With the continuous improvement of coal mining mechanization, the proportion of fine coal and coal powder in raw coal is increasing, accounting for 40% to 50%. Different particle size coal and gangue are mixed together, and screening equipment is needed to screen out gangue to improve coal quality and meet user requirements.

Due to the high moisture content in coal, wet fine-grained and sticky materials tend to stick together, be difficult to loosen, and easily clog screen holes, resulting in a decrease in screening efficiency, non-dispersed particle groups, and overall movement, making the screening process difficult to complete. Therefore, the screening of wet fine-grained and sticky materials is an urgent problem to be solved in the screening operation of coal preparation plants. At the same time, the screening of coal is very important for the rational utilization of coal resources and is an important link in coal preparation.

With the increase in the proportion of washed coal and the amount of fine coal powder, as well as the water and dust removal during the coal mining process, the moisture content of raw coal underground has greatly increased. Even for 13mm grading, it is quite difficult to use conventional screening methods. Currently, the traditional screening equipment used in coal preparation plants for grading has low screening efficiency and is prone to screen hole blockage, causing many problems for the normal production and operation of coal preparation plants.

The application of Flip Flow Screen in coal preparation plants, with its unique alternating tension and relaxation movement of the screen surface, can continuously subject sticky materials on the screen surface to throwing and loosening effects, effectively avoiding the problems of material sticking together and clogging screen holes.

The application of Flip Flow Screen

Dry screening is a technical challenge for wet and fine-grained sticky materials. Vibrating screens are commonly used in coal preparation plants. However, due to the moisture and viscosity of raw coal, vibrating screens tend to clog when screening fine particles, resulting in low screening efficiency and significantly affecting the separation effect.

Flip Flow Screen is a device designed for screening difficult-to-screen materials such as fine, wet, and sticky materials. Especially in cases where the screen is prone to clogging, the elastic screen plate of Flip Flow Screen can ensure efficient screening without clogging. Flip Flow Screen has the advantages of simple and reliable structure, low failure rate, and high screening efficiency, which can guarantee the long-term reliable operation of the washing process. Compared with ordinary screening equipment, the screen plate replacement of Flip Flow Screen is simple and quick, saving time and effort, and can greatly reduce the input of human and material resources, providing reliable protection for the normal operation of the washing process.

Flip Flow Screen can improve the screening efficiency of fine particles and high-moisture coal types that are difficult to screen, reduce the amount of coal slime for washing, effectively alleviate the pressure on the downstream coal slime water treatment system, save the investment and burden of subsequent coal slime treatment equipment, and enhance the overall washing capacity of the coal preparation plant.

The working principle of the Flip Flow Screen

The main screen frame of the Flip Flow Screen uses a flywheel and a pendulum block to provide vibration force to the screen body, causing it to move in a circular motion. High-efficiency polyurethane screen plates are installed on the fixed crossbeam (connected to the screen body) and the floating crossbeam (connected to the floating balance beam). Due to the interlaced movement of the screen body and the floating balance beam, the screen plates are tightened and relaxed, forming a tension-relaxation motion. Rubber support blocks and balance leaf springs transfer the vibration force of the screen body to the floating balance beam, causing the floating balance beam to move linearly relative to the main screen frame.

Its uniqueness lies in the principle of generating dual vibrations with a single drive, that is, through resonance, one driver provides two vibrations: one basic vibration (rotating eccentric block) and one additional vibration (floating screen frame). During this process, the elastic polyurethane screen surface is continuously tightened and relaxed (more than 800 times/min), achieving a high acceleration (50g), effectively preventing screen hole blockage.

Advantages of Flip Flow Screen

(1) The polyurethane screen plate is specially designed to withstand a gravitational acceleration of 50g, ensuring a long service life.

(2) The Flip Flow Screen is mounted on hollow rubber springs, generating low noise and featuring a long lifespan for the springs. The force transmitted to the foundation by the screen is no greater than that of traditional vibrating screens (despite the Flip Flow Screen generating a gravitational acceleration of 50g, which is much higher than the 5g of traditional screens).

(3) Due to the tensioning and relaxing motion of the screen surface, it can effectively screen difficult materials and the screen holes are less prone to clogging.

(4) The Flip Flow Screen features a horn-shaped design on the sides to form a seal, preventing wear on the side plates and preventing material on the screen from entering the undersize fraction.

(5) The Flip Flow Screen does not require any bolts for installation, making it easy to disassemble and assemble, and facilitating quick replacement.

(6) The Flip Flow Screen has few moving parts, ensuring high operational reliability, minimal daily maintenance, and high utilization.

Conclusion

The application of Flip Flow Screen in coal preparation plants provides an effective solution to the screening problems of wet fine-grained and sticky materials. The advantages of Flip Flow Screen, such as easy disassembly and assembly, fast replacement, and high operational reliability, further reduce the operating costs and maintenance difficulties of coal preparation plants.