Seeking advice on difficult issues with Roots pumps!
Thread Content
Our company has recently installed a new set of vacuum units, with an oil pump as the pre-stage pump and a rotary vane pump as the subsequent stage. The pre-pump achieves an absolute vacuum of around 100 Pa, after which the Roots pump is turned on, causing the vacuum level to drop to 700 Pa. The secondary Roots pump was a brand-new unit; upon contacting the manufacturer to have another Roots pump replaced, the same problem persisted. However, using an old Roots pump that was three years old allowed the system to reach a pressure of 50 Pa. The issue of leaks in the pipes has been ruled out. Does anyone know what the problem might be? I would appreciate any advice you can offer!
Are the pump model parameters the same for new and old pumps? I suspect it’s a problem with the selection of the new pump itself – the two units might differ from each other; P
I need to go out urgently; I’ll get back to you tomorrow
The old and new models are the same; the difference is that one was produced four years ago while the other was produced this year
Just looking at the supplier and model, there is no change; later, a water pump was connected to the same rotary vane pump – the water pump can generate 2000 Pa of pressure, while the rotary vane pump can reach 200 Pa under that pressure. But the oil pickup pump is wrong; it’s very strange.
We can replace the unit set for free, and use the electricity savings generated over two years to cover the costs associated with the vacuum level issue. If you are interested, feel free to contact me.
There must be a problem with this Roots pump
You’re welcome. I’m not sure if my answer can help you, but I hope it will resolve the inconvenience as soon as possible... 1. There is a problem with the casting of the Roots pump. (The manufacturing process for castings has changed; are the rotary pump castings now produced using investment casting?) 2. There is a problem with the oil used in rotary pumps. Check it out. If needed, you can also contact Engineer Hu at 0533-3881899
Our company has recently installed a new set of vacuum units, with an oil pump as the pre-stage pump and a rotary vane pump as the subsequent stage. The pre-pump achieves an absolute vacuum of around 100 Pa, after which the Roots pump is turned on, causing the vacuum level to drop to 700 Pa. The secondary Roots pump was a brand-new unit; upon contacting the manufacturer to have another Roots pump replaced, the same problem persisted. However, using an old Roots pump that was three years old allowed the system to reach a pressure of 50 Pa. The issue of leaks in the pipes has been ruled out. Does anyone know what the problem might be? I would appreciate any advice you can offer! 1. You concealed the fact that this is only an initial phenomenon and it will pass in a while... 2. If the vacuum pump with a water intake ring can reach 2000 Pa when started, it further illustrates the problem