Magnetic pump (also known as the magnetic drive pump) is mainly composed of a pump head, a magnetic actuator (magnetic cylinder), a motor, a base and other components. The magnetic pump magnetic actuator is composed of an outer magnetic rotor, an inner magnetic rotor and a non-magnetic magnetic isolation sleeve. When the motor drives the outer magnetic rotor to rotate through the coupling, the magnetic field can penetrate the air gap and the non-magnetic material isolation sleeve, and the inner magnetic rotor connected with the impeller is synchronously rotated to realize the contactless synchronous transmission of the power, which will be easily leaked. The dynamic sealing structure transforms into a static leakage structure with zero leakage. Since the pump shaft and the inner magnetic rotor are completely closed by the pump body and the isolation sleeve, the problems of “running, running, dripping and leaking” are completely solved.
Advantage
The advantages of the magnetically driven centrifugal pump include: no leakage at all, there may be a large interval between the inner and outer rotors, when the non-metallic isolating sleeve is used, the thickness is not more than 8mm, and when the metal isolating sleeve is used, the thickness is not more than 5mm, and the wall thickness of the isolating sleeve is more than Large, the isolation sleeve is less likely to wear through, the gap between the isolation sleeve and the inner and outer magnetic rotors is also large, the magnetic centrifugal pump runs reliably, and the inner magnetic rotor and the isolation sleeve are less likely to wear due to the wear of the shaft seal, and the isolation is small. The kit is easy to disassemble and can be replaced in the field. It is easy to maintain and can be applied to SIC bearings. It has good wear resistance and long service life. The speed of the pump is not limited by the motor. It can be different from the motor speed, in addition to the magnetic centrifugal pump has the following advantages:
1. The magnetic centrifugal pump does not need to penetrate the pump casing, but uses the magnetic field to transmit the magnetic field and the thin-wall drive torque of the isolation sleeve to drive the inner magnetic rotor. Therefore, the leakage channel of the shaft seal is completely eliminated, and the complete sealing is realized.
2. The magnetic drive pump has overload protection when transmitting power.
3, magnetic pump magnetic material and magnetic circuit design have higher requirements, the rest of the technical requirements are not high.
4. The maintenance and repair work of the magnetic drive pump is small.
Disadvantage
1. The efficiency of the magnetic centrifugal pump is lower than that of the ordinary centrifugal pump. It cannot be operated at 30% of the low rated flow rate, and it is forbidden to idle.
2. Magnetic centrifugal pump Because the wear resistance of the isolation sleeve material is generally poor, the magnetic pump is generally used to transport media without solid particles and the magnetic particle material is prohibited from entering the pump.
3. The general structure of the magnetic centrifugal pump allows the transport of liquids containing solid particles with a diameter of less than 0.15 mm (100 mesh) and a mass fraction of not more than 5% (additional systems are required when excess).
4. The pump and the motor have a coupling link. The coupling requires high precision for the center line installation. If the alignment is not correct, it will cause damage to the bearing at the entrance and prevent the wear of the single-sided side leakage isolation sleeve.
5. The magnetic drive of the magnetic centrifugal pump has two modes: synchronous drive and asynchronous drive. The inner and outer magnetic rotors of the synchronous drive are equipped with permanent magnets, so the temperature of the liquid to be delivered must be lower than the maximum temperature allowed by the permanent magnet. There must be a certain amount of surplus. Although the cobalt and bismuth permanent magnets can reach 350 degrees Celsius, the actual operating temperature generally does not exceed 260 degrees Celsius. Otherwise, the high temperature may cause the permanent magnet to lose magnetism. The special structure of the magnetic pump can reach 450 degrees Celsius.
6. The magnetic centrifugal pump has high requirements on the material and manufacturing process of the isolation sleeve. If the material is improperly selected or the manufacturing quality is poor, the isolation sleeve cannot withstand the wear of the inner and outer magnetic rotors, and once it is broken, the transported medium will Spillage, causing equipment failure, affecting the normal operation of the device.
7. When the temperature of the magnetic centrifugal pump conveys the medium exceeds the specified temperature, external cooling is required. For example, if the heat insulation chamber is provided, the coolant in the pump chamber is injected with a pressure higher than the sealing pressure, and the inner magnetic rotor and the bearing are cooled. The isolation sleeve, the coolant is introduced into the interlayer, or the pump body is provided with a cooling jacket and a cooling coil, and the single structure is complicated and the cost is high.
