The advantages of magnetically driven centrifugal pumps include that there is no leakage at all, and there can be large gaps between the inner and outer rotors. When using non-metallic isolating sleeves, the thickness is not greater than 8mm, and when using metallic isolating sleeves, the thickness is not greater than 5mm. Large, the possibility of wearing of the isolation sleeve is small, the gap between the isolation sleeve and the inner and outer magnetic rotor is also large, the magnetic centrifugal pump operates reliably, and the possibility of abrasion of the inner magnetic rotor and the isolation sleeve due to the wear of the shaft seal is small. The set is easy to disassemble, can be replaced on site, easy to maintain, and can be applied to SIC bearings. It has good wear resistance, long service life, and the speed of the pump is not limited by the motor. It can be different from the motor speed. In addition, the magnetic centrifugal pump also has the following advantages:
1. Because the transmission shaft of the magnetic centrifugal pump does not need to penetrate into the pump casing, the internal magnetic rotor is driven by the magnetic field through the magnetic field and the thin-walled transmission torque of the isolating sleeve. Therefore, the leakage passage of the shaft seal is completely eliminated and the complete seal is achieved.
2, the magnetic drive pump has overload protection when transmitting power.
3. In addition to the high requirements for the magnetic materials and magnetic circuit design of the magnetic pump, the remaining parts are not technically demanding.
4. The maintenance and repair work of the magnetic drive pump is light.
Disadvantage
1. The efficiency of the magnetic centrifugal pump is lower than that of the ordinary centrifugal pump, and it cannot be operated at 30% of the rated flow with a low flow rate, and it is also contraindicated to idling.
2. Magnetic centrifugal pumps generally have poor abrasion resistance due to the material's abrasion resistance. Therefore, magnetic pumps are generally used to transport media that does not contain solid particles and magnetic particles are strictly prohibited from entering the pump.
3. The magnetic centrifugal pump with a general structure allows the delivery of liquids containing solid particles with a diameter of less than 0.15mm (100 mesh) and a mass fraction of not more than 5% (additional auxiliary systems are required when exceeding).
4. The pump and the motor have a coupling link. The coupling requires high accuracy on the centerline installation. Improper alignment will cause damage to the bearing at the inlet and wear of the single-sided side leakage isolation sleeve.
5. The magnetic drive of the magnetic centrifugal pump has two methods of synchronous transmission and asynchronous transmission. The inner and outer magnetic rotors of the synchronous transmission are equipped with permanent magnets, so the temperature of the liquid transported must be lower than the maximum temperature allowed by the permanent magnets. A certain amount of margin must be left. Although cobalt and samarium permanent magnets can reach 350 degrees Celsius, the actual use temperature generally does not exceed 260 degrees Celsius. High temperature may cause permanent magnet demagnetization. Magnetic pumps with special structures can reach 450 degrees Celsius,
6. Magnetic centrifugal pumps have high requirements for the material and manufacturing process of the isolating sleeve. If the material is not selected properly or the manufacturing quality is poor, the isolating sleeve cannot withstand the wear of the inner and outer magnetic rotors and cause abrasion. Once broken, the transported medium will Overflow, causing equipment failure and affecting the normal operation of the device.
7. When the temperature of the magnetic centrifugal pump is higher than the specified temperature, external cooling is required. For example, if a heat insulation cavity is set, the pump cavity is filled with a coolant with a pressure higher than the sealing pressure, and the inner magnetic rotor and bearings are cooled. Isolation sleeve, cooling liquid is inserted into the interlayer, or the pump body is provided with a cooling jacket and a cooling coil, etc., the single structure is complicated and the cost is high.
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