What is the stainless steel magnetic pump, stainless steel magnetic pump works

Stainless steel magnetic pump is a magnetic pump, made of stainless steel, widely used in petroleum, chemical, pharmaceutical, electroplating, environmental protection, water treatment, national defense and other departments, is the ideal equipment for transporting flammable, explosive, toxic and valuable liquid , Is to create a leak-free, pollution-free civilization, the best choice for the workshop. What is the stainless steel magnetic pump, stainless steel magnetic pump working principle First, the definition of stainless steel magnetic pump Stainless steel magnetic pump is a magnetic pump by the pump, magnetic actuator, the motor consists of three parts. The key components of the magnetic actuator consists of an outer magnetic rotor, an inner magnetic rotor and a non-magnetic isolation cover. When the motor drives the outer magnet rotor to rotate, the magnetic field can penetrate the air gap and the non-magnetic substance to drive the inner magnet rotor connected with the impeller to rotate synchronously to realize the powerless contact transmission and transform the dynamic seal into the static seal. As the pump shaft, the inner rotor is completely closed by the pump body and the isolation sleeve, thus completely solving the problems of running, running, dripping and leakage, and eliminating the leakage of flammable, explosive, toxic and harmful media through the pump seal in the refining and chemical industry Of the security risks, effectively guarantee the physical and mental health and safety of workers. Second, the working principle of stainless steel magnetic pump The n pairs of magnets (n is even) according to the law arranged in the magnetic clutch on the inner and outer rotor, the magnet part of each other to form a complete coupling of the magnetic system. When the inner and outer two poles are in opposite polarities, that is, the displacement angle between the two poles is Φ = 0, the magnetic energy of the magnetic system is the lowest. When the poles rotate to the same poles, that is, the displacement angle Φ = 2π / n, the magnetic system at this time the maximum magnetic energy. After removing the external force, due to the mutual exclusion of the magnetic poles of the magnetic system, the magnetic force will restore the magnet to the state with the lowest magnetic energy. So the magnet produces the movement, drives the magnetism rotor to rotate. Third, the structural characteristics of stainless steel magnetic pump 1, permanent magnet Permanent magnet made of rare earth permanent magnet material operating temperature range (-45-400 ℃), high coercivity, the magnetic field direction has a good anisotropy, in the When the same pole close to the demagnetization will not happen, is a good source of magnetic field. 2, the isolation sleeve In the use of metal isolation sleeve, isolation sleeve in a sinusoidal alternating magnetic field, in the direction perpendicular to the direction of the magnetic line induced eddy current cross-section and converted into heat. The eddy current is given by: where Pe-eddy current; K-constant; n-pump rated speed; T-magnetic drive torque; F- pressure inside the spacer; D- spacer inner diameter; resistivity of a material; Tensile strength. When the pump is designed, n, T is given conditions, to reduce eddy current only from the F, D and other considerations. Selection of high resistivity, high strength non-metallic materials made isolation sleeve, the effect of reducing eddy current is very obvious. 3, the cooling fluid flow pump operation, you must use a small amount of liquid on the inner rotor and the spacer between the ring gap region and the sliding friction bearing pair for cooling. Coolant flow is typically 2% to 3% of the pump design flow, and the annulus area between the inner magnet rotor and the isolation sleeve generates high heat due to eddy currents. When the cooling fluid is not enough or flushing hole poor, blocked, it will lead to the medium temperature is higher than the permanent magnet operating temperature, the magnetic rotor gradually lost magnetism, the magnetic actuator failure. When the medium is water or water-based liquid, the annulus area can be maintained at 3-5 ℃. When the medium is hydrocarbon or oil, the annulus area can be maintained at 5-8 ℃. 