What problems should be paid attention to when using a canned pump

The canned pump is a type of centrifugal pump, but there are some differences in use:

1. Before starting, open the inlet valve to let the liquid enter the pump chamber, and discharge the gas in the pump through the exhaust needle valve at the end of the pump.

2. Because the motor of the shielded pump is in the pump body, it is necessary to prevent foreign matter from entering the pump body and damaging the insulation layer of the coil, and generally install a filter at the inlet of the pump.

3. When the pump starts, the outlet of the pump should be slightly open and cannot be closed, which is different from the ordinary centrifugal pump, because the shielded pump is to reduce the temperature of the motor by circulating the material in the pump through the pressure difference between the inlet and outlet of the pump, so the pump outlet must not be closed.

4. When the canned pump is running, it is necessary to observe the bearing indicator, and the pointer can not be in the red area, if it is in the red area, it is necessary to confirm whether the bearing is seriously worn, and the bearing should be replaced immediately.

5. The canned pump can not be seen to be positive or negative externally, and it can be judged according to the outlet pressure when it is used for the first time.

6. Before using the canned pump with jacket, the jacket should be filled with suitable medium and preheated or cooled in advance.

7. When conveying volatile materials, when the deactivation time is long, it is necessary to exhaust first and start it. If the pressure or flow rate is less than the normal value during use, the exhaust can be exhausted first, and then other factors can be judged.

The canned pump should be installed in a well-ventilated, dry, and chemical-free environment.

Before using a canned pump, you should check whether the various parts of the pump are in good condition, such as impellers, bearings, seals, etc.

When using a canned pump, you should pay attention to whether the inlet and outlet of the pump are properly connected to avoid water leakage or poor operation of the pump.

When using a canned pump, you should pay attention to whether the power supply of the pump is stable, so as not to affect the operation of the pump due to too high or too low voltage.

When using the canned pump, you should pay attention to whether the pump is running normally, and if there is any abnormality, it should be stopped in time for inspection.

When using a canned pump, you should pay attention to the maintenance of the pump, such as regularly changing the lubricating oil, cleaning the filter, etc.

When using a canned pump, attention should be paid to the safety of the pump, such as prohibiting maintenance, cleaning and other operations when the pump is running.

1. The resistance of the motor winding coil is normal, and the pump cannot be rotated. The reason is that the dry grinding caused by the liquid-free operation, and the rotor sleeve and graphite bearing are stuck. or other mechanical failures caused by jamming.

Solution: Disassemble the canned pump, clean the accessories, and find the fault point. Repair or replacement of accessories.

2. The motor is fine, but the running current is too large, the reason is that the liquid is not delivered enough. There is a dry grinding situation. Or there is an inherent deviation between the mechanical jam and the motor end cap.

Solution: After decomposition. Cleaning and reassembly.

3. The operation noise is very large, and the running current is also unstable。The reason is that the rotor sleeve, thrust disc and graphite bearing are severely worn. Dismantle the canned pump.

Wash and replace worn parts. The graphite bearing and the bearing end cover are over-mated, and the bearing end cover must be heated before the graphite bearing can be removed or installed. Pay attention to the fit size when assembling.

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Precautions for the use of canned pumps.

1. In the normal operation process, the outlet valve should not be closed, and the slightly open state should be maintained to prevent air resistance in the pump.

2. It is strictly forbidden to run without liquid and run without flow for more than 1 minute to prevent damage to the motor and bearing.

3. It is strictly forbidden to run in reverse direction for more than 1 minute, as reverse operation may lead to abnormal wear of the bearing.

4. It is strictly forbidden to operate in the cavitation state, otherwise it will lead to early wear of the bearing.

Because the canned pump is a sliding bearing, it needs to be lubricated by the conveying medium, and the canned pump cannot run without the medium.

