What Is The Function Of The Crushing Beam In a Mineral Sizer

In modern industrial production, the mineral sizer plays a crucial role and is widely used in various fields such as coal, mining, metallurgy, construction materials, and chemicals. It is responsible for precisely crushing large materials into specific particle sizes, laying a solid foundation for subsequent production processes.

The mineral sizer mainly consists of a frame, transmission device, crushing rollers, crushing beam, bearings, and drive unit. The frame serves as the solid skeleton of the entire equipment, bearing various powerful forces generated during the crushing process. The transmission device acts as a link connecting various power components, typically composed of a motor, reducer, and coupling, responsible for efficiently transmitting the motor’s power to the crushing rollers to drive their stable rotation. The crushing rollers are undoubtedly the core component of the entire machine, like the “teeth” of the crusher, consisting of two parallel and counter-rotating rollers, with carefully installed crushing teeth on the rollers. These crushing teeth are the direct executors of material crushing.

Its working principle is based on the combined effect of shearing and tensile forces. When materials are fed into the crushing chamber of the crusher, it is like prey entering a “hunting ground”. Particles smaller than the discharge particle size can easily pass through the gaps between the toothed rollers like agile fish and quickly enter the discharge chute. However, large pieces of material will be subjected to powerful splitting, shearing, and tensile forces from the teeth of the toothed rollers, as if being acted upon by sharp scissors and powerful pliers. Under the combined “attack” of these forces, they are gradually crushed into small pieces that meet the requirements and finally discharged from the discharge port. In the coal processing field, when raw coal is fed into the mineral sizer, smaller coal particles can directly pass through the gaps between the toothed rollers and enter the subsequent process, while larger coal blocks are crushed by the toothed rollers, achieving efficient size classification and crushing of coal to meet the strict requirements for coal particle size in different production stages.

In the complex structure of the mineral sizer, the crushing beam plays an indispensable key role, and its structure and characteristics are closely related to the overall performance and working efficiency of the crusher.

From a structural perspective, the crushing beam is mainly composed of the beam body, crushing teeth, and connecting components. The beam body, as the core component for bearing and transmitting forces, is typically made of high-strength high-quality steel, such as common high manganese steel and alloy structural steel. High manganese steel, with its excellent wear resistance and good toughness, can operate stably for a long time in working environments with huge impact and friction forces without easily breaking or experiencing excessive wear. Alloy structural steel, with its high strength, high toughness, and good processing performance, ensures the reliability and stability of the crushing beam in complex working conditions. For example, in a large-scale mining operation, the beam body of the crushing beam in the mineral sizer uses a special alloy structural steel, which undergoes strict heat treatment processes, achieving a yield strength of over 800 MPa and a tensile strength exceeding 1000 MPa, effectively ensuring the safe operation of the equipment under high-intensity work.

The shape design of the crushing beam is ingenious, usually presenting as a long strip and installed parallel to the crushing rollers at a specific position in the crusher. This shape design maximizes the contact area with the material, allowing the crushing force to be evenly distributed, thereby significantly improving the crushing efficiency and quality. In some specially designed crushers, the shape of the crushing beam is also optimized according to the characteristics of the material and the requirements of the crushing process. For instance, designs with a certain curvature or special tooth arrangement are adopted to better meet the crushing needs of different materials. The size and specifications of the crushing beam vary depending on the model of the crusher, its processing capacity, and the nature of the material. Generally, the crushing beam of large crushers is larger in size to withstand greater crushing forces and handle more materials; while that of small crushers is relatively smaller, emphasizing compactness and flexibility. In large mineral sizers for processing medium-hard materials like coal, the length of the crushing beam may reach 2 to 3 meters, with a width of 0.5 to 1 meter and a thickness of 0.2 to 0.3 meters, to meet the demands of large-scale production.

