How does a diffusion pump work?
The diffusion pump uses the vapor of a boiling fluid to capture air molecules. The fluid is then moved to another location and cooled. The cooling forces the air molecules to be released. The combination of gravity and the downward direction of the vapors move the air molecules toward the bottom of the pump.
How does a turbomolecular pump work?
These pumps work on the principle that gas molecules can be given momentum in a desired direction by repeated collision with a moving solid surface. In a turbomolecular pump, a rapidly spinning fan rotor ‘hits’ gas molecules from the inlet of the pump towards the exhaust in order to create or maintain a vacuum.
What ways turbomolecular pump is susceptible to damage?
Turbo-molecular pumps (TMP) often incur damage because of damage to external gas inlets such as clamp and view port, which often occur in industries or university laboratories where vacuum is applied.
Where are diffusion pumps used?
INTRODUCTION. Diffusion pumps are probably the most commonly used mechanisms for creating a high vacuum in industrial vacuum processing. It is also commonly used in mass spectrometry, analytical instrumentation, research and development, and nanotechnology.
What is dry pump?
The definition of a dry vacuum pump is a pump that does not use any fluids to create a vacuum or contact the process gas and can also discharge to atmosphere. Timing gears with oil reservoirs and close clearances between the rotors and housing are additional attributes that make up a dry vacuum pump.
What is mechanical pump?
In mechanical pumps, the gas present in a vacuum system is transferred from a low pressure to a higher pressure region. In order to be efficient, the pump has to provide simultaneously a finite pumping speed and compression. This category is known as: “Momentum transfer pumps”.
What is a turbo pump used for?
A turbopump is a propellant pump with two main components: a rotodynamic pump and a driving gas turbine, usually both mounted on the same shaft, or sometimes geared together. The purpose of a turbopump is to produce a high-pressure fluid for feeding a combustion chamber or other use.
When should I turn on my turbo pump?
Question: When can I turn on my Turbo pump? Answer: If the turbomolecular pump is valved off from the chamber an at atmosphere, the turbo pump can be turned on right after the mechanical pump is started and the foreline valve is open.
What makes a turbomolecular pump a turbo pump?
Key Performance Factors A turbomolecular pump (TMP) is a multi-stage axial-flow turbine in which high speed rotating blades provide compression by increasing the probability of gas molecules moving in the pumping direction.
What kind of pump is a compound molecular pump?
The turbomolecular pump is optimised for molecular flow conditions and requires a suitably sized two stage rotary vane pump or an oil free scroll pump to exhaust to atmosphere. A compound molecular pump (CMP) is based on the concept of combining bladed turbomolecular stages with molecular drag stages on the same rotor.
What is the maximum crossover pressure for a turbo pump?
Operational Aspects of Turbomolecular Pumps The maximum crossover pressure for turbomolecular pumps is approximately 1 Torr, this is a factor of ten times higher pressure than the maximum suggested crossover pressure for most oil vapor diffusion pumps (100 mTorr).
What is the critical backing pressure for a turbo pump?
During the run-up time, or when operating at high gas throughput or above the critical backing pressure, the pump power dissipation will rise and approach the maximum power output for the turbo controller used. Critical backing pressure for compound turbomolecular pumps is approximately 10 to 20 mbar.