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Failure analysis and judgment of canned pump:

1. Judged by the analysis of the wear and tear of the parts when the pump is dismantled

a. The mouth ring of the pump body and the impeller mouth ring are worn, indicating that the inner diameter of the bearing is worn excessively and the bearing needs to be replaced.

b. The front cover plate of the impeller and the pump body are worn, indicating that the end face of the front bearing is worn excessively and the bearing needs to be replaced.

c. The inner diameter of the bearing is worn, the shaft sleeve and thrust plate are worn and the color turns black, indicating that the gas in the motor cavity is not discharged, lacks liquid or idle, and the spare parts need to be replaced.

d. The end face of the front bearing and the surface of the thrust plate are worn, and the rear bearing and thrust plate are not worn, indicating that the shaft thrust is forward and the pump is in a state of lack of liquid. Check the inlet filter for clogging, the system for insufficient liquid supply, and the pump for cavitation.

e. The end face of the rear bearing and the surface of the thrust plate are worn, and the front bearing and thrust plate are not worn, indicating that the shaft thrust is backward, and the flow rate may be too large, check whether the outlet valve is opened too much.

f. The stator and rotor shielding sleeves are worn, and the inner diameter of the bearing does not exceed the limit value, indicating that there are foreign objects entering the motor cavity, and check whether the inlet filter is damaged.

2. Judged by the vibration and noise analysis of the pump

a. The pump has vibration, and the vibration source comes from the two bearings of the motor part, which means that the bearing is worn, and the bearing wear needs to be checked.

b. The pump has vibration, the vibration source comes from the pump body, the outlet valve is closed, the pump pressure is normal, but the valve is opened, the pressure gauge indicates a sudden drop, and the operating current is lower than the normal value, indicating that the pump cavitation state, and the inlet liquid level height needs to be increased to meet: device NPSH = pump NPSH.

c. The pump is vibrating, there is noise, the TRG meter indicates that it is in the red zone, and the pump outlet pressure gauge is large or not the normal pressure, indicating that the pump is reversed, and the phase sequence of the power line needs to be adjusted.

3. Analyze and judge by the TRG table

a. The table indicates that the bearing is in the yellow area or red area (other conditions are normal), indicating that the bearing has been worn and needs to be replaced.

b. The table indicates that it is in the green area, but there is vibration in the bearing part of the motor side, and the bearing has been worn out excessively after disintegration, indicating that the module is faulty and cannot be indicated normally and needs to be replaced.

c. After the pump is turned on for the first time or the power line is reconnected (that is, when the bearing is not worn), the table indicates that it is in the red zone, indicating that the pump is reversing and the phase sequence of the power line needs to be adjusted.

d. After the pump is opened, there is no reaction on the surface and the motor is very small humming, indicating that the pump power line is out of phase, and the electrical circuit needs to be checked.

e. After the pump is turned on, there is no reaction in the meter, but the outlet pressure and current are normal, indicating that the meter has been damaged and needs to be replaced with a new one.

f. After starting, the meter indication is too large and not in the zero position (in the case of confirming the non-bearing wear) after disconnecting the U, V and W wires on the module from the binding post, and then opening the pump pointer indicating at the zero position, indicating that the voltage is too high, there is a magnetic field or the frequency conversion equipment interferes with the meter, and the frequency conversion module can be replaced.

A canned pump is a sealless pump in which both the pump and the drive motor are sealed in a pressure vessel filled with pumped medium, which is only statically sealed and consists of a set of wires to provide the rotating magnetic field and drive the rotor. This structure eliminates the need for a rotating shaft seal with conventional centrifugal pumps, so it is completely leak-free.

The canned pump connects the pump and the motor together, the rotor of the motor and the impeller of the pump are fixed on the same shaft, and the rotor and stator of the motor are separated by the shielding sleeve, and the rotor runs in the medium to be conveyed, and its power is transmitted to the rotor through the stator magnetic field. Shanghai Aier pump valve reference selection.

The pumping medium is filled with a pressure housing in which there is only a static seal. The rotor of the motor and the impeller of the pump are fixed on the same shaft, and the rotor and stator of the motor must be separated by a shielding sleeve, and the rotor rotates in the medium to be conveyed, and its power is transmitted to the rotor through the stator magnetic field. This structure eliminates the need for a rotating shaft seal with traditional centrifugal pumps, allowing for a complete leakage of religious ceremonies.

Structural features of the canned pump.

Advantages: Compared with the sealed pump, it saves the trouble of repairing and replacing the seal, and also saves the coupling, so the number of parts is less and the reliability is high; The fan of the motor without rolling bearings does not need to be lubricated, and the operation is smooth and the noise is low. Plain bearing wear monitor can be configured to detect bearing wear; Compact structure, small space occupation, low requirements for base and foundation, no coupling centering problems, easy installation and low cost, less daily maintenance workload, low maintenance cost; Can be used in a vacuum system or:

"Vacuum" and "positive pressure" alternate operation without leakage, can be used to send materials from the vacuum tank to other containers under high vacuum level; It has a wide range of applications, and can meet the requirements for various working conditions such as high temperature, high pressure, extremely low temperature, and high melting point.

