The Roots vacuum pump unit is a vacuum unit composed of a Roots vacuum pump and a front stage pump in series. The vacuum limit usually reaches 0.02 from a vacuum degree of 2pa. The method to start the Roots vacuum pump is to connect the unit to the suction container, add cooling water from the Roots vacuum pump, open the front stage pump, and then slowly open the main valve (usually the inlet valve of the Roots vacuum pump). At this point, the Roots pump starts to rotate. When the vacuum of the container reaches 1000-500pa, start the Roots pump until the required vacuum degree is reached. Now, let's learn about the starting and stopping methods and operating precautions of the Roots vacuum pump unit together!

1. Preparation before starting the Roots vacuum pump

Check if the liquid level in the water tank of the flushing pump (front stage pump) reaches more than 3/4 of the water tank, and supplement it if it is insufficient.

Check if the water in the water tank is clean, do not use sewage containing sediment or block the pipeline. Roots vacuum pump will increase the wear of the pump impeller, increase the motor load and cause malfunctions, affecting the pump's lifespan.

Check the height of the lubricating oil level in the middle pump and main pump body, to at least 3/4 of the oil window. At the same time, check the color of the lubricating oil. When there are many milky white or black foreign objects in the Roots vacuum pump, notify the machine to replace the lubricating oil.

Check if the circulating cooling water circuit of the intermediate pump and main pump is normal with the Roots vacuum pump. Open the inlet and outlet valves of the circulating cooling water and check if the inlet and outlet of the circulating cooling water are normal.

Check if the discharge valve of the buffer tank at the bottom of the intermediate pump is closed.

Check whether the circuit of the vacuum pump unit and the various indicators of the control cabinet are normal.

Check if the starting pressure of the intermediate pump and main pump on the electrode contact pressure gauge of the vacuum pump unit is normal (the starting inlet pressure of the intermediate pump is not less than 0.065Mpa, and the starting inlet pressure of the main pump is not less than 0.085Mpa).

After the above inspection is completed and confirmed to be correct, start the vacuum unit.

2. Working of Roots vacuum pump unit

Open the inlet and outlet valves for the circulating cooling water of the intermediate pump and main pump, and confirm that the circulating cooling water is in and out normally.

Close the drainage valve of the pump buffer tank, start the pump, wait for normal operation, and slowly open the valve on the bypass pipeline of the front stage pump and the intake valve of the Roots vacuum pump.

When the system pressure reaches the allowable inlet pressure set by the intermediate pump, start the intermediate pump. When using the automatic control range, directly switch to the automatic control range to automate the unit startup process.

When manually controlled, start the main pump after the outlet pressure of the intermediate pump reaches the allowable inlet pressure of the main pump.

3. Precautions for the operation of Roots vacuum pump

The acoustic response of the vacuum unit during operation is uniform, without any noise, and there is no irregular abnormal vibration during operation.

Pay attention to the motor load and the temperature rise of each part of the pump. Under normal circumstances, the Roots vacuum pump should not exceed a high temperature rise of 40. The maximum working temperature should not exceed 80.

When oil leakage is found during homework, please stop the work immediately, release the pressure, and then inspect and repair. Roots vacuum pump is not allowed to continue working or apply pressure for inspection after discovering oil leakage. It is necessary to ensure the normal inflow and outflow of circulating