One of the notable features of the crushing beam is its high strength and high wear resistance. During the operation of the crusher, the crushing beam continuously endures various forces such as impact, compression, and friction from the materials, working in an extremely harsh environment. Therefore, its high strength ensures that it can maintain structural integrity under powerful external forces without deformation or fracture. High wear resistance ensures that the crushing beam has a slow wear rate during long-term use, extending the service life of the equipment, reducing maintenance costs, and minimizing downtime. To further enhance the wear resistance of the crushing beam, special surface treatment processes are often applied, such as overlay welding of hard alloys or thermal spraying of wear-resistant coatings, significantly increasing the surface hardness and effectively resisting material wear.

In the working process of the mineral sizer, the crushing beam plays a crucial role in the crushing task and is a key link in achieving fine crushing of materials. Its main working area is in the secondary crushing zone, where it closely cooperates with the crushing roller teeth to perform secondary crushing of the materials.

When materials enter the crusher, they first undergo primary crushing in the primary crushing zone through the initial engagement of the crushing roller teeth, breaking large pieces into smaller fragments. These materials then enter the secondary crushing zone, where the crushing beam begins to play its significant role. The crushing teeth on the crushing beam interlock with the crushing roller teeth, forming an efficient crushing area. Within this area, the materials are subjected to a combination of complex forces such as impact, shearing, and compression. When the materials come into contact with the crushing teeth of the crushing beam, due to the special shape and arrangement of the teeth, they are subjected to a powerful impact force, causing them to break instantly. At the same time, the relative motion between the crushing teeth and the materials also generates shearing force, cutting the materials like sharp scissors. Under the combined compression of the crushing beam and the crushing roller, the materials are further compressed and crushed, resulting in a finer particle size.

Through this secondary crushing method, the mineral sizer can significantly increase the crushing ratio, effectively controlling the particle size of the materials and producing products with uniform particle size. In the process of handling limestone, the limestone particles after primary crushing are further processed in the secondary crushing zone by the collaborative action of the crushing beam and the crushing roller teeth, allowing the output particle size to be precisely controlled within the required range, meeting the strict requirements for uniform particle size in the production of building materials. In the production process of the mineral sizer, precise control of the output particle size is crucial to meet the requirements of different production processes, and the crushing beam plays a key regulatory role in this. By adjusting the gap between the crushing beam and the crushing roller, operators can flexibly control the output particle size, enabling the crusher to adapt to diverse production needs.

When smaller particle size products are required, operators can use the adjustment device of the crusher to reduce the gap between the crushing beam and the crushing roller. In this case, the material is subjected to more intense squeezing and shearing forces in the secondary crushing zone, allowing it to be crushed into smaller particles and achieving a smaller output particle size. Conversely, if larger particle size products are needed, simply increasing the gap between the crushing beam and the crushing roller reduces the force exerted on the material during the crushing process, resulting in a larger output particle size. In mining, for different uses of mineral products, the gap between the crushing beam and the crushing roller needs to be adjusted to produce the required particle size. For instance, when providing raw materials for construction aggregates, larger particle size mineral particles are needed, which can be achieved by appropriately increasing the gap; while for providing raw materials for fine chemical products, smaller particle size mineral powders are required, and reducing the gap can meet the production needs.

This method of controlling the output particle size by adjusting the gap between the crushing beam and the crushing roller has the advantages of simple operation and rapid response, enabling quick adaptation to changes in production processes, improving production efficiency and product quality. Compared with other methods of adjusting the output particle size, such as changing the speed of the crusher or replacing crushing rollers with different tooth shapes, adjusting the gap between the crushing beam and the crushing roller is more direct and efficient, and does not require large-scale disassembly and replacement of components, significantly reducing production costs and maintenance workloads.

The crushing beam plays a vital role in the mineral sizer. It not only undertakes the key crushing task, but also, through the coordinated cooperation with the teeth of the crushing roller, achieves secondary crushing of the material, effectively increasing the crushing ratio and the uniformity of the product particle size; it also stabilizes the operation of the equipment, with its high-strength structure and high-quality materials, it can withstand the huge impact force and reaction force generated during material crushing, maintaining the overall stability of the equipment and reducing equipment failures and maintenance costs; at the same time, by flexibly adjusting the gap with the crushing roller, it precisely controls the output particle size, meeting the strict requirements of different production processes for product particle size.