Speedy Cnc Engraving Machine,Automatic Speedy Cnc Engraving Machine,Carving Machine Cnc Engraving,Precision Speedy Cnc Engraving Machine WEISS MACHINERY CO., LTD. , https://www.weissmachinerys.com
First, the principle of magnetic pump The n pairs of magnets (n is an even number) are arranged in a regular arrangement on the magnetic drive of the magnetic rotor, the magnetic rotor, so that the magnetic parts of the complete composition of the magnetic system. When the inner and outer magnetic poles are opposite each other, ie, the displacement angle Φ=0 between two magnetic poles, the magnetic energy of the magnetic system is the lowest; when the magnetic pole rotates to the same polarity, ie, the displacement angle between two magnetic poles Φ=2π /n, the magnetic energy of the magnetic system is maximum at this time. After removing the external force, because the magnetic poles of the magnetic system repel each other, the magnetic force will restore the magnet to the state with the lowest magnetic energy. The magnet then moves to drive the magnetic rotor.
Second, the structural characteristics Permanent magnet valve Permanent magnets made of rare earth permanent magnets have a wide operating temperature range (-45-400°C), high coercive force, good anisotropy in the direction of the magnetic field, and will not be close to the same polarity. Demagnetization is a good source of magnetic field.
2. Insulating sleeve pump valve In the use of metal isolation sleeve, the isolation sleeve is in a sinusoidal alternating magnetic field, and the eddy current is induced in the section perpendicular to the direction of the magnetic force line and converted into heat. The vortex expression is:. Among them, Pe-vortex, K-constant, n-rated speed of the pump, T-magnet drive torque, pressure in the F-spacer, D-spacer inner diameter, resistivity of a material, tensile strength of the material. When the pump is designed well, n and T are given by working conditions. To reduce eddy currents, only F, D, and so on can be considered. The use of high-resistivity, high-strength non-metallic materials to make isolation sleeves is very effective in reducing eddy currents.
3. Control of Cooling Lubricant Flow When the pump is running, a small amount of liquid must be used to flush and cool the annulus region between the inner magnetic rotor and the isolation sleeve and the friction pair of the sliding bearing. The coolant flow rate is typically 2%-3% of the pump design flow rate, and the annulus area between the inner magnetic rotor and the isolation sleeve generates high heat due to eddy currents. When the cooling lubricating fluid is not enough or the flushing hole is not smooth and blocked, the medium temperature will be higher than the working temperature of the permanent magnet, so that the magnetic rotor will gradually lose its magnetism, and the magnetic actuator will fail. When the medium is water or a water-based liquid, the temperature rise in the annular region can be maintained at 3-5°C. When the medium is hydrocarbon or oil, the temperature rise in the annular region can be maintained at 5-8°C.
4. Sliding bearing magnetic pump sliding bearing materials are impregnated graphite, filled PTFE, engineering ceramics and so on. Because the engineering ceramics have good heat resistance, corrosion resistance, and friction resistance, the magnetic bearings of the magnetic pump are mostly made of engineering ceramics. Because the engineering ceramics are brittle and the expansion coefficient is small, the bearing clearance must not be too small to avoid shaft accidents.
Since the magnetic pump's sliding bearings are lubricated with the medium being transported, bearings should be made of different materials according to different media and operating conditions.
5. Protection measures When the driven parts of the magnetic drive are operated under overload conditions or the rotor is stuck, the main and driven parts of the magnetic drive will automatically slip off and protect the pump. At this time, the permanent magnets on the magnetic actuator will generate eddy loss and magnetic loss under the action of the alternating magnetic field of the active rotor, causing the permanent magnet temperature to rise and the magnetic actuator to slip out of effect.
Third, the advantages of magnetic pumps Compared with the use of mechanical seals or packing sealed centrifugal pumps, magnetic pumps have the following advantages.
1. The pump shaft changes from a dynamic seal to a closed static seal, completely eliminating media leakage.
2. No need for separate lubrication and cooling water, reducing energy consumption.
3. The coupling is driven synchronously by the coupling and there is no contact and friction. The utility model has the advantages of small power consumption, high efficiency, damping effect, and reduction of the influence of motor vibration on the pump and the influence of the cavitation vibration of the pump on the motor.
4. When overloaded, the inner and outer magnetic rotors are relatively slippery, which protects the motor and the pump.
Fourth, the operation of attention 1. Prevent particles from entering (1) Do not allow ferromagnetic impurities, particles into the magnetic actuator and bearing friction pairs. (2) After the easy-to-crystallize or sedimentation medium is conveyed, it should be rinsed in time (pump water into the pump chamber after pump is stopped, discharge it clean after 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. Preventing demagnetization (1) Magnetic torque cannot be designed too small. (2) It should be operated under the specified temperature conditions, and the medium temperature is strictly prohibited. A platinum resistance temperature sensor can be installed on the outer surface of the isolation sleeve of the magnetic pump to detect the temperature rise in the annular area so that the temperature can alarm or stop when the temperature exceeds the limit.
3. Prevent dry friction (1) Never run dry. (2) The medium is forbidden to be evacuated. (3) When the outlet valve is closed, the continuous operation time of the pump must not exceed 2 minutes to prevent the magnetic actuator from overheating and losing.
Magnetic pump working principle and precautions
The magnetic pump consists of a pump, a magnetic actuator, and an electric motor. The key components of the magnetic actuator consist of an outer magnetic rotor, an inner magnetic rotor, and a non-magnetically conductive isolation cover. When the motor drives the outer magnetic rotor to rotate, the magnetic field can penetrate the air gap and the non-magnetic material, drive the inner magnetic rotor connected with the impeller to rotate synchronously, realize the dynamic non-contact transmission, and transform the dynamic seal into a static seal. Because the pump shaft and the magnetic rotor are completely closed by the pump body and the isolation sleeve, the problem of “running, running, dripping, and leaking†is completely solved, and the leakage of flammable, explosive, toxic, and harmful media through the pump seal in the oil refining chemical industry is eliminated. The security risks have effectively ensured the physical and mental health and safety of employees.