies to get a better sense of how the equipment performs in real-world scenarios. You should also ask about the manufacturer's after-sales service policy, including installation, commissioning, maintenance, and spare parts supply.
5. Compare Price and Value After meeting the above conditions, compare prices from different manufacturers. However, don't just look at the price tag. You must consider the machine's quality, performance, and after-sales service to choose the one with the best overall value. Choosing a cheap, low-quality machine could lead to high maintenance costs and low production efficiency in the long run.

In summary, choosing a rotary drum screen requires a thorough understanding of material properties, clear production needs, a focus on equipment performance, an evaluation of quality and service, and a comparison of price and value. This approach will help you select the most suitable equipment to ensure smooth production.

6. Rotary Drum Screen Pricing

The price is determined by factors such as product specifications, material of construction, and capacity, based on customer requirements. Please contact our sales team for a specific quote.

7. Company and Product Introduction

Founded in 1997, Tai'an Hongxin Environmental Protection Technology Co., Ltd. is located at the foot of Mount Tai, one of China's most famous mountains. Our facility spans 100,000 square meters, with 66,000 square meters of floor space. We hold an A2 pressure vessel manufacturing license and are ISO9001 certified. We are a high-tech enterprise in Shandong Province, a strategic partner of the Shandong Academy of Agricultural Sciences, and a member of the National Fertilizer Industry Technology Innovation Alliance.

Our team consists of 216 technical staff and over 100 sets of large, precision, and specialized processing equipment. Our professional technical and manufacturing teams provide comprehensive services, including technical consultation, process design, installation, commissioning, personnel training, and full turnkey project solutions. We also guarantee excellent after-sales service. Our products are sold both domestically and internationally, with exports to countries like Indonesia, the UAE, Malaysia, Vietnam, Bangladesh, and Myanmar.