Introduce

The mineral sizer is a widely used crushing equipment in various industries. It crushes materials of different hardness and properties. Therefore, during operation, overloading is inevitable. This requires the equipment itself to have a good self-protection system to ensure safe operation and keep the failure rate at a low level.

Therefore, in the design of the Mineral sizer, there are five protection measures against motor overload and one mechanical protection measure. When overload occurs, these protection mechanisms will respond quickly, effectively reducing the equipment failure rate.

Overload protection measures for the motor of the Mineral Sizer

Short-circuit protection

Using fuses, air circuit breakers, etc. as short-circuit protection devices can quickly cut off the power supply when a short-circuit fault occurs in the circuit, preventing the irreversible damage to the motor of the Mineral sizer caused by excessive short-circuit current. The rated current value should match the rated current of the motor, so that it can respond promptly when a fault occurs and will not malfunction during normal operation, ensuring that the Mineral sizer can stably perform material crushing operations.

Overload protection

Using a thermal relay as the overload protection device for the motor is the most commonly used method for protecting the motor. When the motor of the Mineral sizer operates under excessive load for a long time, causing the current to exceed the rated value, the thermal relay will act within the set time based on the changes in heat generated by the current, cutting off the power supply to the motor and preventing the motor from being burned out due to overheating.

The setting value of the thermal relay must match the rated current of the motor and be able to accurately sense the overload condition of the motor, providing reliable overload protection for the motor of the Mineral sizer and ensuring the continuous operation of the equipment.

Temperature probe protection

Large motors should be equipped with temperature probes in the stator windings. When the motor of the Mineral sizer is in operation, the winding temperature gradually rises and approaches its maximum allowable temperature. At this point, the temperature probe will send a signal, causing the circuit to automatically cut off, thereby preventing the motor's insulation layer from being damaged due to high temperature and ensuring that the large Mineral sizer can operate stably within a safe temperature range, thus extending the service life of the equipment.

Phase loss protection

A phase-break protection device is installed in the control circuit. When the power supply is disconnected, the phase-break protection device can quickly detect this abnormality and immediately cut off the power supply to the motor, preventing the motor from continuing to operate in a phase-deficient state. This effectively protects the motor of the Mineral sizer and ensures the safe and stable operation of the equipment.

Voltage protection

A voltage protector is installed in the control circuit. When the voltage drops below a certain level, the voltage protector will immediately act and cut off the power supply, preventing the motor from operating under low voltage conditions and thus providing effective protection for the motor of the Mineral Sizer.

The mechanical protection device of the Mineral sizer

When the Mineral sizer is operating normally, the safety pin transmits torque to ensure that the power can be delivered to all working components, enabling the equipment to complete the crushing operation of the materials smoothly.

When an overload occurs during the operation of the Mineral sizer, the safety pin will be cut, cutting off the power transmission, thus preventing the power device from being damaged due to excessive load.

During the material processing by the Mineral sizer, if iron filings and other inedible debris enter the crushing chamber and cause the toothed rollers to get stuck and unable to be crushed, the safety pin of the coupling will be cut, providing mechanical protection.

This will interrupt the power transmission and prevent the important components such as the toothed rollers and the motor from being damaged due to forced operation, thus ensuring the overall structural safety of the Mineral sizer.

When the safety pin of the Mineral sizer is cut off due to overload or debris jamming, the replacement process is very simple. Just insert the spare safety pin accurately into the corresponding position of the coupling, without the need for complex debugging or disassembly procedures.

The feasibility of the mineral sizer protection device

Comprehensive nature

The motor protection covers all aspects from circuit short-circuit, overload, phase failure, abnormal voltage, to temperature changes of the core components (stator windings) of the motor, comprehensively monitoring the risks that may cause damage to the motor; the mechanical protection targets mechanical overload scenarios such as foreign objects entering the crushing chamber and gear rollers getting stuck.

The combination of the two almost covers all electrical and mechanical overload risks that may occur during the operation of the Mineral sizer, avoiding the limitations of a single protection device.

Complementarity

Thermal relays and temperature probes focus on overheating problems caused by long-term overload of the motor. Safety pins respond quickly to instantaneous mechanical overload (such as getting stuck with hard objects). Phase failure and voltage protectors address hidden overload caused by abnormal power supply. This mode can trigger protection quickly in various overload scenarios, minimizing the damage to the mineral sizer to the greatest extent.

Maintenance convenience

Whether it is replacing the safety pin or resetting the thermal relay or voltage protector, the operation is relatively simple. No complex professional tools or techniques are required, and the Mineral sizer can be quickly restored to operation, reducing downtime.

Stability

The protective devices used, such as fuses, thermal relays, and safety pins, are all mature industrial-grade components. They exhibit stable performance during long-term use and are less affected by environmental factors such as dust and vibration. They can maintain reliable protection capabilities in the continuous and high-intensity crushing operations of the Mineral sizer.

Maintenance of the protection device

The high operating rate of any crushing equipment is achieved under good daily maintenance conditions. Appropriate maintenance (repair and upkeep) is extremely important. Correct operation, meticulous maintenance, timely inspection and repair, and overhaul can ensure the normal operation of the mineral sizer and extend its service life, improve the operational rate of the equipment, and fully utilize its potential.

Daily maintenance mainly refers to the inspections before and after shifts, regular maintenance, and timely overhaul. Fault analysis and elimination are also included. Depending on different usage scenarios and different working environments, specific standards of relevant industries and the specific circumstances of the enterprise should be referred to for formulation and implementation.

Conclusion

The overload protection of the Mineral Sizer integrates multiple electrical and mechanical protection measures to handle various possible overload situations. The diverse protection measures, their complementary functions, as well as the reliability and maintainability of the system, make the overload protection system of the Mineral Sizer perform extremely well in ensuring safe and stable operation, reducing failure rates, and extending the service life of the equipment. Regular maintenance (daily inspections, regular maintenance, prompt repairs) further enhances the system's performance and ensures the high availability of the equipment.