Disadvantages: Because the sliding bearing is used and the medium to be conveyed is lubricated, the medium with poor lubrication is not suitable for the shielded pump to be transported. Generally, the viscosity range of the medium suitable for canned pumps is; The efficiency of canned pumps is generally lower than that of sealed centrifugal pumps, but in the case of medium and low power, the total efficiency of the latter is not much different compared to double-acting mechanical seal pumps due to the increased power consumption of the cooling and flushing system; When moving, the flow rate should be higher than the minimum continuous flow, because in the case of small flow rates, the pump efficiency is low and will cause heating, which will cause the fluid to evaporate and cause the pump to run dry, causing damage to the plain bearing.

The canned pump mainly works in water or liquid, also known as submersible pump and submersible pump, its power consumption is about the same as that of centrifugal pumps of the same specification, and the noise is smaller than that of ordinary centrifugal pumps. The advantages of the canned pump are very obvious, it is designed for shielding purposes, and the disadvantage is that the process is more complicated, and the shielding sleeve requires special materials, such as stainless steel.

Shielded pumps are also called packless pumps. It is a fully enclosed pump formed by connecting the impeller and the rotor of the motor in the same sealed shell, which is called a canned pump. Its structural features:

The impeller of the pump and the rotor of the motor are on the same shaft, installed in the same sealed housing, and there is no coupling and shaft sealing device, which fundamentally solves the problem of leakage of the conveyed liquid. Advantages: no media leakage; Compact structure, vertical small pipeline canned pump can be installed directly on the pipeline without setting the foundation; There is no coupling, no need to align when disassembling and assembling, and it is convenient to operate and maintain; The bearing does not need to be lubricated with oil or grease; It is suitable for conveying flammable, explosive, toxic, radioactive and valuable liquids.

Disadvantages: difficult to manufacture and high cost of shielding sleeve; Because the rotor of the motor rotates in the liquid, the frictional resistance increases, and the view of the original post

Remember to adopt it.

It belongs to centrifugal pumps, and generally the motor shaft and pump shaft are one shaft.

Working principle: The drive of the ordinary centrifugal pump is to connect the impeller shaft of the pump with the electric shaft through the coupling, so that the impeller and the motor rotate together and work, while the shielded pump is a sealless pump, and the pump and the drive motor are sealed in a pressure vessel filled with pumped medium;

The pressure vessel is statically sealed and consists of a set of wires that provide a rotating magnetic field and drive the rotor, eliminating the need for a rotating shaft seal with conventional centrifugal pumps, resulting in complete leakage-free.

Yes, but there may be some damage to the pump, and it will increase the resistance of the pipeline, you can make a bypass for the pump, and you can use the bypass after the power supply is disconnected, so that it will not increase the resistance and have no impact on the pump industry.

Can you elaborate on that? After the power is off, the motor stops running, the impeller does not rotate, how can there be water flow, and there will be no water flow without power for vertical conveying.

Your question is too vague by what does it mean? What do you do when the power is off, don't you have to close the valve when the pump is stopped?

Wait a few minutes for a given sub cooling time.

A canned pump is a device used to control the flow of fluids and is commonly used in industrial and construction fields. The following are the steps to operate a canned pump in general: Preparation:

Make sure you understand how the canned pump works and safe operating procedures, and wear the necessary personal protective equipment. Check the status of the pump: Check that the power to the pump is turned off and make sure that all valves and pipe closures of the pump are closed.

Open the pump's inlet valve: As needed, open the pump's inlet valve so that fluid can enter the pump. Power on the pump:

According to the pump's operating manual or instructions, turn on the pump's power and start the pump's motor. Monitor pump operation: Once the pump is started, you need to monitor the operation of the pump to ensure that it is working properly.

Pay attention to the pressure, flow and temperature parameters of the pump, as well as any abnormal noise or vibration. Turn off the pump: When you need to stop the pump from running, first turn off the power to the pump and then close the inlet valve.

Please note that the above steps are for reference only and may vary depending on the canned pump model and application scenario. Before operating the canned pump, be sure to carefully read and follow the relevant operating manuals and safety procedures, and follow the relevant operating instructions. If you are not familiar with the operation of a canned pump or have any questions, please consult a professional or relevant technical support.