Working principles and structural features
Magnetic pump is a new pump that uses magnetic couplings working principle to transfer torque without contact, when the motor drive external magnetic rotor rotating, through the effect of magnetic field to drive internal magnetic rotor and impeller rotating synchronously, thus achieved pumping fluid, due to the liquids was closed in static isolation, so it is a kind of whole sealing, no leakage pump.
Magnetic pump is composed by pumps, magnetic transmission device, the motor three parts. The key components of the magnetic driver consists of external magnetic rotor, internal magnetic rotor, and non-magnetic isolate sleeve. When the motor drive external magnetic rotor rotating, the magnetic field can penetrate the non-magnetic material, and connected with the impeller in magnetic rotor synchronized spinning, realize dynamic no contact transmission, changing the dynamic sealing by static sealing. Because pump shaft, internal magnetic rotor is fully closed by pump body and isolated sleeve, thus completely slove the run, emit, drop, leak problems, eliminate petrochemical industry inflammable, explosive, toxic and harmful media through pump seal leakage safe hidden trouble, guarantee worker's physical and mental health and safety production.
working principles
Put n pairs of magnets (n is even number) according to law arranged in magnetic transmission internal and external magnetic rotor, make each component magnets to form completely coupling magnetic system. When internal and external two pole is different, the displacement angle between two poles Φ = 0, the lowest magnetic energy, When the poles to turn a relative, namely the displacement angle between two poles Φ=2π/n, magnetic system energy is maximum. Remove external power, due to external magnetic system poles repel each other, magnetic energy back to the lowest. Hence, magnet movs and drive magnetic rotor rotating.
structural features
1． permanent magnet
Permanent magnets made by rare earth permanent magnet working temperature range is wide(-45－400℃), coercive force is high, magnetic field has very good anisotropic, with extremely closed also won't happen demagnetization phenomenon, is a good source of magnetic field.
2. distance sleeve
When using metal distance sleeve, it should be in alternating magnetic field, in the field of perpendicular to the direction of the induction heat and turned out varies. Eddy expression: including Pe - vortex, K? D constants; N? D the rated speed pump, T - magnetic transmission torque, F -sleeve inside pressure, D - sleeve diameter, material of resistivity, ? D materials tensile strength. When the pump is designed, n, T is given by working condition, to reduce the eddy, only from F, D. Etc consideration. Choose high resistivity, high strength non-metallic material produced sleeve, in reducing vortex aspects effect is very obvious
3． Cooling lubrication fluids flow control
When pump operation, must use a small amount of liquid to wash and cool the magnetic rotor and isolating sleeve internal gaps region and sliding bearing friction pair. The coolant flow is usually 2-3% of pump designed flow, the gap area between internal magnetic rotor and isolating sleeve due to vortex to produce high heat. When the cooling lubricant is not enough or rinse pore jams, will result in the medium temperature higher than permanent magnet working temperature, makes internal magnetic rotor gradually lose magnetic, make magnetic transmission device failure. When the media is water or aqueous solution, can make the gap temperature maintaining in 3-5 ° c, When the media is hydrocarbon or oil, can make the gap area temperature maintaining in 5-8℃.
4． slide bearing
Magnetic pump sliding bearing material have dipping graphite, filling ptfe, engineering ceramics, etc. Because of engineering ceramics has good heat resistance, corrosion resistance, anti-friction properties, so the sliding bearing uses engineering ceramics production. Because of engineering ceramics is crisp and low expansion coefficient, so the bearing clearance shall not too small, lest produce an accident of holding shaft
Because of the magnetic pump sliding bearings lubricate conveyed medium, so according to different media and operating conditions, choose different material to manufacture bearing.
5． protection
When magnetic transmission device driven components in overload running or rotor dies, magnetic transmission device, driven components will be automatically slippage to protect the pump. This magnetic transmission device permanent magnets under the effect of active rotor alternate magnetic field will produce vortex loss, magnetic loss, cause permanent magnets temperature rised, magnetic transmission slippage failure
