How to solve the high temperature of the stator of the shielded pump?

Judging from the phenomenon you said, the temperature of the stator shell is 60 degrees, the temperature of the motor winding should be 60-80 degrees, or higher, the motor winding of the shielded pump is generally H or C, the winding should be no problem, the pump you said is not the maximum allowable temperature, it should be the maximum allowable temperature of the motor inlet is 70 degrees, I don't know the characteristics of the medium you are conveying, how high the temperature will be vaporized, according to what you said, the analysis should lead to medium cavitation, resulting in dry operation of the motor, resulting in local temperature rise, or the bearing is broken, Resulting in the leakage of the shielding sleeve, the medium enters the motor cavity, resulting in the insulation of the winding The bearing lubrication of the shielding pump and the heat of the motor are all realized by the circulation of the medium itself, you can verify the characteristics of the medium, if this is the case, you have no good way to solve it in addition to pouring cooling water on the site, or change the form of the pump, the shielding pump has products designed for transporting easily vaporized media, and can only be replaced.

Then you turn off the backflow, as long as the working flow is higher than the minimum allowable flow rate of the pump, there is no effect on the motor under normal circumstances.

Do canned pumps rely on self-cooling? If you rely on self-cooling, the temperature of your own medium is so high, there is really no good way. It is estimated that the medium temperature is high not because of the high stator temperature, but because the medium temperature is high, because of self-cooling, the stator temperature is high.

The valve is closed small, and the medium works in the pump body and cannot be beaten, so the temperature rises, the temperature is high, and the NPSH also changes, which is likely to lead to cavitation.

If the import pressure is high, it may be better.

If it is self-cooling, he allows the medium to be 70, but the stator temperature is 60 to burn off, which is completely the responsibility of the manufacturer.

Ask the manufacturer, find the relevant technical personnel, guess by yourself or find someone who doesn't want to care, and something will happen.

There are two main structures of shield sleeve, one is welded, and the other is used as a separate wearing part; If it is welded, it can only be cut. On-site or general maintenance conditions can not be handled, find the manufacturer! If the motor winding is fine, the main difficulties after cutting are the welding and leak detection of the shielding sleeve and the vacuum packaging of the shielded motor!

Welding with argon arc welding, this process is more delicate, and it is difficult and difficult for unprofessional personnel to operate.

Beijing** has a special stator sleeve.

Electrical inspection: The unbalance of the three-phase resistance shall not exceed 2%. Insulation Resistance Check:

The insulation resistance of the motor winding of the shielded pump can generally reach more than 100m. If it is less than 5m, it is necessary to analyze the reason, whether the insulation is wet, or whether the shield sleeve has leakage points, etc., if there is no problem with the leakage detection of the stator shielding sleeve, it is purely insulation moisture, and it needs to be dried, if the stator shielding sleeve has a problem, the shielding sleeve needs to be replaced. Restorative overhaul of canned pumpsRestorative overhaul of canned pumps with damaged windings or shield sleeves is required.

The damage is roughly divided into two types: one is that the stator shield is good, and the stator winding has a breakdown to the ground and between phases, and the coil is short-circuited between turns, and the winding is burned out due to overload. The other is that the stator winding is damaged due to the damage of the stator shield sleeve, which causes the medium to invade the stator winding.

In either case, the stator coil and shield will need to be replaced. Due to the special structure of the canned pump, it becomes more complicated to replace the stator winding, and the stator shield sleeve and the sealing plate at both ends must be removed before the stator winding can be removed. After the windings were repaired, new shielding sleeves and seals had to be remade.

The material requirements are special, and the production accuracy is also high.

Shielded pumps and magnetic pumps are different. The stator of the canned pump is energized to produce a magnetic field, and the magnetic field drives the rotor, that is, the shaft of the canned pump, to do work.

The main components of the canned pump are the impeller and volute of the centrifugal pump. However, since both the body of the pump and the driving machine are enclosed in a pressure vessel filled with water pumping medium, the pressure vessel has a static seal. However, there is no traditional rotary pump seal.

Static seals, on the other hand, are easier to achieve than dynamic seals to achieve a complete seal. As a result, the canned pump can be completely leak-free.

The canned pump is mainly used to transport flammable, explosive, highly toxic and other petrochemical liquids, so as to improve the safety and reliability of the operation of petrochemical plants.

The shield pump uses the same shaft to fix the rotor of the motor and the impeller of the pump together, and then shields this group of rotors with a shield sleeve. The stator of the motor surrounds the shield sleeve, which is made of metal, so that the power can be transmitted to the rotor through the magnetic field. The entire rotor is run in the pumped liquid.

The end of the shield is statically sealed by flange or welded structure. The shield sleeve is actually a pressure vessel.

In addition to the shielding sleeve, there is also a component that is the circulation tube. The use of pumped fluids plays a very important role in lubricating and cooling bearings, and sometimes in cooling motors.

The inner surface of the stator and the outer surface of the rotor are equipped with stator and rotor shields made of corrosion-resistant sheet metal. The respective end faces are welded with corrosion-resistant metal sheets. It is separated from the conveyed liquid, so that the stator winding core and the rotor core are not corroded.

The circulating pipe generally introduces a small part of the conveyed liquid (about 1% of the total flow rate) from the pump discharge outlet, after filtration, through the circulating pipe, first lubricates and cools the bearing, and then cools through the gap between the stator shield sleeve and the rotor shielding sleeve, and then lubricates the cooling front bearing, and finally flows back to the impeller inlet through the impeller balance hole.

The shielding sleeve of the canned pump, i.e., the stator shield and the rotor shield, are used to prevent the conveying medium from soaking the stator winding and rotor core. However, due to the existence of the shielding sleeve, the gap between the stator and the rotor of the motor increases, resulting in eddy currents in the shielding sleeve, resulting in the decline of motor performance and the increase of power loss.

In order to reduce power loss, the inner diameter of the stator of the shielded motor is usually relatively small, the wall thickness of the shielding sleeve is as thin as possible, and the shielding sleeve material is selected as a non-magnetic material. Therefore, the shielded motor is usually a slender structure. The shielding sleeve material is mostly L, 316,316L stainless steel.

Although the eddy current loss of Hastelloy C and titanium is small, the cost is high, so it is rarely used. The thickness of the shield sleeve is generally.