PTFE magnetic pump working principle and structure characteristics

First, the principle of magnetic pump, PTFE magnetic pump uses the magnetic drive of permanent magnet, to achieve torque of non-contact transfer of kinetic energy of a pump, driven by the motor, the motor to rotate the outer rotor assembly

一、The principle of magnetic pump

PTFE magnetic pump uses the magnetic drive of permanent magnet, to achieve torque of non-contact transfer of kinetic energy of a pump, driven by the motor, the motor to rotate the outer rotor assembly, through the role of the magnetic field, the magnetic force line through the isolation sleeve to drive the inner rotor assembly and impeller rotation, to achieve the purpose of conveying media. PTFE magnetic pump is composed of magnetic coupling mechanism and pump three parts, also known as fluorine lined magnetic pump and fluorine plastic alloy magnetic pump.

PTFE magnetic pump

二、The classification of magnetic pump

 There are many kinds of magnetic pumps, which can be divided into many types according to the type, working condition and driving principle.
 
(1) PTFE magnetic pump type classification, magnetic driven centrifugal pump, magnetic driven gear pump, magnetic driven screw pump, etc., of which magnetic driven centrifugal pump is the main type of magnetic pump used at present;
 
(2) Classification of PTFE magnetic pump conditions, divided into ordinary magnetic pump, high temperature magnetic pump and corrosion resistant magnetic pump;
 
(3) The driving principle of PTFE magnetic pump is classified into synchronous magnetic drive magnetic pump and asynchronous magnetic drive magnetic pump.
 

 
三、The structural characteristics of magnetic pump (centrifugal)
 

The magnetic pump is mainly composed of pump body, impeller, inner and outer shaft, magnetic coupling mechanism, sliding bearing, coupling and motor.

(1) Magnetic coupling mechanism. The magnetic coupling mechanism of the magnetic pump is composed of an inner and outer magnetic cylinder and an isolating sleeve. The inner and outer magnetic cylinders of the magnetic pump are permanent magnets made of even pairs of rare earth permanent magnet materials, arranged according to the regular distribution, and the working temperature can reach -45~100℃, and the magnetic field direction of the permanent magnet has good anisotropy, and it is not easy to demagnetization.
 
The isolation sleeve of the magnetic pump is mostly made of non-magnetic metal or ceramic material, and the pumping medium and the inner magnetic cylinder are completely sealed, so as to avoid the leakage of the pumping medium.
 
(2) plain bearings. Since the sliding bearing of the magnetic pump is self-lubricating using the transported medium, different materials should be selected to make bearings according to different transport media, of which silicon carbide ceramic bearings and graphite bearings are the main ones.
 
The bearing capacity of silicon carbide ceramic bearing is strong, with strong erosion resistance, chemical corrosion resistance, wear resistance and heat resistance, the use temperature can reach about 500℃, and the service life is long, generally can reach more than 3 a.
 
Compared with silicon carbide ceramic bearings, graphite bearings have good self-lubrication and can withstand short dry runs. Graphite shaft
 
The bearing temperature can be up to 450 ° C, but because of its poor wear resistance, the service life will be less than that of silicon carbide bearings.
 
(3) Cooling lubrication system. When the magnetic pump is running, the annular gap area between the inner magnetic cylinder and the isolation sleeve will produce high temperature due to the magnetic eddy current, and a small amount of medium must be used to wash and cool the annular gap area between the inner magnetic cylinder and the isolation sleeve and the friction pair of the sliding bearing. The washing medium will take away the high temperature, so as to ensure the safe operation of the magnetic pump.
 
If the cooling lubrication inside the magnetic pump is not sufficient, it will cause the temperature of the medium in the ring gap area to be higher than the working degree of the permanent magnet, so that the internal magnetic cylinder gradually loses its magnetism, so that the magnetic drive fails, so the magnetic pump requires that the amount of cooling lubricating media must be ensured.