Why is it necessary to use a hydraulic coupling in mineral sizer

Introduce

With the development of the coal industry and the increase in coal demand, the application of mineral sizer in the coal mining industry is becoming increasingly widespread. Its reliability is crucial for the safe production of coal mines.

However, during the current operation of the equipment, direct start and stop cause heavy load impact on the motor, which easily leads to motor overload burnout, shaft breakage and other equipment failures, requiring production suspension for maintenance, resulting in serious economic losses.

Fluid coupling, which uses oil as the transmission medium, is currently the most widely used transmission device in the coal mining field. In small and medium power transmission applications, torque-limiting type hydraulic couplings are mostly configured, which can achieve flexible start and have overload protection functions.

In large power megawatt-level and above transmission fields, speed-regulating type hydraulic couplings are mostly used, which have good soft start and multi-machine drive power balance functions.

Fluid coupling

The pump wheel and turbine of the Fluid coupling form a closed working chamber that enables the liquid to circulate. The pump wheel is mounted on the input shaft, and the turbine is mounted on the output shaft.

When the power machine (such as an internal combustion engine or an electric motor) rotates the input shaft, the liquid is ejected by the centrifugal pump wheel. When the high-speed liquid enters the turbine, it drives the turbine to rotate and transmits the energy obtained from the pump wheel to the output shaft.

Finally, the liquid returns to the pump wheel, forming a repetitive circulation. The hydraulic coupling transmits torque by changing the momentum moment through the interaction between the liquid and the blades of the pump wheel and turbine. Its output torque is equal to the input torque minus the frictional torque, so its output torque is always less than the input torque.

The input and output shafts of the hydraulic coupling are connected by liquid, and there is no rigid connection between the working components. The characteristics of the hydraulic coupling are: it can eliminate shock and vibration; the output speed is lower than the input speed, and the speed difference between the two shafts increases with the increase of the load; it has good overload protection performance and starting performance, and when the load is too large and the machine stops, the input shaft can still rotate without causing damage to the mineral sizer motor; when the load decreases, the output shaft speed increases until it approaches the speed of the input shaft.

The protection function of the fluid coupling

Soft start

The soft start function of the Fluid coupling can gradually transfer power when the Mineral Sizer is started, avoiding high current impacts on the motor and the power grid. This is because the startup of the equipment often involves significant load fluctuations. The Fluid coupling achieves a smooth transition, reducing the current and the load on the power grid and the motor, thereby protecting the power grid and the motor.

Buffering

The hardness, humidity and particle size of the materials may change during operation, resulting in sudden load variations. The fluid coupling can automatically adjust the torque and speed when the load changes, buffering load fluctuations and avoiding the impact of these changes on the Mineral Sizer transmission system. Due to the continuous impact of the materials and the wear of the toothed rollers, the equipment is prone to vibration during operation. The fluid coupling can effectively reduce this vibration, thereby reducing equipment wear and improving the stability of operation.

Easy-flooding plug

When the Mineral Sizer encounters abnormal load or blockage, the easy-flooding plug function of the Fluid coupling will come into play. In this situation, the Fluid coupling will disconnect the power transmission through the internal fluid flooding mechanism to prevent the motor and the transmission system from being damaged by excessive pressure. This design is very effective when the material is hard or when the crushing teeth get stuck, and it can protect the mineral sizer from damage.

Explosive plug

When the Mineral Sizer operates under high load conditions and an abnormality occurs, the explosive plug protection function of the Fluid coupling will automatically activate. The explosive plug will burst or fall off when the pressure is too high, preventing the internal pressure from accumulating to a dangerous level and avoiding damage to the equipment. For the Mineral Sizer, this protection function can effectively prevent equipment damage caused by overload and ensure the safe and stable operation of the equipment.

The on-site operating conditions of the Mineral Sizer

High-load operation

The materials in coal mines are usually quite hard, especially coal gangue and mudstone. The crushing equipment needs to withstand a large crushing load. The Mineral Sizer was designed with this in mind, and its double-disk roller structure can withstand a large working pressure. Through the rotation of the roller, large coal mine materials are gradually crushed into the required particle size.

Continuous operation and high stability

Coal mine crushing equipment usually needs to operate continuously in harsh environments for a long time, and the stability of the equipment is crucial. The Mineral Sizer uses high-maintenance-resistant materials and optimized roller design, which can maintain efficiency during long-term operation and reduce downtime.

High humidity and sticky materials

Coal and coal gangue in coal mines often contain a high amount of moisture, which may cause equipment blockages and jamming problems. The design of the Mineral Sizer has good adaptability and is particularly suitable for handling moist and sticky materials. The gap between the rollers can be flexibly adjusted to adapt to different particle sizes and moisture levels of the materials, avoiding equipment stalling due to material adhesion or clumping.

Screening and control of crushing particle size

Coal in coal mines needs to be crushed into a certain particle size for subsequent processing. The Mineral Sizer can precisely control the output particle size and provide flexible particle size adjustment options. By adjusting the gap between the rollers, the crushed materials can be ensured to reach the particle size required by the coal mine, avoiding over-crushing and energy waste.

Durability and maintenance

Due to the high wear caused by dust and materials in the coal mine production environment, the Mineral Sizer is equipped with advanced protection devices, such as overload protection, to help avoid equipment damage. In addition, the rollers of the Mineral Sizer adopt replaceable tooth designs, allowing for convenient maintenance and component replacement after long-term operation, thereby extending the equipment’s service life.

Sealing and dust prevention design

The coal mine site has a lot of dust, especially during crushing operations. The Mineral Sizer adopts a sealed design to reduce the leakage of material dust, protect the health of operators, and improve the safety of the working environment.

Conclusion

In the process of coal mining and mineral processing, the use of Fluid coupling by mineral sizers is crucial for ensuring their reliable, safe and efficient operation. At the same time, Fluid coupling has advantages such as soft start capability, load buffering, overload protection and extended equipment lifespan, and is a key component of mineral sizers.