Installation, use and maintenance methods for chemical centrifugal pump

The working principle of the chemical centrifugal pump is that when the pump is filled with water, the impeller rotates to produce centrifugal force, and the water in the impeller groove is thrown to the periphery and flows into the pump casing under the action of centrifugal force, so the pressure in the center of the impeller decreases, and the pressure is lower than the pressure in the inlet pipe, and the water flows into the impeller from the suction pool under the action of this pressure difference. In this way, the pump can continuously draw water and supply water continuously. In addition to the role of the impeller, the role of the spiral pump casing is also very important. The liquid that has gained energy from the impeller has a large function when it flows out of the impeller, and the liquid is collected in the spiral pump casing and converts the kinetic energy into pressure energy in the diffusion tube at the back.

Compared with other types of pumps, chemical centrifugal pumps have the advantages of simple structure, not easy to wear, stable operation, low noise, uniform water output, convenient adjustment and high efficiency, so chemical centrifugal pumps have been widely used.

Precautions for the use of chemical centrifugal pumps

Installation instructions

1. The weight of the pipeline should not be added to the pump during installation, and there should be their own supporting body, so as not to affect the operation performance and life of the deformation.

2. The pump and motor are integral structure, and there is no need to align them during installation, so it is very convenient to install.

3. The anchor bolts must be tightened during installation to avoid the impact of vibration on the performance of the pump during starting.

4. Before installing the pump, carefully check whether there are hard objects (such as stones, iron particles, etc.) in the pump flow channel that affect the operation of the pump, so as to avoid damage to the impeller and pump body during the operation of the pump.

5. In order to facilitate maintenance and use safety, install a regulating valve on the inlet and outlet pipelines of the pump and a pressure gauge near the outlet of the pump to ensure the operation within the rated head and flow range, ensure the normal operation of the pump, and prolong the service life of the pump.

6. The pump should be equipped with a foot valve when used for suction lift occasions, and there should be no too many curves in the inlet pipeline, and there should be no water leakage or air leakage.

7. The discharge line, such as check valve, should be installed outside the gate valve.

8. After installation, toggle the pump shaft, the impeller should have friction sound or jamming, otherwise the pump should be disassembled to check the cause.

9. The installation method of the pump is divided into rigid connection and flexible connection installation.

Starting & Parking:

1. Preparation before starting

① Turn the motor blade by hand, and the impeller should be free of jamming and flexible rotation.

② Open the inlet valve, open the exhaust valve to fill the entire pump chamber with liquid, and then close the exhaust valve.

③ Rotate the pump by hand to allow the lubricating fluid to enter the end face of the mechanical seal.

④ Jog the motor to determine if the steering is correct.

2. Start and run

① Open the inlet valve fully and close the discharge line valve.

② Turn on the power supply, when the pump reaches the normal speed, gradually open the valve on the discharge pipeline, and adjust to the required working conditions.

③ Pay attention to observe the instrument reading, check the leakage of the shaft seal, the mechanical seal leakage under normal times, < 3 drops/min, check the temperature rise of the motor and bearing ≤=70 degrees C, if any abnormal situation is found, it should be dealt with in time.

3. Parking

① Gradually close the valve of the discharge line and cut off the power supply.

② Close the inlet valve.

③ If the ambient temperature is lower than 0°C, the liquid in the pump should be drained to avoid freezing and cracking.

④ If it is out of use for a long time, the pump should be disassembled and cleaned, packaged and stored.

Pump Maintenance & Maintenance:

1. Maintenance and maintenance in operation

① Water lines must be highly sealed.

② It is forbidden for the pump to run for a long time in the cavitation state.

③ It is forbidden for the pump to run for a long time when the flow rate is running, and the motor is overcurrent.

④ Check the pump regularly when it is running, and the motor is running for a long time with overcurrent.

⑤ The pump should be supervised by a special person during operation to avoid accidents.

⑥ The bearings should be refueled every 500 hours of pump operation. The motor power is more than 11KW and equipped with a lubrication device, which can be directly injected by a high-pressure oil gun to ensure that the bearing is lubricated well.

⑦ After the pump is operated for a long time, due to mechanical wear, the noise and vibration of the unit increase, it should be stopped for inspection, and the wearing parts and bearings can be replaced if necessary, and the overhaul period of the unit is generally one year.

2. Maintenance and maintenance of mechanical seals

① Mechanical seal lubrication should be clean and free of solid particles.

② It is strictly forbidden for the mechanical seal to work in the case of dry grinding.

③ The pump (motor) should be coiled several times before starting, so as to avoid the breaking and damage of the sealing ring caused by sudden starting.