The inability of a magnetic pump to produce liquid is the most common malfunction of the pump, and there are also many reasons for it. Firstly, check whether there is any leakage in the suction pipeline of the pump, whether the air inside the suction pipeline is discharged, whether the amount of liquid filled in the magnetic pump is sufficient, whether there is any debris blocking the suction pipeline, and whether the pump is reversed. Also, pay attention to whether the suction height of the pump is too high. If the above inspection still cannot solve the problem, the pump can be disassembled for inspection to see if the pump shaft is broken. The dynamic and static rings of the pump should also be checked for integrity, and the entire rotor should be able to move slightly axially. If axial movement is difficult, check if the carbon bearing is too tightly combined with the pump shaft.
The material used for the pump shaft of the magnetic pump is 99% alumina ceramic. The main reason for the pump shaft breaking is that the shaft is twisted and broken due to the dry wear of the bearings during the pump's idle operation. When disassembling the pump for inspection, it can be seen that the bearings are severely worn. The main way to prevent the pump from breaking is to avoid idling the pump.
The material used for the bearings of the magnetic pump is high-density carbon. If the pump runs out of water or there are impurities inside the pump, it will cause damage to the bearings. If the coaxiality requirement between the inner and outer magnetic rotors of the cylindrical coupling cannot be guaranteed, it will directly affect the service life of the bearing.
The reasons for this malfunction caused by insufficient head include: air in the conveying medium, damaged impeller, insufficient rotational speed, excessive specific gravity of the conveyed liquid, and excessive flow rate. The main reasons for insufficient flow are: impeller damage, insufficient speed, high head, and blockage of debris inside the pipe.
The power transmitted by a magnetic steel decreases continuously with the increase of temperature. Generally, the decrease in its transmission capacity is reversible below the working limit temperature of the magnetic steel, while it is irreversible above the limit temperature. That is, after the magnetic steel cools down, the lost transmission capacity can no longer be restored. In special circumstances, when the magnetic coupling slips, the eddy current heat in the spacer will increase sharply, and the temperature will rise sharply. If not handled in a timely manner, it will cause demagnetization of the magnetic steel, leading to the failure of the magnetic coupling. Therefore, a reliable cooling system should be designed for magnetic pumps.
For media that are not easy to vaporize, the cooling circulation system generally leads out the liquid flow from the impeller outlet or pump outlet, and returns to the suction port through the bearing and magnetic transmission part. For media that is easy to vaporize, heat exchangers should be added or the liquid flow should be directed to the storage tank outside the pump to avoid heat returning to the suction port. For media with solid or ferromagnetic impurities, filtration should be considered, and for high-temperature media, cooling should be considered, To ensure that the magnetic coupling does not exceed the operating limit temperature.