Failure analysis and protection measures for magnetic pumps(2)

Protection measures

1. When operating under overload, the follower parts of the magnetic drive slip on the shaft, effectively protecting the motor.

When the pump is running, the ring gap area between the inner magnetic rotor and the isolation sleeve and the frictional side of the sliding bearing must be flushed and cooled with a small amount of liquid. The flow rate of the cooling fluid is usually 2-3% of the design flow rate of the pump. The ring gap area between the inner magnetic rotor and the isolation sleeve generates high heat due to eddy currents. When the cooling lubricant is not enough or the flushing hole is not smooth or blocked, it will cause the medium temperature to be higher than the working temperature of the permanent magnet, so that the inner magnetic rotor gradually loses its magnetism and the magnetic drive fails. When the medium is water or water-based liquid, the temperature rise in the ring gap area can be maintained at 3-5°C; when the medium is hydrocarbon or oil, the temperature rise in the ring gap area can be maintained at 5-8°C.

Advantages

The magnetic pump is a pump that is completely leak-free by means of a magnetic drive to achieve contactless torque transmission and thus a static seal instead of a dynamic seal. As the pump shaft and inner magnetic rotor are completely enclosed by the pump body and isolation sleeve, the problem of "running, bubbling, dripping and leaking" is completely solved, eliminating the safety hazard of flammable, explosive, toxic and harmful media leaking through the pump seal in the oil refining and chemical industry, and strongly ensuring the physical and mental health of workers and safe production.

Compared with the motor type DC brushless water pump, the magnetic pump has the following advantages.

⒈ pump shaft from the dynamic seal into a closed static seal, completely avoid the leakage of media. It can be used both on land and water and is completely waterproof.

⒉ No need for independent lubrication and cooling water, reducing energy consumption.

The low power consumption, high efficiency and damping effect reduce the impact of motor vibration on the pump and the impact on the motor when the pump vibrates with cavitation.

The rotor slips on the ceramic shaft during overload, which protects the motor and pump.