Vacuum Pump Rotary Pump Diffusion Pump Molecular PumpPublished on 26/8/2018 and last updated on 1/9/2018
The pump utilized to create a vacuum inside a closed container is called a vacuum pump. Absolute vacuum cannot be created, hence the degree of vacuum comes into picture when we discuss a vacuum pump. Any vacuum pump has three main features.Please Rate this Article
Degree of Vacuum
Degree of Vacuum
Exhaust Pressure of a Vacuum PumpAny vacuum pump has an outlet and an inlet. The gaseous substance or air of the vessel to be vacuum enters in the pump through the inlet and gets out from the pump to the atmosphere through the outlet of the pump. The process is controlled by a valve mechanism. Exhaust pressure is the pressure measured at the outlet of the pump. This pressure can be equal to or lower than the atmospheric pressure. Different vacuum pumps are rated for different exhaust pressure. Normally, pumps for creating high vacuum have low exhaust pressure. For very creating a very high vacuum, very low exhaust pressure of the pump is required such as 10 - 4 or 10 -7 Torr. For creating a very high vacuum backing pump is used along with the main vacuum pump. Here, the vacuum pressure or exhaust pressure of the vacuum pump is first maintained by the backing pump then the main vacuum pump is run. The vacuum pressure created by a backing pump is called forced vacuum or blacking pressure.
Degree of Vacuum of a Vacuum PumpThe minimum pressure can be created by a vacuum pump is called the degree of vacuum of that pump. Theoretically, it is not impossible to make any vessel absolutely vacuum but practically it is not possible to create a vacuum below 10-13 Torr. This is because, when the difference between the pressure of the outside atmosphere and inside of the vessel is being increased, the effectiveness of the motor and other movable parts of the pump gets decreased proportionately.
Pumping Speed of a Vacuum PumpIt is defined as the rate at which a pump can suck the volume of the air or gaseous substance at the instantaneous pressure inside the vessel. The pumping speed is measured in the suction of air or gaseous volume per second.
Types of Vacuum PumpThere are many types of vacuum pump available
- Rotary Oil Vacuum Pump
- Molecular Vacuum Pump
- Diffusion Vacuum Pump
Rotary Oil PumpWolfgang Max Paul Gaede a German Physicist invented rotary oil pump. This pump is of two types
- Rotary Vane Oil Pump
- Stationary Vane Oil Pump