Momentum transfer pump is also known as molecular pumps. It uses high speed jets of dense fluid or high speed rotating blades which knock gaseous molecules out of the chamber.
How does a Momentum Transfer Pump works?
In a momentum transfer pump, gas molecules are accelerated from the vacuum side to the exhaust side. Based on the laws of fluid dynamics, matter flows differently at different pressures. At atmospheric pressure and mild vacuums, molecules interact with each other and push on their neighboring molecules. When the distance between the molecules increases, the molecules interact with the walls of the chamber more than the other molecules, and thus molecular pumping becomes more effective than positive displacement pumping.
Types of Momentum Transfer Pumps:
There are two main types of molecular pumps. Both types of pumps blow out gas molecules that are diffused into the pump.
- Diffusion pump : Diffusion pumps blow out molecules with jets of oil.
- Turbomolecular pump :Turbomolecular pumps use high speed fans.