4, sliding bearing magnetic pump sliding bearing materials impregnated graphite, filled with PTFE, engineering ceramics. As the engineering ceramics have good heat resistance, corrosion resistance, abrasion resistance, so the use of magnetic bearings multi-purpose sliding bearing made of engineering ceramics. As the engineering ceramics are very brittle and the expansion coefficient is small, so the bearing clearance must not be too small, in order to avoid the occurrence of axial accidents. As the magnetic pump sliding bearings to the lubrication of the media, it should be based on different media and the use of conditions, the use of different materials made of bearings. Fourth, the advantages of stainless steel magnetic pump 1, because the drive shaft does not need to penetrate the pump housing, but the use of magnetic field through the air gap and the isolation sleeve thin-walled transmission torque, driven by the rotor, thus fundamentally eliminating the shaft seal leakage channel , To achieve a complete seal. 2, there is overload protection when power transmission. 3, in addition to magnetic materials and magnetic circuit design have higher requirements, the remaining part of the technical requirements are not high. 4, stainless steel magnetic pump maintenance and repair workload is small. Fifth, stainless steel magnetic pump defects 1, stainless steel magnetic pump efficiency lower than ordinary centrifugal pump. 2, on the prevention of single-sided leakage of materials and manufacturing requirements set higher. Such as improper choice of materials or manufacturing quality is poor, the isolation sleeve can not withstand the friction between the inner and outer magnets is easy to wear, and once broken, the media will be spilled. 3, stainless steel magnetic pump due to material and magnetic drive restrictions, it is generally only used for domestic transport 100 ℃, 1,6 Mpa below the media. 4, the isolation sleeve material wear resistance is generally poor, so the stainless steel magnetic pump is generally used for conveying medium without solid particles. 5, the coupling requirements of the high, right in the wrong, it will lead to the import of bearing damage and anti-single-sided leakage isolation sleeve wear. Sixth, the failure analysis of stainless steel magnetic pump 1, the magnetic pump due to cavitation problems: pump cavitation caused mainly by the pump inlet tube resistance, gas transmission medium more, filling pump is not enough, pump head can not enough And other reasons. Cavitation is the most damaging to the pump. The pump vibrates violently when cavitation occurs. The serious balance will destroy the pump bearing, rotor or impeller. This is a common cause of magnetic pump failure. 2, no medium or medium flow is small: the rotor shaft and the stability of the dry friction bearings, burning bearings. Magnetic pump is provided by the transmission medium to the sliding bearing lubrication and cooling, without opening the valve or outlet valve in the case of sliding bearing lubrication and cooling without the transmission medium caused by high temperature and thus damaged. 3, the isolation sleeve damage: Magnetic pump magnetic coupling pump is transported by the media cooling, if the media has hard particles, it is easy to cause the isolation sleeve scratched or scratched, and sometimes if the maintenance of improper methods may also cause isolation Set of damage. Seven, stainless steel magnetic pump operation precautions 1, to prevent particles from entering (1) does not allow ferromagnetic impurities, particles into the magnetic clutch and bearing friction. (2) After conveying the easily crystallized or precipitated medium, it should be rinsed promptly (after the pump is stopped, pour water into the pump chamber and discharge clean after running 1min) to ensure the service life of the sliding bearing. (3) When transporting media containing solid particles, filter at the inlet of the pump tube. 2, to prevent demagnetization (1) magnetic moment can not be designed too small. (2) It should be run under the specified temperature, the medium temperature is strictly not allowed. A platinum resistance temperature sensor can be installed on the outer surface of the magnetic pump isolation sleeve to detect the temperature rise in the annulus area so as to alarm or stop when the temperature exceeds the limit. 3, to prevent dry friction (1) is strictly forbidden. (2) It is forbidden to use the medium to empty. (3) With the outlet valve closed, the continuous operation of the pump must not exceed 2 minutes to prevent the magnetic actuator from overheating. In summary: stainless steel magnetic pump is widely used, is a relatively high and expensive production equipment, in the actual production process, proper maintenance, strict compliance with operating procedures is necessary. (Editor: Huang Nengwen QQ :)