Reasons why the rotary vane pump in the oil-free vacuum pump and rotary vane pump-based vacuum system fails to start
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WLW oil-free vertical vacuum pump: primary pump model 300, secondary Roots pump models ZJ.ZJB600; buffer tank capacity of around 1 m3. During use in the workshop, the primary pump is operated at a pressure of around -0.095 before the Roots pump is started, but it shuts down after operating for a short time. What are the main reasons for this? Thank you! The installation diagram is as follows:
Maintenance and troubleshooting of Roots vacuum pumps https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=3283699&shareuid=4554153
Thanks, I went to see it! A bit too simple and general
Is the oil level in the Roots pump too high? Judging from the design of the diagram, if there is no buffer tank for the exhaust gases, over time condensate may cause blockages in the exhaust system. By measuring the operating current of the pumps at the front and back stages, it is possible to determine where the problem lies
It’s the Roots pump motor that has an overcurrent
It’s already running. I cleaned and replaced the air valves that didn’t have oil pumps in the preceding stage. Overall, I think the exhaust pipe should point downward to avoid any resistance. Thank you for your attention!
The Roots pump should have an oil level gauge, which allows one to see if it has been overfilled with oil or if water has entered it； The buffer tank should have a liquid level gauge or a drain bottom valve.
If there are no faults with the Roots pump, it has a start-up pressure limit, which depends on the maximum pressure difference of the Roots pump as well as the compression ratio with the pump upstream of it. It is recommended that your company set the startup pressure to -0.097 MPa ； If the Roots pump fails, it is recommended to repair the pump by cleaning its internal components and rotor; as long as the load is not high, it should not trip. For further discussion: 0576-88206580.