Analysis of the advantages of magnetic pump structure
Magnetic pumps are widely used in chemical companies and electronics factories. They are mainly used to transport HF, nitric acid, sulfuric acid, hydrochloric acid and other materials, and are suitable for transporting highly corrosive materials. So what are the advantages of magnetic pumps compared to other water pumps? This article will explain in detail.
To understand the advantages of magnetic drive pumps, it is necessary to start with the structure principle of magnetic drive pumps: Magnetic drive pumps are composed of three parts: pump, magnetic drive, and motor. The key component of the magnetic drive consists of an outer magnetic rotor, an inner magnetic rotor and a non-magnetic isolation sleeve. When the motor drives the outer magnetic rotor to rotate, the magnetic field can penetrate the air gap and non-magnetic materials, and drive the inner magnetic rotor connected to the impeller to rotate synchronously, realizing the contactless transmission of power and transforming the dynamic seal into a static seal. Because the pump shaft and inner magnetic rotor are completely enclosed by the pump body and the isolation sleeve, the problem of "running, emitting, dripping and leakage" is completely solved, and the leakage of flammable, explosive, toxic and harmful media in the petrochemical industry through the pump seal is eliminated. The potential safety hazards effectively ensure the physical and mental health and safe production of employees. N pairs of magnets (n being an even number) are assembled on the inner and outer magnetic rotors of the magnetic drive in a regular arrangement, so that the magnet parts form a complete coupled magnetic system with each other. When the inner and outer magnetic poles are opposite to each other, that is, the displacement angle between the two magnetic poles Φ=0, the magnetic energy of the magnetic system is the lowest; when the magnetic poles rotate to the same pole, the displacement angle between the two magnetic poles is Φ=2π /n, the magnetic energy of the magnetic system is maximum at this time. After removing the external force, since the magnetic poles of the magnetic system repel each other, the magnetic force will restore the magnet to the lowest magnetic energy state. Then the magnets move, driving the magnetic rotor to rotate.
Compared with centrifugal pumps using mechanical seals or packing seals, magnetic pumps have the following advantages:
a. The pump shaft changes from a dynamic seal to a closed static seal, which completely avoids medium leakage.
b. No need for oil lubrication and cooling water, reducing energy consumption.
c. From coupling drive to synchronous drag, there is no contact and friction. Low power consumption, high efficiency, and has the effect of damping and vibration reduction, reducing the impact of motor vibration on the pump and the impact on the motor when the pump occurs cavitation vibration.
d. When overloaded, the inner and outer magnetic rotors slip relatively, which protects the motor and pump. When the driven part of the magnetic drive is running under overload or the rotor is stuck, the main and driven parts of the magnetic drive will automatically slip off to protect the pump.
At this time, the permanent magnet on the magnetic actuator will produce eddy loss and magnetic loss under the action of the alternating magnetic field of the active rotor, which will cause the temperature of the permanent magnet to rise and the magnetic actuator to slip and fail.
